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The AAPG/Datapages Combined Publications Database

AAPG Bulletin


Volume: 65 (1981)

Issue: 5. (May)

First Page: 999

Last Page: 999

Title: Synsedimentary Tectonic Controls on Facies Evolution of Late Miocene Barrier Reef Complex: Upper Coralline Limestone, Maltese Islands: ABSTRACT

Author(s): Sidney R. Storey

Article Type: Meeting abstract


The central Mediterranean Maltese Islands constitute a local high on the Malta-Ragusa platform, a positive bathymetric feature extending northward to southeastern Sicily. Three main structures are recognizable within the islands and adjacent offshore areas: (1) a prominent north-south structural high through Malta which has been a positive feature since at least the Oligocene; (2) a northwest-southeast fault that has formed the western margin of the islands and controlled facies patterns since the late Miocene; and (3) east-west normal faults of post-Miocene age that form horst and graben structures in north Malta and south Gozo.

The upper Coralline Limestone was deposited in a shallow basin bounded to the east by north-south structure. Evolution of facies patterns with progressive shallowing started with open circulation and deposition of relatively condensed glauconitic grainstones and foraminiferal rudstone shoals. These shoals were then colonized and stabilized by a Lithophyllum-Thalassia? association, which on further shallowing was replaced by frame-building coralgal reef and associated facies, or high-energy oolitic and bioclastic grainstones. Terminal stages of deposition are represented by shallow intertidal/supratidal sediments, followed by complete subaerial uplift.

High-energy frame-built and grainstone facies are localized by the northwest-southeast fault. Restricted circulation and shoreline sediments initially formed close to the north-south structure. As basin filling continued, more open-circulation, higher energy facies extended eastward until finally, highest units of the formation are represented 15 km east of the north-south structure. This apparent eastward "transgression" concurrent with shallowing to the west can be explained in terms of regional hinging about the north-south structure. Rotation to the east would allow transgression eastward while simultaneously uplifting western areas.

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Copyright 1997 American Association of Petroleum Geologists