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近年来对秦岭地区勉略缝合带的研究已引起了人们的关注。已有研究报道勉略混杂带中存在着蛇绿岩块,它们所代表的古洋形成于晚古生代,可能是古特提斯的一部分。但是,该地区是否存在真正的古洋盆,还缺少确凿的地质、地球化学等证据。最近李曙光研究了勉略带内的黑沟峡双峰式火山岩块,指出它们是初始裂谷向成熟洋盆转化阶段的产物。勉略带内是否保留有古洋壳的残余呢?本文报道了在勉略构造混杂带内发现的与蛇纹石化变质橄榄岩共生的高亏损N-MORB火山岩剖面,证明曾有真正的古洋盆存在。
In recent years, researches on Mianlue suture in Qinling area have aroused people’s attention. It has been reported that there are ophiolite blocks in the Mirexo mixed zone. The ancient ocean represented by them is formed in the late Paleozoic and may be part of the ancient Tethys. However, whether there is a real paleo-basin in the area or not, there is still a lack of conclusive geological and geochemical evidence. Recently, Li Shuguang studied the Heigou gorge bimodal volcanic rocks within the Mianleo area, pointing out that they are the product of the initial rift to mature oceanic transformation stage. Whether the remnants of the paleo-oceanic crust are preserved in the Mianleo zone? This paper reports the high depletion N-MORB volcanic rock profile that was found in the Mianleo tectonic mixing zone and symbiotic with the peridotitic metamorphic peridotite, proving that there was a true ancient ocean The pots exist.