Tarfaya Mid-Jurassic Platform Fm

Record of EA-1 and CHBK-1 wells (Choubert et al., 1966; LeRoy & Piqué, 2001). NOT an official name, but used here to enable a Lexicon entry and description or this thick carbonate succession.

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).]

A progressive transgression after the major Initial Drift Unconformity (IDU) continued through the Middle Jurassic to enable the development of a carbonate platform that continued into the Late Jurassic Puerto Cansado Fm. On the cross-section of Wenke (2014), the basinal succession was characterized by clayey limestone, whereas the most landward margin received conglomerate deposits from the hinterland. The entire Lower-Middle Jurassic is about 2000 m thick (fig. 4 of El Jorfi et al., 2015).

Toarcian through Callovian, but the major basal unconformity (IDU) implies onset is Toarcian in the basin, but delayed until within late Aalenian in the inner shelf regions. A generalized onset during late Toarcian is used here for schematic graphics.

Shallow-marine setting and a sea-level fall during this period (El Jorfi et al., 2015). The Early Jurassic witnessed tectonic instability due to the initiation of continental drifting. This tectonic setting was responsible for the development of carbonate ramps in the Early- to Mid- Jurassic followed by regressive marine siliciclastic environments (Ghassal et al., 2016).