Chasma Boreale, Mars: A Sapping and Outflow Channel with a Tectono-thermal Origin

Abstract

A detailed geomorphological study of Chasma Boreale, a widely known feature of Mars’ north polar cap, has been carried out for the first time, along with a quantitative paleohydro logical model. It is concluded that the chasma was eroded by a flow whose discharge was on the order of magnitude of 109 m sec21. This catastrophic flow is thought to have been preceded by a powerful sapping process, caused by a tectonic control in the distribution and present aspect of most of the polar troughs. This tectonic forcing probably played a major role in the inception of not only Chasma Boreale but also other polar reentrants as well