Kalınçam (Tonya-Trabzon, KD Türkiye) Yöresi Geç Kretase Yaşlı Volkanitlerin Jeokimyası ve Petrojenezi.

Volcanics around the Kalınçam (Tonya, Trabzon) in eastern Black Sea Region of Turkey, is of Late Cretaceous age, basalts, andesites and pyroclastics occur at the base; over these comes dacite, rhyodacite and their pyroclastics, andesite and its pyroclastics with dacite and its pyroclastics, respectively. The vesicular, porphyritic and open space textures are observed in basalts and andesites and as mineralogical components plagioclase in basalt, on the other hand, plagioclase and lesser amount amphibole are seen in andesite. Dacite and rhyodacite rocks have microgranular porphyritic and glassy porphyritic textures, and hey consist of quartz and hornblende. The andesites ion have glassy- microlitic- porphyritic texture and have a composition consisting of plagioclase and hornblende. The dacitic rocks located at the top exhibite microgranular porphyritic and glassy porphyritic textures, and mainly they consist of plagioclase, quartz and hornblende. The investigated volcanics are of calc-alcaline-transitional? in character and have high large ion lithophile elements (LILE) and low High field strength elements (HFSE) content and high LILE/HFSE ratio, so they reflect the geochemical features of subduction related rocks. Chondrites normalized rare earth element patterns (LaN/LuN=3.11-13.10) show a moderate enrichment pointing similar source for volcanics around Kalınçam. 87Sr/86Sr values changes between 0.70727 and 0.70779; and 143Nd/144Nd values ranges from 0.512318 to 0.512656. The fact that the rocks in the studied volcanic formations are of a basic-acidic character indicate that both the mantle which is affected by the subduction and crustal resources are possible. [ABSTRACT FROM AUTHOR]