ALBERT

Notes: Abstract Ferrocene and nickelocene have pseudo-isomorphous structures at room temperature but only ferrocene undergoes a second-order phase transformation on cooling. Calculation and analysis of appropriate lattice-energy surfaces as a function of concerted ring rotation showed that ferrocene has a disordered structure at room temperature different from nickelocene which exhibits a single minimum in the lattice-energy function. The results readily suggest a mechanism for the ferrocene phase transformation. The correct low-temperature structure is predicted only after taking intramolecular interactions into account.

Notes: Abstract A single crystal X-ray investigation of the purple nickel (II) complex Ni[L(en)](NO3)2, produced by condensation of 1,2-diaminoethane (en) with the thiodiketone S(CH2COCH3)2 in the presence of nickel (II) nitrate (L is NH2(CH2)2N=C(CH3)CH2SCH2COCH3), shows that the metal ions are six coordinate. The new ligand L is tetradentate, with the N,N and S donor atoms arranged meridionally, and the coordination shell completed by the carbonyl oxygen atom of L and the nitrogen atoms of 1,2-diaminoethane. Metal-ligand bond distances are Ni-N: 2.08 av. (en), 2.10 and 2.05 (NH2 and N=C respectively of L); Ni-O, 2.16; Ni-S, 2.45 Å. There is considerable angular distortion from regular octahedral values of the bond angles at nickel. The crystals are monoclinic,P21/c (No. 14),a=12.433(2),b=11.709(1),c=13.150(2) Å,β=103.93(1)°,V c=1858.2(4) Å3. The structure was solved by the heavy-atom method and refined by full-matrix least squares to anR value of 0.055 for 3633 reflections.

Notes: Abstract The crystal structure of bis(potassium hydrogenl-malate)·malic acid, 2[K+(C4H5O5)−]·C4H6O5, has been determined: C12H16K2O15, M r =1913.9, orthorhombic, space groupP212121 a=7.719(5),b=7.916(5),c=29.863(20) Å,V c=1824.7 Å3,Z=4. The structure was determined by a new application of theDirdif procedure using MoKα automatic diffractometer X-ray data, and refined by full-matrix least squares toR=0.059 for 962 reflections. A question on space-group assignment and composition was resolved only after the structure had been determined. The conformation of the central carbon skeleton of all three crystallographic independent malate moieties isanti. The potassium ions are coordinated by eight oxygen atoms, forming face-sharing distorted square antiprisms.

Notes: Abstract The crystal structure of metalaxyl (C15H21NO4) was determined by three-dimensional X-ray analysis from diffractometer data. The crystals are monoclinic,P21/c,a=7.851(3) Å,b=13.119(10) Å,c=15.107(7) Å,β=101.71(6)°,Z=4,D x=1.218 g cm−3, μ (MoKa)=0.095 mm−1. FinalR=0.079 for 1203 observed reflections. The dimethylphenyl ring is almost perpendicular to the amidic plane of the molecule.

Notes: Abstract The various conformations of δ-lactone rings are described and parametrized.

Notes: Abstract The structure of MeGeI3 is orthorhombic with space groupPnma,a=6.374(3),b=10.412(4),c=12.683(4) Å, andz=4. It has been solved by direct methods and refined by full-matrix least-squares techniques to a conventionalR factor of 0.0791 for 653 unique reflections. The crystal structure contains discrete molecules with mirror symmetry which are separated by normal van der Waals distances. The mean Ge-I distance is 2.500(2) Å.

Notes: Abstract Crystals ofN,N′-(3,3′-dipropylamine)bis(3-methoxysalicylideneiminato) oxovanadium(IV) dihydrate are monoclinic, space groupP21/n (No. 14) with four molecules in the unit cell of dimensionsa=8.667(4),b=20.617(4),c=12.744(3) Å,β=91.48(3)°. The structure was solved by the heavy-atom method and refined by block diagonal least-squares calculations with anisotropic thermal parameters for nonhydrogen atoms.R=0.038 for 1457 reflections withI〉3σ(I). This structure is the first reported for an oxovanadium(IV) complex involving complexation of a pentacoordinate Schiff-base ligand. The coordination polyhedron is based on a distorted octahedron. Three nitrogen and one oxygen atom from the ligand form an equatorial plane around vanadium with V-N(1) 2.096(4), V-N(2) 2.180(4), V-N(3) 2.088(4), V-O(2) 1.961(3) Å, and octahedral coordination is completed by the vanadyl oxygen [V-O(1) 1.617(3) Å] and the remaining ligand oxygen [V-O(3) 2,098(3) Å]. The relatively long V-O(1) distance correlates well with the low value ofv(V=O) of 919 cm−1. The molecules of the complex are linked by water molecules of crystallization to form infinite hydrogen-bonded chains parallel toa.

Notes: Abstract An X-ray structure analysis of three trimethylarsine-boron trihalide adducts has been undertaken. Crystals of (CH3)3AsBCl3 and (CH3)3AsBBr3 are monoclinic with space groupP21/m (No. 11) withZ=2 while those of (CH3)3AsBI3 are orthorhombic with space groupPnma (No. 62) withZ=4. For (CH3)3AsBCl3,a=6.497(3) Å,b=10.735(3) Å,c=7.070(2) Å,β=111.8(3)°,V=458.4(3) Å3,R=0.0343. For (CH3)3AsBBr3,a=6.672(4) Å,b=11.135(7) Å,c=7.199(4) Å,β=111.5(1)°,V=497.7(5) Å3,R=0.0434. For (CH3)3ÅsBI3,a=13.113(7) Å,b=11.733(5) Å,c=7.387(3) Å,V=1136.5(5) Å3,R=0.0329. The As-B bond lengths are 2.065(6), 2.04(1), and 2.03(1) Å, respectively, for the chloride, bromide, and iodide. These and other structural parameters are discussed with reference to previous predictions based on vibrational spectra and previous structural studies on the trimethyl-phosphine and trimethylamine adducts.

Notes: Abstract The crystal structure of a dihydrothiapyranS-oxide was determined from single-crystal diffractometer data, C19H27NO4S2, MoKα radiation: orthorhombic, space groupP212121, usinga=8.9604(10),b=13.5928(15),c=16.5621(19) Å,z=4. The molecule has theE-geometry, and the absolute configuration isR at C1 andS at S1.

Notes: Abstract For Cs2LiM(CN)6 (M=Co, Fe), prepared by an improved method, extensive X-ray and neutron-diffraction measurements on powders and single crystals by several techniques have established the unit cells at 300 K as very close to faceentered cubic with lattice constantsa=10.488(1) (M=Co) and 10.561(1) Å (M=Fe) (powders). Least-squares refinements of the crystal structures in space groupFm3m with single-crystal neutron data toR indices of 0.03 yield bond lengths (corrected for thermal motion) Co-C=1.894(3), Fe-C=1.935(4) Å, and C-N=1.178(3) (cobalt salt), 1.189(4) Å (iron salt), i.e., in close agreement with those from X-ray analyses. Less detailed powder neutron intensity data at 4.2 K indicate small distortions fromFm3m symmetry.

Notes: Abstract The crystal and molecular structure of dimethylpyridazino[2,3-b]benzo-1,2,4-triazine-3,4-dicarboxylate radical, C14H11N4O4, has been determined from X-ray diffractometer data by direct methods and refined by least-squares methods toR=0.040 for 590 observed reflections. Crystals of C14H11N4O4 are monoclinic:a=9.222 (7),b=15.335(10),c=9.544(2) Å,β=102.18(2)),Z=4, space groupP21/c. Bond distances and internal angles in the ring system have average values:C-C 1.387, C-N 1.358, and N-N 1.356 Å, and C-Ĉ-C 121.5, C-Ĉ-N 120.4, C- $$\hat N$$ -C 117.8, N- $$\hat C$$ -N 121.4, and N- $$\hat N$$ -N 119.8°, respectively. All these bonds have a partial double-bond character, consistent with an extensive conjugation within the molecule, thus giving stability to the free radical. The condensed rings are nonplanar. The carbomethoxy groups show a different slant, owing to overcrowding.

Notes: Abstract The crystal and molecular structure of 1-amino-1-methylethylphosphonic acid monohydrate (C3H10NO3P·H2O) has been determined by single-crystal X-ray diffraction methods. The crystals are orthorhombic:Pna21,a=11.665(2),b=9.415(1),c=6.386(1) Å,Z=4. The structure was solved by the heavy-atom method and refined to a finalR=0.028. The molecule exists as a zwitterion, H 3 + N-C-(CH3)2-PO34H−. There are six independent hydrogen bonds in the structure, three of the type N-H⋯O with lengths 2.904(5), 2.745(6), and 2.765(5) Å and three of the type O-H⋯O with lengths 2.754(4), 2.833 (7), and 2.548(5) Å.

Notes: Abstract The X-ray crystal structure of glechomafuran (1β,10α,4α,5β-diepoxy-7,8-furanogermacrane), a natural product obtained from seeds ofSmyrnium olusatrum L., has been determined in order to establish the correct relative configuration of the molecule. Crystals are monoclinic, space groupP21 witha=6.785(4),b=12.325(9),c=16.390(6) Å,β=97.89(4)°, and four molecules in the unit cell. The two epoxides are found to be α,β-attached, and the associated methyl groups are positionedsyn to each other. The furan ring is essentially flat, and shows no evidence of any double bond delocalization.

Notes: Abstract The crystal and molecular structure of the title compound, C76H64BBrP4Co, is reported. Crystals are orthorhombic, space groupP212121 (No. 19) withZ=4 in a unit cell of dimensionsa=15.342(3),b=18.527(2), andc=22.223(1) Å. The structure was solved by the heavy-atom method and refined by full-matrix least squares toR=0.094 for 2356 unique diffractometer data. The coordination geometry around Co atom is that of a distorted trigonal bipyramid. Each diphos ligand bridges an axial and equatorial coordination site with the bromine atom occupying the remaining equatorial position. The symmetry can only be approximated toC 2 because of the large angular deviations from three-fold symmetry and difference in groups in the equatorial plane. The boron atom of the anion has an approximate tetrahedral configuration.

Notes: Abstract Triphenylarsine crystallizes in the triclinic space groupP¯1 (No. 2),a=11.200(2),b=15.263(7),c=17.871(6) Å,α=84.63(5),β=80.21(5), γ=86.41(6)°,Z=8, with four molecules in the asymmetric unit. The structure was solved by direct methods and refined in the initial stages by full-matrix least squares and finally by block-diagonal least-squares methods toR=0.055 for 3537 reflections. The dimensions and the conformations of the four independent molecules are almost identical. The molecules do not exhibitC 3v symmetry.

Notes: Abstract The 4∶3 complex formed between 2-aminopyridine (ampy) and AgNO3 belongs to the orthorhombic space groupPccn. The unit cell of dimensionsa=7.992(4),b=16.788(5),c=21.034(8) Å contains four formula units. The structure was refined on 998 nonzero reflections toR=0.038. The crystal contains the dimeric [Ag3(ampy)4]3+ cation. Two of the three independent Ag atoms are each coordinated to two ampy ligandsvia the heterocyclic nitrogen lone pair (mean Ag-N=2.18 Å), and the N-Ag-N angle in this [ampy-Ag-ampy]+ unit is 154.0°. By using the two available amino groups, the [ampy-Ag-ampy]+ unit acts as a bidentate “ligand,” and two such units related by a twofold axis achieve a roughly tetrahedral environment of NH2 lone pairs about the third Ag atom (mean Ag-N=2.39 Å). The infrared spectra of [Ag3(ampy)4](NO3)3, [Ag(ampy)2]ClO4, [Ag3(ampy-H)2]NO3, and [Ag3(ampy-H)2]ClO4, and those of their amino-deuterated derivatives, are discussed. Diagnostic regions are proposed to identify coordinationvia the amino group and the heterocyclic nitrogen atom.

Notes: Abstract The crystal and molecular structure of the title compound, C21H11N6S4Au, is reported. The crystals are triclinic:P¯1,Z=2,a=7.739(1),b=8.415(1),c=17.815(1) Å,a=101.31(1),β=86.20(1), γ=98.17(1)°. The structure was solved by the heavy-atom method, and refined by full-matrix least squares toR=0.046. Both the Au(mnt) 2 − and NMP+ ions are planar, and form a kind of mixed stack alonga, with slightly alternating NMP+-Au(mnt) 2 − distances of 3.46(8) and 3.59(5) Å.

Notes: Abstract The crystal and molecular structure of 1,2,6-trichlorotris(pyridine)chromium(III) is discussed. Monoclinic crystals were indexed in the nonstandard space group, P21/n (No. 14). The unit cell contains four molecules:a=9.088(1) Å,b=12.442(1) Å,c=15.557(1) Å, andβ=91.33°;d x=1.49 g cm−3,d m=1.49 g cm−3. A total of 4056 unique reflections was recorded on a Syntex automated four-circle diffractometer usingMo Kα radiation. After the appropriate Lorentz and polarization corrections were made, the structure was solved by standard Patterson techniques. Least-squares refinement and difference Fourier analysis revealed all other atoms. The final agreement factors areR=0.062 andR w=0.052. The nearly planar pyridine ring systems were found to pivot in a fan-blade arrangement about the plane described by the three nitrogen atoms and one chlorine atom. The geometry about the central chromium atom agrees with the expected octahedral configuration.

Notes: Abstract The crystal structures of the phosphoric amides dimethyl-N-(2-ethylphenyl)-phosphoramidate (I) and dimethyl-N-(2,6-dimethylphenyl)-phosphoramidate (II) have been determined by direct methods and refined by full-matrix least squares. Compound (I) crystallizes in two polymorphic forms, both monoclinicP21/c, but with different cell parameters. Parameters for compound (I) are: FormA:a=10.878(5),b=8.890(4),c=25.11(1) Å,β=92.18(2)°; FormB:a=7.071(4),b=17.059(9),c=10.221(5) Å,β=97.07(2)°. Compound (II) is also monoclinicP21/c witha=8.453(4),b=14.231(7),c=10.283(5) Å,β=108.95(2)°. Compound (I) exists as a hydrogen-bonded dimer, whereas compound (II) exists as a hydrogen-bonded polymeric species.

Notes: Abstract The X-ray crystal structures ofE-N, N-dimethyl-3-phenyl-2-propenylideniminium perchlorate,1, andE-N, N-dimethyl-3-(p-methoxyphenyl)-2-propenylideniminium perchlorate,2, have been determined.E-N,N-dimethyl-3-phenyl-2-propenylideniminium perchlorate, (C11H14N+)(ClO4 −),1, is orthorhombic:Pmcn (No. 62)a=6.595(1),b=18,288(4),c=10.216(2) Å,Z=4.E-N, N-dimethyl-3-(p-methoxyphenyl)-2-propenylideniminium perchlorate, (C12H16NO+)(ClO4 −),2, is triclinic:P1 (No. 2) with cell dimensionsa=6.862(1),b=9.830(2),c=13.376(3) Å,α=119.05(1),β=114.99(2), γ=90.79(2)°, andZ=2. Data for both crystals were collected with the use of MoKα radiation and a Syntex P21 diffractometer. The crystal structures were solved by standard methods and refined toR 1=0.0688,R 2=0.0772 for1 andR 1=0.0790 andR 2=0.0757 for 2 based on 869 and 1765 independent reflections, respectively. The bond distances are consistent with a highly localized structure with the positive charge situated principally in the iminium moiety. The13C NMR spectra of these salts were obtained on the crystalline solids by CPMAS methods. Since the13C chemical shifts of the salts were very similar, in both solution and solid states, it was concluded that the structures of the salts were comparable in both phases and were analogous.

Notes: Abstract The crystal structures of the title compounds have been determined from diffractometer data and refined by full-matrix least squares. NaAlMe4 is orthorhombic,Cmcm,a=9.234(3),b=9.221(3),c=8.303(2) Å,Z=4,D c=1.03 g cm−3,R=0.029 for 278 data. NaAlEt4 is monoclinic,P21/c (No. 14),a=13.900(2),b=13.207(2),c=14.443(1) Å,β=117.43(1)°,Z=8,D c=0.94 g cm−3,R=0.056 for 2747 data. NaAl(n-Pr)4 is monoclinic,C2/c,a=9.802(5),b=15.336(4),c=21.611(10) A,β=98.34(4)°,Z=8,D c=0.92 g cm−3,R=0.072 for 899 data. Coordination of Al is essentially tetrahedral in all structures, and closest contacts to Na+ involveα-carbon atoms of alkyl groups.

Notes: Abstract The crystal and molecular structure of glycinium diphenylphosphate, C14H16NO6P, has been determined by X-ray methods. The crystals are orthorhombic:Pbca (No. 61),a=11.412(3),b=24.624(7),c=10.775(3) Å,Z=8. The structure was solved by direct methods and refined to anR value of 0.043 for 1289 nonzero independent amplitudes. The molecule exists in the structure as+NH3CH2CO2H,(C6H5O)2PO 2 − and is planar except for the N atom, which deviates by 0.49 Å from the plane defined by C(1), C(2), O(5), and O(6) atoms, respectively. The conformation of the diphenylphosphate anion isgauche with respect to both P-O ester bonds. There are four crystallographically independent hydrogen bonds, three of the N-H⋯O type and one of the O-H⋯O type.

Notes: Abstract The X-ray crystal structure and absolute configuration of 3,6-epidithio-l-prolyl-l-proline-anhydride (C10H12O2N2S2) have been determined from single-crystal diffraction data. The compound crystallizes in the orthorhombic space groupP21212 with two molecules in a unit cell having dimensionsa=9.573(3),b=10.143(2), andc=5.761(2) Å. The structure was solved by the Patterson method and refined to a finalR value of 6.7%. The Bijvoet test, performed using CuKα radiation, shows that the configuration at both chiral carbons is (R) for the diastereoisomer having a specific rotation [α] D 25 =−54.5°. The torsion angle of the C-S-S-C fragment is −8.5°, giving helical sense (M), and the CD spectrum shows four major chiro-optical regions: 366(+), 336.5(−), 262(+), and 235(−) nm. The S-S bond length of 2.078 Å is intermediate between the values found in aliphatic disulfides having torsion angles near 0° and those with angles near 90°. The C-S distance of 1.899 Å is unusually long for disulfides, but seems to be characteristic of the small number of epidithiodiketopiperazines which have been studied.

Notes: Abstract From an equimolar mixture of guanidine and maleic acid, two different crystal modifications of guanidinium hydrogen maleate, CH6N 3 + ·C4H3O 4 − , were isolated and their crystal structures determined using three-dimensional diffractometer data. Crystals of both forms are orthorhombic:Pca21,a=19.012(8)b=3.758(1),c=11.119(5) Å,Z=4 for form I;Fdd2,a=18.505(2),b=20.007(3),c=8.406(2) Å,Z=16 for form II. The structures were solved by direct methods and refined by full-matrix least squares to conventionalR values of 0.064 for form I and 0.043 for form II, with 488 and 605 reflections respectively. The structures consist of planar guanidinium cations C(NH2) 3 + and hydrogen-maleate residues C4H3O 4 − . There are no significant differences in distances and angles within the guanidinium and hydrogen-maleate units. However, a substantial difference appears in the length and geometry of the intramolecular hydrogen bond O⋯H⋯O. The packing of cations and anions is also completely different in the two forms. Infrared and Raman spectra of the title compound are presented, and salient differences between them and the spectrum of the symmetrically bonded potassium hydrogen maleate are discussed briefly.

Notes: Abstract The synthesis and selected aspects of the UV, IR, and1H NMR spectra of the title compound are described. The crystals of the title compound are triclinic witha=12.999(9),b=8.911(4),c=9.199(5) Å;α=105.56(3),β=113.50(4), γ=92.53(3)°;Z=2; space groupP¯1. Its X-ray crystal structure analysis provides information regarding the conformational features of the amide linkage when no intermolecular hydrogen bonding involving this group is present. The X-ray study shows that the C′-N bond is longer [1.363(4) Å] than that found normally in peptide molecules. The compound shows a peculiar disorder involving one of the two amide groups present in the molecule. The conformation of theN-methyl acetanilide moiety and its relation to the1H NMR spectrum of the compound are discussed.

Notes: Abstract The title compound has been prepared and its crystal structure determined by X-ray crystallography. The compound is monoclinic,P21/m,Z=2, witha=9.842(5),b=22.136(6),c=5.939(4) Å, and β=108.71(3)°. The complex is ionic and hasC s symmetry. The uranyl group is equatorially bonded to three bidentate acid molecules in a distorted hexagonal bipyramidal coordination geometry. Bond distances are: U-O(uranyl) 1.76(1) Å, U-O(equatorial) 2.47–2.48 Å, C-O 1.25–1.28 Å, Cl-O 1.40–1.43 Å. The amino acid is zwitterionic with the ionized carboxyl chelate to uranium and the amino terminus protonated. The structure is stabilized by hydrogen bonding.

Notes: Abstract Oxidation of Mo2[S2CN(C2H5)2]6 with iodine in a 1∶2 molar ratio yielded the complex MO[S2CN(C2H5)2]4 I3, for which magnetic susceptibility, NMR, IR, UV/visible spectra, and single crystal X-ray structure are reported. Crystals of Mo[S2CN(C2H5)2]4 I3 are monoclinic, space groupC2/c (No. 15),a=26.242(7),b=7.003(1),c=20.447(3) Å,D o =1.97,Z=4,D c =1.890 g cm−3. The structure was determined from 1909 observed reflections and refined by blocked cascade least squares to anR factor of 0.042. The core of the cation, Mo[S2CN(C2H5)2] 4 + , is dodecahedral with approximate point symmetryD 2d (¯42m). The eight S atoms coordinated to the Mo center can be divided into two sets, each forming a distorted tetrahedron. The set constituting a flattened tetrahedron has a mean Mo-S distance of 2.545(2) Å, whereas the set that forms an elongated one has a mean value of 2.500(2) Å. The oxidation state of +5 for the molybdenum atom is supported by the thioureide band [v(RNC)] at 1507 cm−1, which lies between those of similar Mo(IV) and Mo(VI) complexes.

Notes: Abstract The crystal structure of Pd(N-PropIm)2Cl2 has been determined from X-ray data collected by counter methods. The compound crystallizes in the monoclinic space groupP21/n with four molecules per unit cell, the dimensions of which area=14.554(5),b=8.204(2),c=14.860(3) Å,β=115.63(2)°. Full-matrix least-squares refinement gave a final R value of 0.0263 for 1913 independent observed reflections. The Pd atom is four-coordinated and is surrounded in atrans square planar fashion by two N atoms of the imidazole groups and by two Cl ions.

Notes: Abstract The crystal and molecular structure of the title compound, (C13H11N2)[Ni(S2C6H4)2], is reported. Crystals are triclinic, space groupP¯1(No.2) withZ=2 in a unit cell of dimensionsa=9.363(1),b=10.148(1),c=13.623(1) Å,α=85.64(1),β=107.33(1), and γ=113.10(1)°. The structure was solved by the heavy-atom method and refined by the method of full-matrix least squares toR=0.036 for 2874 unique reflections. The metal atom of the anion has an approximate square-planar configuration. The metal atoms occupy the origins and A-face centers of the lattice. The anions with the metal atoms in the origins stack along thec-axis, the interplanar separation being thec-axis lattice repeat of 13.623(1) Å. The anions with the metal atoms in theA-face centers and the cations form a “mixed stack” along the short diagonal of theab-plane. The short interplanar distances (C−A=A−C=3.43 Å and C-C=3.91 Å) in the mixed stack (CAC-CAC⋯) show the possibility of unusual electrical behavior. There is no evidence of direct or indirect metal-metal interaction.

Notes: Abstract The crystal and molecular structure of the title compound, C21H11N6S4Ni, is reported. The crystals are triclinic:P¯1 (No. 2),Z=4,a=8.768(1),b=11.817(3),c=22.131(3) Å,α=97.44(1),β=91.90(1), and γ=94.04(1)°. The structure was solved by the heavy-atom method, and refined by full-matrix least squares toR=0.039 for 3213 unique reflections. The Ni atoms of both anions in the asymmetric unit have an approximately square-planar configuration. Anions and cations form segregated stacks alonga. The stacking of the anions along this direction is dimeric, with alternating Ni-Ni distances 4.111(2) and 7.593(2) Å for molecule I and 4.208(1) and 8.155(2) Å for molecule II. Static susceptibility measurements show strong antiferromagnetic coupling (2J=-241 cm−1) between the two anions of the dimers.

Notes: Abstract A crystalline modification of the title compound (C17H19NO4) was determined by three-dimensional X-ray analysis from diffractometer data. Crystal data: monoclinic,Cc,a=15.997(12) Å,b=7.929(7) Å,c=14.664(11) Å,β=118.70(5)°,Z=4;Dx=1.227 Mg m−3,μ(MoKα)=0.094 mm−1. FinalR=0.068 for 852 observed reflections. The dimethylphenyl ring is strongly twisted (94.9°) with respect to the amidic plane of the molecule, which almost coincides with the furan ring (6.9°).

Notes: Abstract The crystal structure of 2-(N,N-dimethylaminomethyl)-4-nitrophenol, C9H12N2O3 has been determined by X-ray diffraction methods. The crystals are monoclinic;C2/c (No. 15),a=23.437(6),b=5.334(2),c=17.444(4) Å,β=119.90(5)°,Z=8. The structure was solved by direct methods, and refined to anR value of 0.032 for 1095 nonzero independent amplitudes. Molecules of the title compound are found to exist in a zwitterionic form. Differences in hydrogen bonding in solution and in the solid phase are discussed. In nonpolar and weakly polar solvents, intramolecular O-H⋯N hydrogen bonding is predominating. In the solid state, two N+-H⋯O− bonds related through an inversion center form a cyclic dimer.

Notes: Abstract The crystal structure of the title compound (C14H18N2O4) was determined by three-dimensional X-ray analysis from diffractometer data. Crystal data are: monoclinic,P21/n,a=9.363(1) Å,b=12.715(1) Å,c=12.360(1) Å,β=102.64(10)°,Z=4,D x =1.288 Mg m−3,μ(MoKα)=0.10 mm−1. FinalR=0.062 for 1175 observed reflections. The dimethylphenyl group and the planar portion of the oxazolidinone ring are steeply inclined to the amidic plane of the molecule (76.0° and 66.5°, respectively); the oxazolidinone ring is in a half-chain form.

Notes: Abstract The crystal structure of di(ethyleneglycol)di(para-methylbenzoate), C20H22O5, has been determined by direct methods from 1400 observed reflections collected on a Nonius CAD-4 automatic diffractometer. The crystals have a monoclinic unit cell of dimensionsa=11.408(2),b=5.808(3),c=8.542(4) Å andβ=109.50(2)° and belong to theP21/c space group (No. 14). The finalR value is 0.049. The benzene rings are planar and show the usual distortions due topara-substitutions. The carboxylate planes are inclined by 2.2(4) and 4.7(4)° from their respective benzene ring planes. The conformation of the di(ethyleneglycol) moiety,tg − gtg − g − (t=trans, g=gauche), differs considerably from that of the methylenic sequences in pentamethyleneglycoldi(para-nitrobenzoate) which is alltrans, or in pentamethyleneglycoldi(para-chlorobenzoate) which isg t t t t g.

Notes: Abstract Crystals of this calabash curare alkaloid, space groupP21; havea=12.695(4), Å,b=7.424(2) Å,c=21.762(6) Å,β=98.03(5)°,Z=2,F(000)=884. The structure was solved by direct methods and refined by least squares toR=0.10. The alkaloid cation, with two-fold molecular symmetry, has a highly fused ring system and is structurally rigid. This determination provides accurate stereochemical parameters for those atoms and groups (N+ centers, aromatic rings, and hydrogen bond acceptors) postulated by various theories as involved in binding to the acetylcholine receptor. In the crystal, layers of alkaloid cations parallel to thebc plane alternate with layers containing two Cl− ions and eight water molecules distributed almost randomly over ten sites. Electrostatic attractions between N+ and Cl− bind the alternating layers together. Each one of the ten sites is, on average, 4.60 Å from one or two N+, allowing the two Cl− ions to be disordered. Binding interactions within the alkaloid layers are solely van der Waals attractions. Within each H2O/C1− layer there is a complex hydrogen bond system, including four infinite spirals parallel to theb axis, with an average bonding distance of 2.94 Å. There are no hydrogen bonds between layers. The possible relevance to the activity of the alkaloid of its ability to organize large amounts of water is discussed.

Notes: Abstract The crystal and molecular structure of the title compound is reported. The crystals are orthorhombic:Pcmn, Z=4,a=6.414 (4),b=6.581 (4),c=10.412 (3) Å. The structure was solved by direct methods, and refined by full-matrix least squares toR=0.048 andR w =0.044 for 296 unique reflections. Hydrogen bonds exist between the cations and anions. Differential scanning calorimetry and vibrational studies indicate phase changes at 355 and 245 K.

Notes: Abstract X-ray analysis has established the “semicoordination” bonding mode for one tetrafluoroborate anion in tetrafluoroborato-2,2′-bipyridyl{2,6-bis[1-(p-ethylphenylimino)ethyl]pyridine}copper(II) tetrafluoroborate, [Cu(bipy) (C25H27N3)(FBF3)]BF4. Crystals of the title compound are monoclinic, space group P21/n with four molecules in the unit cell ofa=14.991(3),b=14.989(3),c=16.933(4) Å,β=109.33(2)°. The structure was solved by the heavy-atom method and refined by blocked full-matrix least squares calculations with anisotropic thermal parameters for nonhydrogen atoms toR=0.049 andR w=0.051 for 3311 reflections withI〉3σ(I). The copper atom coordination is pseudo-octahedral, with one nitrogen atom of the bipyridyl ligand [Cu-N(2)1.985(4) Å] and three nitrogen atoms of the terdentate NNN donor ligand [Cu-N(3) 1.923(4), Cu-N(4) 2.073(4), Cu-N(5) 2.073(4) Å] forming the equatorial plane. The axial sites are occupied by the second nitrogen atom of the bipyridyl ligand [Cu-N(1) 2.186(5) Å] and a loosely bound fluorine atom [Cu-F(21) 2.692(5) Å] of the “semicoordinated” tetrafluoroborate group. The other BF 4 − anion is ionic. Electronic and vibrational spectral data for the complex are discussed in terms of the geometry of the cation.

Notes: Abstract The title compound is C16H12N8O8, monoclinic,P21/n,a=4.995(1),b=13.931(3),c=26.065(5) Å andβ=90.99(2)°. The structure was solved by direct methods and refined by least-squares techniques to anR factor of 0.051 for 2040 observed reflections. The adenine moiety is protonated at N(3) and N(7). The crystallographic evidence for proton transfer corroborates earlier conclusions from IR spectroscopy.

Notes: Abstract The X-ray crystal structures of 1,4,6,9-tetrathiaspiro[4.4]nonane (4) and 1,5,7,11-tetrathiaspiro[5.5]undecane (3) have been determined. Crystals of4 are tetragonal, space groupI41 cd, with eight molecules in a unit cell of dimensionsa=9.521 (2) andc=19.052(5) Å. Crystals of3 are orthorhombic,Pbca, with eight moleucles in a cell havinga=8.955(3),b=12.356(4), andc=18.425(4) Å. Compound4 was solved from the Patterson map and3 by use ofMultan, and they refined to finalR values of 6.4 and 2.5%, respectively. Compound4 consists of two 1,3-dithiolane rings connected via C(2), both of which appear to be somewhat disordered at room temperature. The uncorrected C-C distance is 1.476 Å and the average S-C distance is 1.786 Å. Compound3 consists of two 1,3-dithiane rings connected at C(2), both in chair conformations. In both compounds there appear to be electronic repulsions between S lone pairs and axial hydrogens of the opposite ring system. Analysis of endocyclic torsion angles in3 indicates that the ring conformations themselves are not significantly altered by the positional shift caused by the repulsion.

Notes: Abstract The structure of the title compound has been established by means of the x-ray diffraction method on a single crystal. The crystals are othorhombic, space groupP212121 (No. 19) witha=10.222(4),b=10.622(2),c=16.434(3) Å,z=4. Full-matrix least squares refinement led toR=4.9%. The molecular stereochemistry, bond distances, bond angles, torsion angles, and hydrogen bond scheme have all been determined.

Notes: Abstract A series of triple orthoarsenates CaLnTh(AsO4)3, where Ln=lanthanide or yttrium, are synthesized and spectrostructurally studied to evaluate the effect of rare earth ionic contraction on the crystal habitat of this class of arsenates. The results are analyzed and interpreted in comparison with the isostructural arsenates.

Notes: Abstract The title compound is monoclinic,M r =337.8,P21/c-C 2h 5 (No. 14),a=5.508(2),b=13.944(6),c=18.238(5) Å,β=95.99(3)°,V=1393.1(9) Å3,Z=4,D x =1.61 g cm−3, λ(MoKα)=0.71073 Å,F(000)=660.0,μ=10.3 cm−1, finalR=0.051 for 2122 observed [I〉3σ(I)] reflections. The two six-membered rings resulting from the coordination of the 1,3-propanediamine ligands to the chromium atom are in the chair conformation. The Cr-N and Cr-F distances average 2.085(4) and 1.876(3) Å, respectively.

Notes: Abstract The reaction of 7-benzyloxy-6,2′,3′,4′-tetramethoxyisoflavylium perchlorate with 1-(2,4-dimethoxyphenyl)-3-(3,4-dimethoxyphenyl)-prop-l-ene and of 6,7,2′,3′,4′-pentamethoxyisoflavylium perchlorate with the same propene yielded respectively 7-benzyloxy-6,2′,3′,4′-tetramethoxyisoflav-3-ene (5) and 2,6,7,2′,3′,4′-hexamethoxyisoflav-3-ene (7) whose structures have been established by X-ray crystallography. Crystals of (5) are monoclinic, space groupP21/a (No. 14) with four molecules in a unit cell of dimensionsa=8.528(2),b=13.294(3),c=19.629(4) Å,β=99.92(2)°. Crystals of (7) are also monoclinic, space groupC2/c (No. 15) with eight molecules in a unit cell of dimensionsa=28.088(3),b=10.662(3),c=12.869(1) Å,β=97.32(1)°. Both structures were solved by direct methods and refined by full-matrix least-squares calculations to finalR values of 0.053 and 0.041 for 1673 and 1424 observed data for (5) and (7) respectively. The molecular dimensions are in accord with accepted values.

Notes: Abstract α-Parabutylchloral (2,4,6-tris(1′,1′,2′-trichloropropyl)-1,3,5-trioxane, C12H15Cl9O3) crystallizes in the orthorhombic space groupP212121 (No. 19) witha=12.165(6),b=9.964(5),c=17.433(9) Å,Z=4. The finalR value is 0.043 for 1667 observed reflections.β-Parabutylchloral crystallizes in the orthorhombic space groupPna21 (No. 33), witha=12.387(6),b=10.488(5),c=16.605(8) Å,Z=4. The finalR value is 0.047 for 1417 observed reflections. Unlike the geometric isomersα- andβ-parachloral (CCl3CHO)3 which exist in boat andcis,cis-chair conformations, theα- andβ-forms of parabutylchloral (CH3CHClCCl2CHO)3 are now shown by X-ray crystallography not to be geometric isomers. Both forms exist incis,cis-chair conformations and the isomerism arises from the chirality of the side chains at theβ-carbon atoms. In theα-form only two of the side chains have the same chirality, but in theβ-form the chirality at all theβ-carbon atoms is the same. The X-ray results are supplemented by1H and13C nuclear magnetic resonance spectroscopy and by mass spectrometry.

Notes: Abstract The synthesis and structural characterization of the title compound, C28H24N8O8S4Cl2Te·6H2O are reported. The crystals are triclinic, space group P¯1 (No. 2), withZ=1 in a unit cell of dimensionsa=10.312(7),b=7.144(6),c=14.256(7) Å,α=83.04(5),β=92.15(5), andγ=101.25(6)°,V c =1022 Å3. The structure was solved by Fourier methods, and refined by full-matrix least squares toR=0.073 andR w =0.077 for 1305 unique reflections. The tellurium atom in the molecule lies at a crystallographic center of symmetry, and is bonded to four phenylenethiourea sulfur atoms in a near square-planar arrangement with Te-S(1)=2.666(5), Te-S(2)=2.675(6) Å, and S(1)-Te-S(2)=88.7(3)°. The ligands behave as thiones. The crystal packing is stabilized by the extensive hydrogen bonding involving oxygen and nitrogen atoms. The Cl-O bond lengths are 1.29-1.36 Å and the O-Cl-O angles are 90–130° in the ClO4 – moiety, and differ considerably from the normal values of 1.44 Å and 109°, respectively.

Notes: Abstract Air oxidation of Mo2(S2CNEt2)6 in chloroform yielded a disordered crystalline form of tetrakisdiethyldithiocarbamatomolybdenum(V) isohexamolybdate, [Mo(S2CNEt2)4]2 Mo6O19, which is monoclinic, space groupC2/c,a=28.61(2),b=25.74(2),c=12.892(7) Å,β=115.26(4)°, andZ=4. The structure, refined from 2167 observed MoKα reflections to anR factor of 0.12, consists of discrete Mo(S2CNEt2)4 + cations and Mo6O 19 2− anions. One of the two cations per asymmetric unit is located on a two-fold axis, whereas the other is randomly distributed over two general sites. The two “half” Mo(V) atoms in the two disordered molecules are separated by 1.60(2) Å. The anion is located at a center of symmetry. This phase exhibits different IR, UV, and visible spectra from those of the ordered phase, though both belong to the same space group. The IR spectrum of the product has characteristic features of dithiocarbamate complexes. However, the splitting of theμ s(CS) band in the 1000 cm−1 region, a triplet ofμ as(CS) at about 600 cm−1, and a shoulder of theμ(MS) band in the 350–370 cm−1 region suggest a highly complex mode of bonding between Mo and dithiocarbamate. Many bands attributable to Mo-O(t) (terminal) and Mo-O(b) (bridge) were observed, indicating substantial deviation of the anion from idealizedO h symmetry.

Notes: Abstract The reaction of bis(hydroxymethyl)phenylphosphane withtert-butyldichlorophosphane leads to the formation ofcis-2-tert-butyl-5-phenyl-1,3,2,5-dioxadiphosphorinane (1). Thecis configuration was definitively proven by the X-ray diffraction study of the 2, 5-dithioxo derivative (2), which was obtained from (1) by a stereoselective reaction. The diselenoxo compound (3) was also prepared. These three new compounds were subjected to a complete NMR study (1H,13C,31P, and77Se).

Notes: Abstract The title compound was prepared by the addition of A1Me3 to a suspension of 18-crown-6 inp-xylene. The large, colorless, air-sensitive crystals belong to the monoclinic space group P21/n witha=14.822(6),b=7.894(4),c=18.805(6) Å,β=105.40(4)°, andD calc=1.03 g cm−3 forZ=2. The finalR value based on 1758 observed reflections is 0.043. The molecule lies on a crystallographic inversion center and exhibits four strong Al-O bonds. The two independent Al-O distances are 1.978(3) and 2.000(3) Å. The oxygen atoms deviate from the mean plane of the crown, alternating above and below, by 0.13, 0.15, and 0.20 Å, respectively. Thep-xylene molecule is also positioned about a center of inversion.

Notes: Abstract The X-ray crystal structure of the title compound has been determined. The crystals are orthorhombic:Pcab, a=9.857(5),b=15.274(5),c=32.601(14) Å,V c =4908.4 Å3;Z=8;D x =1.279 Mg m−3; λ(MoKα)=0.71069 Å;μ=0.88 cm−1,F(000)=2016, temperature of measurement 294 K. The structure was solved by direct methods, and refined with 932 reflections to a finalR value of 0.071. The two six-membered rings show distorted boat conformations and the tetrahydrofuran ring exhibits a half-chair conformation. Mass spectra, IR spectrum, and1H and13C NMR spectra are also reported.

Notes: Abstract The molecular structures of two medium-ring heterocycles, C16H26NO4I and C17H28NO4I, have been determined by X-ray analysis. The compounds are of potential pharmacological interest, and their conformations have now been fully determined.

Notes: Abstract Ca2P2O7·4H2O, monoclinicP21/c, a=6.008(1),b=25.034(4),c=6.837(1) Å,β=109.7 (1)°,Z=4,D 0=2.20,D c =2.24 g cm−3. The structure was solved by direct methods and refined by block-diagonal matrix least squares to a finalR value of 0.038. Both calcium atoms are seven coordinate. The $$\overline {P - O_T } $$ distance is 1.510(6) Å, whereas the $$\overline {P - O_B } $$ distance is 1.619(1) Å and the P-OB-P angle is 125.9(1)°.

Notes: Abstract Attempts to characterize nucleic acid-silver interactions raise questions about how the free nucleic acid bases interact with silver ions in dilute aqueous solution. Studies of ultraviolet and infrared dichroism lead to the conclusion that with silver(I) ions in dilute solution adenine forms linear polymers, whereas 1-methyladenine forms dimers. The composition and structure of the complexes are further discussed against the background of the spectroscopic results.

Notes: Abstract C38H35Cl2O2P2Re,M r=842, triclinic,P¯1,a=17.71(2),b=11.33(1),c=9.82(1) Å,α=114.60(3),β=90.84(3), γ=78.05(3),V=1747(2) Å3,D m(flotation)=1.60,D x=1.60 Mg m−3 forZ=2, MoKα, λ=0.7107 Å,μ=41.6 cm−1,F(000)=836, room temperature. The structure was solved by standard methods from diffractometer data and refined to a conventionalR of 3.4% for 5412 observed reflections. The Re atom is six coordinate octahedral withtrans-Cl atoms andtrans-Ph3P groups. Relevant bond distances are: Re-P 2.533(1) and 2.535(1) Å, Re-O(ethoxo) 1.888(4) Å, and Re-O(oxide) 1.699(4) Å. The ethyl chain is partially disordered.

Notes: Abstract Raman and infrared spectra of disilver sulfamide, Ag2(HNSO2NH), and tetrasilver sulfamide, Ag4(NSO2N), together with their15N and2H derivatives (at 300 and 80 K), are reported and interpreted. Resonance conditions for the Raman spectrum of the deep red tetrasilver sulfamide is assumed, but no overtone progression of any band is observed. Silver-nitrogen stretching bands appear in the frequency region 300−200 cm−1. Although the X-ray crystal structures of the compounds reveal short Ag⋯Ag distances, no frequency assignable to metalmetal stretching vibrations could be clearly located except for Ag4(NSO2N) in the case of the strong band at 288 cm−1 appearing in the infrared only. This band is assigned to a lattice vibration having high frequency due to strong metalmetal interaction. Optical diffuse reflectance and fluorescence emission/excitation spectra are included and compared to the literature data for silver-exchanged zerolites.

Notes: Abstract Glycinehydroxamic acid, C2H6N2O2 (NH2CH2C(O)NHOH), was synthesized and its crystal and molecular structure determined by single-crystal X-ray diffraction methods. The crystals are monoclinic:P2 1/c C 2h 5 , No. 14),a=5.682(2),b=7.133(2),c=9.540(3) Å,β=104.38(4)°,Z=4. The structure has been solved by direct phase determination methods, and refined to anR value of 0.042 for 633 nonzero independent amplitudes. The molecule of the title compound exists in the structure as a zwitterion, NH 3 + -CH2-C(O)-N-OH. The hydroxamate group is planar and the Nα (amino) atom, from the glycine part of the molecule, deviates by 1.43 Å from the best molecular plane defined by O(1), N(1), C(1), and O(2) atoms, respectively. The molecules are held together by a network of N+-H⋯O, N+-H⋯¯N, and O-H⋯O hydrogen bonds.

Notes: Summary The paper describes the application of a recently developed joint element to the analysis of a jointed rock foundation of an arch dam. The most relevant joint system and the concrete-rock interfaces were simulated by means of joint elements. Parameters for the constitutive behaviour of the joints were derived from large scale “in situ” shear tests. The analysis showed the suitability of the jointed model to predict not only stresses and deformations but also the shape of the failure surface al ultimate conditions. This allows an easy determination of conventional safety factors. A parallel “no tension” analysis incorporating a “cohesion threshold” was also carried out. The comparison of both approaches indicates that the “no tension” hypothesis is a crude approximation of the rock response to dam loads and may lead to unsafe estimates of stability and stress conditions. The analysis performed also showed the relevance of initial stress conditions inside the rock mass in controlling the overall foundation response.

Notes: Summary This paper describes a mathematical model for analyzing progressive failure in a stratified and jointed rock mass dipping parallel to the slope face. The relationship between the necessary support forces and permissible displacement in the rock mass is discussed. An analytical expression is provided for the minimum required support force corresponding to a critical displacement. This expression is used to evaluate the potential of unstable failure propagation. The effect of time on progressive failure is considered by using a simple rheological model for joints. A case study, involving an excavation in a stratified medium, is used to compare model prediction with monitored performance.

Notes: Summary Whenever solid or hollow inclusions are used as instrumented probes in overcoring techniques, “residual stresses” remain in the overcored rock sample and in the probes. When using such devices for computing the in-situ stress field components from measured strains or displacements, it is common practice to assume that the overcoring diameter is infinite and that there is a perfect bonding between the rock and the probes. The validity of these assumptions depends on the magnitude of the residual stresses at the rock-probe contact as compared to the tensile and shear strengths of the rock-probe bond material. It also depends on the distribution of residual stresses in the overcored sample. In comparison to previous work, new expressions are proposed in this paper for the residual stresses associated with solid or hollow inclusion type stress probes in anisotropic ground. These expressions are presented in dimensionless form and are used to show that the distribution and magnitude of residual stresses depend on the isotropic-anisotropic rock character, the degree and type of rock anisotropy, the orientation of the rock anisotropy with respect to the hole in which the probes are located and the relative deformability of the rock with respect to the deformability of the material comprising the probes. The conditions that are required for neglecting the overcored sample diameter are also discussed. This is shown for rocks that can be described as isotropic, transversely isotropic and orthotropic materials.

Notes: Summary The significance of prefailure joint dilatancy is investigated by means of a simple analysis of a single span beam. The beam is modelled as a number of discrete blocks separated by vertical joints. The compliance of the system is concentrated at these joints which have dilatant shear behaviour. As well as showing how dilatant behaviour generates an axial thrust, which tends to suppress the tensile forces due to bending effects, it is shown that the phenomenon might provide an explanation for some observations of stresses in the roof of an underground mine.

Notes: Abstract A microprobe investigation of the high grade metamorphic zones from the Barrovian type area in Angus, Scotland, shows the importance of local zones of retrograde cation exchange between garnet, staurolite and biotite. The interpretation of this zoning, established during a slow cooling history, is critical to any study of metamorphic reactions or conditions. The extent and intensity of these diffusion effects are dependent on a number of parameters including grainsize, fabric orientation, heating and cooling history, and the modal abundance of the phases. Increasing diffusion within garnets with metamorphic grade, and the subsequent retrograde effects are modelled using Temperature-Time-Transformation diagrams and provide information on the activation energy for Fe-Mg diffusion in garnet.

Notes: Abstract Staurolite-kyanite schists from the Dalradian of Scotland and Ireland show two types of retrograde alteration. In the Irish examples staurolite and kyanite are replaced by muscovite and paragonite, often with margarite and sometimes chloritoid. Plagioclase in these samples may be albitized. In contrast one Scottish sample shows replacement of both staurolite and plagioclase by muscovite. Retrogression resulted from infiltration of fluid, but while in some samples the large number of retrograde phases internally buffered the fluid composition and cation metasomatism cannot be proven, in others the fluid composition was externally controlled and there was cation metasomatism indicating more extensive infiltration. It is demonstrated by the use of activity diagrams showing the relationships between Al-silicate, white mica and alkali feldspar that wholesale alteration to muscovite was most likely caused by fluids moving down-temperature from a granitic or arkosic source. In contrast, if growth of retrograde albite is actually accompanied by Na-metasomatism then the infiltrating fluids are likely to have been moving up-temperature through pelitic lithologies. Large fluid: rock ratios of around 10∶1 are needed to achieve significant alkali metasomatism except in extreme situations of large temperature changes and highly concentrated fluids.

Notes: Abstract Regional variations in initial 87Sr/86Sr ratios (r i) of Mesozoic plutons in central Idaho locate the edge of Precambrian continental crust at the boundary between the late Paleozoic-Mesozoic accreted terranes and Precambrian sialic crust in western Idaho. The r i values increase abruptly but continuously from less than 0.704 in the accreted terranes to greater than 0.708 across a narrow, 5 to 15 km zone, characterized by elongate, lens-shaped, highly deformed plutons and schistose metasedimentary and metavolcanic units. The chemical and petrologic character of the plutons changes concomitantly from ocean-arc-type, diorite-tonalite-trondhjemite units to a weakly peraluminous, calcic to calcalkalic tonalite-granodiorite-granite suite (the Idaho batholith). Plutons in both suites yield Late Cretaceous ages, but Permian through Early Cretaceous bodies are confined to the accreted terranes and early Tertiary intrusions are restricted to areas underlain by Precambrian crust. The two major terranes were juxtaposed between 75 and 130 m.y. ago, probably between 80 and 95 m.y. Oxygen and strontium isotopic ratios and Rb and Sr concentrations of the plutonic rocks document a significant upper-crustal contribution to the magmas that intrude Precambrian crust. Magmas intruding the arc terranes were derived from the upper mantle/subducted oceanic lithosphere and may have been modified by anatexis of earlier island-arc volcanic and sedimentary units. Plutons near the edge of Precambrian sialic crust represent simple mixtures of the Precambrian wall-rocks with melts derived from the upper mantle or subducted oceanic lithosphere with r i of 0.7035. Rb/Sr varies linearly with r i, producing “pseudoisochrons” with apparent “ages” close to the age of the wall rocks. Measured δ 18O values of the wall rocks are less than those required for the assimilated end-member by Sr-O covariation in the plutons, however, indicating that wall-rock δ 18O was reduced significantly by exchange with circulating fluids. Metasedimentary rocks of the Belt Supergroup are similarly affected near the batholith, documenting a systematic depletion in 18O as much as 50 km from the margin of the batholith. Plutons of the Bitterroot lobe of the Idaho batholith are remote from the accreted terranes and represent mixtures of Precambrian wall-rocks with melts dominated by continental lower crust (r i〉0.708) rather than mantle. “Pseudoisochrons” resulting from these data are actually mixing lines that yield apparent “ages” less than the true age of the wall rocks and meaningless “ri”. Assimilation/ fractional-crystallization models permit only insignificant amounts of crystal fractionation during anatexis and mixing for the majority of plutons of the region.

Notes: Abstract The Kallithea intrusive complex on Samos forms part of the Miocene granitoid province of the central Aegean. The complex consists of numerous composite dikes consisting of different I-type diorites, monzodiorites, (quartz) monzonites, granodiorites, and granites, as well as rare pegmatites. Within individual dikes the different rock types display various structural relationships to each other, most of which indicate that multiple intrusion was the main process responsible for the association of different rock types. Petrographical, geochemical, and Sr isotope data prove that at least some of the different magma pulses were genetically unrelated. For others, a comagmatic relationship cannot be excluded. The most spectacular feature of the composite dikes are net-veined parts in which spherical (pillow-like) to angular bodies of microdiorite are surrounded by a network of more felsic rocks of varying compositions (monzonites, granodiorites, and monzogranites). — For the microdiorite/monzogranite pairs, a formation by unmixing due to liquid immiscibility is suggested by the following facts: (a) the presence of monzogranite ocelli within the microdiorite bodies, (b) similar compositions of those minerals present in both the basic and felsic parts, (c) the enrichment of HFS elements in the basic parts and the depletion of these elements in the acid parts, (d) similar Sr isotope initial ratios. Such an origin, however, is excluded for the other net-veined parts having felsic veins of either monzonitic or granodioritic compositions. In these pairs, the HFS elements are enriched in the acid parts, common minerals may have different compositions, and Sr isotope initial ratios are different. These net-veined parts can only be explained by the model of multiple injections whereby a felsic melt intruded into a basic magma.

Notes: Abstract This investigation describes five Mesozoic dolerite dikes which intrude Paleozoic metamorphic and igneous rocks of the Inner Piedmont of western South Carolina. The dikes are vertical or nearly so and strike approximately N40° W. Three major northeast-trending faults also occur in the study area. Left lateral displacement of one dolerite is documented at a locality near Cleveland, South Carolina. Elsewhere, several of the dolerite dikes appear to terminate at or near the faults. — The dolerite dikes have subophitic to microporphyritic textures and consist principally of plagioclase (generally An70–80), olivine (dominantly Fo80–90) and augite with subordinate pigeonite, titanomagnetite, chromite and brown, partly glassy mesostasis. In one dike pyroxene compositions trend from augite to ferroaugite in contrast to an augite→subcalcic augite→pigeonite trend characteristic of the other dolerites. The contrasting trends primarily result from differences in SiO2 abundance in the dolerite magmas. — Major and trace element analyses indicate the presence of two different olivine-normative dolerite magma types. The two magma types are not related by near surface crystal fractionation. Models for genesis of the olivine-normative dolerite magmas by partial melting of a plagioclase peridotite upper mantle source region are presented. The models require that the source region be enriched in LREE and incompatible elements such as Rb, Ba, Hf and Th relative to Cl chondritic abundances. One magma type appears to represent a primary dolerite magma that ascended from the source region with little subsequent compositional change. The second magma type most likely experienced assimilation of clinopyroxene-garnet (eclogite) during ascent, thereby acquiring a REE pattern with a less steep negative slope for the LREE and a slight positive slope in the HREE.

Notes: Abstract Continental tholeiites have higher SiO2, K2O and light rare earth element contents and more evolved isotopic characteristics than their oceanic counterparts. These differences can be explained if the compositions of the parent magmas to both types of tholeiites are similar but if continental magmas assimilate significant amounts of continental crust en route to the surface. Although there is little doubt that most continental tholeiites have assimilated crustal material, the lcoation and mechanism of assimilation remain uncertain. Longhi (1981) has argued that magmas derived directly from the mantle should crystallize little orthopyroxene. The abundance of orthopyroxene in most continental layered intrusions suggests that they have crystallized from magmas which have assimilated continental crust. Since orthopyroxene is an early crystallizing phase in layered intrusions, this assimilation must occur early, before the magma enters the chamber. Assimilation can occur at the margins of the dykes which feed magma chambers, depending on the nature of the flow. If the flow is turbulent the high temperatures at the centre of the dyke will extend to the margins and the magma will erode the dyke walls. If the flow is laminar, a conductive profile develops at the margin and the flowing magma chills against the walls, protecting them from thermal erosion. The nature of flow in a dyke can be predicted from the Reynolds number, the criteria for turbulence. Reynolds number calculations suggest that the flow of primitive magmas in continental dykes will be fully turbulent and, if this is the case, assimilation of low melting point components in the walls of the dyke is inevitable. It is therefore suggested that many of the geochemical characteristics of continental tholeiites result from melting at the walls of dykes as primitive magmas ascend through the crust.

Notes: Abstract In the Heathcote Greenstone Belt of central Victoria, a sequence of boninites and low-Ti andesites is overlain and intruded by tholeiitic basalts with affinities to backarc basin basalts. Two suites of boninites have been identified: one (Type A) with Ti/Zr ratios of 63±4, (La/Yb)N of 2–3 and HREE 5 times chondritic levels. The other suite (Type B) overlies Type A boninites and has Ti/Zr ratios of 23±3 and lower TiO2 and HREE contents (2–3 × chondrite), but shows significantly greater LREE enrichment, with (La/Yb)N greater than 5. Fractionation within both suites was largely controlled by the low-Ca pyroxenes protoenstatite and enstatite. Plagioclase-phyric low-Ti, high-Mg andesites occur in fault contact with the boninites, and have Ti/Zr and (La/Yb)N ratios very close to those of Type B boninites, but at higher absolute abundances of TiO2 and HREE. They are not related to either boninite suite by any realistic fractionation scheme, but originated from the same source as Type B boninites by approximately half the degree of partial melting that generated the boninites. Type A boninites could have been generated when LILE-enriched hydrous fluids derived from a subducted slab invaded depleted, clinopyroxene-poor lherzolite at depths less than 30 km, and initiated H2O-undersaturated partial melting. In a later partial melting event at similar depths, continued influx of metasomatic fluids into by now highly-depleted peridotite could have generated Type B boninites and low-Ti andesites. The presence of boninites and low-Ti andesites in the Cambrian Heathcote and Mount Wellington Greenstone Belts in southeastern Australia suggests that the early history of the Lachlan Foldbelt took place in a subduction-related, intraoceanic setting.

Notes: Abstract Ilmenite macrocrysts in olivine melilitites from Namaqualand-Bushmanland, South Africa, have decomposed by subsolidus reduction to form oriented Mg-titanomagnetite along {0001} ilmenite planes. Residual ilmenite contains 10–11 wt% MgO, ∼1 wt% MnO, and ∼0.1 wt% Cr2O3. This macrocryst assemblage is mantled by an annulus of Mg-titanomagnetite, followed by an overgrowth of radiating magnetite + perovskite. Terminal compositions of these magnetites are similar to groundmass spinels, and to the outermost margins of magnetite macrocrysts that have very high Fe3+ core contents. The assemblages are remarkably similar to oxide intergrowths in kimberlites and an upper mantle derivation is proposed for ilmenite macrocrysts in these melilitites. Oxidation states in the source regions are also very similar, whether on-or off-craton, being slightly above FMQ (∼NNO), but reduced to FMQWM with the onset of decompression, volatile loss, and carbonate immiscibility. In the case of the melilitites, late stage, low pressure crystallization above NNO precipated abundant magnetite + perovskite. The oxide fO2 data are consistent with, and refine the fO2 estimates obtained previously for the behavior of Fe/Mg and Ni contents in olivine from the same suite of samples.

Notes: Abstract Anomalously low and variable 18O/16O ratios (whole rock δ 18OSMOW=−1.9 to +6.0) have been measured in several Late Proterozoic metamorphic units associated with a large scale low-angle ductile shear zone at Meatiq Dome in the central Eastern Desert of Egypt. The low-18O units consist of granite gneiss, quartzofeldspathic mylonite, and quartz phyllonite. These are intruded by syntectonic diorite-tonalite-granodiorite and post-tectonic granite, both having normal δ 18O. No evidence for other low-18O country rock units has been found. Oxygen isotope fractionation between quartz and magnetite in the granite gneiss (Δ QZ-MT=8.0 to 9.3) is consistent with equilibration at amphibolite grade temperatures, suggesting that 18O depletion occurred prior to metamorphism. Whole rock geochemical analyses indicate that the low-18O units were derived from two granitic protoliths, one of which apparently underwent local sericitic alteration prior to metamorphism; it is proposed that 18O depletion and sericitic alteration occurred simultaneously in a high-temperature meteorichydrothermal system associated with emplacement of these granitic protoliths. The relatively high ductility of the sericitically altered rock may have been an important factor in the subsequent localization of the shear zone.

Notes: Abstract Petrology and oxide mineral chemistry are presented on 5 kimberlite dikes that are classified into three groups: (1) one dike is highly carbonated and highly oxidized (〉 MH) and is characterised by chlorite+Mn-titanomagnetite+rutile+hematite (after chlorite)+maghemite (after titanomagnetite), with ilmenite and perovskite being absent; (2) three dikes are typified by atoll-textured spinels +phlogopite+euhedral Mn-picroilmenite, of intermediate oxidation state (WM-FMQ) with coexisting deuterically serpentinized olivine+Ni-Fe alloys and magnetite; (3) the remaining dike records an early crystallization event under very low (≤ WM) redox conditions that precipitated anionic-deficient spinels and a Mg-Ti-Cr-wüstite-type phase, followed by late stage more oxidizing (=FMQ) Mnpicroilmenite. Spinels are complexly zoned and crystallization trends among the dikes are diverse, underscoring the fact that no single compositional trend, or evolutionary sequence is typical of kimberlites. Ilmenites are euhedral, and criteria for groundmass crystallization are established. Extraordinarily high MnO (max 17 wt%) contents and high geikielite (62 mole%) concentrations expand the ilmenite field typically assigned to that of kimberlites. Zirconium, Nb and Cr are present in concentrations of 0.5–3 wt% (as oxides) in ilmenite. These highly incompatible elements, along with Mn, are concentrated in late stage melt fractions. The high pyrophanite contents, which are more typical of silicic alkali suites, are accompanied by phlogopite in the Koidu dikes. Objective evaluations of kimberlite-carbonatite relations, as outlined in the literature, cannot be made based on the oxide mineral group. Much of the compositional data for oxides in kimberlites are on mantle-derived xenolith suites and are not from oxides derived from the crystallization of kimberlitic melts. Assessments of the fO2's of kimberlites have considerable potential in evaluating diamond survival through redox reactions. Manganese-rich (+Nb, Zr, Cr) ilmenites are typical of many kimberlites and should be considered in the suite of index minerals employed in prospecting.

Notes: Abstract Hydrothermal alteration of Tertiary granites from Skye involed the reaction of igneous amphibole, biotite, ferroaugite, fayalite, alkali feldspar, plagioclase feldspar, magnetite, and ilmenite with aqueous fluid primarily to combinations of secondary alkali feldspar, chlorite and montmorillonite. Lesser amounts of muscovite, calcite, epidote, prehnite, zeolite, and pyrite also developed. During mineralogical alteration of the granites there was a net addition to rock of H and a net loss of Ca, Fe, and probably Na. There is no positive evidence for a significant change in their Al, Si, Mg, or K contents. Hydrothermal alteration of Skye granite involved not only large-scale migration of 18O, 16O, D, and H but also of Ca, Fe, and probably Na. Mineral thermometry combined with textural observations suggests that chemical, isotopic, and most mineralogical alteration were synchronous and occurred at 350°–450° C. Textural observations further suggest that the mechanism of isotopic exchange between granite and hydrothermal fluid primarily was solution/reprecipitation. Mineral thermometry and oxygen fugacity barometry indicate that some minerals in the granites — clear alkali and plagioclase feldspars, Fe-Ti oxides, biotite, fayalite, and probably amphibole and pyroxene — have compositions that record physical conditions during crystallization or at high temperatures slightly below the crystallization temperature (650°–750° C). These minerals have chemistries that were later unaffected by the hydrothermal event. Mineral thermometry also indicates that other minerals — turbid feldspar and all secondary minerals — have compositions that record physical conditions of hydrothermal alteration (350°–450° C). The isotope chemistries of the high-temperature minerals are inferred to be those in unaltered “normal” granite while the isotope chemistries of the low-temperature minerals are inferred to be those of minerals equilibrated with the hydrothermal fluid at low temperature. The close correspondence between the isotopic and major element composition of minerals in altered granites leads to an integrated mineralogic/isotopic model that considers the granites as composed of two families of minerals: an“igneous” family and a “hydrothermal” family. Comparison of data for altered Skye granites with data from hydrothermally altered synmetamorphic granites from Maine shows the important control that depth exerts on the isotopic composition and mineral chemistry of altered granites. Because the hydrothermal fluids that altered epizonal Skye granites were meteoric in origin, altered rocks are isotopically lighter than “normal” granite. In part because the hydrothermal fluids that altered the mesozonal granites from Maine were metamorphic in origin, altered rocks are isotopically heavier then “normal” granite. The hydrothermal event on Skye was shallow and hence short-lived; mineral-fluid reactions did not go to completion. Minerals in altered Skye granites therefore show large departures from both chemical and isotopic exchange equilibrium. The hydrothermal event in Maine was deeper and hence long-lived; reactions more closely approached equilibrium. Minerals in altered Maine granites therefore show a much closer approach to both chemical and isotope exchange equilibrium.

Notes: Abstract Structural and crystal-chemical observations on acicular and skeletal silicate-carbonate-hydroxyapatite crystals (SCHap) from comb-layer alvikite dykes of the Kaiserstuhl carbonatite complex yield strong evidence for their being quenched products. As well as being intimately intergrown with calcite, they also contain distinctive primary phosphate inclusions. In contrast to the host apatite, these inclusions are free of Si, low in LREE but enriched in Sr and the volatiles F and S, and contain a high concentration of Na. This pronounced fractionation combined with the absence of x-ray diffraction and electron diffraction patterns suggests that the phosphate inclusions represent portions of a trapped residual phosphate melt. Therefore the SCHap are considered to be the direct liquidus phase of a carbonate-phosphate melt. That two phosphate phases coexist, however, presumes strong enrichment of phosphorous in the parental carbonatitic melt, since the eutectic would otherwise produce calcite and apatite only. The formation of sharply interfaced apatite- and calcite-comb-layers and the occurrence of trapped phosphate melt inclusions in the quench apatites argue for the existence of two immiscible liquids such as a phosphate-rich and a carbonate-rich melt.

Notes: Abstract Three kornerupine occurrences are reported in distinctive SiO2-poor, MgO- and Al2O3-rich paragneisses from the Namaqualand Metamorphic Complex in South Africa. Kornerupine coexists stably with phlogopite, cordierite, orthopyroxene, gedrite, sapphirine, sillimanite and plagioclase and, in sapphirine-free rocks, with spinel and corundum. Tourmaline of a texturally older generation than kornerupine is commonly present in the same samples. Ten analysed kornerupines show a variation in total Fe as FeO from 1.8 to 10.9 weight per cent. B2O3 contents are estimated from x-ray data and a few spectrochemical analyses to range from 0.9 to 3.5 weight per cent. There is a strong inverse correlation between B3+ and Al3+. Total iron content has a strong and systematic effect on refractive index, colour and dispersion. Fe and Mg are systematically partitioned with the other minerals, and Mg/(Mg+Fe) ratios increase as follows: spinel 〈gedrite≈orthopyroxene〈 sapphirine ≈kornerupine≈tourmaline≈phlogopite〈cordierite. Kornerupine commonly forms rims on sapphirine or sapphirine-cordierite aggregates, idioblastic prisms in phlogopite, or coarse intergrowths with gedrite or orthopyroxene. Kornerupine probably grew at, or shortly after, a metamorphic climax under granulite-facies conditions of 750°–800° C and 4 to 6.5 kbar. Late formation and good crystal shape suggest a model for kornerupine development in which fluids provided a medium for the redistribution of mobile species (including boron) and caused the stabilization of kornerupine rather than tourmaline as the boron-bearing silicate in these rocks. A possible source of fluids at an appropriate stage in the metamorphic development is from crystallizing migmatite leucosomes in adjacent metapelitic and biotite gneisses. The unusual bulk compositions of these gneisses are interpreted to result from the isochemical metamorphism of a Mg-Al-rich, locally boron-bearing, sedimentary precursor.

Notes: Abstract Glass inclusions trapped in bytownite phenocrysts (from the Ardoukoba eruption, Djibouti Republic, 7 November 1978) are used as an experimental environment to follow the evolution of crystallization and residual liquids in a magma with tholeiitic affinities. The results are compared with those obtained from abyssal tholeiites by Walker et al. (1979). In near equilibrium crystallization conditions, simultaneous crystallization of olivine and pyroxene is obtained in the enclosed silicate liquid as well as plagioclase as overgrowths on the cavity walls. Oxides only appear at lower temperatures. The olivine is homogeneous and rather rare (≦5% in weight). It forms at a temperature between 1,186° C±3(Fo85) and 1,126° C(Fo66). The distribution coefficient of Mg between the liquid and the olivine varies regularly with the temperature until titanomagnetite appears. The augite is much more abundant (〉20% in weight of the original trapped melt) and is characterized by a composition that varies from the centre to the edges of the crystals Wo 43.5–36.2, En 43.8-41.7, Fs 12.7–22.1. Composition shows an unsatisfactory correlation with temperature and, at most, an Fs enrichment may be noted with temperature decrease. The composition of the plagioclase deposited on the cavity walls varies linearly with temperature from An 73.3 at 1,186° C to An 56.5 at 1,135° C in the case of contemporaneous crystallization of Pl, Cpx, Ol and Ox. If experiments are carried out by undercooling (as much as 150° C) in relation to crystallization of the ferromagnesian minerals, the composition of the plagioclase changes from An 78.8 at 1,160° C to An 52.8 at 1,025° C. In the case of the Pl, Ol, Cpx and +OX crystallization, the included liquids evolve from tholeiitic basalts to ferrobasalts in the same way as the lavas studied in the Asal rift (Demange et al. 1980). The advantages and limitations of the method are discussed.

Notes: Abstract Major and trace element analyses for 103 volcanoes of the Quaternary West Eifel volcanic field show the lavas to be dominantly primitive (MgO〉7 wt.%) and potassic (Na2O/K2O∼1). The rocks are divided into (1) a foidite (F)-suite, volumetrically dominant and consisting of four types: leucitites and nephelinites, melilite-bearing foidites, olivine-free foidites, sodalite-bearing melilite-free foidites, and (2) a younger olivine-nephelinite and basanite (ONB)-suite, concentrated in the southeastern part of the field. Dominantly cpx-phyric F-suite magmas differ from the dominantly ol-phyric ONB-suite mainly in higher K2O/ Na2O and CaO/Al2O3-ratios, higher Rb, Cu, H2O, CO2 and LREE concentrations and slightly lower Sr, Ni and Y contents. Most magmas have fractionated small amounts of olivine, clinopyroxene, and minor phlogopite. Systematic compositional variations within volcanoes or volcano groups are rare. Five more differentiated volcanoes (2 tephrites, 3 phonolites) occur in the center of the field. Their magmas are interpreted to have formed by fractionation within crustal magma chambers. Chemical differences between primary magmas (43% of volcanoes sampled) within both suites can be explained by different degrees of crystal fractionation at high pressures in the ascending magma column and possibly by varying degrees of partial melting (about 2–8%) in a garnetlherzolite mantle source. Distinct isotope ratios, parallel element variations, and different ratios of similarly incompatible elements, however, indicate a heterogeneous mantle beneath the West Eifel. The F-suite magmas originated from a mantle source more strongly enriched in alkalis and incompatible elements than the ONB-suite mantle source. The following model is proposed, based also on experimental studies and geophysical data: Within a large low velocity body of garnet-lherzolite, enriched in fluids and LIL elements (metasomatized mantle) between about 50 and 150 km depth, two different magma types were produced at different depths. Above a detachment level at about 50 km depth, these magmas rose to different stagnation levels or rapidly directly to the surface along vertical, dominantly NW-SE orientated fissures. The F-suite magmas probably formed in a phlogopite-bearing, CO2-rich, strongly metasomatized source at about 100 km, the ON-Bmagmas from an amphibole-bearing, CO2-poorer melting anomaly at about 60–75 km depth.

Notes: Abstract The Gibbs free energy and volume changes attendant upon hydration of cordierites in the system magnesian cordierite-water have been extracted from the published high pressure experimental data at $$P_{{\text{H}}_{\text{2}} {\text{O}}} $$ =P total, assuming an ideal one site model for H2O in cordierite. Incorporating the dependence of ΔG and ΔV on temperature, which was found to be linear within the experimental conditions of 500°–1,000°C and 1–10,000 bars, the relation between the water content of cordierite and P, T and $$f_{{\text{H}}_{\text{2}} {\text{O}}} $$ has been formulated as $$\begin{gathered} X_{{\text{H}}_{\text{2}} {\text{O}}}^{{\text{crd}}} = \hfill \\ \frac{{f_{{\text{H}}_{\text{2}} {\text{O}}}^{{\text{P, T}}} }}{{\left[ {{\text{exp}}\frac{1}{{RT}}\left\{ {64,775 - 32.26T + G_{{\text{H}}_{\text{2}} {\text{O}}}^{{\text{1, }}T} - P\left( {9 \times 10^{ - 4} T - 0.5142} \right)} \right\}} \right] + f_{{\text{H}}_{\text{2}} {\text{O}}}^{{\text{P, T}}} }} \hfill \\ \end{gathered} $$ The equation can be used to compute H2O in cordierites at $$P_{{\text{H}}_{\text{2}} {\text{O}}} $$ 〈1. Our results at different P, T and partial pressure of water, assuming ideal mixing of H2O and CO2 in the vapour phase, are in very good agreement with the experimental data of Johannes and Schreyer (1977, 1981). Applying the formulation to determine $$X_{{\text{H}}_{\text{2}} {\text{O}}}^{{\text{crd}}} $$ in the garnet-cordierite-sillimanite-plagioclase-quartz granulites of Finnish Lapland as a test case, good agreement with the gravimetrically determined water contents of cordierite was obtained. Pressure estimates, from a thermodynamic modelling of the Fe-cordierite — almandine — sillimanite — quartz equilibrium at $$P_{{\text{H}}_{\text{2}} {\text{O}}} = 0$$ and $$P_{{\text{H}}_{\text{2}} {\text{O}}} $$ =Ptotal, for assemblages from South India, Scottish Caledonides, Daly Bay and Hara Lake areas are compatible with those derived from the garnetplagioclase-sillimanite-quartz geobarometer.

Notes: Abstract Data from experimentally-induced diffusion profiles at approximately 40 Kbar, 1,300–1,500° C in spessartine-almandine couples and a pyrope-almandine couple at ∼ 40 Kbar, 1,440° C, described in Part I, were used to derive tracer diffusion coefficients (D *) of Fe, Mn and Mg in garnet. The experimental data were fitted by numerical simulations that model multicomponent, compositionally-dependent difussion, including the effects of nonideal thermodynamic mixing. The simulations use the formalism of irreversible thermodynamics and an eigenvector technique of solution. We were able to fit the asymmetrical spessartine-almandine profiles using constant D * and either the Darken/Hartley-Crank or Manning-Lasaga models relating D * and interdiffusion coefficients, and both models yielded D Mg * consistent with the direct measurement of D Mg * in by Cygan and Lasaga (1985) at lower temperatures (750–900° C). The results (equations 4.1–4.3 and Table 1) indicate that D Fe * ≅D Mg * 〈D Mn * and Q Fe≅Q Mg〉Q Mn, where Q is the activation energy. In contrast, the asymmetry of pyrope-almandine profiles is too great to fit with either tracer model assuming constant D * and indicates that D Mg * is similar to its value in spessartine-almandine couples but D Fe * is an order of magnitude less. The fit also suggests that D Ca * 〈 D Fe * 〈D Mg * in pyrope-almandine couples. Synthesis of data from the two types of diffusion couples suggests that D Mg * is insensitive to compositional changes, whereas D Fe * is affected by Mn/Mg and Fe/Mg ratios and probably by other factors. These compositional effects on tracer coefficients are compatible with those documented by Morioka (1983) for cation diffusion in olivine.

Notes: Abstract The viscosities of supercooled melts of 13 different plagioclase compositions have been measured in the range 1013–108 dPas with a micro-penetration viscometer. Application of the most common empirical and theoretical viscosity-temperature models to the present data and plagioclase viscosity data available from the literature showed that the configurational entropy theory represents the best approach. Using this theory together with an entropy of mixing term evaluated from a modified “two-lattice” mixing model, the viscosities of intermediate plagioclase compositions have been calculated as a function of temperature and anorthite content solely from the appropriate data of the end members albite and anorthite. The agreement between experimental and calculated viscosity data is excellent.

Notes: Abstract Lead isotopes of K-feldspars from five granites of the SE-Schwarzwald and from metamorphites are positively correlated in 207/204 as well- as 208/204- vs. 206/204-diagrams. The linear alignments may be due to correlated laststage lead isotope evolution (lead-lead isochron) and result in a secondary isochron model age of nearly 3 Ga for the Southern Schwarzwald basement. This calculation implies a long-lasting undisturbed lead isotope evolution in the Schwarzwald basement since the Archaean. This is not supported however by geochronological studies. On the other hand the data together with U/Pb-analyses of whole rock samples from metamorphites are consistent with pre-Hercynian mantle lead addition to the basement. This presumably happened during early Paleozoic polymetamorphism. The interpretation of the lead isotope correlations as mantle-crust mixing lines needs a rather homogeneous pre-Hercynian mantle lead of the MORB-type, delivered to the crust probably in part by ascending volatile phases. Thus geodynamical models are supported which involve subduction of oceanic crust or mantle pluming during the early Paleozoic. In Part I of this report, the trends in Schwarzwald lead isotopes are discussed as secondary isochrons and as mixing lines. Constraints are derived for a pre-Hercynian mantlecrust interaction and for lead redistribution by the Hercynian basement activation.

Notes: Abstract Zeolites from the most important volcanoclastic deposits of Italy include: (1) phillipsite and heulandite from the cinerite of the central northern Apennines; (2) chabazite and phillipsite from the phonolitic tephritic ignimbrite with black pumices; (3) phillipsite from the “tufo lionato” of Vulcano Laziale; (4) chabazite and phillipsite from the Campanian ignimbrite; (5) phillipsite from the Neapolitan yellow tuff; and (6) chabazite and phillipsite from the pyroclastics of Monte Vulture. Compared with sedimentary phillipsites and chabazites described in the literature, the chabazites and phillipsites studied here have lower Si/Al ratios and higher K contents. These chemical peculiarities are correlated with both the K-rich vesuvitic-leucititic, latitic-phonolitic, and potassic alkali-trachytic chemistry of the ash from which they were derived and, very likely, with the character of the hydrologically open system environment in which they formed. The zeolite of the heulandite-clinoptilolite group from the cinerite of the central northern Apennines is classified as a true heulandite on the basis of its chemical composition and thermal behavior.

Notes: Abstract Several gneissic xenoliths occur in granite which has been intruded along the contact between an anorthosite body and gneisses in the Nain complex, Labrador. One of these xenoliths is a ferro-aluminous gneiss with ovoids, 1–3 cm in diameter, consisting of an intimate mixture of fine, granular cordierite-olivine-spinel-orthopyroxene-plagioclase-ilmenite-pyrrhotite enclosed by poikilitic grains of garnet and orthoamphibole. Biotite occurs as both granular and poikilitic grains. The textures indicate a two-stage contact metamorphic history characterized by the simplified reaction: cordierite+olivine+spinel+plagioclase +orthopyroxene→garnet+orthoamphibole Although, on the basis of texture, the reactants represent the early stage assemblage and the products represent the final stage, the distribution coefficient data for Fe-Mg indicate that, except for orthopyroxene, all of the minerals were stable and in equilibrium during the final stage. The coexistence of cordierite and olivine indicates that pressure was less than 3 kbar. The phase relationships agree well with the experimental work of Hsu and Burnham (1969) on the almandine-pyrope join at 2 kbar and indicate a temperature of 800° C for the first stage and 615° C for the second stage of contact metamorphism. This close agreement also suggests that the ovoids at one time may have been garnet porphyroblasts that were decomposed during the first stage. These data correlate well with the field relations: the first-stage, high-temperature effects were likely caused by the intrusion of the anhydrous anorthositic body and the second-stage, low-temperature effects by the invasion of the volatile-rich granite.

Notes: Abstract During prograde metamorphism garnet and, in some higher grade samples, staurolite were produced in a chlorite-chloritoid schist, part of the Precambrian Z to Cambrian Hoosac Formation near Jamaica, VT. Garnet grew during two prograde events separated by a retrogression. This sequence resulted in distinctive inclusion textures and zoning anomalies in garnet produced by diffusive alteration. Textures, reaction space analysis, and mineral compositional variations constrain the possible sequence of reactions in these rocks. Below the staurolite isograd, and to some unknown extent above it, garnet grew by the reaction chloritoid+chlorite+quartz→garnet+H2O. With increasing grade the mineral compositions are displaced towards lower Mn/Fe and higher Mg/Fe ratios. The data are compatible with equilibrium with respect to exchange reactions for the matrix assemblages on a thin section scale and with minerals having closely followed equilibrium paths during reaction. The staurolite isograd coincides with the reaction chloritoid+quartz→garnet+staurolite+chlorite+H2O. This reaction is continuous and trivariant with ZnO becoming an additional component concentrated in staurolite. During this reaction both the Mn/Fe and Mg/Fe ratios of the phases appear to have decreased. This new chemical trend is recorded by garnet zoning profiles and is compatible with trends predicted from phase diagrams. Thus there are two distinct types of garnet zoning reversals in these samples. One is near the textural unconformity and is best explained by diffusive alteration during partial resorption of first stage garnet. The other occurs near the outer rim of garnet in staurolite zone samples and marks the onset of a new prograde garnet producing reaction.

Notes: Abstract A large difference of about 5‰ in the O-isotopic composition of quartz characterizes the transition from very low grade or even anchimetamorphic slates to pelites metamorphosed at greenschist facies conditions. A further increase in temperature does not result in systematic isotopic shifts (mean around +15.5‰). However, immediately at the isograds marking the transition from greenschist to amphibolite facies and amphibolite facies to higher amphibolite facies the quartz δ 18O values are significantly higher by 〉1‰. This increase is restricted to the area immediately at the isograds. It can be shown that during the low grade transformation a fluid phase is present in excess; the metamorphism of this stage therefore can be described as “water present metamorphism”. This fluid phase leaves the system during pervasive deformation of the rocks, during which large scale homogenization processes are possible. At higher temperatures a free fluid phase is only present at specific isograds, where it is produced by mineral dehydration reactions. If the production rate of the fluid phase is sufficiently slow, this results in a re-equilibration of the mineral phases with the newly generated fluid phase, the isotopic composition of which is completely controlled by the primary mineral phases. In intermediate regions with enlarged fluid production and escape rates, a free fluid phase is present only for short periods of time at fractures which form due to fluid overpressure. The high escape rate inhibits the solid phases from re-equilibration with the generated fluid. The term “water absent metamorphism” can be used to describe this state of reduced H2O activity within a rock.

Notes: Abstract Thermal treatments of anorthite carried out at up to 1,547° C show that the γ unit cell parameter changes as a function of the treatment temperature. The best fit curve found by non-linear least squares analysis is: γ=91.419-(0.327·10-6)T 2+(0.199·10-12)T 4-(0.391·10)T 6. The results obtained support significant Al,Si disorder (ΔAl∼0.10, where ΔAl=t 1(0)-1/3 [t 1(m)+t 2(0)+t 2(m)], Ribbe 1975), in anorthite equilibrated near the melting point and confirm a “high temperature” series differentiated from the “low temperature” series for calcic plagioclases in the An85–An100 range also. In the plot γ vs. An-content the “high” and “low temperature” curves intersect at An85 composition and progressively diverge in the An85–An100 range. The trends of the “high” and “low temperature” curves in this range are interpretable on the basis of the degree of Al, Si order in the average structures of calcic plagioclases.

Notes: Abstract Field and petrologic studies along the Adirondack Lowlands — Highlands boundary near Harrisville, NY, indicate that heat from the synmetamorphic intrusion of the Diana syenite complex (intrusion temperature of ∼1,050° C) played a major role in the local metamorphic thermal regime and was responsible for extensive partial melting of adjacent metasedimentary units (Major Paragneiss of Engel and Engel). Metamorphic temperatures inferred from two — feldspar and spinel — quartz assemblages decrease from 850–950° C along the Diana — metasediment contact to 650–700° C, 2–3 km away from the contact. Metamorphic pressures are 7±0.5 kb as determined from coexisting plagioclase — garnet — sillimanite — quartz, kyanite — sillimanite, and garnet — rutile — ilmenite — sillimanite — quartz (GRAIL). In the paragneiss, migmatites consisting of quartz — microcline perthite — sodic plagioclase leucosomes are generally concordant with the melanosome consisting of biotite — sillimanite — garnet — spinel — plagioclase ±corundum±cordierite. Qualitatively the amount of partial melt and occurrences of corundum-bearing assemblages decrease away from the Diana contact. Activity of H2O inferred from coexisting biotite — sillimanite — quartz — garnet — K-feldspar ranges from 0.01 to 0.17 and is five to ten times lower in corundum-bearing rocks. Melting proceeded via vapor-absent reactions involving biotite in response to localized heating by synmetamorphic intrusion of magma. This unusually preserved, synmetamorphic contact aureole in a regional granulite terrane supports the concept that granulites owe their origin to magma intrusion and/or the ponding of magmas at the base of the crust.

Notes: Abstract Experimental determination of over seventy sets of clinopyroxene/silicate liquid (glass) partitition coefficients (D) for four rare earth elements (REE — La, Sm, Ho, Lu) in a range of REE-enriched natural rock compositions (basalt, basaltic andesite, andesite and rhyodacite) demonstrate a convex upward pattern, favouring the heavy REE (Ho, Lu) and markedly discriminating against the light REE (La). These patterns are consistent with previously documented clinopyroxene D values reported from natural phenocryst/matrix pairs and from experimental work using either REE-enriched compositions and electron microprobe analytical techniques (as in the present study) or natural or synthetic undoped compositions and mass spectrometric, ion probe or X-ray autoradiographic analytical techniques. However, the large data base in the present study allows evaluation of the effect of compositional and physical parameters on REE partitioning relationships. Considering DHo, it is shown that (1) D increases 6-fold with increasing SiO2 content of the coexisting liquid from ∼ 50 to ∼ 70 wt% SiO2 (2) D increases 4-fold with decreasing temperature from 1,120°C to 900° C (3) D increases 2-fold with increasing pressure from ∼ 2.5 to 20 kb. (4) D increases ∼ 2-fold fO2 increases from approximately that of the MW buffer to the HM buffer (5) D remains unchanged within experimental error as the water content of the melt changes from ∼ 0.3 to ≳ 10% by weight H2O. The absolute REE content of the clinopyroxene shows no consistent trend with temperature, but decreases slightly with increasing pressure, paralleling an increase in the jadeite component of the pyroxene. Thus the increase in D with increasing pressure is attributed to changes in the silicate liquid structure, which discriminate against accommodation of REE with increasing pressure. The clinopyroxene REE content increases with increasing fO2, and in this case the increase in D with increasing fO2 may be attributed mainly to this change in the clinopyroxene composition. Application of the present results to geochemical modelling allows a more appropriate choice of D values, according to the liquid composition and physical conditions applicable in the modelled system. They may also be used to evaluate cognate or xenocrystic relationships between clinopyroxene megacrysts and their host matrix.

Notes: Abstract Oxygen isotopic analyses of 95 metamorphic and igneous rocks and minerals from a Hercynian metamorphic sequence in the Trois Seigneurs Massif, Pyrenees, France, indicate that all lithologies at higher metamorphic grades than the “andalusite in” isograd have relatively homogeneous δ 18O values. The extent of homogenization is shown by the similarity of δ 18O values in metacarbonates, metapelites and granitic rocks (+11 to +13), and by the narrow range of oxygen isotopic composition shown by quartz from these lithologies. These values contrast with the δ 18O values of metapelites of lower metamorphic grade (δ 18O about +15). Homogenization was caused by a pervasive influx of hydrous fluid. Mass-balance calculations imply that the fluid influx was so large that its source was probably high-level groundwaters or connate formation water. Hydrogen isotopic analyses of muscovite from various lithologies are uniform and exceptionally heavy at δD=−25 to −30, suggesting a seawater origin. Many lines of petrological evidence from the area independently suggest that metamorphism and anatexis of pelitic metasediment occurred at depths of 6–12 km in the presence of this water-rich fluid, the composition of which was externally buffered. Deep penetration of surface waters in such environments has been hitherto unrecognized, and may be a key factor in promoting major anatexis of the continental crust at shallow depth. Three types of granitoid are exposed in the area. The leucogranites and the biotite granite-quartz diorite are both mainly derived from fusion of local Paleozoic pelitic metasediment, because all these rocks have similar whole-rock δ 18O values (+11 to +13). The post-metamorphic biotite granodiorite has a distinctly different δ 18O (+9.5 to +10.0) and was probably derived from a deeper level in the crust. Rare mafic xenoliths within the deeper parts of the biotite granite-quartz diorite also have different δ 18O (+8.0 to +8.5) and possibly represent input of mantle derived magma, which may have provided a heat source for the metamorphism.

Notes: Abstract Ordered illite/smectite is the most abundant and widespread product of argillic alteration associated with the Oligocene, epithermal, Ag-Pb-Zn-Cu-Au Amethyst vein system, southwest Colorado. Hydrothermal illite/smectites exhibit all Reichweite from 1 to ≧3 and span the composition range from about 25% to about 3% illite.— The composition and Reichweite of illite/smectite vary smoothly with distance from the Amethyst vein. With increasing distance from the vein, percent illite and the Reichweite decrease. When composition-temperature relationships of illite/smectite from modern geothermal systems are applied to the fossil Amethyst system, isotherms describing the thermal regime at the time of argillization can be estimated. Temperatures near 240° C appear to have existed near the Amethyst vein; these temperatures agree with homogenization temperatures obtained from fluid inclusions in vein minerals. The most distal illite/smectites, sampled about 260 m from the vein, indicate temperatures near 110° C. Estimated thermal gradients are on the order of 0.4 to 1° C per meter. — Although illite/smectite composition and structure vary systematically with distance from the Amethyst vein, there are no systematic trends associated with the numerous, smaller veins and veinlets in the hanging wall of the system. This indicates that temperatures of both wallrock and the fluids in all but the major Amethyst vein were nearly the same during clay formation. Apparently, the hydrothermal system had reached a fairly steady, mature, thermal state at the time of argillization.

Notes: Abstract Eclogites are found as lenses or layers in the Precambrian gneiss terrain of the Bitlis Massif in eastern Turkey. Kyanite-eclogites from the region of Gablor Hill in the Bitlis Massif exhibit relatively minor alteration, and consist of garnet, omphacite, kyanite, zoisite, calcic amphibole, phengite, rutile and quartz. In terms of geological setting and mineral compositions, Gablor eclogites are very similar to eclogites from high-grade gneiss terrains. Metamorphic conditions during the eclogite crystallisation are determined as 625±35° C and 16±3 kbars. The coexistence of white mixa, omphacite and kyanite constrains $$a_{{\text{H}}_{\text{2}} {\text{O}}} $$ between 0.4 and 1. Primary calcic amphiboles from the Gablor eclogites exhibit conflicting textures, indicating stable coexistence with, as well as growth from omphacite and garnet. This is explained by a buffering reaction between amphibole, garnet, omphacite, zoisite and kyanite during the eclogite crystallisation, whereby $$a_{{\text{H}}_{\text{2}} {\text{O}}} $$ is controlled and buffered by the mineral assemblage.

Notes: Abstract Hydrothermal alteration of Tertiary gabbros from Skye involved the reaction of igneous olivine, augite, hypersthene, plagioclase, magnetite, and ilmenite with aqueous fluid primarily to combinations of talc, chlorite, montmorillonite, calcic amphibole, biotite, and secondary magnetite. Lesser amounts of calcite, epidote, quartz, sphene, prehnite, and garnet also developed. During mineralogical alteration of gabbro there was a net addition to rock of K, Na, Sr, and H2O and a net loss of Mg. Gabbro was oxidized early in the hydrothermal event and later reduced. Iron and silicon were probably initially lost and later added. There is no evidence for significant change in the Al or Ca content of the gabbros. Hydrothermal alteration of Skye gabbro involved not only large-scale migration of 18O, 16O, D and H but also of K, Na, Sr, Mg, and probably Fe and Si. Mineral thermometry indicates that pyroxenes in the gabbros crystallized at 1000° C–1150° C and were very resistent chemically as well as isotopically to later hydrothermal alteration. Hypothetical equilibrium between primary and secondary mafic silicates suggests that mineralogical alteration of gabbro occurred at ∼450°–550° C. The lack of correlation between mineralogical and isotopic alteration of gabbro requires that much isotopic alteration occurred at temepratures above those at which the secondary minerals developed, 550°–1000° C. The chemical alteration of gabbro is correlated with its mineralogical alteration and therefore occurred at 450°–550° C. Measured progress of the mineral-fluid reactions was used to estimate the amount of H2O fluid that infiltrated the gabbro as primary olivine was converted to talc+magnetite at 525°–550° C. Calculated fluid-rock ratios are in the range 0.2–6 (volume basis) and are smaller than values estimated from isotopic data (fluid/rock ∼1–10, volume basis). Both isotopic and petrologic data point to pervasive flow of fluid through crystalline rock at elevated temperatures of 500°–1000° C. Isotopic fluid-rock ratios are larger than petrologic fluid-rock ratios because isotopic alteration of cooling gabbro began earlier and at higher temperatures than did the mineralogical alteration.