کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5786794 | 1640779 | 2017 | 14 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Authigenic Nd isotope record of North Pacific Intermediate Water formation and boundary exchange on the Bering Slope
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
علوم زمین و سیارات
زمین شناسی
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چکیده انگلیسی
The reconstructed authigenic εNd record for the last 520 kyr exhibits large temporal variations depending on whether the NPIW formation or the boundary exchange process is dominant. Periods of radiogenic εNd can be attributed to NPIW formation triggered by brine rejection, as evidenced by the difference in δ18O of benthic foraminifera between sites (Îδ18Obf), high % sea-ice related diatoms, and low abundance of Bulimina aff. Exilis (low-oxygen deep fauna). Diminished supply of unradiogenic Nd from boundary exchange seems to intensify these radiogenic peaks. On the other hand, the unradiogenic εNd intervals can be attributed to stagnant bottom water conditions, as can be deduced from the Îδ18Obf values, low % sea-ice related diatoms, abundant B. aff. Exilis, and laminations. When there is no NPIW formation, the continental margin sediments are exposed to boundary exchange for a longer period of time, leading to release of unradiogenic Nd. The mid-MIS 6 and mid-MIS 5 are exceptions in that NPIW formation occurred yet the εNd compositions are unradiogenic. NPIW formation and cold climate (closed Bering Strait) are not always correlated. Comparison against εNd records of the South Atlantic suggests only an ambiguous NPIW-NADW seesaw for the last 200 kyr.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Quaternary Science Reviews - Volume 156, 15 January 2017, Pages 150-163
Journal: Quaternary Science Reviews - Volume 156, 15 January 2017, Pages 150-163
نویسندگان
Kwangchul Jang, Youngsook Huh, Yeongcheol Han,