| Linear structure refers to the structure phenomenon that landform extend as line on the lunar surface. Compared with doughnut structure, linear structure can express the structural feature and the stress state integrally or locally, even can show geological information of the interior of the moon. As a common kind of linear structure on the surface of the moon, lunar ridges have the largest number and a certain distribution regularity among the linear structures, and always be the focus of domestic and overseas lunar tectonic research. Also, mare basins have a obvious symbiotic relationship with most lunar linear structure, the analysis of eruption history and tectonism of them has very important geological significance in understanding the lunar evolution. The main contents of this paper and the results are as follows:(1) Multi-source remote sensing data domestic and overseas combined with related papers was analysed to classify and interpret the lunar linear structure. At last,10kinds of linear structure were distinguished, and the causes of them were also discussed comprehensively. Through analysing profile maps of lunar ridges which obtained by processing DEM data of LRO, the authors thought that most lunar ridges are compressional formation mechanisms as a combination of drag fold on the surface and thrust fault underneath.(2) About the dynamic origin of lunar ridges, Previous researchers always explained it by a combination of mare basin subsidence by basalt filling and thermal shrinking of the whole moon, but cannot explained the preferred NS orientation of lunar ridges in the central areas of the mare basins, this kind of phenomenon is probable influenced by the east-west regional compressional stress, and is agreed with the stress state of the tidal forces at low and middle latitudes, so inferring tidal forces maybe the main factor for its formation; And on the basis of Chang’e I CCD images with Lunar Orbiter and LRO images, the authors interpreted1464lunar ridges at low and middle latitudes, through a statistical analysis of orientations of them, found the overall trends are roughly consistent with the tectonic pattern predicted by Melosh who using tidal forces. So, presumably, there has a strong correlation between tidal forces and the spreading styles of lunar ridges, and then, It further proved that the formation of lunar ridges are connected with tidal forces.(3) Taken two connected mare basins (Mare Serenitatis and Mare Tranquillitatis) as study area, the topographic features of the two basins were obtained by processing the DEM data of LRO. The maps of the percentage composition distribution of TiO2, FeO and maturity were obtained using Clementine multispectral data. According to the basis maps of Chang’e I CCD images and Lunar Orbiter and LRO panchromatic images,126wrinkle ridges and114linear and arcuate rilles in this area were identified, and combined with gravity map the distribution of these linear structures was discussed. the comprehensive analysis results showed that the lithology and tectonism of the two mare basins are very different, although they are so near. The boundaries were clear between different eruption times. Generally, the ages of basalts in Mare Serenitatis were younger than those in Mare Tranquillitatis. Basalts in the connected areas have the same origin with the north mare Tranquillitatis. The spread patterns of the linear structures in Mare Serenitatis showed very different patterns with the Mare Tranquillitatis, distributed regularly, were connected with the formation of the mascon and the distribution of the gravity. |
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