کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
6444054 1640361 2015 19 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
An integrated biostratigraphy (conodonts and foraminifers) and chronostratigraphy (paleomagnetic reversals, magnetic susceptibility, elemental chemistry, carbon isotopes and geochronology) for the Permian-Upper Triassic strata of Guandao section, Nanpanji
ترجمه فارسی عنوان
یک بیواستراتیگرافی یکپارچه (کنودونت و فروینیفرها) و کرونواستراتیگرافی (واکنش پالئومغناطیسی، حساسیت مغناطیسی، شیمی عنصری، ایزوتوپهای کربن و ژئوشنولوژی) برای لاشه های تریاسی پرمین بخش گواندوو، نانانجی
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات زمین شناسی
چکیده انگلیسی
The section contains primary magnetic signature with frequent reversals occurring around the Permian-Triassic, Olenekian-Anisian, and Anisian-Ladinian boundaries. Predominantly normal polarity occurs in the lower Smithian, Bithynian, and Longobardian-Cordevolian. Predominantly reversed polarity occurs in the upper Griesbachian, Induan-Olenekian, Pelsonian and lower Illyrian. Reversals match well with the GPTS. Large amplitude carbon isotope excursions, attaining values as low as −2.9‰ δ13C and high as +5.7‰ δ13C, characterize the Lower Triassic and basal Anisian. Values stabilize around +2‰ δ13C through the Anisian to Carnian. Similar signatures have been reported globally. Magnetic susceptibility and synthetic gamma ray logs show large fluctuations in the Lower Triassic and an overall decline in magnitude of fluctuation through the Middle and Upper Triassic. The largest spikes in magnetic susceptibility and gamma ray, indicating greater terrestrial lithogenic flux, correspond to positive δ13C excursions. High precision U-Pb analysis of zircons from volcanic ash beds provide a robust age of 247.28 ± 0.12 Ma for the Olenekian-Anisian boundary at Guandao and an age of 251.985 ± 0.097 Ma for the Permian-Triassic boundary at Taiping. Together, the new U-Pb geochronology from the Guandao and Taiping sections suggest an estimated duration of 4.71 ± 0.15 Ma for the Early Triassic Epoch.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Asian Earth Sciences - Volume 108, 15 August 2015, Pages 117-135
نویسندگان
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