--> ABSTRACT: Sedimentology and Petroleum Potential of Cretaceous Limestones in the Preapulian Zone, Ionian Islands, Western Greece, by Peter A. Scholle and Marios Patsoules; #90906(2001)

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Peter A. Scholle1, Marios Patsoules2

(1) New Mexico Tech, Socorro, NM
(2) Hellenic Petroleum, 151 24 Maroussi, Greece

ABSTRACT: Sedimentology and Petroleum Potential of Cretaceous Limestones in the Preapulian Zone, Ionian Islands, Western Greece

Cretaceous (Aptian to Maastrichtian) rudist reefs and associated platform and slope facies were examined on the islands of Zakinthos, Kefallonia, Lefkada, and Paxos. These modern islands correspond roughly to the geometry of a series of Cretaceous platforms. Each island exposes one or more thick carbonate platform complexes (hundreds of meters to >1000 m in thickness) or has indicators of platform proximity in areas not presently exposed on the islands. The Cretaceous of Zakinthos includes only platform interior and platform margin facies; Kefallonia has platform interior, platform margin, slope, and proximal basin facies; and Lefkada and Paxos encompass only slope deposits. Field and petrographic examination demonstrated extensive synsedimentary submarine cementation and porosity occlusion primarily in reef and immediate back-reef facies. Extensive subaerial exposure, leaching, and secondary porosity development followed during development of a widespread latest Cretaceous to Early Eocene unconformity, and probably also during later tectonic uplift. Leaching produced micromoldic or chalky porosity in the fine-grained shelf-interior strata. In reefal strata, porosity consists mainly of poorly-connected, primary intragranular voids plus some moldic pores created by removal of coarse, originally aragonitic debris. The best porosity (locally >20%) is developed in fore-reef slope to toe-of-slope environments, with extensive molds connected by primary intragranular pores. Known oil seeps in this region, coupled with excellent potential Cretaceous reservoirs, make this largely undrilled region an interesting exploration target, comparable perhaps to the Cretaceous of Mexico. Deeper burial and overlying seals are required; these conditions may exist beneath major thrust sheets east of the Preaupulian Zone.

AAPG Search and Discovery Article #90906©2001 AAPG Annual Convention, Denver, Colorado