Ancient drainage basin of the Tharsis region, Mars: Potential source for outflow channel systems and putative oceans or paleolakes

Abstract

Abstract. Paleotopographic reconstructions based on a synthesis of published geologic information and high-resolution topography, including topographic profiles, reveal the potential existence of an enormous drainage basin/aquifer system in the eastern part of the Tharsis region during the Noachian Period. Large topographic highs formed the margin of the gigantic drainage basin. Subsequently, lavas, sediments, and volatiles partly infilled the basin, resulting in an enormous and productive regional aquifer. The stacked sequences of water-bearing strata were then deformed locally and, in places, exposed by magmatic-driven uplifts, tectonic deformation, and erosion. This basin model provides a potential source of water necessary to carve the large outflow channel systems of the Tharsis and surrounding regions and to contribute to the formation of putative northernplains ocean(s) and/or paleolakes.

Extraterrestrial hydrogeology

“…Elemental information obtained through the gamma ray spectrometer (GRS) instrument onboard the Mars spacecraft Odyssey Feldman et al 2002) supports the conclusion that there is a dynamic climate system operating on seasonal time scales with water vapor diffusing into and out of the surface. The efforts of the GRS Team have led to the recent discovery of large quantities of near-surface water ice, corroborating published geologic, geomorphic, and paleohydrologic information that had indicated a water-enriched planet sculpted by water/water-ice (Baker et al 1991;Kargel and Strom 1992;Baker 1993;Parker et al 1993;Scott et al 1995;Dohm et al 2001a) (e.g., Fig. 2).…”

Claritas rise, Mars: Pre-Tharsis magmatism?

“…These include magnetic signatures Arkani-Hamed, 2003;Connerney et al, 2005), complex tectonic structures, cuestas, and hog backs. Individually, their implications may be minor, but taken collectively, they have a bearing on the current understanding of the early phase of the evolution of Mars (Dohm et al, 2001a(Dohm et al, ,b, 2007Baker et al, 2007).…”

“…Thus, a substantial archive of the paleotectonic history (a record of structural development through time) has been recorded in the crustal rocks. This record is particularly distinct in the western equatorial region where the five major stages of Tharsis-driven activity (Dohm et al, 2001a(Dohm et al, ,b, 2007 contributed to the formation of both large and small extensional and contractional structures, including the vast canyon system, Valles Marineris (Dohm et al, 2009 this issue). Associated with the growth of Tharsis is an enormous radiating system of grabens, Claritas Fossae (the southern arm of the Tharsis axial trend of faults), which fans outward for thousands of kilometers from near the shield complex, Syria Planum, to the south (Figs.…”

“…Noachian-Early Hesperian (stages 1-3 of Tharsis development; Dohm and Tanaka, 1999) tectonism associated with the early development of Tharsis, as well as pre-Tharsis activity, is much more complex, diverse, and dense when compared to its Late Hesperian and Amazonian (stages 4-5) development, when the giant shield volcanoes were forged (Anderson et al, 2001;Dohm et al, 2001a). The ancient Thaumasia highlands mountain range (Figs.…”

“…This activity may include possible reactivation of older basement structures such as Claritas rise-centered faults. Claritas rise has been interpreted to be an ancient center of magmaticdriven activity, which includes uplift, tectonism, and possible hydrothermal and volcanic activity (Dohm et al, 2001a;Schulze-Makuch et al, 2007), though some of the strain history could result from stresses indicative of loading at the surface from volcanic construction (thus, we refer generally to the Claritas rise as magmatic-driven). Possibly corresponding with a distinct magnetic signature (Fig.…”