Bright carbonate surfaces on Ceres as remnants of salt-rich water fountains

By: , and 



Vinalia and Cerealia Faculae are bright and salt-rich localized areas in Occator crater on Ceres. The predominance of the near-infrared signature of sodium carbonate on these surfaces suggests their original material was a brine. Here we analyze Dawn Framing Camera's images and characterize the surfaces as composed of a central structure, either a possible depression (Vinalia) or a central dome (Cerealia), and a discontinuous mantling. We consider three materials enabling the ascent and formation of the faculae: ice ascent with sublimation and carbonate particle lofting, pure gas emission entraining carbonate particles, and brine extrusion. We find that a mechanism explaining the entire range of morphologies, topographies, as well as the common composition of the deposits is brine fountaining. This process consists of briny liquid extrusion, followed by flash freezing of carbonate and ice particles, particle fallback, and sublimation. Subsequent increase in briny liquid viscosity leads to doming. Dawn observations did not detect currently active water plumes, indicating the frequency of such extrusions is longer than years.
Publication type Article
Publication Subtype Journal Article
Title Bright carbonate surfaces on Ceres as remnants of salt-rich water fountains
Series title Icarus
DOI 10.1016/j.icarus.2018.01.022
Volume 320
Year Published 2019
Language English
Publisher Elsevier
Contributing office(s) Astrogeology Science Center
Description 10 p.
First page 39
Last page 48
Other Geospatial Ceres
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