Journal of Petroleum Geology, Vol.8,
No.3, pp. 323-329, 1985
©Copyright 2000 Scientific Press,
Ltd.
MESOZOIC COLUMNS BELOW THE
SEYCHELLES BANK, WESTERN INDIAN OCEAN
Maurice Kamen-Kaye*
*1 Waterhouse St., Cambridge,
Mass. 02139, USA.
Abstract
Exploratory drilling on the Seychelles
Bank, in a sector west of outcrop granite on Mahé Island, has
revealed the presence of substantial Mesozoic columns. Their
thickness approaches 3,000 m; and total Phanerozoic down to true
basement probably exceeds 4,500 m. Still greater depths are
possible, not only in this drilled NW-most sector of the island
arc of the Mascarene Ridge, but also elsewhere along the arc,
whose total cross-latitudinal dimension is more than 2,000km.
Volcanics, like those in the African borderlands, repeatedly
enter the Phanerozoic column of the Seychelles. The young
"basaltic basement" of geodynamic theory, consequently,
cannot exist on the Seychelles Bank. The same negative may hold
true for the whole arc of the Mascarene Ridge and for its
marginal waters westward as far back as the African borderlands
themselves. In the domain of exploration, the prime parameter of
sedimentary volume is acceptable along much of the Mascarene
Ridge, for which reason wells drilled to true basement merit
consideration in future drilling. Such wells in central and
southern sectors might recover basement rocks whose petrology
could offer a strong challenge to present concepts of
paleogeography in the whole back-arc area of the western Indian
Ocean.
