PROBABLE MUD VOLCANOES IN CHYSE PLANITIA, MARS: UPDATES ON MORPHOLOGICAL, SEDIMENTROGICAL, AND SPECTRAL STUDIES

Features interpreted to be mud volcanoes occur at various locations in and along the northern plains of Mars, including Isidis Planitia, Utopia Planitia, the Utopia/Isidis overlap, Acidalia Planitia, Chryse Planitia, and... [ view full abstract ]

Features interpreted to be mud volcanoes occur at various locations in and along the northern plains of Mars, including Isidis Planitia, Utopia Planitia, the Utopia/Isidis overlap, Acidalia Planitia, Chryse Planitia, and Arabia Terra. However, there is no place on Mars where the presence of mud volcanoes is fully confirmed to date. Here, we update on our continuous investigation [1, 2] of small edifice features less than a few kilometers in diameter and up to a few hundred meters in height in Chryse Planitia, which have been originally proposed to be mud volcanoes [3].
The study area is located in relatively flat plains emplaced and modified by outflow events from Tiu and Ares Valles. These small edifices occur within the Late Hesperian unit HCc4 [4], which represents deposits in Chryse Planitia where circum-Chryse outflow channels enter the northern plains. [5] presented multiple geological conditions on Mars that might favor plausible mud volcanism. One of these is rapid deposition of sediments and loading, which may fit well with the situation in Chryse Planitia. It is hypothesized that large quantities of water-rich sediments were delivered into the plains by cataclysmic flooding or debris flows related to the development of the gigantic circum-Chryse outflow channel system (e.g., [6]). The study area may also occur above a relatively rapidly deposited clastic wedge laid, possibly under a primordial northern plains ocean, within a paleo-basin located in the southern circum-Chryse region during the Late Noachian [7].
The small edifice features in Chryse Planitia exhibit a broad range of morphological properties. Their origins have not been determined with certainty, but our study utilizing HiRISE images supports the interpretation of mud volcanism, based on the observed morphological characteristics of these small edifices and comparisons with terrestrial analogs. Hydrated minerals detected on these edifice features in data from CRISM, further support the mud volcano hypothesis. Alternative mechanisms such as magmatic volcanism are not excluded, but they have less support from our remote sensing observations.
[1] Komatsu G. et al. (2012) LPS XLIII, Abstract #1103. [2] Komatsu G. et al. (2016) Icarus, in press. [3] Komatsu G. et al. (2011) PSS, 59, 169–181. [4] Tanaka K.L. et al. (2005) USGS, SIM-2888, scale 1:15,000,000. [5] Skinner J.A., Jr., and Mazzini A. (2009) Marine and Petroleum Geology, 26, 1866–1878. [6] Baker V.R. (1982) The Channels of Mars, Univ. of Texas Press, 198 pp. [7] Rodriguez J.A.P. et al. (2015) Sci. Rep., 5, 13404.