The Karoo Supergroup revisited and Madagascar-Africa fits

Citation
Na. Rakotosolofo et al., The Karoo Supergroup revisited and Madagascar-Africa fits, J AFR EARTH, 29(1), 1999, pp. 135-151
Citations number
27
Categorie Soggetti
Earth Sciences
Journal title
JOURNAL OF AFRICAN EARTH SCIENCES
ISSN journal
08995362 → ACNP
Volume
29
Issue
1
Year of publication
1999
Pages
135 - 151
Database
ISI
SICI code
0899-5362(199907)29:1<135:TKSRAM>2.0.ZU;2-L
Abstract
New palaeomagnetic data from the Late Permian-Early Jurassic Sakamena and t he Late Carboniferous(?)-Early Permian Sakoa Group from Madagascar (Karoo S upergroup) show gross similarities with earlier published data. Palaeomagne tic poles based on all studies of the Sakamena and Sakoa Groups average to 76.7 degrees N and 290.8 degrees E, and 51.3 degrees N and 252.6 degrees E, respectively, and imply palaeolatitudes of 28 degrees S and 55 degrees S f or southwest Madagascar in Late Permian-Early Triassic and Late Carbonifero us(?)-Early Permian times. The majority of the data, however, are of relati vely poor quality and there is no firm evidence for primary magnetic signat ures. A comparison with West Gondwana palaeomagnetic poles shows that the L ottes and Rowley fit produces the best palaeomagnetic match between Madagas car and East Africa (Somalia). The precise Pangaea configuration is still n ot known, but taken at face value, the Madagascar Sakamena pole and West Go ndwana reference data indicate a Pangaea B or C configuration in Late Permi an-Early Triassic times. However, high quality West Gondwana poles from Lat e Permian-Early Triassic times are clearly absent, and there is stronger co nfidence in West Gondwana pores of Late Carboniferous-Early Permian age. Th e latter poles place parts of Gondwana at high southerly latitudes and in g ood agreement with the distribution of climatically sensitive lithological data. (C) 1999 Elsevier Science Limited. All rights reserved.