Nature and hydrological relevance of the Shalbatana complex underground cavernous system

Abstract

The geomorphology of the North East trending long fractured depression between the Ganges Chasma and the Shalbatana Vallis headwater source region is examined and interpreted to be the result of collapse of part of an extensive underground cavernous system. We propose that this cavernous system undermines at least a valley, which extends from the vicinities of the Ganges Chasma and terminates in the Shalbatana Vallis headwater source region and the Aromatum Chaos. We believe that the origin of this cavernous system was related to the formation and interconnection of discrete cavernous bodies and propose a hypothesis, which involves the interaction of permafrost and intrusive magmatism to explain their formation. The Shalbatana Vallis headwater source is interpreted as produced by a Noachian impact crater and surface collapse over part of the underground cavernous system. Finally, we propose that the water sources, which were involved in the excavation of the Shalbatana and Ravis outflow channels might have included water segregated from the permafrost through interaction of intrusive magmatism and permafrost, water drained from a paleolake in the Ganges Chasma and water released from the catastrophic evacuation of confined aquifers.