ALBERT

Notes: The occurrence of the rare phenomena of a booming sand is recorded and an account given of its behaviour in the field. Its sedimentological properties are compared with those of a squeaking sand from the seashore. Both sands are moderately to wellsorted, and show similar roundness and sphericity. The desert sand is silent, whereas the seashore sand can be made to emit a noise in the laboratory. The marked distinction between the sands lies in the mechanical analyses based on the number frequency of grains, rather than on the weight frequency. A “body-centred cubic” packing has been proposed for the desert sand and a “rhombic” packing for the seashore. Shear-box tests on the disturbed sands appear to support the hypothesis of two different modes of packing. The source of the characteristic booming sound is discussed, but it is suggested that an explanation is more likely to be forthcoming from field investigation than from small-scale laboratory studies.

Notes: Zircons have been studied in the sedimentary rocks of the Sparagmite Group (Eocambrian) and their metamorphic associates from the Trondheim area and the adjacent regions in Norway and Sweden. The majority of zircon population (type B) has been formed in the sediments by authigenesis. Another authigenic associate is rutile. The authigenic zircons have irregular, round and ellipsoidal habits. In metamorphic rocks the same grains show a greater tendency of euhedrism, forming drum-like crystals with acute (331) pyramids and short prisms. Authigenic zircons are usually clear and transparent but some grains may show cloudy appearance. A few other grains (type A) with different habit and many inclusions appear to be of detritai nature.Dissolution of a metamictized zircon population in the source rock is possible in many ways. An important possibility is the dissolution of zircons in alkaline solution. Carbonated lime-rich waters or other acidic solutions could be equally effective. Zirconates, so formed, are transported to the basin of deposition as colloidal particles or as ionic complexes. The authigenic process is visualized as a deposition of the zirconates by adsorption or by precipitation as zirconium hydroxide, possibly due to change in the Eh and pH in the environment. The hydrated oxide subsequently reacts with silica to form metastable hydrozircon. In course of time hydrozircon dehydrates and becomes a normal zircon.Numerous growths have been noted and are classified genetically into (l) late authigenic growths, and (2) growths syngenetic with metamorphism. The shape of the host grain usually controls the final shape of the overgrown grain.There is some effect of metamorphism on the morphology of the authigenic zircons. In view of the characters of the newly generated zircons, the use of shape, size, zoning and such other parameters of zircons in petrogenetic problems, has to be retested to ensure its reliability.Rather than being a mineral of igneous derivation only, zircon is from three parentages: igneous, authigenic and metamorphic. It is argued that the persistence of the authigenic zircons should be greatest because of very low concentration of radioactive elements.

Notes: Book reviewed in this article:Geochemistry of Sediments E. T. Degens.Identification of Mineral Grains. M. P. Jones and M. G. Fleming.

Notes: The present paper describes the use of cellulose acetate replicas in the study of silicate rocks, particularly indurated sandstones. The procedure of Boardman and Utgaard (1964) for the reproduction of surface structures of polished limestone slabs for the study of Paleozoic Bryozoa, was modified and applied on silicate rocks using HF instead of formic acid as the etching agent.The polished slabs are etched with 40 % HF for 5–10 seconds and then washed, dried, wetted with acetone and gently pressed towards a mount of cellulose acetate. After drying, the specimen is quickly removed and an imprint is left on the acetate peel. By using thick (1.6 mm) cellulose acetate sheets no mounting on glass slides is needed, and the replica can be studied directly under the microscope or be used as a photographic negative.

Notes: In the middle Mississippian Salem Limestone of central Indiana 693 measurements showed that sediment transport during Salem deposition was to the southwest, as during deposition of most of the late Paleozoic sands of the Illinois Basin. Crossl bedding direction is variable, however, and noticeably bimodal. Oscillating tida-currents on a shallow marine shelf are believed to have caused pronounced bimodality in the Salem Limestone and in the associated Ste. Geneviève and Harrodsburg Limestones.

Notes: Careful sampling of the constituent laminae of cross-stratified units and their subsequent mechanical analyses have revealed a rhythmic pattern of size differentiation. The cross-strata have been analysed in terms of our existing knowledge of the mechanics of layering in granular sediments. The concept of “elementary rhythm-unit” has been introduced and the genesis of a cross-stratified unit has been reviewed in terms of the growth and interplay of the elementary rhythm-unit.

Notes: Summary. Applications of several herbicides -were made to roots and to the bases of shoots of peas, cucumber, mustard and barley grown in soil, sand or water culture.Localized applications (variation horizontal) of atratone and MCPA to roots of peas and barley in soil produced effects similar to those observed in water euluire, described in Pan I. Airatone killed the plants whether available to the whole or to only a portion of the root system whereas MCPA affected only the roots with which it was in direct contact, and growth continued when a portion of the root system was in herbicide-free environment.In water culture, MCPA was more effective when applied to the lower (younger) roots with the upper (older) roots kept dry than when twice the concentration was applied evenly to the whole root system in water. When all the roots were kept wet the effect of application to the upper roots was greater than the effect of application to the lower roots. The response of plants to atratone was not appreciably altered whether applications were made to the upper or lower parts of the root system in water culture. Variations in water level had little effect.Even when the herbicide solution was confined to the stem or hypocotyl, atratone and DNOC were little, if any, less effective than when applied to roots. MCPA, both as ester and sodium salt, was significantly less effective.Partial replacement of solution in the root zone by sand and air did not reduce the activity of atratone at a given concentration. Similar replacement in the zone of the stem or hypocotyl greatly reduced the effectiveness of all herbicides. When sand of low water content was used, atratone and MCPA-sodium became quite ineffective via the stem, but DNOC and MCPA-ethyl ester remained active.Études sur les réactions de certaines plantes á des herbicides appliqués aux racines II. Observations nouvelles sur l'effet de l'application localisée.

Notes: Summary. Seeds of Polygonum lapathifolium were collected from eight localities during 1962. Plants of these populations were grown in the field and sampled at fortnightly intervals during June and July 1964. There were significant differences between populations in dry weight, leaf area index and nitrogen content at all samplings, and populations also differed in date of flowering and in certain morphological feature. Smooth curves were fitted to some of the growth data, and an account of the fitting procedure is given. For comparison, certain growth functions were calculated from the smooth curves as well as from the observed data. The populations differed in relative growth rate, net assimilation rate, relative nitrogen absorption rate and in certain other calculated functions, A number of growth attributes were significantly correlated with the latitude, longitude or length of the growing season of the locality of origin, and it is tentatively suggested that the populations represent climatic ecotypes.Études sur des espèces de mauvaises herbes du genre Polygonum L. II. Variations physiologiques dans P. lapathifolium L.