珠江口盆地中生代陆缘岩浆弧地质特征及构造背景

明确珠江口盆地中生代陆缘岩浆弧特征及构造演化过程对于古潜山勘探至关重要.综合构造学、岩石学、年代学、地球化学与地球物理学现有成果，认为珠江口盆地基底主要为燕山期岩浆杂岩，以中酸性侵入岩为主，中生代岩浆活动以105~165 Ma最为强烈，发育了NE-NEE走向和NW-NWW走向两组中生代断裂.区域构造研究表明中生代期间，珠江口盆地处于古太平洋板片俯冲作用控制的陆缘岩浆弧构造环境，岩浆岩具有流体活动元素富集、Ta-Nb-Ti亏损的特征，形成复合火山岩-侵入岩“双层”岩性组合.重建了珠江口盆地中生代陆缘岩浆弧5个阶段的形成演化过程，揭示了珠江口盆地古潜山的成山背景. 

Geological Characteristics and Tectonic Settings of Mesozoic Continental Margin Magmatic Arc in Pearl River Mouth Basin

The characteristics and tectonic evolution of Mesozoic continental margin magmatic arc are crucial to the buried hill exploration and research in Pearl River Mouth Basin. By integrating studies of structural geology, petrology, geochronology, geochemistry and geophysics, it is confirmed that the basement is mainly Yanshan period complex, the lithology is mostly intermediate-acidic igneous and the most intense magmatic event is between 105-165 Ma. Regional tectonic studies suggest that during Mesozoic period, Pearl River Mouth Basin was in the margin magmatic arc environment caused by the subducted paleo-Pacific Ocean Plate. The magmatic rocks are enriched with fluid-indication elements and depleted in Ta-Nb-Ti. "Double layers" of composite volcanic rocks and deep igneous rocks developed. This study has reconstructed five episodes of formation and tectonic evolution of Mesozoic continental margin volcanic arc in Pearl River Mouth Basin, and revealed the orogenic foundation of buried hills in Pearl River Mouth Basin.