A. Ciner et al., CYCLICITY IN THE MIDDLE EOCENE YAMAK TURBIDITE COMPLEX OF THE HAYMANABASIN, CENTRAL ANATOLIA, TURKEY, Geologische Rundschau, 85(4), 1996, pp. 669-682
The Haymana basin in central Anatolia (Turkey) formed on a Late Cretac
eous to Middle Eocene fore-are accretionary wedge. A sequential model
is proposed for the 1-km-thick Lutetian Yamak turbidite complex (YTC)
which is the youngest paleotectonic unit of the basin. The YTC represe
nts a prograding submarine fan subdivided into three depositional sequ
ences (DS), each several hundred meters thick. Each depositional seque
nce consists of a turbidite system (TS), with sandstone and conglomera
tic sandstone beds alternating with mudstones, overlain by basin plain
mudstones. In each turbidite system, the sandstone and mudstone seque
ntial organization allows the distinction of smaller subdivisions, nam
ely, basic sequences (BS) and basic units (BU), with each basic sequen
ce being composed of several basic units. This subdivision, associated
with a two-dimensional geometric reconstruction of the YTC, leads to
a better understanding of the evolution in time and space of the subma
rine fan system. Lower to middle fan depositional lobes, and upper fan
and slope channels, are represented. As a whole, the YTC progressed f
rom a sand-poor to a sand-rich system. Depositional sequences (DS) of
the YTC may correspond to third-order sea-level cycles of tectonic ori
gin. Accordingly, fourth- and fifth-order cycles might be proposed for
the BS and BU, respectively. However, partly because of the limited e
xtent of exposures, the allocyclic origin of these finer subdivisions
remains problematic.