西南印度洋构造地貌与构造过程

基于高精度地形数据，将西南印度洋中脊（11.88°E—66.75°E）分为6个区域，按不同区域分析洋脊轴部形态及其两侧基底沉降曲线的变化，由此探讨西南印度洋中脊的岩浆活动及其受热点影响的机制。结果显示：① 对于整个西南印度洋中脊，轴部隆起占13.38%，轴部裂谷占82.8%，平坦过渡形占3.82%，其中19°E，36°E，41.2°E，43.7°E，50.4°E和64.5°E等处为较集中的洋脊轴部隆起；② 埃里克辛普森—英多姆转换断层之间的区域（39.4°E—45.77°E）显示出异常浅的轴部裂谷和异常小且南北不对称的基底沉降速率，这表明埃里克辛普森—英多姆转换断层之间的区域是热点对洋中脊影响较为明显的区域，南侧较北侧异常小的基底沉降速率表明热点与洋中脊的相互作用主要表现为热点岩浆从洋中脊南部向上流动到岩石圈底部，然后与岩石圈发生相互作用。

Morphotectonics and tectonic processes of the southwest Indian Ocean

Based on high resolution seafloor bathymetry map, we divided the Southwest Indian Ridg （SWIR） （11.88°E—66.75°E） into six regions. In each region, we estimate the variation of the axial morphology, and the basement subsidence curve over the flanks of the spreading ridge, which can be used to indicate the spreading process of the SWIR and how it was affected by the hot spot. The result shows that: ① For the entire SWIR, axial uplift accounts for 13.38%, axial rift accounts for 82.8%, and flat transitional shape accounts for 3.82%, the areas at 19°E, 36°E, 41.2°E, 43.7°E, 50.4°E, 64.5°E have focus magmatic ridge representing axial ridge uplift; ② The area between the Eric Simpson-Indomed transition faults （39.4°E—45.77°E） shows axial valley with anomalous shallow bathymetry and asymmetrical anomalous low basement subsidence rates between north and south. Therefore, we believe that the area between the Eric Simpson-Indomed transition faults has been significantly affected by the hot spots. Compared with the subsidence rate north of the spreading ridge, the anomalous low subsidence rate in the south indicates that the interaction between the hot spots and the ridge is characterized by the hot spots flowing upward from the south of the SWIR to the bottom of the lithosphere, and then interact with the lithosphere.