Chapter 1 Introduction to the Jurassic Arabian Intrashelf Basin

Abstract

The Jurassic Arabian Intrashelf Basin provides the setting for the world's greatest conventional oil reserves, including the world's largest oilfield, the supergiant Ghawar field. The stratigraphic interval corresponding to the development and infill of the Arabian Intrashelf Basin is from the uppermost Dhruma Formation to the top of the Hith Anhydrite Formation, spanning the late Bathonian–early Callovian to Tithonian. Many areas of the intrashelf basin have been well described in recent years and the stratigraphic succession has been defined in sequence concepts, but the regional development of the intrashelf basin has not been well synthesized. This Memoir builds on published data to give a regional interpretation of the geological evolution of the Arabian Intrashelf Basin. This introductory chapter reviews some of the earlier work, summarizes the key events and elements in the geological history of the Arabian Intrashelf Basin and gives a brief review of the history of petroleum exploration in this region. It is intended to serve as an extended abstract to introduce the general setting and summarize the contents of this Memoir, including some of the proposed revisions of depositional models, correlations and the sequence nomenclature, providing a context for considering and evaluating each subsequent chapter. The themes summarized in this chapter are documented and discussed in much greater detail in the subsequent chapters of this Memoir.

Sedimentological and sequence-stratigraphic analyses of the Tithonian Hith Anhydrite Formation in the Dahal Hit outcrop, Saudi Arabia

“…The extent of the Hith Anhydrite indicates that the marine setting was spread out farther than the underlying Oxfordian-Kimmeridgian Arab Formation (Wilson 2020). This extensive depositional setting is consistent with a steady rise in relative sea levels throughout the Late Jurassic.…”

“…The depositional environment of the Hith Formation has been the subject of several studies and discussions (Murris 1980;Alsharhan and Kendall 1994;Hughes et al 2009;Wilson 2020). Before focusing on the depositional setting, it is important to understand the regional context and the development of the Arabian intra-shelf basin during the Jurassic.…”

“…Before focusing on the depositional setting, it is important to understand the regional context and the development of the Arabian intra-shelf basin during the Jurassic. The evolution of the basin and the importance of the barrier towards the Neo-Tethys Ocean in the east is discussed in detail by Wilson (2020) and sketched in Fig. 20.…”

Dolomitization of the Lower Part of the Sargelu Formation, Northeastern Iraq

“…Near the completion of the Late Toarcian time, a wet climate caused evaporites cyclicity to stop. At the same time, a transgression filled in isolated basins and made them more similar [1,11] The Arabian Intrashelf Basin, as well as the Gotnia-Mesopotamian Basin, were episodically cut off from the Tethys Ocean by uplift and a tilt toward the west, with further variations brought on by eustatic sea-level rise and fall [19].…”

“…6). Furthermore, the lower part of the Sargelu Formation is underlain by the Sehkaniyan Formation, which contains of saccharoidal dolomite, dolomitic limestone, and solution-collapsed breccia [15,19]. The burial dolomitization model could be another scenario, as the Sehkaniyan Formation is well known as an evaporitic-bearing sequence (fig 6).…”