ALBERT

Description: The collision of India with Asia had a profound influence on Cenozoic topography, oceanography, climate, and faunal turnover. However, estimates of the time of the initial collision, when Indian continental crust arrived at the Transhimalayan trench, remain highly controversial. Here we use radiolarian and nannofossil biostratigraphy coupled with detrital zircon geochronology to constrain firmly the time when Asian-derived detritus was first deposited onto India in the classical Sangdanlin section of the central Himalaya, which preserves the best Paleocene stratigraphic record of the distal edge of the Indian continental rise. Deep-sea turbidites of quartzarenite composition and Indian provenance are replaced upsection by turbidites of volcano-plutoniclastic composition and Asian provenance. This sharp transition occurs above abyssal cherts yielding radiolaria of Paleogene radiolarian zones (RP) 4–6 and below abyssal cherts containing radiolaria of zone RP6 and calcareous shales with nannofossils of the Paleocene calcareous nannofossil zone (CNP) 7, constraining the age of collision onset to within the middle Paleocene (Selandian). The youngest U-Pb ages yielded by detrital zircons in the oldest Asia-derived turbidites indicate a maximum depositional age of 58.1 ± 0.9 Ma. Collision onset is thus mutually constrained by biostratigraphy and detrital zircon chronostratigraphy as 59 ± 1 Ma. This age is both more accurate and more precise than those previously obtained from the stratigraphic record of the northwestern Himalaya, and suggests that, within the resolution power of current methods, the India-Asia initial collision took place quasi-synchronously in the western and central Himalaya.

Description: 〈span〉This study focused on uppermost Cretaceous sedimentary rocks deposited in the Himalayan region and around the core of peninsular India just before the eruption of the Deccan Traps. Detailed stratigraphic and sedimentological analysis of Late Cretaceous successions in the Himalayan Range together with literature data from the Kirthar fold-and-thrust belt and central to southeastern India document a marked shallowing-upward depositional trend that took place in the Campanian−Maastrichtian before the Deccan magmatic outburst around the Cretaceous-Tertiary boundary. Topographic uplift of the Indian peninsula began in Campanian time and is held responsible for thick sediment accumulation associated with shorter periods of nondeposition in peripheral areas (Himalayan Range, Kirthar fold belt, and Krishna-Godavari Basin) than in the central part of the Deccan Province. Surface uplift preceding Deccan volcanism took place at warm-humid equatorial latitudes, which may have led to an acceleration of silicate weathering, lowered atmospheric 〈span〉p〈/span〉CO〈sub〉2〈/sub〉, and climate cooling starting in the Campanian−Maastrichtian. The radial centrifugal fluvial drainage in India that is still observed today was established at that time.〈/span〉

Description: A novel metal–organic framework based on 1,3-bis(imidazol-1-ylmethyl)benzene (1,3-bimb), [Cd(NO3)2(C14H14N4)2]n, has been synthesized hydrothermally. The structure exhibits a two-dimensional metal–organic (4,4)-net composed of CdII atoms and bimb ligands, and such layers are further joined through interlayer C—H...O hydrogen bonds to generate a three-dimensional supramolecular structure.

Description: The tectonic evolution of the Lhasa terrane (southern Tibetan Plateau) played a fundamental role in the formation of the Tibetan Plateau. However, many uncertainties remain with regard to the tectonic and paleogeographic evolution of the Lhasa terrane prior to the India-Asia collision. To determine the early tectonic processes that controlled the topographic evolution of the Lhasa terrane, we analyze the Cretaceous strata exposed in the Coqen Basin (northern Lhasa subterrane), which comprises the Langshan and Daxiong Formations. The Langshan Formation unconformably overlies the volcanic rocks of the Lower Cretaceous Zelong Group and consists of ~80 m of Orbitolina -bearing limestones, which were deposited in a low-energy, shallow marine environment. Micropaleontological analysis indicates that the Langshan Formation in the Coqen Basin was deposited from late Aptian to early Cenomanian times (ca. 113–96 Ma). The overlying Daxiong Formation (~1700 m thick) consists of conglomerate, coarse sandstone, and siltstone with interbedded mudstone, and represents deposits of alluvial fans and braided rivers. The Daxiong Formation was deposited after the early Cenomanian (ca. 96 Ma) and accumulated until at least ca. 91 Ma, indicating accumulation rates of greater than 0.3 km m.y. –1 . By combining paleocurrent data, sandstone petrology, detrital zircon U-Pb ages, and Hf isotope analysis, we demonstrate that the Daxiong Formation was derived from Lower Cretaceous volcanic rocks and pre-Cretaceous strata in the northern Lhasa subterrane. During Late Cretaceous time, two thrust systems with opposite vergence were responsible for transforming the northern Lhasa subterrane into an elevated mountain range. This process resulted in the evolution from a shallow marine environment (Langshan Formation) into a terrestrial depositional environment (Daxiong Formation) on the southern margin of the northern Lhasa subterrane. Given the regional paleogeographic context, we conclude that the Daxiong Formation in the Coqen Basin records local crustal shortening and flexure resulting in foreland basin development on the southern margin of the northern Lhasa subterrane, which implies early topographic growth of the northern Lhasa subterrane in southern Tibet prior to the India-Asia collision.

Description: In the title compound, {[Ag3(C10H8N2)3](ClO4)3·2H2O}n, one of the AgI ions, one of the 4,4′-bipyridine (bipy) ligands and one of the perchlorate anions are each situated on a twofold rotation axis. Each AgI ion is coordinated by two N atoms from two bridging bipy ligands, forming chains along [101]. π–π interactions between the pyridine rings [centroid–centroid distances = 3.638 (8) and 3.688 (8) Å] connect the chains. Intermolecular O—H...O hydrogen bonds link the uncoordinated water molecules and the perchlorate anions.

Description: In the title compound, C10H15N1O2, the cyclohexane ring adopts a chair conformation and the piperidine ring adopts an envelope conformation. In the crystal structure, hydrogen-bonded dimers are formed via N—H...O interactions, and the molecular packing is stabilized by van der Waals interactions.

Description: The asymmetric unit of the title compound, di-μ-aqua-1:2κ4O:O-triaqua-1κ3O-dilosartanido-1κN;2κ2N,N′-dipotassium dihydrate, [K2(C22H22ClN6O)2(H2O)5]·2H2O, is composed of two losartan anions, two K+ cations and seven water molecules. Some water molecules bridge the potassium ions linking the molecules to form an infinite chain. The two potassium ions have different environments; one is six-coordinated by three water O atoms and three tetrazole N atoms, whereas the other is five-coordinated by five water O atoms. Extensive hydrogen-bonding interactions lead to a three-dimensional structure.

Description: The Gd atom in the title compound, [Gd(C33H39N11)]Cl3·3H2O, lies on a position of 32 point symmetry and exhibits a tricapped trigonal prismatic coordination geometry. A twofold rotation axis passes through the coordinated N atom and the opposite C atom of the pyridyl ring of the ligand, while a threefold rotation axis passes through the aliphatic N atom. The Cl atom and O atom of the uncoordinated water molecule both lie on twofold rotation axes.

Description: The dimeric title complex, [Ho2(CH3COO)6(C12H8N2)2], lies about a centre of symmetry. Each cation is coordinated by a chelating 1,10-phenanthroline and two chelating acetato ligands, one of which also bridges the two Ho atoms. Two other bridging acetate ligands complete the coordination of the nine-coordinate holmium(III) atoms.

Description: In the mononuclear title compound, [Ni(C10H9N4O2S)2(C12H8N2)], the NiII atom has a distorted octahedral coordination geometry comprising four N atoms from two 4-amino-N-(pyrimidin-2-yl)benzenesulfonamidate ligands and two N atoms from a 1,10-phenanthroline ligand. In the crystal, molecules are connected into a three-dimensional supramolecular network via N—H...O hydrogen bonds and weak C—H...O and C—H...N contacts.