Paleoenvironment, deposition conditions, and geochemical characteristics of the Permian Karoo hydrocarbon source rocks, Mid-Zambezi Basin, Zambia, based on paleontology and geochemistry studies: a review

Abstract

Hydrocarbon prospection and scholarly research have centered around three basins: the Barotse, Luangwa, and Mid-Zambezi Rift. Research work has so far been reliant on exposed sedimentary outcrops. However, basin correlation is challenging as relatively little work has been conducted to constrain the depositional ages of the Karoo Basin that outcrops in Zambia, despite their rich paleontological records. One such basin, the mid-Zambezi Basin, contains Karoo-aged sediments that have been studied since the 1970s, and it has been observed that the Madumabisa Mudstone fluvial sequence within the lacustrine origin overlies the coal-bearing sequence, the Permian Gwembe Coal. Studies have been done to fully characterize the petroleum system elements and processes in this part of the basin. A few thermal alteration index (TAI) values range from − 2 to + 2, total organic content (TOC) from 0.71 to 50.65 wt.%, hydrogen index from 90.68 to 168.85 mg HC/g TOC, and oxygen index from 1.35 to 22.6 mg CO2/g. Rock has been presented. There was little attention to non-coal-bearing sequences during the 1960s subsurface investigations and a small sampled area for palynological studies. Therefore, studies suggested that pollens and spores were not sufficiently abundant for quantitative analyses. Samples from previous work were thus far only subjected to standard palynological processing techniques. The occurrence of macrofossils and microfossils gives interest to further micropaleontological and geochemical studies; for significant microfossil distribution and frequency, TOC contributes to the conclusion of hydrocarbon potential.