Page 316 - Introduction to Mineral Exploration

13: SOMA LIGNITE BASIN, TURKEY 299

Istanbul
North Anatolian Fault
Ankara
Soma N
TURKEY

+

DENIS
BASIN
Soma
l

Bergama
l
STUDY SOMA
Kinik AREA BASIN
l
EYNEZ
BASIN
Quaternary
Neogene 39°00'S
Cretaceous
Jurassic Limestone
Palaeozoic basement
Akhisar
+ Granodiorite l
Andesite
Ophiolite

0 10 km

27°30'E 28°00'E

FIG. 13.2 Generalized geology of the Soma area (taken from the 1:250,000 Izmir sheet regional geological map
published by MTA). The inset shows the regional structural setting for the Soma Basin in relation to the major
structural feature of northern Turkey, the North Anatolian Fault (NAF).

and geophysical logs identify this contact shows a distinct change from the very high sig-
clearly. The KM2 has a distinctly low natural nature of the marl to a medium response in the
gamma signature in contrast to the very high limestone. The Yatagan Formation contains
signature of the marl. The sharp change from the KM3 Lignite which is interbedded with a
peat (lignite) formation to the marlstone is series of thick calcareous clastic units, making
believed to be the result of a change to an arid the economic assessment of this unit more
climate (Sengor et al. 1985). difficult. The freshwater limestone is con-
In cores and in the open pit, the contact formably overlain by massive marlstone the
with the overlying freshwater limestone of basal half of which contains thin, laterally
the Yatagan Formation is unconformable and impersistent, lignite seams. Gökçen (1982)
marked by a color change. The gamma log considered these marlstones to belong to the