NÝÐDE, ELMALI GÜNEYÝ S-TÝPÝ BÝYOTÝT GRANÝTOÝDLERÝ VE ANKLAVLARININ PETROLOJÝSÝ

Biyotit granitoidler baþlýca kuvars, biyotit, plajiyoklas, K-feldispat, muskovit nadiren amfibol içerirler. Tali bileþen olarak apatit, zirkon, allanit ve ikincil olarak klorit ve serisit içerirler. Anklavlar baþlýca plajiyoklas, amfibol, ojit, biyotit, tali bileþen olarak sfen, zirkon ve ikincil olarak kalsit ve epidot minerallerini içerirler. Metalumino bileþimli anklav içeren, granitoidler S-tip granitlere ait kimyasal ve mineralojik özellikler gösterirler: peralumino (A/CNK oraný >1.15) bileþim ve muskovit minerali. Granitoidler büyük iyonlu litofil element (BÝLE) ve hafif nadir toprak elementlerce (HNTE) zenginleþme ve aðýr nadir toprak elementlerce fakirleþme (ANTE) sunarlar. Bu durum granitoidlerin kabuk ergimesiyle oluþtuðunu, negatif Eu anomalisi ve büyük iyon litofil elementlerince zenginlik göstermeleri plajiyoklaslarýn fraksiyonlaþmada etkisini göstermektedir. Anklavlarda büyük iyonlu litofil element (BÝLE) zenginleþmesi, yüksek alan enerjili elementlerde (YAEE) fakirleþme, nadir toprak element (NTE) daðýlýmlarýnda yataya yakýn desen vermeleri ve negatif Eu anomalisi göstermeleri, anklavlarýn litosferik mantodan kaynaklandýðýný ve hornblend, plajiyoklaslarýn fraksiyonlaþmada etkisini göstermektedir. Arazi, petrografik ve jeokimyasal verilere dayanarak, volkanik yay özellikli granitlerin mafik magmanýn kabuða sokulmasý ve muhtemelen kabuk kalýnlaþmasý ile oluþtuðu ve mafik magma ile fiziksel olarak karýþarak anklavlarý oluþturduðu ileri sürülmüþtür.

PETROLOGY OF S-TYPE BIOTITE GRANITOIDS AND THEIRS MAFIC ENCLAVES, SOUTH OF ELMALI, NÝÐDE

Biotite granitoid contain mainly quartz, biotite, plagioclase, K-feldspar, muscovite as main phases with minor amphiboles, and apatite, zircon, allanite and chlorite and serisite as accessory components. In contrast, enclaves are composed mainly of plagioclase, amphibole, augite, biotite, with accessory sphene, zircon and calcite and epidote. The granitoids including enclaves with metaluminous composition, display chemical and mineralogical characteristics of S-type granitoids, such as peraluminous composition (A/CNK ratio mostly >1.15) and existence of muscovites. Granitoids are enriched in LILEs and LREEs, and depleted in HFSEs; suggesting that they were developed by crustal melting. Granitoid also have negative Eu anomalies and large ion lithophile element enrichment suggest crystal fractionation of plagioclase. Enclaves are enriched in LILEs and depleted in HFSEs and show flat REE pattern with large negative Eu anomaly, suggesting they were derived from enriched lithospheric mantle, with possible crystal fractionation involving plagioclase and amphibole. Based on field, petrographic and geochemical data, it has been suggested that volcanic-arc granitoids could be formed by intrusion of mantle-derived mafic magmas into the lower crust and with possible crustal thickening, and mingled with mafic magma producing enclaves.