CAJ | 학술논문

提阿勒泰南缘诺尔特地区晚古生代火山岩十分发育，其中正格河一带出露一套片理化蚀变流纹岩与含凝灰质英安流纹岩的岩石组合，呈北西-南东向带状展布，前人将其划为石炭纪红山嘴组a段。本次工作对其进行的LA-ICPMS锆石U-Pb测年结果显示为早泥盆世（206Pb/238U加权平均年龄值为(400.4±3.6) Ma），时代不同于红山嘴组所属的石炭纪。其岩性明显区别于红山嘴组b、c段地层，且稳定成规模出露，故对此套流纹岩组合进行了重新厘定，暂命名为正格河火山岩。岩石SiO2含量在69.77%~75.16%，里特曼指数为1.26~1.70，(Na2O+K2O)介于5.90%~7.28%，A/CNK值介于0.88~1.16，显示钙碱性、偏铝质岩石特征。微量元素富集Rb、Th等大离子亲石元素，亏损Nb、Ta、Hf等高场强元素，稀土元素总量变化较大，∑REE介于189.20×10-6~308.47×10-6，轻、重稀土元素分馏较强（（La/Yb）N=5.82~7.86），铕负异常（δEu=0.45~0.75），具有与俯冲作用有关的岩浆作用特征。结合区域地质资料，表明正格河火山岩形成于活动大陆边缘构造环境。
제아륵태남연낙이특지구만고생대화산암십분발육，기중정격하일대출로일투편이화식변류문암여함응회질영안류문암적암석조합，정북서-남동향대상전포，전인장기화위석탄기홍산취조a단。본차공작대기진행적LA-ICPMS고석U-Pb측년결과현시위조니분세（206Pb/238U가권평균년령치위(400.4±3.6) Ma），시대불동우홍산취조소속적석탄기。기암성명현구별우홍산취조b、c단지층，차은정성규모출로，고대차투류문암조합진행료중신전정，잠명명위정격하화산암。암석SiO2함량재69.77%~75.16%，리특만지수위1.26~1.70，(Na2O+K2O)개우5.90%~7.28%，A/CNK치개우0.88~1.16，현시개감성、편려질암석특정。미량원소부집Rb、Th등대리자친석원소，우손Nb、Ta、Hf등고장강원소，희토원소총량변화교대，∑REE개우189.20×10-6~308.47×10-6，경、중희토원소분류교강（（La/Yb）N=5.82~7.86），유부이상（δEu=0.45~0.75），구유여부충작용유관적암장작용특정。결합구역지질자료，표명정격하화산암형성우활동대륙변연구조배경。
The Nurt area is located in the southern part of Altay, where Late Paleozoic volcanic rocks are well developed. There exists a set of rock assemblages of altered rhyolite and tuff dacite rhyolite in Zhenggehe area, which are in zoned distribution from northwest to southeast and were originally assigned to member a of Hongshanzui Formation. The LA-ICPMS zircon U-Pb dating has revealed that the volcanic rocks formed in the Early Devonian (the zircon 206Pb/238U weighted average age is (400.4 ± 3.6) Ma), unlike Hongshanzui,whose age is of Carboniferous. The lithologic characteristics are obviously different from members b, c of Hongshanzui Formation, and are extensively stably distributed, so this set of rhyolites was re-determined, and tentatively assigned <br> to Zhenggehe volcanic rocks. The SiO2 values range from 69.77% to 75.16%, and σ from 1.26 to 1.70, Na2O+K2O values range between 5.90% and 7.28%, A/CNK ratios range between 0.88 and 1.16, with sub-alkaline, calc-alkaline and meta-aluminum characteristics. The pluton is characterized by enrichment of trace elements Rb, Th and other large LILE, loss of high field strength elements Nb, Ta, Sr, Hf. The content of REE changes considerably,ΣREE range between 189.20 × 10-6 and 308.47 × 10-6, light and heavy REE show strong fractionation ((La/Yb) N being 5.82-7.86), Eu exhibits negative anomalies (δEu=0.45-0.75), and the REE characteristics are similar to features of island-arc volcanic rocks. Combined with the data of southerner margin of Altay, the authors hold that the Zhenggehe volcanic rocks were formed in an active continental margin tectonic environment.