As on the Moon, the water came mostly from gypsum rock or occasionally from soil frost, both found on nearby Crustal asteroids.
"The Planet Strappers"
Raymond Zinke Gallun
The sub-aereal current of dissolved matter from the land to the ocean was accompanied by a sub-Crustal flux from the ocean areas to the land areas; the heated viscous materials creeping from depths far beneath the ocean floor to depths beneath the roots of the mountains which arose around the oceans.
"The Birth-Time of the World and Other Scientific Essays"
J. (John) Joly
We have referred to these well-known episodes with two objects in view: to recall to mind the time-interval involved, and the evidence of intense Crustal disturbance, both dynamic and thermal.
"The Birth-Time of the World and Other Scientific Essays"
J. (John) Joly