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Detrital zircon evidence for Paleoproterozoic West African crust along the eastern North American continental margin, Georges Bank, offshore Massachusetts, USA.
- Source :
-
Geology . Sep2017, Vol. 45 Issue 9, p811-814. 4p. 2 Graphs. - Publication Year :
- 2017
-
Abstract
- Basement rocks from the Continental Offshore Stratigraphic Test (COST) No. G-1 petroleum exploration well, Georges Bank, offshore Massachusetts, USA, show the first direct evidence for a fragment of Paleoproterozoic West African crust preserved along the eastern North American continental margin. Detrital zircon from two metawacke samples near the base of the core yielded ca. 3.05-1.90 Ga laser ablation-inductively coupled plasma-mass spectrometry dates, with a predominant 2.2-2.0 Ga population. This detrital zircon signature is consistent with that in the Taghdout Group of the Anti-Atlas region, which is part of the Paleoproterozoic passive margin rocks deposited directly on the Archean-Paleoproterozoic WAC shortly after its formation. African provenance has previously been recognized for the Suwannee and Meguma terranes in the southern and northern Appalachians, respectively. However, these areas represent Neoproterozoic-Paleozoic sedimentary basins, deposited well over a billion years after formation of the Paleoproterozoic WAC and cover rocks, including those in the COST No. G-1 well. The Paleoproterozoic rocks in the COST No. G-1 well were likely amalgamated with the North American margin during final closure of the Rheic Ocean and assembly of Pangea near the end of the Paleozoic. [ABSTRACT FROM AUTHOR]
- Subjects :
- *ROCKS
*PETROLEUM prospecting
*ZIRCON
*SEDIMENTARY basins
*STRATIGRAPHIC geology
Subjects
Details
- Language :
- English
- ISSN :
- 00917613
- Volume :
- 45
- Issue :
- 9
- Database :
- Academic Search Index
- Journal :
- Geology
- Publication Type :
- Academic Journal
- Accession number :
- 125222977
- Full Text :
- https://doi.org/10.1130/G39203.1