Nitrogen abundances in damped Lyman α systems: the combined effects of SNII and SNIa in a hierarchical clustering scenario     

Patricia B. Tissera  Diego G. Lambas  †  Sofia A. Cora ‡  Mirta B. Mosconi 《Monthly notices of the Royal Astronomical Society》2002,337(3):L27-L30

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Differentiation of clay resources on a limestone plain: The analysis of clay utilization during the Maya Formative at K'axob Belize     

Mary Lee Bartlett  Hector Neff  Patricia A. McAnany 《Geoarchaeology》2000,15(2):95-133

Differentiating clay resources in a uniform limestone plain, such as occurs in northern Belize, offers special challenges for the archaeologist. Combining data from soil mapping with petrographic and neutron activation analysis provides a mechanism for distinguishing possible resource areas. This study employed each of these differing avenues of analysis to determine possible clay resource areas used during the Maya Formative in northern Belize Central America. The results indicate that clay usage changed significantly from the Middle Formative period to the end of Late Formative period. These changes suggest a move to increased localized production and resource exploitation by the end of the period. © 2000 John Wiley & Sons, Inc.  相似文献   

Stone artifact scatters in western NSW,Australia: Geomorphic controls on artifact size and distribution     

Patricia Fanning  Simon Holdaway 《Geoarchaeology》2001,16(6):667-686

Surface scatters of Aboriginal stone artifacts have been exposed in many parts of inland Australia by accelerated erosion that followed the introduction of pastoralism by European settlers in the 19th century. This paper reports on a set of techniques developed to investigate and quantify the effects of these post‐discard disturbance processes in Sturt National Park in northwest NSW, Australia. Backwards, stepwise, linear regression showed the influence of geomorphic parameters such as slope gradient, elevation, landform, and contemporary surface processes on artifact distribution, with artifact maximum dimension as the dependent variable. The results indicate that, even at low gradients, artifact size and slope angle are significantly related, but that the variance in maximum dimension explained by gradient is very low. Similar results were found for the other geomorphic variables. We conclude that artifact movement by surface wash across these surfaces is unlikely to significantly affect artifact distribution. While vertically conflated surface scatters do not preserve “living floors” in a short‐term, functional sense, their apparent horizontal integrity allows investigation of the long‐term use of place by hunter‐gatherer people in the past. Insofar as assemblage integrity is important for assessing site significance in the heritage management industry, our methods provide a means for assessing the degree to which a site has been damaged by water flow. © 2001 John Wiley & Sons, Inc.  相似文献