TY - JOUR

T1 - Diverse Lava Flow Morphologies in the Stratigraphy of the Jezero Crater Floor

AU - Alwmark, S.

AU - Horgan, B.

AU - Udry, A.

AU - Bechtold, A.

AU - Fagents, S.

AU - Ravanis, E.

AU - Crumpler, L.

AU - Schmitz, N.

AU - Cloutis, E.

AU - Brown, A.

AU - Flannery, D.

AU - Gasnault, O.

AU - Grotzinger, J.

AU - Gupta, S.

AU - Kah, L.

AU - Kelemen, P.

AU - Kinch, K.

AU - Núñez, J.

N1 - Publisher Copyright: © 2023. The Authors.

PY - 2023

Y1 - 2023

N2 - We present a combined geomorphologic, multispectral, and geochemical analysis of crater floor rocks in Jezero crater based on data obtained by the Mast Camera Zoom and SuperCam instruments onboard the NASA Mars 2020 Perseverance rover. The combined data from this analysis together with the results of a comparative study with geologic sites on Earth allows us to interpret the origins of rocks exposed along the Artuby ridge, a ∼900 m long scarp of lower Máaz formation rocks. The ridge exposes rocks belonging to two morphologically distinct members, Artuby and Rochette, both of which have basaltic composition and are spectrally indistinguishable in our analysis. Artuby rocks consist of morphologically distinct units that alternate over the ridge, bulbous, hummocky, layers with varying thicknesses that in places appear to have flowed over underlying strata, and sub-planar thinner laterally continuous layers with variable friability. The Rochette member has a massive appearance with pronounced pitting and sub-horizontal partings. Our findings are most consistent with a primary igneous emplacement as lava flows, through multiple eruptions, and we propose that the thin layers result either from preferential weathering, interbedded ash/tephra layers, ʻaʻā clinker layers, or aeolian deposition. Our analyses provide essential geologic context for the Máaz formation samples that will be returned to Earth and highlight the diversity and complexity of geologic processes on Mars not visible from orbit.

AB - We present a combined geomorphologic, multispectral, and geochemical analysis of crater floor rocks in Jezero crater based on data obtained by the Mast Camera Zoom and SuperCam instruments onboard the NASA Mars 2020 Perseverance rover. The combined data from this analysis together with the results of a comparative study with geologic sites on Earth allows us to interpret the origins of rocks exposed along the Artuby ridge, a ∼900 m long scarp of lower Máaz formation rocks. The ridge exposes rocks belonging to two morphologically distinct members, Artuby and Rochette, both of which have basaltic composition and are spectrally indistinguishable in our analysis. Artuby rocks consist of morphologically distinct units that alternate over the ridge, bulbous, hummocky, layers with varying thicknesses that in places appear to have flowed over underlying strata, and sub-planar thinner laterally continuous layers with variable friability. The Rochette member has a massive appearance with pronounced pitting and sub-horizontal partings. Our findings are most consistent with a primary igneous emplacement as lava flows, through multiple eruptions, and we propose that the thin layers result either from preferential weathering, interbedded ash/tephra layers, ʻaʻā clinker layers, or aeolian deposition. Our analyses provide essential geologic context for the Máaz formation samples that will be returned to Earth and highlight the diversity and complexity of geologic processes on Mars not visible from orbit.

KW - Artuby

KW - Jezero crater

KW - Lava

KW - Maaz formation

KW - Mars 2020 Perseverance

U2 - 10.1029/2022JE007446

DO - 10.1029/2022JE007446

M3 - Journal article

AN - SCOPUS:85163364182

VL - 128

JO - Journal of Geophysical Research: Solid Earth

JF - Journal of Geophysical Research: Solid Earth

SN - 0148-0227

IS - 7

M1 - e2022JE007446

ER -