云海撞击盆地的恢复及其地质演化研究

Impact basin of Mare Nubium:Reconstruction and geological evolution

研究月海撞击盆地,尤其是古老的月海撞击盆地,有助于深入认识月球乃至太阳系中两种动力学即内动力和外动力地质作用的演化过程,也是研究月球早期演化和现今状态的重要纽带。云海撞击盆地为古老的撞击盆地之一,形成于前酒海纪,在后期的内外动力地质作用下,盆地有很大程度的改造。为了恢复云海撞击盆地原貌,深入认识该地区的地质演化过程,本文利用了LRO宽角相机影像数据、LOLA地形数据和GRAIL重力数据等多种类型的遥感数据,开展了云海撞击盆地演化的研究。结果显示,云海盆地是由一次撞击事件形成,具中央隆起的三环结构的撞击盆地,三环直径分别约为740km、500km、340km,盆地中心约为16°W,21°S。云海撞击盆地事件破坏了该地区原始月壳结构,随后岩浆喷出或溢流充填在撞击盆地中形成云海,塑造了现今观察到的云海地形特征和重力异常特征。

Investigation of Mare impact basin, especially ancient Mare impact basin, can contribute to deeply understand two kinds of geological processes on the moon and even on the solar system, which are endogenous and exogenous geological processes, respectively. And, study of ancient Mare impact basin is an important tie between early evolution and current state. Mare Nubium impact basin is one of the most ancient impact basins, forming at Pre-Nectarian Period, and has been modified extensively by later endogenous and exogenous geological processes. In order to reconstruct the original Mare Nubium impact basin and understand the geological evolution processes, we attempt to investigate its geological evolution through multi-source remote sensing data, such as LRO WAC image data, LOLA topographic data and GRAIL gravity data. The results show that the Mare Nubium basin is a triple-concentric rings impact basin with central uplift, and the diameters of triple-concentric rings are 740km, 500km, 340km, whose center location is at 16°W, 21°S, approximately. The event of Mare Nubium impact basin destroyed the primeval structure of crust in this region and subsequently flooded by mare basalt, forming the current terrain features and gravitv anomalv features that we observed.