Abstract: Evolution of Tertiary Basin Margin Depositional Systems, Black Sea, Offshore Turkey
CUCCI, MAURICE A., and WILLIAM H. ABBOTT, ARCO Exploration and Production Technology; DENNIS YARWOOD, FRANK S. BARKER, and DAVID S. CAMPBELL, ARCO International Oil and Gas Co.
Summary
On the southwestern margins of the Black Sea several Tertiary lowstand-events, of likely Eocene to Late-Miocene age, have eroded canyons and incised-valleys. Reservoirs that were formed during intervals of rapidly changing relative water levels reside in canyons, valleys, and on interfluves. Thus, the same systems evolve paleogeographically from submarine canyons, to incised valleys. Finally when the basin fills with fresh water, these systems become sublacustrine canyons. The resultant stratigraphy is heterogeneous, evolving from pre-canyon marginal marine and marine deposits to marine turbidites to marine and lacustrine deltaics, to fluvial sediments and back to lacustrine deposits. Canyon reservoirs are ultimately sealed by transgressive fine-grained lacustrine sediments.
Exploration targets comprise a variety of non-marine and/or
marine sands overlain and sealed by fine-grained, deep-water
lacustrine strata. These include lowstand deposits such as: canyon
fill sediment; incised-valley fill; toe-of-slope fan (proximal
turbidite) facies; and lowstand fluvio-deltaic reservoir.
Transgressive system deposits comprise upper shoreface reservoir in
proximal positions. However in more distal or basinal settings
transgressive deposits can be fine-grained seal
and source rock
deposits. Proximal, coarse-grained highstand deposits (near upland
areas) comprise fluvio-deltaic reservoir. Distal, fine-grained
highstand deposits in basinal areas can include source rock and
seal
.
AAPG Search and Discovery Article #90937©1998 AAPG Annual Convention and Exhibition, Salt Lake City, Utah