HARTLEY, ADRIAN J. Department of Geology and Petroleum Geology, University of Aberdeen, Aberdeen; and LEIGH P. SEBASTIAN, Chevron U. K. Ltd., London

ABSTRACT: Correlation, Geometry and Architecture of Submarine Gravity Flow Conglomerates, Pindos Foreland Basin, W. Greece: Implications for Reservoir Architecture

The Pindos Forland Basin of western mainland Greece consists of a NNW-SSE trending elongate trough stretching from Albania to the northern Peleponesse. Distribution of the Oligocene-Miocene basin-fill was dominated by a major sediment entry point in the south of the basin through which pebble and boulder-rich gravity flows were concentrated. A 600 m thick section adjacent to this entry point, allows constraints to be placed on the geometry and architecture of conglomerate-dominated submarine turbidite systems. Features such as lateral dimensions, inter-well scale correlation and internal heterogeneity can be constrained.

The conglomerate package can be divided into a lower 80 m thick incised valley-fill unit which includes debris flow and slump deposits and an overlying 520 m thick non-incised unit. Conglomerates within the upper unit abruptly wedge out into mudstones; no transitional facies are present. Individual conglomerate channels average 50 m in width (maximum 70 m), are 3-5 m thick and pass laterally into pebbly sandstones. Amalgamated conglomerate bodies form packages 5-15 m thick, traceable over 500 to 3000 m. No discernible difference was recorded in the geometry and architecture of the conglomerate bodies in the two units.

Individual structure of conglomerate bodies was defined on fabric variations (e.g. changes in clast size, sorting, clast to matrix ratio etc.). Correlation of units defined by these variations over distances >4 m is not feasible. Dominant flow processes are therefore inferred from the overall geometry and internal architecture of the conglomerate bodes, whilst smaller scale (<4m) textural differences are attributed to intra-flow variations in transport mechanism.

AAPG Search and Discovery Article #90987©1993 AAPG Annual Convention, New Orleans, Louisiana, April 25-28, 1993.