EVA # 7
Author: Hunter Vannier
Purpose of EVA: Investigate boulders within Candor Chasma and gypsum deposits.
Start time: 1100
End time: 1456
Narrative: EVA began at 1100 led by Hunter and joined by Jilian, Ryan, and Jesus. Curiosity started with 100% charge and 261.5 hours, and Perseverance started with 100% charge and 280.0 hours. The crew took Curiosity and Perseverance rovers north on Cow Dung Road and parked at the Gateway to Candor. The crew unloaded sampling tools and walked east along the streambed and admired the intact layers of conglomerate and sandstone that are largely converted to soil in other parts of MDRS. The crew also may have observed a fossilized bone in a boulder in the middle of the riverbed. Just before 12:00, they observed a pronghorn in the distance just as they descended into Candor Chasma, and then walked 2-3 km along the stream bed. Through this traverse, the crew noticed multiple changes in local geology, starting with the Morrison formation dominating the walls and much of the erosional material that was light-toned loose sand, some of which formed ripples that were covered in frost and scattered pawprints of pronghorn, coyote, and rabbit. The sand was present in the stream bottom along with red clay/sand sized particles, and at one point observed large limestone boulders 2-4 m tall. The crew then entered a region with abundant gypsum layers and veins intersecting darker brown/orange/grey thinly bedded layers. Finally, the crew descended far enough to see a 1-2 m exposure of limestone that was often in contact with the streambed and had rounded bulbous shapes due to weathering. In this area the crew also observed more significant walls of the thinly bedded brown/dark brown/tan layers dominating the walls of Candor Chasma. The eroded scree transitioned from lighter to a darker tone as we walked, likely due to a transition from more to less exposures of the sandstone capping unit. In this darker brown region, there were fewer obvious veins of gypsum and the paleosol/scree slopes reached as high as ~5 m from the top of the cliff face and was abundant through the gully. They then began returning to the rovers at 1300 and collected a few different forms of weathered limestone (crystalline green and orange) and examples of fresh and weathered gypsum. The team made it back to the HAB with Curiosity at 61% charge and 261.7 hours and Perseverance at 66% and 280.1 hours. They began the reentry process for the HAB at 1451.
Destination: Candor Chasma
Coordinates (use UTM WGS 84): N521500, E4251000
Participants: Jilian Welshoff (Health and Safety Officer), Ryan DeAngelis (Green Hab Officer), Jesus Galvan (Crew Engineer), Hunter Vannier (Crew Geologist)
Road(s) and routes per MDRS Map: Drove north on Cow Dung Road and parked at the Gateway to Candor. Then walked east 2-3 km.
Mode of travel: driving and walking (Curiosity and Perseverance)