CO2 and clathrate as past erosive agents on Mars

The debate on the history of the Martian atmosphere continues without resolution. Much hinges on a satisfactory solution to the problem of what liquid was responsible for the extensive development of canyons, channels, fretted terrain, and similar features. The 1960s and 1970s saw much debate about the roles of various fluids, namely water or brine, liquid CO2, or H2O sources in CO2 clathrate (CC), or magma. The last was discounted long ago, CC is largely ignored, and the most recent look at CO2 was by ourselves, utilizing the phase diagrams for the CO2-H2O system. In this article, we will further investigate this dilemma.