Deep Cycles and Super-Terrans

Possibly the most important consequence of plate tectonics is the cycling of materials into and out of the mantle. Such a conveyor belt delivers carbon dioxide into the interior in the form of carbonate rock and returns this gas to the atmosphere, thereby modulating the planetary greenhouse effect. One of the more subtle and poorly understood processes is the modulation of surface water—and with it the abundance of many of the ions (both metal and non-metal ions) that regulate the biological capacity of any biosphere that we hope caps our planets of interest.