P059-03
Identifying the products of volcano-ice interaction in Icelandic Mars analog sedimentary environments using Mars rover techniques.
Monday, 14 December 2020: 08:36
Virtual
Candice Ceilidh Bedford1,2, Elizabeth B Rampe2, Michael Thorpe3, Ryan Ewing4, Kashauna Mason5, Emily Champion6, Marion Nachon7, Briony H. N. Horgan8, Prakhar Sinha9, Ewan Reid10, Mathieu Gaetan Andre Lapotre11 and Patrick Clifton Gray12, (1)Lunar and Planetary Institute, Houston, TX, United States, (2)NASA Johnson Space Center, Houston, TX, United States, (3)NASA JSC, Houston, TX, United States, (4)Texas A&M, Department of Geology and Geophysics, College Station, TX, United States, (5)Texas A&M University College Station, College Station, AR, United States, (6)Texas A&M University College Station, College Station, United States, (7)Texas A&M University College Station, College Station, TX, United States, (8)Purdue University, Department of Earth, Atmospheric, and Planetary Sciences, West Lafayette, IN, United States, (9)Purdue University, West Lafayette, United States, (10)Mission Control Space Services, Ottawa, ON, Canada, (11)Stanford University, Geological Sciences, Stanford, CA, United States, (12)Duke University, Duke University Marine Lab, Durham, NC, United States
Abstract:
Iceland is used as a Mars analog due to the basaltic composition of its rocks and the prevalence of volcano-ice interactions throughout its geological history. Volcano-ice interactions form landforms such as tuyas that are largely composed of pillow basalt, kubbaberg, and hyaloclastite tuff. Candidate tuyas have been identified on the Martian surface in orbiter-based studies, with volcano-ice interactions suggested as a possible cause of episodic flooding on ancient Mars and a potential contributor to its global dust inventory. However, despite the prevalence of glaciovolcanism on Iceland and potentially Mars, little is known about how these deposits are eroded, weathered, and incorporated into sedimentary-transport pathways.
We investigate 10 km of a glacio-fluvio-aeolian sedimentary system and its source rocks at the Þórisjökull area in SW Iceland, using analytical techniques available to Mars rovers such as XRF, XRD, and VNIR. Sedimentary samples were collected at three sites along the system in the 2019 SAND-E: Semi-Autonomous Navigation for Detrital Environments Mars 2020-style rover simulation. Samples of the tuyas Lítla and Stóra Björnsfell, and the Skjaldbreiður shield volcano situated in the sediment catchment area were collected and analyzed using the same methods, in addition to optical microscopy. Results of the source rocks show that Lítla Björnsfell contains both olivine-phyric and plagioclase-phyric lava and tuff, meanwhile Stóra Björnsfell and Skjaldbreiður are plagioclase-phyric. Sediments analyzed among the three field sites show variations in geochemistry indicative of sediment sorting and/or changes in sediment source between the subglacial endmembers. Sand compositions are most similar to the tuya kubbaberg and pillow and shield lava flow source rocks, and increase in MgO from the proximal site to the distal site indicating an increase in mafic mineral abundance downstream, linked potentially to sorting. Tuffaceous materials are rarely present in the studied sediments, suggesting they may bypass the studied sites and deposit further downstream. Our results suggest that the high-erodibility of glassy and palagonite-rich subglacial volcanoes could contribute in a similar way to Martian sedimentary systems and be detectable using Mars rover techniques.
