تعیین سن اورانیم - سرب کمپلکس نفوذی ژوراسیک بروجرد و توده‌های وابسته در زون سنندج - سیرجان
| دسته | پترولوژی |
|---|---|
| گروه | سازمان زمین شناسی و اکتشافات معدنی کشور |
| مکان برگزاری | بیست و سومین گردهمایی علوم زمین |
| نویسنده | مجید قادری، جهاندار رمضانی، محمدولی ولی‌زاده، زهره فردین‌دوست، احمد احمدی‌خلجی |
| تاريخ برگزاری | ۰۷ بهمن ۱۳۸۳ |
U-Pb geochronology of the Jurassic Boroujerd plutonic complex and associated intrusions within the Sanandaj-Sirjan Zone
Majid Ghaderi, Jahandar Ramezani, Mohammad-Vali Valizadeh,Zohreh Fardindoost, Ahmad Ahmadi-Khalaji
New U-Pb zircon geochronologic data from a variety of granitoid rocks within, and closely associated with, the Boroujerd plutonic complex in the Sanandaj-Sirjan Zone indicate an extensive, but short-lived episode of magmatic activity in the period ۱۷۲ Ma to ۱۶۹ Ma in the middle Jurassic. The age of the massive granodiorite plutons of the complex are indistinguishable within analytical uncertainties from the timing of emplacement of the late-stage pegmatitic dikes which represent the final stages of magmatism. Our results are in sharp contrast to the earlier K-Ar and Rb-Sr age data that suggest significantly younger dates, as well as longer endurance for the magmatic activity in this area. The plutonism and associated regional metamorphism of middle Jurassic in this part of the Sanandaj-Sirjan Zone is different in age from the documented tectonic events throughout the greater central Iranian province and Zagros, and thus require a distinct tectonic setting for their origin.