کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
9462468 1621746 2005 13 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Clay-mineral assemblages in high-resolution Plio-Pleistocene interval at ODP Site 1165, Prydz Bay, Antarctica
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات فرآیندهای سطح زمین
پیش نمایش صفحه اول مقاله
Clay-mineral assemblages in high-resolution Plio-Pleistocene interval at ODP Site 1165, Prydz Bay, Antarctica
چکیده انگلیسی
According to the existing age model, the upper 50 mbsf stratigraphic sequence of Site 1165 reaches back to ∼4.9 Ma. Throughout this interval, the clay-mineral content is characterized by fluctuations of individual clay minerals, particularly smectite and chlorite. The smectite concentration varies mainly between 0% and 30%. Illite fluctuates less between 50% and 80%, and kaolinite varies mainly between 10% and 20%. Chlorite concentrations are mainly 0% to 10%. There is also a noticeable change in magnetic susceptibility at ∼34 mbsf that is clearly indicated in the composition of the clay-mineral suite. At this level, smectite decreases and illite, kaolinite and chlorite show some variability. In particular, there is a slight but persistent increase in chlorite. The results from the Plio-Pleistocene transition, with evenly fluctuating smectite and illite contents and the gradually increasing chlorite content, may indicate cooler conditions compared to the mid-Pliocene conditions. Slight increase in illite content and decrease in smectite content towards Pleistocene supports the previous assumption. The results from the mid-Pliocene with the increasing smectite content and decreasing illite content may indicate warmer and possibly interglacial conditions.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Global and Planetary Change - Volume 45, Issues 1–3, February 2005, Pages 151-163
نویسندگان
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