سنگ‌نگاری، زمین‌شیمی و خاستگاه زمین‌ساختی سنگ‌های آتشفشانی منطقه آسفیچ (جنوب باختری سربیشه- خراسان جنوبی)

چکیده مقاله

The magmatic activities of Lut block started from the middle of Jurassic (165-162 Ma) with the intrusion of Kalate Ahani, Shahkoh and Sorkkoh intrusive masses and reached its peak in the Tertiary. Tertiary volcanic and semi-volcanic rocks cover more than half of the Lot block with a thickness of about 2000 meters, which were formed as a result of subduction before the collision of the Arabian and Asian plates (Camp; Griffis, 1982; Tirrul et al., 1983; Berberian et al., 1982). The studied area with geographic coordinates 14'31°59'' to 59'36°59'' east longitude, 28'32°32'' to 32''32'' north latitude, is located 40 km southwest of Sarbisheh and includes a thick succession of Tertiary volcanic and pyroclastic rocks that are covered by young Quaternary sediments in some places. This area is located in the 1:100,000 Sarbisheh geological map prepared by Nazari and Salamati (1999). In the map prepared by Pang et al. (2012) for parts of Sistan zone and Lut block, the studied area is located on the eastern edge of Lut block and on the border of two structural states of Lut block and Sistan zone (Figure 1). Since the Tertiary volcanic rocks in the mentioned region, despite their wide expansion and having large reserves of perlite and clay minerals, have not been subjected to detailed lithology and geochemistry studies, they have been selected as the subject of this research.