AN APPROACH TO PROVENANCE, TECTONIC AND REDOX CONDITIONS OF JURASSIC-CRETACEOUS AKKUYU FORMATION, CENTRAL TAURIDS, TURKEY

Indexed In

Volume 144 / 2012

Authors:

Ali SARI, Derya KOCA

Keywords:

Late Jurassic-Early Cretaceous, Provenance, Central Taurids, Redox, Major oxide

Abstract:

Late Jurassic-Early Cretaceous Akkuyu formation was deposited on marine carbonate platform in Central Tarurids. The organic material of the unit is composed of Type III kerogen which is woody material transported from the land. Late Jurassic- Early Cretaceous is an important period which great anoxic events in deep sea bottom occurred due to the primary organic productivity in global sea surface. Use of several trace elements values (Ni, V, U, Cr, Co, Th) revealed that Late Jurassic-Early Cretaceous Akkuyu formation shows oxic, disoxic and anoxic paleoredox conditions.  In this period the primary productivity was considerably high. Examination of specimen derived from Akkuyu formation revealed that there exist a very good positive relationship between the major oxides of Al2O3, SiO2, Fe2O3, TiO2, and K2O. These combinations of major oxides indicate a detrital origin of source rock. Chemical weathering evaluations of Central Taurids in Jurassic-Cretaceous period indicated moderate and strong weathering of source rock. K2O/Na2O versus SiO2; SiO2/Al2O3 versus K2O/Na2O; Al2O3/ SiO2 versus Fe2O3 + MgO ve TiO2 versus Fe2O3 + MgO diagrams indicated that Akkuyu formation was deposited along active and/or passive continental margin and derived from basalt and basalt+granite mixed rocks.