ABSTRACT

A flysch succession more than 2 km thick is exposed between the Gulf of Patras and the Lake Trikhonis depression. A monocline repeats the stratigraphic sequence, such that sediments can be correlated for at least 10 km across the depositional strike. The flysch was deposited on two overlapping deep sea fans, each with a deltaic source. Marine shale, cut by channels filled with conglomerate and massive sandstone, comprises upper fan areas. Conglomerate dies out distally, and shaly and sandy flysch are the dominant lithologies in the mid-fan area. There is one suprafan sand sheet about 10 km wide, which changes from pebble conglomerate to medium grained sandstone over a distance of 5 km downstream. Otherwise, mid-fan sediments consist of sandy channel sands separated by extensive interd stributary shaly flysch. Paleocurrents on the fans are broadly radial.

Disorganized conglomerates containing large shale and shaly flysch intraclasts fill channels. There is a gradation from pebbly mudstone near channel margins to conglomerate with a sandy matrix in channel axes. These disorganized conglomerates are cut by narrow channels, which are filled by pebbly sandstone and organized conglomerate. The disorganized conglomerates probably were deposited from mass flows initiated by slumping of unstable deltaic sediments.