Author: H.ALİM BARAN, Hulisi KARGI
Publishing Date: 2005
Volume 20 Issue 4
In this study, origin of chromite and dolerite dikes in the Andızlık-Zımparalık region was investigated by field observations, microscopic studies and chemical analyses. The ultramafic rocks in the region are tectonites and harzburgite is the dominant lithological unit. Dunite crops around out less than harzburgite. It appears as an envelope chromite deposit if it exists. Basic dikes widespreadly observed in the study area and pyroxenite dikes crosscut these units. Chromites are disseminated, spotted, layered and massive in character and present a serie from harzburgites to massive chromite in the sequence of disseminated-spotted and massive chromite. Layered chromites have a general strike of N 50o-70o W and a dip of 60o-70o SW. General setting of the dolerite and pyroxenite dikes in the study area are parallel to eachother having strike of N 50o-70o W and dip of 80o-85o NE. Dolerit dikes having low K content (0,07%- 0,34) and low Nb content (1,1- 4,4 ppm) are geochemically toleitic in character and plot on subduction fields rather than N-MORB in the discriminating diagrams. Pyroxenites dikes usually accompany to chromites. Presence of intense chromite deposits in the Andızlık-Zımparalık region, high chromium contents of chromites, pyroxenite dikes occurrences accompanying to chromites, being subduction related origin of dolerite dikes show that podiform chromites of the region formed in a island-arc environment by rock-melt interaction.
Key Words: Chromite; dolerite dikes; ophiolite; Andızlık-Zımparalık.