Ghawwas Fm

Period:

Neogene

Age Interval:

Tortonian – Messinian, Sa3

Province:
Red Sea (Saudi Arabia)

Type Locality and Naming

The type section was established by Saudi Aramco using the subsurface succession in Ghawwas-1 (GHWS-1: 19°49′21.18″N, 40°23′02.88″E; between 3,359–7,299 ft) exploration well (Figure 5) in the southern part of the Saudi Arabian Red Sea (Johnson et al., 1995). Hughes and Filatoff (1995) named the Ghawwas formation. Column: Red Sea Saudi Arabia. The Reference section for the Ghawwas Formation is in the Saudi Aramco exploration well Midyan S-1 (MDYN-1) between 1,424–5,804 ft, onshore coastal Saudi Arabian Red Sea.

Synonym: Ghewas Fm. In Midyan, it was previously included within the middle Raghama Fm (Skipwith, 1973), the upper part of the Al Bad Fm (Dullo et al., 1983), the Bad Fm of the Raghama Gr (Clark, 1986), the Raghama Fm (Brown et al., 1989), and the Bad Fm (Jado et al., 1990).

Lithology and Thickness

The Ghawwas Fm consists of conglomerate, sandstone, minor claystone, carbonates, and local thin beds of anhydrite. thickness of the Ghawwas Formation is 3,940 ft (1,201.2 m) in the type section, and 4,380 ft (1,335.4 m) in the reference section.

Lithology Pattern:

Sandstone

Relationships and Distribution

Lower contact

It overlies the Mansiyah Fm with probable conformity.

Upper contact

Unconformably (quite angular in some sites) overlain by the Pliocene-Pleistocene Lisan Fm.

Regional extent

The formation is distributed widely along the Saudi Arabian Red Sea. The formation is equivalent to the Zeit Fm of the Gulf of Suez and other areas of the Red Sea (Hughes et al., 1992; Hughes and Beydoun, 1992), and to the upper part of the Dungunab Fm of Sudan (Carella and Scarpa, 1962; Sestini, 1965; Hughes and Beydoun, 1992). The Ghawwas Fm is also equivalent to the open-marine, syn-rift tectono-sedimentary unit C of Plaziat et al. (1990).

GeoJSON

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Fossils

Age

A middle to late Miocene age is based on diatom evidence within the region together with the stratigraphic position of the formation above rocks regionally dated as middle Miocene (Hughes et al., 1992; Hughes and Filatoff, 1995). A Late Neogene age is suggested by the relatively common occurrences of Plumbaginaceae-, Papilionaceae- and Nyctaginaceae-type pollen " (Hughes et al., 1999). Late Tortonian – Early Messinian indicated on 2008 chart of Middle East (used here).

Age Span:

Beginning stage:

Tortonian

Fraction up in beginning stage:

0.5

Beginning date (Ma):

9.44

Ending stage:

Messinian

Fraction up in the ending stage:

0.5

Ending date (Ma):

6.29

Depositional setting

"Regional studies indicate that the Ghawwas formation was deposited under a variety of shallow-marine to marginal-marine environments, perhaps with the periodic development of sabkha conditions. Marine microfauna, for example, are scarce (Hughes and Filatoff, 1995; Filatoff and Hughes, 1996) but freshwater Pediastrum spp. and Anthoceros-type spores are common.." (Hughes et al., 1999)

Depositional pattern:

Additional Information

Compiler:

From Hughes, G.W., Grainger, D.J., Abu-Bshait, A-J., and Jarad, A-R. M., 1999. Lithostratigraphy and depositional history of part of the Midyan Region, northwest Saudi Arabia. GeoArabia, 4: 503-542. Middle East Geological Timescale 2008 Al-Husseini, Journal of Middle East Petroleum Geosciences v 13. no. 4.