کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4467885 1622286 2010 11 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Neogene clay mineral assemblages in the AND-2A drill core (McMurdo Sound, Antarctica) and their implications for environmental change
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات فرآیندهای سطح زمین
پیش نمایش صفحه اول مقاله
Neogene clay mineral assemblages in the AND-2A drill core (McMurdo Sound, Antarctica) and their implications for environmental change
چکیده انگلیسی

Clay mineral assemblages in sediments from ANDRILL drill core AND-2A were used to reconstruct the Neogene palaeoenvironment. For the first time a clay mineral data set can be presented for southern McMurdo Sound, Ross Sea, Antarctica, that covers an expanded and fairly continuous Lower and Middle Miocene section. Although the occurrence of some authigenic smectites, zeolites and opal-CT documents diagenetic processes, the clay mineral assemblages allow a subdivision of the core into three intervals that reflect changes in provenance and volcanic activity. Interval I (1000–440 mbsf, 20.0–16.5 Ma) is characterised by a dominant sediment source in the Transantarctic Mountains. Frequent and short-term changes in the illite and smectite concentrations were caused by the influx of volcanic sediment components from southern McMurdo Sound and by diagenesis. Interval II (440–225 mbsf, 16.5–15.0 Ma) has much more uniform illite and smectite contents. The assemblage is derived from the Transantarctic Mountains. Interval III (225–0 mbsf, 15.0–0 Ma, containing major hiatuses) shows a distinctly enhanced volcanic influence and sediment components that come from the south of McMurdo Sound. The AND-2A clay mineral assemblages indicate persistent physical weathering conditions and do not mirror the Mid-Miocene Climatic Optimum. They indicate that the climatic changes were probably not strong enough to cause a modification in the weathering regime on the Antarctic continent.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Palaeogeography, Palaeoclimatology, Palaeoecology - Volume 286, Issues 1–2, 1 February 2010, Pages 55–65
نویسندگان
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