--> Abstract: Integrated Diagenesis and Sequence Stratigraphic Study of Tidal Sandstones: the Adedia Formation (Cambro-Ordovician), Sinai, Egypt, by Khalid Al Ramadan, Sadoon Morad, and Essam El-Khoriby; #90105 (2010)

Datapages, Inc.Print this page

AAPG GEO 2010 Middle East
Geoscience Conference & Exhibition
Innovative Geoscience Solutions – Meeting Hydrocarbon Demand in Changing Times
March 7-10, 2010 – Manama, Bahrain

Integrated Diagenesis and Sequence Stratigraphic Study of Tidal Sandstones: the Adedia Formation (Cambro-Ordovician), Sinai, Egypt

Khalid Al Ramadan1; Sadoon Morad2; Essam El-Khoriby3

(1) Earth Sciences Department, KFUPM, Dhahran, Saudi Arabia.

(2) Petroleum Geoscience Division, The Petroleum Institute, Abu Dhabi, United Arab Emirates.

(3) Department of Geology, Mansoura University, El-Mansoura, Egypt.

This work examines the effects meteoric vs. marine diagenesis on Cambro-Ordovician tidal sandstones owing to fluctuation of relative sea level (RSL). The distribution of diagenetic alterations is thus constrained within the sequence stratigraphic framework of the succession. Initially, a rise in RSL resulted in the deposition of transgressive systems tract (TST) sands directly onto crystalline basement. These sandstones display evidence of limited cementation by marine, grain-fringing dogtooth-like and fibrous calcite. A fall in RSL resulted in the progradation of a tidal flat complex and deposition of highstand systems tract (HST) and lowstand systems tract (braided fluvial) sandstones. Contemporaneous meteoric-water flux into sands of all the systems tracts resulted in the dissolution and kaolinitization of feldspars, micas and mud intraclasts in all systems tracts. Sequence boundaries (SB) are marked by fluvial incision of tidal sands and by the development of palaeosols. Mesogenetic alterations include partial transformation of kaolinite into dickite, intergranular pressure dissolution, and formation of variable amounts of syntaxial quartz overgrowths in all systems tracts. Telogenetic alteration (i.e. weathering) in the sandstones includes the formation of goethite and calcite. Thus, the integration of diagenesis with sequence stratigraphy provides a useful tool with which to understand reservoir quality distribution in sand-dominated, tidal sediments.