Mk. Yaliniz et al., SUPRA-SUBDUCTION ZONE OPHIOLITES OF CENTRAL ANATOLIA - GEOCHEMICAL EVIDENCE FROM THE SARIKARAMAN-OPHIOLITE, AKSARAY, TURKEY, Mineralogical Magazine, 60(402), 1996, pp. 697-710
The Central Anatolian Crystalline Complex (CACC), situated between the
northern and southern oceanic strands of Neotethys, contain a number
of little-studied ophiolitic bodies of late Cretaceous age that have a
bearing on the Mesozoic development of this region. The pillow lavas
and sheeted dykes of the Sarikaraman Ophiolite were originally a comag
matic differentiated series of vesicular, aphyric and olivine-poor, pl
agioclase-clinopyroxene phyric tholeites, but now exhibit greenschist
facies assemblages. A set of late dolerite dykes cross-cutting the who
le volcanic sequence are more chemically evolved and were probably der
ived from a different source. Relative to N-MORB the lavas and dykes a
re enriched in some LIL elements (K, Rb, Cs, U, Th and Sr) and deplete
d in HFS elements (Nb, Ta, Hf, Zr, Ti and Y) and light REE. In terms o
f immobile elements the ophiolitic basalts have the broad chemical cha
racteristics of island are tholeiites that were formed in a supra-subd
uction zone setting, whereas the late dykes are more akin to N-MORB. I
n this respect the Sarikaraman Ophiolite is similar to other ophiolite
s found in the eastern Mediterranean region and emphasizes the preserv
ation of this particular environment in the CACC. If all the Central A
natolian Ophiolites (of which the Sarikaraman Ophiolite is one example
) were derived via southward thrusting from the Vardar-Izmir-Ankara-Er
zincan Ocean branch to the north, age relationships suggest that this
segment of ocean crust was relatively short-lived before obduction ont
o the CACC.