Upcoming international events     

Anne Marie de Grosbois 《Environmental Earth Sciences》2010,60(1):219-224

Events

Upcoming international events  相似文献   

The fluvial and geomorphic context of Indian Knoll,an Archaic shell midden in West‐Central Kentucky     

Darcy F. Morey  George M. Crothers  Julie K. Stein  James P. Fenton  Nicholas P. Herrmann 《Geoarchaeology》2002,17(6):521-553

Indian Knoll is the largest Archaic shell midden excavated by WPA archaeologists in Kentucky. Situated in a large alluvial valley, the site is not associated with a known river shoal as might be expected, making its fluvial and geomorphic setting of interest. Based on sediment cores and auger samples, undisturbed portions of the site remain despite extensive excavations. In undisturbed portions, a shell‐bearing layer is overlain by a shell‐free midden layer. Profiles of organic matter and calcium carbonate content for both layers are similar to those of other Green River shell middens. New radiocarbon determinations date the shell deposit at 5590–4530 cal yr B.P. Analysis of mussel species collected from the Indian Knoll indicates that shell fishing took place in a swiftly flowing, shallow to moderately deep setting of the main river channel. Overall, the prehistoric river setting adjacent to Indian Knoll was characterized by deeper water on average with variable but finer‐grained substrate compared to other Green River shell midden sites. © 2002 Wiley Periodicals, Inc.  相似文献   

Preliminary study on the preservation of giant clam (Tridacnidae) shells from the Balobok Rockshelter archaeological site,south Philippines     

Marie Grace Pamela G. Faylona  Claire E. Lazareth  Anne‐Marie Smah  Sandrine Caquineau  Hugues Boucher  Wilfredo P. Ronquillo 《Geoarchaeology》2011,26(6):888-901

Tridacnidae shells, a valuable archive of past environments, are common in the Balobok Rockshelter archaeological site on Sanga‐Sanga Island in the south Philippines. This site was occupied during the mid‐Holocene (ca. 5000–8800 ¹⁴C yr B.P.), a period of Neolithic cultural expansion in the Philippines. This paper focuses on the preservation of two shell specimens, Hippopus hippopus and Tridacna maxima, unearthed from two mid‐Holocene layers within the rockshelter. The shells' mineralogy and microstructure (prismatic and crossed‐lamellar) were studied using micro‐Fourier transform infrared spectroscopy and scanning electron microscopy to determine if the samples were suitable as paleoenvironmental records. Both shells are still aragonitic but aragonite crystals of both microstructure types are partly dissolved. This dissolution, characteristic of meteoric water alteration, precludes their utility in paleoenvironmental geochemical studies. Nevertheless, these shells are abundant in archaeological sites in the region and may be better preserved in other depositional contexts; more studies on Philippine Tridacnidae shell diagenesis are needed. © 2011 Wiley Periodicals, Inc.  相似文献   

Astrophysikalische Diskussion des COMPTONeffektes im äußeren Magnetfeld     

J. Herrmann  B. KMpfer 《Astronomische Nachrichten》1975,296(6):267-275

We consider the COMPTON scattering of a distribution of photons and relativistic electrons in a constant magnetic field. The influence of the magnetic field upon the energy spectrum of the photons scattered by the electrons has been calculated.  相似文献   

Late Tournaisian (Carboniferous) brachiopods from Mouydir (Central Sahara,Algeria)     

Bernard Mottequin  Marie Legrand‐Blain 《Geological Journal》2010,45(4):353-374

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