کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5780485 | 1635134 | 2017 | 35 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
The new occurrence of Marinoan cap carbonate in Brazil: The expansion of snowball Earth events to the southwesternmost Amazon Craton
ترجمه فارسی عنوان
رخداد جدید کربنات کلسیم مارینو در برزیل: گسترش رویدادهای زمین برفی به جنوب غربی آمازون کراتون
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
علوم زمین و سیارات
علوم زمین و سیاره ای (عمومی)
چکیده انگلیسی
Carbonate deposits exposed in the border of the Pimenta Bueno and Colorado grabens, western part of Parecis Basin, southwestern Amazon Craton, Brazil, have been previously considered as Paleozoic record. These deposits lying unconformably on Mesoproterozoic crystalline rocks, the basement of the grabens, and consist predominantly by pinkish dolomite overlying glacial diamictites, with average negative values of δ13C of â3,10â°VPDB. The contact between the dolostone and diamictites is sharp and deformed similarly with others Neoproterozoic cap carbonates occurrences in the Amazon Craton, also related to the Marinoan Glaciation (635 Ma). This new occurrence of Marinoan cap carbonate is composed by two facies associations. Facies Association 1 consists of pinkish peloidal dolostone with even parallel and quasi-planar laminations, wavy and megarriple bedding, macropeloid lenses associated with low-angle truncations, interpreted as fairwhether- and storm-influenced shallow platform deposits. Facies association 2 consists in dolostone rhythmically interbedded with shale underlaid by 5 m-thick laminated siltstones, interpreted as moderately deep platform deposits. This retrogradational succession is overlaid in angular unconformity by Early Paleozoic diamictites and locally by Mesozoic volcanic rocks. This cap carbonate precedes the Paleozoic deposits of Parecis Basin and represents a post-glacial event linked to the Marinoan glaciation, extending to the southwesternmost Amazon Craton the phenomena of the Snowball Earth hypothesis.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of South American Earth Sciences - Volume 76, July 2017, Pages 446-459
Journal: Journal of South American Earth Sciences - Volume 76, July 2017, Pages 446-459
نویسندگان
Valber do Carmo de Souza Gaia, Afonso César Rodrigues Nogueira, Fábio Henrique Garcia Domingos, Pierre Sans-Jofre, José Cavalcante da Silva Junior, José Guilherme Ferreira de Oliveira, Alcides Nóbrega Sial,