Elemental Chemostratigraphy of the Late Neoproterozoic & Early Cambrian Sediments in Oman

Abstract

Elemental chemostratigraphy is employed on outcrop and well sections in order to produce a regional surface to subsurface correlation framework of the late Neoproterozoic and early Cambrian sediments in Oman. Samples have been analysed using ICP techniques, with high-resolution data acquired for 48 elements. The key elements employed to produce the chemostratigraphic framework are Si, Al, Ca, Mg, Ti, Zr, Y, Th, the rare earth elements, Cr, Mo and U. The relative abundance of these elements are interpreted be influenced by changes in lithology, detrital heavy minerals and redox-sensitive authigenic minerals that themselves are interpreted to reflect temporal variations in environment, weathering and sediment provenance. Based on marked variations in the key elements and derived element ratios, the study interval is divided into six chemostratigraphic sequences and six higher-resolution chemostratigraphic packages. The chemostratigraphic zones can be correlated with confidence from the outcrop to subsurface and, in conjunction with other disciplines, is being employed to refine the lithostratigraphy of the Nafun and Ara Groups in the subsurface of south Oman.