月球正面大型火山穹窿区深部物质结构特征：基于GRAIL重力和LRO地形数据的联合解析

火山穹窿区域是研究月球正面壳幔热演化历史的重要窗口。以往对这些区域的研究多是基于影像和光谱数据的表面形貌和矿物成分分析，缺少火山深部物质结构的信息。本研究将利用新近的GRAIL重力和LRO地形数据，研究月球正面八个不同大型火山穹窿区域的深部物质分布特征。构建适合这些区域地质特征的重力地形建模方法，对表征火山穹窿区深部结构特征的壳密度、表面密度、弹性厚度、载荷比等参数进行定量约束。在此基础上，分析火山穹窿区域物质成分组成并判断内部载荷（冷凝的侵入岩体结构）的加载情况。探索这些区域内部物质随深度的变化特征，判断岩浆的侵入模式，计算岩浆的侵入深度等表征火山内部结构的重要参数。基于以上结果，综合分析不同火山穹窿区域的岩浆形成机制和演化特征，为探讨月球正面壳幔的热演化历史提供依据。

Large volcanic complexes on the nearside of the Moon are important in studying the thermal evolution history of the lunar nearside crust and mantle. Previous works on these regions are mainly focused on surface morphological and geochemical studies using imagery and reflectance spectral data, but little has been performed for understanding their subsurface structures. This proposal is to investigate subsurface structures of large volcanic complexes on the nearside of the Moon. Newly obtained GRAIL gravity and LRO topography, combined with improved gravity modeling methods, will be used to place constraints on their crustal densities, surface load densities, elastic thicknesses and loading ratios. The loading ratios will help on identifying whether or not there are subsurface loads appearing as dense material compared with the primary highland crust. Moreover, gravity and topography data will be used to figure out how subsurface loads varying with depths, from which we can calculate the depth of intruded magmas. Finally, we will comprehensively analyze the formation mechanism and evolution of these volcanic complexes. These results will provide direct evidences on thermal evolutions of the lunar crust and mantle.