Volcanic Recycling of Carbonate Deposits on Mars
Abstract
One question of great interest to those who study the evolution of the Martian atmosphere is: if there was an early, dense atmosphere that was removed, is there any mechanism that could restore it? In the case of an atmosphere removed largely by the formation of carbonates, the only obvious means of restoring it is by the thermal decomposition of the carbonates. Decomposition of carbonates under turbulently flowing lava holds great promise as a means of resupplying the atmosphere with CO2. Huppert and colleagues have modeled the emplacement of terrestrial komatiite flows and found that komatiites, even when flowing over previously emplaced and cooled komatiite flows, could melt and erode this rock to a significant depth. Based on this work, I have begun modeling the erosion of Martian carbonate deposits under turbulently flowing, komatiitic lava. Initial results from this modeling indicate that a high-volume lava flow, emerging at a temperature of, say, 1600 degrees, is capable of eroding several meters of carbonate deposits per day. If such a flow is active for a hundred days, several hundreds of meters of carbonate could be decomposed. If this process occurred over a large area, a bar or more of CO2 could be injected back into the atmosphere over an extremely short period of time. The implications of such an occurrence are intriguing. For instance, if a relatively late pulse of volcanism (such as is suggested by Frey) were to cause a large flow of lava over carbonate deposits in the northern lowlands, the resulting pulse of CO2 into the atmosphere could conceivably restore the climate to one in which liquid water could exist on the surface, or ice could flow.
- Publication:
-
Evolution of the Martian Atmosphere
- Pub Date:
- 1992
- Bibcode:
- 1992LPICo.787...26S
- Keywords:
-
- Carbon Dioxide;
- Carbonates;
- Lava;
- Mars (Planet);
- Mars Atmosphere;
- Mars Surface;
- Planetary Geology;
- Thermal Decomposition;
- Volcanoes;
- Volcanology;
- Climate;
- Deposits;
- Erosion;
- Fluid Flow;
- Ice;
- Igneous Rocks;
- Water;
- Lunar and Planetary Exploration