月球南海地区玄武岩厚度估算

月海玄武岩是月幔部分熔融喷出月表而形成的，其厚度可以反映月海玄武岩源区的深度。研究月海玄武岩厚度，对进一步认识月球区域岩浆作用或火山作用的演化历史具有不可替代的作用，也能够为整个月球的热演化和岩浆演化提供基本的约束条件。同时，玄武岩厚度可以用以推测月球内部产生玄武岩岩浆的体积，对月球火山作用的岩浆喷发总量以及月球内部的热状态具有指示作用。本文基于多源遥感数据，综合利用撞击坑的形貌特征与月坑挖掘深度法对南海地区撞击坑内(crater)和撞击坑间(intercrater)两类玄武岩地层的厚度进行了估算，并对玄武岩的面积、体积、年龄及岩浆活动做了简单分析。研究结果表明：南海地区撞击坑内的玄武岩厚度变化范围为0.11~4.75 km，平均值约为1.32 km，玄武岩的出露面积和出露体积分别为57.06~10 791.66 km2和10.25~51 260.38 km3；撞击坑间的玄武岩厚度变化范围为0.01~2.18 km，平均值约为0.34 km，玄武岩的出露面积和出露体积分别为6 487.89~33 170.55 km2和2 711.97~11 609.69 km3。因此，南海地区玄武岩厚度的变化范围分布在0.01~4.75 km，平均厚度约为600 m，出露的玄武岩总面积约为2.12×105 km2，总体积约为2.71×105 km3。通过分析南海地区的玄武岩年龄及分布特征，发现南海地区内的岩浆喷发活动主要集中发生在雨海纪至爱拉托逊纪时期，且其局部区域存在多次岩浆喷发及充填过程，但由于晚期玄武岩岩浆的喷发总量不足以覆盖早期已形成的玄武岩，导致晚期玄武岩与早期玄武岩同时存在于同一个玄武岩单元内。南海地区独特的玄武岩分布特征也与地形有关。

Thickness estimation of basalts in Mare Australe

Mare basalts were formed from partial melting mantle followed by volcanic eruption to the lunar surface. The thickness of mare basalt plays an important role in the study of magmatic process during Moons evolution and can reflect the depths of the mare basalts source region. It can help us understand the regional volcanism and provide the basic constraints for the thermal and/or magma evolution of entire Moon. Also, the thickness of mare basalt can be used to estimate basalt volumes and indicate the total amount of magma eruption and the thermal state of the Moon. In this paper, by using multi-source remote sensing data and combing the crater morphological characteristics with crater excavation method, we estimated the thickness of Mare Australe basalts in crater and intercrater and analyzed the area, volume, age and magmatic activities. The results showed that the thickness of basalts in crater ranged between 0.11 and 4.75 km with an average thickness of 1.32 km, and the total area and volume of exposed basalts were approximately 57.0610791.66 km2 and 10.2551260.38 km3, respectively. The thickness of basalts in intercrater was found to be 0.012.18 km with an average thickness of 0.34 km, and the total area and volume of exposed basalts were about 6487.8933170.55 km2 and 2711.9711609.69 km3, respectively. As a result, we estimated the thickness of basalts in Mare Australe to be 0.014.75 km and averaged at 600 m, and the total area and volume of exposed basalts to be approximately 2.12×105 km2 and 2.71×105 km3, respectively. By analyzing the ages and distribution characteristics of basalts, we found that the magma eruption activities were mainly concentrated between the Imbrian and Eratosthenian era, along with many localized multi-stage magmatic eruptions and filling processes in Mare Australe, which led to coexistence of the early and late stage basalt in a same basalt unit simultaneously, and the unique distribution characteristics of Mare Australe basalts are related to their topography.