| Wrinkle ridge,a kind of positive terrain,widely distribute on terrestrial planets.Lunar wrinkle ridges are mainly distributed in maria,which are regarded as a product from contraction of mare basalt units.The morphology of wrinkle ridges can reflect the penetration characteristics of underground faults,and the spatial distribution of wrinkle ridges is associated with the filling and cooling of basalt lava in different periods.In addition,the growth pattern of wrinkle ridges indicates the intensity of regional stresses and properties of surrounding rocks,and it is an epitome of long time series of local contraction in basins and the lunar crust contraction process.The research of wrinkle ridges is indispensable and basic in lunar topographic studying.This paper mainly includes the following three aspects:(1)The Planetary Data System is an online platform for managing and publishing data that obtained from planetary exploration missions,and it is used as the basis for planetary science research.In this paper,a planetary data system(SDU-PDS)is designed to analysis the raster and vector data of wrinkle ridge.On basis of the three-layer distribution structure of WebGIS and the object-oriented spatiotemporal data model,SDU-PDS is developed.SDU-PDS system can browse and query data,make geometric measurement,display the analyzing results and so on.(2)There is a positive linear relationship between the maximum displacement Dmax and the length L of the planetary fault.The Dmax-L scaling relationship reflects the changes of different geological processes,surface environment and rock properties in planets.Nine maria were chosen as research regions in this paper.Wrinkle ridges in these maria are reselected,and their geometric parameters are measured and calculated,and Dmax/L value of wrinkle ridge group in each mare is fitted.Our results,varying from 6.0×10-3 in Mare Nectaris to 2.74×10-2 in Mare Orientale,are demonstrated the fault growth pattern of Dmax∝L.Lunar wrinkle ridges had a longer time to develop and a larger scale,thus,the Dmax/L values were higher than the theoretical ones(1.0×10-3).(3)Lunar geological factors(such as basin ages,regional gravity anomaly,wrinkle ridge formation times,basalt properties,moonquakes)can affect regional stress state and the growth of wrinkle ridges.Using principal component analysis and correlation analysis methods,the influence from different geological factors on Dmax/L values was studied in this paper.The correlation coefficient between basin formation ages and Dmax/L values is relatively highest.It may be due to that lunar magma intrusions uplifted the regional rocks,resulting in the enhancement of regional contraction and development of wrinkle ridges.The regional gravity anomaly was related to the impact.Wrinkle ridge groups in the mascon basins were concentric,and their maximum displacements were larger than that in non-mascon regions.The correlation between the growing time of wrinkle ridges and Dmax/L value was weak,which indicated that lunar wrinkle ridges should grow consistent with segment-linkage model.Other geological factors(such as ages of basalt units,basalt thicknesses and moonquakes)also had influence on the development of wrinkle ridges though slight.A series of geological events(intensive impacting events,violent volcanic activities,and later tectonic activities)changed the lunar surface topography,which promoted or inhibited linear structures.The formation mechanism of wrinkle ridges was combination influenced by lunar internal and external stresses.Based on the morphology,spatial distribution,and Dmax/L scaling relationship of wrinkle ridges,combining with relevant geological factors,evolution process in lunar maria can be studied.The similarities and differences in maria are helpful to understand the history of lunar evolution and has important scientific significance. |
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