Özet:

The variations in the chemical composition and micro-texture of a mineral from the core to the rim allow the sequencing of the formation of the magma chamber processes and the interpretation of which texture might have been formed by which process. In this study, the textural and chemical zoning of the plagioclases, which are a significant recorder of magma chamber processes, from some enclave-containing andesite (calc-alkaline) and basalts (calc-alkaline) from the Karapınar Karacadağ Volcanic Complex, were examined and their textural stratigraphies were created to enlight the magma chamber processes. Plagioclases in enclave bearing andesites and their enclaves have the same composition and are andesine-bitovnite (An34-An75) in composition. It is noteworthy that the plagioclases in the host-rock are mostly rounded, and reverse and oscillatory zoned with Fe, Mg, An, Sr, and Ba. However in the enclaves they display generally fine sieve texture and dusty sieve texture. Plagioclase micro-phenocrysts in calc-alkaline basalts are andesine-labrador (An32-An66) in composition from core-to-rim, suggesting that they may be xenocrysts rather than phenocrysts. Remarkably, plagioclases in basalts show reverse and oscillatory zoning with Fe, Mg, An, Sr, and Ba, and as well as exhibit coarse-grained sieve texture with glass and microlithic inclusions, and spongy cellular textures. Considering the textural and chemical properties of the plagioclases, in the formation of reverse and oscillatory zoning in the basaltic rocks, the decompression processes in addition to the magma mixing processes (magma mixing/self-mixing) also affect the genesis of the basalts. However, in the formation of andesitic rocks, the magma replenishment processes have a key role rather than decompression or temperature-pressure change.

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