PSI Personnel
Project Description
NOTE: On August 22, 2024, the PI was changed to Dan Berman, and Alexis Rodriguez (now at Marshall Space Flight Center) becomes a Co-I.
The southern circum-Chryse and Margaritifer Terra regions of Mars (herein, Margaritifer chaos region (MCR), 10° N. to 17° S., 320° to 347° E.,) exhibit the planet’s most extensive highland plateau areas modified by collapse, subsidence and surface flow erosion (e.g., Aureum chaos, Simud Valles). Using Viking image data, Rotto and Tanaka (1995) produced the most recent geologic map encompassing the MCR [(Rotto, S., Tanaka, K. L., Geologic/geomorphic map of the Chryse Planitia Region of Mars. U.S. Geol. Surv. Misc. Inv. Ser. Map, I-2441-A (1:5000,000) (1995)]. The broad geologic history that they documented includes the identification of Noachian channels that they attribute to run-off and sapping activity. During the Late Hesperian extensional tectonic structures due to stresses produced during the formation of the Tharsis rise. During this geologic period, and perhaps during the Early Amazonian widespread highland collapse formed vast, chaotic terrain areas, and released enormous groundwater volumes to form the planet’s most extensive system of outflow channels.
The objective of this four-year project is to reconstruct the MCR’s geologic history using the most recently acquired, and publically released, image and topographic datasets. To this purpose, we propose to produce the region’s first post-Viking USGS geologic map of a 27° by 27° region at a scale of 1:2,000,000, which will be generated using Geographic Information System (GIS) software. Since the publication of Rotto and Tanaka’s (1995) map, we have made significant discoveries regarding the MCR’s geologic history. For example, we now know that there are several types of chaotic terrains – some that apparently formed suddenly, others that developed gradually. We have recognized the presence of extensive areas of subsidence; some linked to chaotic terrain formation. Moreover, we find that outflow channel activity occurred in numerous phases, some predating and postdating the formation of valley networks in the region. Finally, we know that subsidence was a major cause of extensional tectonism. Nevertheless, we do not know the stages that occurred during these forms of geologic activity. The proposed geologic map will allow us to derive these stages and produce a refined geologic history of the region. These results will enable us to address some critical issues regarding the nature of Martian subsurface processes (e.g., extent of potential subterranean rivers (e. g., Rodriguez, J.A.P. et al., Martian outflow channels: How did their source aquifers form, and why did they drain so rapidly?, Nature Scientific Report, 5:13404, 2015.)) and the planet’s hydrologic history resulting from outflow channel floods (e.g., stages of potential northern plains ocean formation).