Abaruk Bed Fm

See Dammam Fm

Synonym: Abarug Dolomitic Limestone and Marl Member; Abarug Beds Fm

Reference Section:

The reference section (Fig. 1) of this member was surveyed South of Zekreet, in the Ras Abarug Peninsula, just behind the Cuban Hospital.

[Figure 1: Abarug Dolomitic Marl (8.5 m) and Dolomitic Limestone (~2 m). See “A” in section shown in Fig. 1 in Dammam Fm]

In this locality, two units crop out that are found everywhere in Ras Abarug. A basal unit, resting on the crystalline limestones of the Umm Bab Member (or the Bir Zekreet Member when present), is comprised of dolomitic marls and soft, but compact, argillaceous dolomite, yellow-orange to green, nodular at the top, of a fairly constant thickness (27.9 ft (8.5 m)), called Abarug dolomitic Marl; an upper unit comprised of an irregularly dolomitized limestone that frequently changes to a calcareous dolomite (or not), grayish yellow to brown, hard, cavernous due to the dissolution of abundant Mollusc impressions and molds, generally not too thick (about 6.6 ft.(2 metres)) called Abarug dolomitic Limestone.

The fauna of the Abarug dolomitic Marl is restricted to poorly defined Mollusc impressions observed in the nodular level at the top. The Abarug dolomitic Limestone is rather rich in Molluscs (Gastropods, bivalves) (Fig. 2) impressions and molds that are more or less determinable, Echinoderms (Figs. 3 & 4), Trace fossils (Figs. 4 & 5) and Large Foraminifera.

[Figure 2: Gastropod.]

[Figure 3: Echinoderms]

[Figure 4: Echinoderm with a trace fossil (burrow)]

[Figure 5: Trace fossil]