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New ages from the Mauritanides Belt: recognition of Archean IOCG mineralization at Guelb Moghrein, Mauritania
Author(s) -
Michael Meyer Franz,
Kolb Jochen,
Sakellaris Gregori Aarne,
Gerdes Axel
Publication year - 2006
Publication title -
terra nova
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.353
H-Index - 89
eISSN - 1365-3121
pISSN - 0954-4879
DOI - 10.1111/j.1365-3121.2006.00698.x
Subject(s) - geology , archean , iron oxide copper gold ore deposits , craton , proterozoic , geochemistry , terrane , supercontinent , metamorphism , paleozoic , monazite , gondwana , laurentia , paleontology , hydrothermal circulation , zircon , tectonics , fluid inclusions
The Guelb Moghrein Fe oxide–Cu–Au–Co (IOCG) deposit is located in the northern part of the Mauritanides chain at the western edge of the West African Craton. It is commonly held that the orogenic belt has experienced a polyphase tectonothermal evolution, including two Panafrican and one Variscan event. Dating of two distinct morphological types of hydrothermal monazite and xenotime from Guelb Moghrein yielded in situ U–Pb ages of 2492 ± 9 and 1742 ± 12 Myr respectively. Such ages have not been reported previously from the region which is conspicuous by the widespread occurrence of banded iron formations, more akin to Proterozoic or Archean than to Paleozoic settings. The supracrustal rocks are thought, therefore, to represent a greenstone terrane that was mineralized by hydrothermal fluids during the late Archean and reactivated by middle Proterozoic fluid flow. Final emplacement at the current position on the West African Craton was at ∼300 Ma during Gondwana–Laurentia collision.