کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
6446641 | 1640862 | 2013 | 18 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Changes in silicate utilisation and upwelling intensity off Peru since the Last Glacial Maximum - insights from silicon and neodymium isotopes
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
علوم زمین و سیارات
زمین شناسی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
The εNd signatures of the coatings extracted from sediment core SO147-106KL located in the present day centre of coastal upwelling near 12°S have been essentially constant (â1.5) throughout the past 20,000 years, while the detrital εNd (87Sr/86Sr) varied between values of â0.7 (0.70620) during the Last Glacial and â4.5 (0.70849) during the late Holocene reflecting changes in the origin of the sediment and current transport from a more northerly towards a more southerly source and from overall stronger to weaker upwelling. The δ30Si signature of both total biogenic opal (δ30Siopal) and of hand-picked diatoms (δ30Sidiatom) ranged from +0.3â° (Last Glacial) to +1.4â° (late Holocene) confirming large variations in upwelling intensity driving silicic acid utilisation by diatoms. Our combined bSiO2 MAR, δ30Siopal and detrital radiogenic isotope results demonstrate that the strongest El Niño-Southern Oscillation conditions off Peru of the past 20 ka have prevailed during the past 5 ka.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Quaternary Science Reviews - Volume 72, 15 July 2013, Pages 18-35
Journal: Quaternary Science Reviews - Volume 72, 15 July 2013, Pages 18-35
نویسندگان
C. Ehlert, P. Grasse, M. Frank,