کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4466506 1622200 2013 31 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Depositional age, provenance, and tectonic and paleoclimatic settings of the late Mesoproterozoic–middle Neoproterozoic Mbuji-Mayi Supergroup, Democratic Republic of Congo
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات فرآیندهای سطح زمین
پیش نمایش صفحه اول مقاله
Depositional age, provenance, and tectonic and paleoclimatic settings of the late Mesoproterozoic–middle Neoproterozoic Mbuji-Mayi Supergroup, Democratic Republic of Congo
چکیده انگلیسی


• Mbuji-Mayi Supergroup deposited in an intracratonic failed-rift basin.
• Minimum LA-ICP–MS U–Pb age for detrital BId zircons gave 1174 ± 22 Ma.
• Provenance of detrital zircon grains is south-east and/or east.
• C and Sr isotopic curves for BII group are coeval with the Bitter Springs anomaly.
• 40Ar/39Ar age on ‘Lomami’ dolerite sill yielded 882.2 ± 8.8 Ma.

The late Mesoproterozoic–middle Neoproterozoic period (ca. 1300 Ma–800 Ma) heralded extraordinary climatic and biological changes related to the tectonic changes that resulted in the assembly (~ 1.0 Ga) and the break-up of Rodinia (880 Ma–850 Ma). In the Democratic Republic of Congo, these changes are recorded in the Mbuji-Mayi Supergroup which was deposited in the SE–NW trending siliciclastic-carbonate failed-rift Sankuru-Mbuji-Mayi-Lomami-Lovoy Basin. New LA-ICP–MS U–Pb laser ablation data on detrital zircon grains retrieved from the lower arenaceous-pelitic sequence (BI group) together with C and Sr isotopic data on carbonates from the upper dolomitic-pelitic sequence (BII group) and an 40Ar/39Ar age determination on a dolerite give a new depositional time frame between 1174 ± 22 Ma and ca. 800 Ma for the Mbuji-Mayi Supergroup. The upper age limit is based on the assumption that the transition between the BIIb and BIIc subgroups recorded the Bitter Springs anomaly. In terms of tectonic and paleoclimatic settings, the BII group was deposited in the eastern passive margin of the Congo Craton during warm periods interlaced with temporarily dry and wet seasons, suggesting greenhouse conditions during the fragmentation of Rodinia.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Palaeogeography, Palaeoclimatology, Palaeoecology - Volume 389, 1 November 2013, Pages 4–34
نویسندگان
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