Bulletin of the Geological Society of Malaysia, Volume 22, Dec. 1988; pp. 45 – 64

Sedimentology of Upper Jurassic Deposits in the Tembesi River Area, Central Sumatra

BEAUVAIS, L., BLANC, PH.

Laborotoire de Paleontologie des Invertebres-Universite, P. et M. Curie, 4 place Jussieu, 75230 Paris-Cedex 05, France (ER 154 du CNRS)

and

BERNET-ROLLANDE, M.C., MAURIN, A.F.

C.F.P.-Total, 39 Guin Andre-Citroen 75015 Paris, France

Abstract: In the Tembesi River area, the Upper Jurassic crops out along two parallel NW-SE oriented lines. It consists of black, massive or bedded limestones interbedded with either black, more or less laminated shales or with more or less shaley sandstones.

The limestones include numerous Madreporaria which indicate an Upper Jurassic age.

Examination of the limestone microfacies leads to them being interpreted as mud-mounds of microbial origin (bioclasts encrusted with micrite and various algal structures, occurrence of filaments in the sparite, rhombohedrons of dolomite, bituminous stylolites, fenestrae, etc.).

The study of the clay minerals contained both in the marls, the shales, the sandstones and in the mud-mounds themselves, indicates a close shore deposit with sporadic influx of terrigenous sediment coming periodically from the continent.

https://doi.org/10.7186/bgsm22198803