سنگ‌نگاری، شیمی کانی تورمالین، ژئوشیمی و جایگاه زمین‌ساختی سنگ‌های آذرین ترشیری منطقه‌ی شوراب (غرب خوسف)، خراسان جنوبی

Tertiary igneous rocks of Shurab area in eastern part of Lut block include pyroxene andesite, andesite, trachy andesite, quartz andesite, diorite, quartz diorite and porphyric quartz monzodiorite. Plagioclase, hornblende, pyroxene, biotite and quartz are common minerals and alkali feldspar, opaque, sphene, apatite, tourmaline and zircon exists as minor minerals. Propylitization, chloritization, silisification and tourmalinization are common alterations. Based on electron microprob analysis, tourmaline in quartz monzodiorite is characterized by weakly chemical zoning, high Mg/Fe ratio from dravite type with alkaline nature that originated from Ca-poor metapelites and metapsammites. The studied rocks have low to medium-K calk-alkaline nature and their spider diagrams display enrichment in LILE such as Cs, Rb ,K , Sr and LREE and depletion in Nb,Ti and HREE that indicate their relation to subduction zone. Geochemical characteristics such as high Sr/Y and La/Yb ratios, high SiO2 and no Eu anomaly are comparable to high-SiO2 adakites. Shuorab adakitic rocks are likely originated from partial melting of the crust during delamination process.