DOI: 10.1016/j.palaeo.2016.06.014
论文题名: Pre- and post-Marinoan carbonate facies of the Democratic Republic of the Congo: Glacially- or tectonically-influenced deep-water sediments?
作者: Delpomdor F. ; Eyles N. ; Tack L. ; Préat A.
刊名: Palaeogeography, Palaeoclimatology, Palaeoecology
ISSN: 0031-0182
出版年: 2016
卷: 457 起始页码: 144
结束页码: 157
语种: 英语
英文关键词: Debrites
; Deep-water carbonates
; Diamictite
; Neoproterozoic
; Snowball Earth
; Tectonics
英文摘要: The upper carbonate-rich parts of theWest Congo Supergroup (~1000-560 Ma) fromthe Democratic Republic of the Congo have hitherto been considered as a record of abrupt eustatic and climatic events accompanying glaciation and deglaciation of a Snowball Earth-type Marinoan ice age that was of global extent. These strata have however never been investigated in detail. Results of new sedimentological work at key outcrops over a 1300 km outcrop belt show that pre -and post-Marinoan carbonates are respectively, storm-influenced sediments deposited principally in a midouter-ramp setting, and deep-water slope carbonates (calicturbidites) representing a lobe-fringe or levee-overbank setting. The Upper Diamictite Formation held previously by some to be a subglacial tillite, comprises gravity flows (debrites) deposited in deep water below wave base along the unstable margins of a carbonate ramp. A direct glacial influence on sedimentation for diamictites or any accompanying facies cannot be readily identified. Sedimentary facies reported here primarily record the presence of deep-water submarine to alluvial fan systems related to extensional tectonic processes of the central-southern Macaúbas Basin (now located in Brazil) between 700 Ma and 660 Ma followed by the 630-Ma onset of the pre-collisional magmatic arc in the Araçuaí-West Congo Orogen. No extreme short-lived climatic or eustatic events of a Snowball Earth-type ice age are recorded in the studied succession, which primarily reflects longterm overriding regional tectonic controls resulting in diachronous sedimentation along the western margin of the Congo Craton. © 2016 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/68342
Appears in Collections: 过去全球变化的重建
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作者单位: Biogeochemistry and Modeling of the Earth System, Université libre de Bruxelles, Brussels, Belgium; Physical and Environmental Sciences, University of Toronto, Scarborough, ON, Canada; Royal Museum for Central Africa, Tervuren, Belgium
Recommended Citation:
Delpomdor F.,Eyles N.,Tack L.,et al. Pre- and post-Marinoan carbonate facies of the Democratic Republic of the Congo: Glacially- or tectonically-influenced deep-water sediments?[J]. Palaeogeography, Palaeoclimatology, Palaeoecology,2016-01-01,457