TY - JOUR
T1 - Episodes of Aqueous Flooding and Effusive Volcanism Associated With Hrad Vallis, Mars
AU - Hamilton, Christopher W.
AU - Mouginis-Mark, Peter J.
AU - Sori, Michael M.
AU - Scheidt, Stephen P.
AU - Bramson, Ali M.
N1 - Funding Information:
The authors acknowledge funding from the NASA Planetary Geology and Geophysics Program (grant NNX13AR14G) NASA Planetary Science Division (grant 80NSSC17K0307), and NASA Earth and Space Sciences Fellowship (NESSF) Program (grant NNX16AP09H). We thank Jim Zimbelman and Francesco Salese for their thorough and insightful reviews. We also thank Vic Baker for constructive discussions, Harold Garbeil for his assistance generating the CTX-derived DTM, and members of the HiRISE DTM production team, including Sarah Sutton, Allison McGraw, William Yingling, and Aaron Kilgallon. All remote sensing imagery for Hrad Vallis (including sterero-derived DTMs) are freely available to the pubic through the NASA Planetary Data System (https://pds.nasa. gov/). The ArcGIS map shown in Figure 1, as well as all thermophysical model inputs and results are available as supporting information.
Publisher Copyright:
©2018. American Geophysical Union. All Rights Reserved.
PY - 2018/6
Y1 - 2018/6
N2 - Hrad Vallis is an Amazonian-age outflow channel located in the northwestern part of the Elysium Volcanic Province of Mars. The formation of Hrad Vallis may have been associated with catastrophic aqueous floods and volcanism, which makes determining its emplacement history important for constraining the planet's hydrological and thermal evolution during the Amazonian Period. Through geological mapping, geomorphologic analysis, and numerical simulations we assess whether Hrad Vallis formed in association with mudflows (i.e., lahars), effusive volcanism, or a combination of both processes. Among the three youngest flows in the region, the lower and upper flow units are inferred to be the products of catastrophic aqueous floods, whereas the middle unit is interpreted to be pāhoehoe-like lava flow formed through the process of inflation over the course of decades. The latter flow unit is similar to terrestrial lava-rise plateaus, but its emplacement may have involved interactions with surficial ice deposits, which affected the flow path and resulted in a range of lava-water interactions. We conclude that Hrad Vallis had a complex history involving episodes of both aqueous flooding and effusive volcanism and that the interactions between lava and ice in these regions may have generated ephemeral hydrothermal systems with potential astrobiological significance.
AB - Hrad Vallis is an Amazonian-age outflow channel located in the northwestern part of the Elysium Volcanic Province of Mars. The formation of Hrad Vallis may have been associated with catastrophic aqueous floods and volcanism, which makes determining its emplacement history important for constraining the planet's hydrological and thermal evolution during the Amazonian Period. Through geological mapping, geomorphologic analysis, and numerical simulations we assess whether Hrad Vallis formed in association with mudflows (i.e., lahars), effusive volcanism, or a combination of both processes. Among the three youngest flows in the region, the lower and upper flow units are inferred to be the products of catastrophic aqueous floods, whereas the middle unit is interpreted to be pāhoehoe-like lava flow formed through the process of inflation over the course of decades. The latter flow unit is similar to terrestrial lava-rise plateaus, but its emplacement may have involved interactions with surficial ice deposits, which affected the flow path and resulted in a range of lava-water interactions. We conclude that Hrad Vallis had a complex history involving episodes of both aqueous flooding and effusive volcanism and that the interactions between lava and ice in these regions may have generated ephemeral hydrothermal systems with potential astrobiological significance.
KW - Hrad Vallis
KW - Mars
KW - flood
KW - lahar
KW - lava
KW - outflow channel
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U2 - 10.1029/2018JE005543
DO - 10.1029/2018JE005543
M3 - Article
AN - SCOPUS:85049825286
SN - 2169-9097
VL - 123
SP - 1484
EP - 1510
JO - Journal of Geophysical Research: Planets
JF - Journal of Geophysical Research: Planets
IS - 6
ER -