کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
9463017 1622387 2005 18 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Rock magnetism and geochemistry of two plio-pleistocene Chinese loess-palaeosol sequences-implications for quantitative palaeoprecipitation reconstruction
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات فرآیندهای سطح زمین
پیش نمایش صفحه اول مقاله
Rock magnetism and geochemistry of two plio-pleistocene Chinese loess-palaeosol sequences-implications for quantitative palaeoprecipitation reconstruction
چکیده انگلیسی
Stratigraphic and spatial variations in the magnetic properties of Chinese loess are widely accepted as reflecting changes in the intensity of soil forming processes over time and space. Recently, several workers have used statistical correlations between the magnetic susceptibility and related parameters of modern loess plateau soils and modern climate to generate transfer functions to reconstruct past temporal and spatial trends in precipitation. Here we try to assess the viability of this approach by conducting magnetic and geochemical measurements of two long (∼2.5 My) loess-palaeosol sequences from different locations on the modern precipitation gradient across the loess plateau. One site, Duanjiapo, is located on the southern humid margin of the plateau; and the other site, Luochuan, is located in a drier modern environment some 160 km further north. Our results indicate discrepancies between magnetic and geochemical indicators of weathering and soil forming intensity and that any attempt to predict palaeoprecipitation at Duanjiapo using published approaches would be significantly in error. Overall our results indicate a complex response of magnetic mineral transformations to climate, including the production of both ferrimagnetic and antiferromagnetic minerals within the same climatic interval, together with the destruction of magnetic material within some of the palaeosols. Therefore we suggest considerable caution should be exercised in generating quantitative climatic reconstructions from a single magnetic parameter.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Palaeogeography, Palaeoclimatology, Palaeoecology - Volume 226, Issues 1–2, 3 October 2005, Pages 149-166
نویسندگان
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