论文部分内容阅读
东秦岭虎豹河砾岩为复成分砾岩层。砾岩中火成岩砾石显示了ＬＩＬＥ中等富集，丰富变化不大，Ｂｂ（Ｔａ）有一定亏损，Ｔｈ／Ｔａ比值高（＞１０），并具有来自岛弧演化不同阶段的两个岩浆源区的地球化学特征，反映它们主要受消减物质影响，且地壳物贡献不大的岛弧钙碱性岩浆的成因特征。综合其它地质事实，这套砾岩是早古生代晚期，其北侧主要物源供给区的岛弧进入到由初始弧向成熟弧过渡演化阶段时，由于洋内岛弧与华北大陆块体发生弧—陆碰撞，在弧前盆地内形成的局部小型沉积裙，并非由于强烈陆—陆碰撞造山作用而形成的磨拉石沉积建造。
The East Qinling Hutaohe conglomerate is a complex component conglomerate. The igneous rocks in the conglomerate show moderate enrichment of LILE with little change in abundance, some loss of Bb (Ta), high Th / Ta ratio (> 10), and the presence of two magmatic source zones from different stages of island arc evolution Geochemical characteristics of the island arc calc-alkaline magma, which reflect the fact that they are mainly affected by the depleted substances and the contribution of the crust to the crust are negligible. In combination with other geological facts, the conglomerate was late Early Paleozoic. When the island arc of the main source supply area on the north side entered into the evolutionary transition from the initial arc to mature arc, since the arc of the intra-island island and the block of North China continent occurred arc - Land collisions in the pre-arcuate basin formed within the small local small skirts, not due to a strong continental collision orogeny formed by the molasse sedimentary deposition.