Petrography and metamorphism of the Téremba Group (Permian—Lower Triassic) and Baie de St.-Vincent Group (Upper Triassic—Lower Jurassic), New Caledonia

Abstract

The oldest known fossiliferous strata in New Caledonia are the Permian to Jurassic basement rocks of the west coast. Approximately 3,000 m of primary volcanic lithologies of basaltic to rhyolitic composition and volcaniclastic sediments of lutite to rudite grade are represented in the Moindou — Teremba area. They have been subdivided into two groups: Téremba Group and Baie de St.-Vincent Group. They show similarities in lithology and chemical composition with the Takitimu Group and Murihiku Group respectively of Southland, New Zealand. However the New Caledonian sedimentary rocks are devoid of plutonic and metamorphic components, and volcanic composition through the sequence is different. Both Teremba and Baie de St.-Vincent Group lithologies have developed metamorphic mineral assemblages characteristic of prehnite — pumpellyite facies.