Mid-Cretaceous shelf carbonates: The Mfamosing Limestone, Lower Benue Trough (Nigeria)

Geochemistry of carbonate cements in Cretaceous sandstones, southeast Benue Trough, Nigeria: Implications for geochemical evolution of formation waters

“…Circumstantial evidence suggests that Mg could be at least partially derived from the host marine carbonate; this assertion is best explained by comparison of the Mg concentrations with Sr. The Mg values for Mfamosing Limestone (Oti, 1990) are consistent with those values recorded in this study.…”

“…The most enriched calcite cement contains 12,600 ppm Mn 2+ and 200 ppm Sr 2+ (Table 2). Sr appears to remain more or less constant around a mean value of 211 ppm in the Mfamosing Limestone (Oti, 1990), which is lower than the values obtained from the Cretaceous sandstone cements. Also calcite phases with relatively high Sr 2+ and low Mn 2+ values are indicative of early stabilization and precipitation in an oxygenated and/or Mn 2+ poor environment.…”

“…The average value of Mn for Asu River Group is 0.68 wt.%, 0.16 wt.% for Eze-Aku and 0.17 wt.% for proto-Niger Delta Sandstones. These values are relatively higher when compared to the published geochemical data by Oti (1990) for the mid-Cretaceous Mfamosing limestone from Calabar Flank, southeastern Nigeria. The simplest explanation for the difference in Mn concentration may be the availability of Mn during the Albian times.…”

Biostratigraphy of Section of Murshe-1 Well, Bornu Basin, Northeastern Nigeria

“…Avbobvo et al [3] identified marine shale sequence deposited over localized conglomerates and poorly sorted alluvial deposits lying unconformably on the basement. The distinct continental deposit (conglomerate) is termed the Pre-Bima and is dated Albian [28,8,9]. The Gongila Formation is a transitional sequence that lies in-between the underlying marine shale of Bima Formation and typical marine setting of the overlying Fika Formation.…”

The Mfamosing Limestone in Se Nigeria: Outcrop‐subsurface Correlation and Reservoir Development

“…Only when rates of sea-level rise increased and surpassed the accretionary potential of the carbonates did regional drowning of the system occur, and transgressive shales were then deposited representing a maximum flooding surface (MFS). In the type-section, the MFS is marked by a hardground (Oti, 1990) topped by shales with ammonites.…”