Hansen V L, López I
Department of Earth and Environmental Sciences University of Minnesota, Duluth Duluth MN USA.
Department of Biology and Geology, Physics and Inorganic Chemistry, Área de Geología Universidad Rey Juan Carlos Móstoles, Madrid Spain.
Earth Space Sci. 2020 Sep;7(9):e2019EA001066. doi: 10.1029/2019EA001066. Epub 2020 Sep 24.
We present a 1:10-M-scale geologic map of the Aphrodite Map Area (AMA) of Venus (0°N-57°S/60-80°E). Geologic mapping employed NASA Magellan synthetic aperture radar and altimetry data. The AMA geologic map, with detailed structural elements and geologic units covering over one eighth of Venus' surface, affords an important and unique perspective to test models of global-scale geologic processes through time. Geologic relations record a history inconsistent with global catastrophic resurfacing. The AMA displays a regional coherence of preserved geologic patterns that record three sequential geologic eras: the ancient era, the Artemis superstructure era, and the youngest fracture zone era. The ancient era and Artemis superstructure, with a footprint covering more than 25% of the surface, are recorded in the Niobe Map Area to the north. The latter two eras likely overlap in time. The fracture zone domain, part of a globally extensive province, marks the most spatially focused tectonomagmatic domain within the AMA. Impact craters are both cut by and overprint fracture zone structures. Twelve percent of AMA impact craters that occur within the fracture zone domain predate or formed during fracture zone development. This observation indicates the relative youth of the fracture zone era and is consistent with the possibility that this domain remains geologically active. The AMA records a rich geologic history of large tract of the surface of Venus and provides an important framework to formulate new working hypotheses of Venus evolution and contribute to planning future studies of the surface of planets.
我们展示了金星阿佛洛狄忒地图区域(AMA)(北纬0°至南纬57°/东经60°至80°)的1:10,000,000比例地质图。地质测绘采用了美国国家航空航天局麦哲伦号合成孔径雷达和测高数据。AMA地质图涵盖了金星表面超过八分之一的区域,具有详细的构造要素和地质单元,为检验全球尺度地质过程随时间变化的模型提供了重要且独特的视角。地质关系记录的历史与全球灾难性重表生不一致。AMA展示了保存下来的地质模式的区域连贯性,记录了三个连续的地质时代:古代、阿耳忒弥斯上层结构时代和最年轻的断裂带时代。古代和阿耳忒弥斯上层结构的覆盖面积超过表面的25%,记录在北部的尼俄柏地图区域。后两个时代可能在时间上重叠。断裂带区域是全球广泛分布的一个省份的一部分,是AMA内空间上最集中的构造岩浆区域。撞击坑既被断裂带结构切割,也有断裂带结构覆盖其上。在断裂带区域内出现的AMA撞击坑中,有12%在断裂带发育之前或发育期间就已形成。这一观察结果表明断裂带时代相对年轻,并且与该区域在地质上仍然活跃的可能性相一致。AMA记录了金星大片表面丰富的地质历史,为形成关于金星演化的新工作假设以及为规划未来行星表面研究提供了重要框架。