The Study On The Compilation Of Digital Geological Map In The North Region Of The Moon

In this paper, through the study on the information of material compositions on lunar surface, structure factors, geological age that taking the North Region of the Moon as an example by using the data which includes the CCD image data,interference imaging spectrometer(IIM) data, laser altimeter(LAM) data received by Chang’E-I lunar exploration project, and the Chang’E-II CCD image data, as well as other existing lunar geological data, we preliminarily determined the division of geological time of the Moon, compiled the Geological Map of the North Region of the Moon(YQ-1) at the scale of 1: 250 000 and established a spatial database based on Arc GIS platform and Geodatabase Model. The main results and innovation points of this paper are as follows:(1)In this paper, we improved the division of geological time of the Moon by summarizing and studying of the division plans of the previous: The first, we tentatively proposed Copernican Period to divide into early Copernican Epoch(C1),middle Copernican Epoch(C2) and late Copernican Epoch(C3) by using the statistical methods dating the time of craters; Followed squaring up the change of the driving force of the lunar evolution process, we proposed Pre-Nectarian Period to divide into Aiken Period and Pre-Aiken Period that making the Antarctic Aiken basin as the standard profile. But establishing the Aiken Period needs to found an accurate and reliable basic rock-stratigraphic unit before it’s formally established. This kind of modified subdivision scheme provides a convenient for the lunar geologic mapping and the comprehensive study on the Moon.(2)Based on the new geologic time subdivision scheme of the Moon, we developed the methods, procedures and standards of the geological mapping of the Moon, and established a symbol librarie of lunar geologic map, designed a legend,built a map templates and a spatial information database based on the Arc GIS platform, which have laid a strong foundation for the compilation of geologic map of global moon, the geological comprehensive study, and also the geological mapping of other celestial bodies in the future.(3)Through the interpretation and analysising of the material composition and structure factors of the North region of the Moon, we thought that the North region mainly distributed the ancient feeoan anorthosite, Mg-suite sporadic development,and the near side of the North region of the Moon distributed a small amount of KREEP and low-Ti, very-low-Ti mare basalts. And it was have multi-phase geological events from Aiken Period to Copernican Period which includes large basins, craters and basalt eruptions and other events, as well as distributed a variety of lineaments and circle structures on the lunar surface and deep structures, which represents a rich geological history of the Moon.(4)In this paper we proposed the tectonic evolution of the Moon to divide into 3main stage roughly from old to new by summarizing the compilation of geologic maps of the Moon and comprehensive research of plenty lunar data, namely: ①the stage of the formation of "magma ocean", the magmatic differentiation and the formation of anorthosite crust of the Moon; ②the stage of the formation of large of craters and the filling of mare basalts; ③the stage of the formation of lunar dust and lunar regolith.