Salmat Fm

Recorded in drilling sites EA-1 and CHBK-1 wells (Choubert et al., 1966; LeRoy & Piqué, 2001) and exposed at the coastline near the village of Lemsid (Wenke, 2011).

Synonym:

References: Wenke, 2014

[Fig. 1. Regional crustal framework of the Moroccan Atlantic rifted-passive margin showing its three, major rifted-passive margin segments that are conjugate with eastern Canada: 1) Northern Central Atlantic; 2) Georges Bank- Tarfaya Central Atlantic, and; 3) Southern Central Atlantic (three zones modified from Nemcok et al., 2005). (Galhom, 2020).]

[Fig. 2. Schematic chrono-lithology chart from the basin to inner shelf settings of the Tarfaya Basin. (Table 6, page 110, in Wenke, 2014)

[Fig. 3. Summary chart for the Tarfaya Dakhla basin showing geologic time scale, lithostratigraphy, controlling tectonic events, and interpreted horizons (Galhom, 2020).]

[Fig. 4. Lithostratigraphy and log characteristics of the Triassic to Miocene succession at well W10, offshore Tarfaya Basin (El Jorfi et al., 2015).]

The Salmat Fm is about 60m thick and composed of three members (Gueran Mbr at the base, Itgui Mbr, Morcba Mbr at top). A lower marl is followed by thin sandstone in the midsection, then shale to the top of the formation (El Jorfi et al., 2015). An important transgression occurred in the Eocene, resulting in upwelling and related high surface water productivity, leading to deposition of organic matter-rich units (Itgui Mbr). The Morcba Member is about 360m thick, and is made up almost entirely of conglomerates, having a thin occurrence of shales at the top of the member (see fig. 4 of El Jorfi et al., 2015). This was followed by a time of non-deposition during the Early Oligocene (Ghassal et al., 2016).

ca. Danian (after a minor Cret/Paleogene unconformity) through mid-Late Oligoene through mid-Early Oligoene; with the extent of the Early/Late Oligocene unconformity depending on location from minor at seaward to major at landward (Wenke, 2014; table 6, p. 110)