CAJ | 학술논문

对内蒙古苏尼特左旗北奥陶系砂岩的岩石学和锆石年龄进行研究。镜下特征显示该套砂岩为岩屑砂岩，含有较多的火山岩屑；砂岩颗粒骨架成分图解显示其来自再旋回造山带。应用LA-ICP-MS测年技术对该套砂岩进行碎屑锆石分析，其年龄峰期从小到大可分为：①440~574Ma，主峰值年龄为506Ma，次峰值年龄为442Ma；②650~799Ma，峰值年龄为767Ma；③874~936Ma，峰值年龄为887Ma；另外大于1000Ma的4颗单颗粒锆石年龄分别为1145Ma、1756Ma、2618Ma和2626Ma。通过邻区相关地块/地体年龄及岩浆事件的对比可知，该套砂岩的沉积时间约为440Ma，沉积物源主要来自于额尔古纳地块和兴安地块，并且沉积过程受到火山事件的影响。
대내몽고소니특좌기북오도계사암적암석학화고석년령진행연구。경하특정현시해투사암위암설사암，함유교다적화산암설；사암과립골가성분도해현시기래자재선회조산대。응용LA-ICP-MS측년기술대해투사암진행쇄설고석분석，기년령봉기종소도대가분위：①440~574Ma，주봉치년령위506Ma，차봉치년령위442Ma；②650~799Ma，봉치년령위767Ma；③874~936Ma，봉치년령위887Ma；령외대우1000Ma적4과단과립고석년령분별위1145Ma、1756Ma、2618Ma화2626Ma。통과린구상관지괴/지체년령급암장사건적대비가지，해투사암적침적시간약위440Ma，침적물원주요래자우액이고납지괴화흥안지괴，병차침적과정수도화산사건적영향。
The petrology and zircon ages of the Ordovician sandstones in northern Sonid Left Banner area of Inner Mongolia were studied in this paper. The sandstones belong to a kind of lithic sandstone with lots of volcanic debris. The sandstone grain matrix com-ponent diagrams show that the sandstones came from the recycled orogenic belts. LA-ICP-MS dating technique was used to make detrital zircon analysis for one sandstone sample, and the age periods obtained are from low to high as follows: ①440~574Ma with the major peak at 506Ma and subordinate peak at 442Ma; ②650~799Ma with the peak at 767Ma; ③874~936Ma with the peak at 887Ma;ages of the other four zircon samples are 1145Ma, 1756Ma, 2618Ma and 2626Ma, respectively. Based on the comparison of ages and magmatic events with relative adjacent cratons and/or terrenes, the authors infer that the sandstones formed at 440Ma, and the provenances were mainly derived from the Erguna and Xing'an terranes, with the sedimentary process affected by volcanic events.