Provenance and Diagenesis of Martian Sedimentary Rocks in the Jezero Crater Delta Front from Microscale Observations by the Mars 2020 PIXL Instrument

International audienceOn ~sol 370 of the Perseverance rover mission, the Mars 2020 Science Team completed its investigation of igneous units of the Jezero crater floor [1] and directed Perseverance to drive towards the topographic scarp that marks the interface between the crater floor and Jezero’s western delta. The “Delta Front Campaign” consisted of close-up investigation and sampling of lithologies located there.Here, we report on the major findings relevant to the provenance and diagenetic history of these lithologies deduced from measurements made by the Planetary Instrument for X-ray Lithochemistry (PIXL), a micro-focus X-ray fluorescence (XRF) microscope [2]. Data were collected from the Shenandoah formation at two stratigraphic sections: Cape Nukshak and Hawksbill Gap [3].Sediment provenance ranges from relatively homogeneous, altered olivine-dominated sources at the base of the section at Cape Nukshak in the Amalik member, to highly heterogeneous and altered (likely serpentinized) mafic to ultramafic sources at the top of the section at Hawksbill Gap in the Rockytop member. The presence of Fe-bearing carbonate at both locations indicates precipitation from anoxic, alkaline waters of moderate pH. The Yori Pass member (Cape Nukshak), and the Hogwallow Flats and Devils Tanyard members (Hawksbill Gap) contain abundant Fe-Mg sulfates and phyllosilicates, with compositions that indicate at least one period of deposition under anoxic, hypersaline conditions. The preservation of the Fe-Mg sulfate component of these rocks is remarkable, given its extreme solubility and susceptibility to oxidation. Fluids that precipitated later cross-cutting anhydrite apparently had little effect on rock bulk compositions. At present, it is uncertain whether observed evidence for oxidation, including ferric-sulfate, results from ~syn-depositional variability in atmospheric and aquatic redox state, or later diagenesis or weathering. A major finding of this investigation is that the Shenandoah formation contains compositionally and mineralogically diverse sedimentary rocks, which bodes well for sample return science, and indicates that paleo-environmental conditions were variable in space and/or time during delta deposition and diagenesis

Provenance and Diagenesis of Martian Sedimentary Rocks in the Jezero Crater Delta Front from Microscale Observations by the Mars 2020 PIXL Instrument

International audienceOn ~sol 370 of the Perseverance rover mission, the Mars 2020 Science Team completed its investigation of igneous units of the Jezero crater floor [1] and directed Perseverance to drive towards the topographic scarp that marks the interface between the crater floor and Jezero’s western delta. The “Delta Front Campaign” consisted of close-up investigation and sampling of lithologies located there.Here, we report on the major findings relevant to the provenance and diagenetic history of these lithologies deduced from measurements made by the Planetary Instrument for X-ray Lithochemistry (PIXL), a micro-focus X-ray fluorescence (XRF) microscope [2]. Data were collected from the Shenandoah formation at two stratigraphic sections: Cape Nukshak and Hawksbill Gap [3].Sediment provenance ranges from relatively homogeneous, altered olivine-dominated sources at the base of the section at Cape Nukshak in the Amalik member, to highly heterogeneous and altered (likely serpentinized) mafic to ultramafic sources at the top of the section at Hawksbill Gap in the Rockytop member. The presence of Fe-bearing carbonate at both locations indicates precipitation from anoxic, alkaline waters of moderate pH. The Yori Pass member (Cape Nukshak), and the Hogwallow Flats and Devils Tanyard members (Hawksbill Gap) contain abundant Fe-Mg sulfates and phyllosilicates, with compositions that indicate at least one period of deposition under anoxic, hypersaline conditions. The preservation of the Fe-Mg sulfate component of these rocks is remarkable, given its extreme solubility and susceptibility to oxidation. Fluids that precipitated later cross-cutting anhydrite apparently had little effect on rock bulk compositions. At present, it is uncertain whether observed evidence for oxidation, including ferric-sulfate, results from ~syn-depositional variability in atmospheric and aquatic redox state, or later diagenesis or weathering. A major finding of this investigation is that the Shenandoah formation contains compositionally and mineralogically diverse sedimentary rocks, which bodes well for sample return science, and indicates that paleo-environmental conditions were variable in space and/or time during delta deposition and diagenesis

THE PETROGENETIC HISTORY OF THE JEZERO CRATER DELTA FRONT FROM MICROSCALE OBSERVATIONS BY THE MARS 2020 PIXL INSTRUMENT

International audienceOn ~sol 370 of the Perseverance rover mission, the Mars 2020 Science Team completed its investigation of igneous units of the Jezero crater floor [1] and directed Perseverance to drive towards the topographic scarp that marks the interface between the crater floor and Jezero’s western delta. The “Delta Front Campaign” consisted of close-up investigation and sampling of lithologies located there.Here, we report on the major findings relevant to the provenance and diagenetic history of these lithologies deduced from measurements made by the Planetary Instrument for X-ray Lithochemistry (PIXL), a micro-focus X-ray fluorescence (XRF) microscope [2]. Data were collected from two sections at Cape Nukshak and Hawksbill Gap; outcrop and member names are from [3]. Lithologies are described here in order from base to top of each section

THE PETROGENETIC HISTORY OF THE JEZERO CRATER DELTA FRONT FROM MICROSCALE OBSERVATIONS BY THE MARS 2020 PIXL INSTRUMENT

International audienceOn ~sol 370 of the Perseverance rover mission, the Mars 2020 Science Team completed its investigation of igneous units of the Jezero crater floor [1] and directed Perseverance to drive towards the topographic scarp that marks the interface between the crater floor and Jezero’s western delta. The “Delta Front Campaign” consisted of close-up investigation and sampling of lithologies located there.Here, we report on the major findings relevant to the provenance and diagenetic history of these lithologies deduced from measurements made by the Planetary Instrument for X-ray Lithochemistry (PIXL), a micro-focus X-ray fluorescence (XRF) microscope [2]. Data were collected from two sections at Cape Nukshak and Hawksbill Gap; outcrop and member names are from [3]. Lithologies are described here in order from base to top of each section

THE PETROGENETIC HISTORY OF THE JEZERO CRATER DELTA FRONT FROM MICROSCALE OBSERVATIONS BY THE MARS 2020 PIXL INSTRUMENT

International audienceOn ~sol 370 of the Perseverance rover mission, the Mars 2020 Science Team completed its investigation of igneous units of the Jezero crater floor [1] and directed Perseverance to drive towards the topographic scarp that marks the interface between the crater floor and Jezero’s western delta. The “Delta Front Campaign” consisted of close-up investigation and sampling of lithologies located there.Here, we report on the major findings relevant to the provenance and diagenetic history of these lithologies deduced from measurements made by the Planetary Instrument for X-ray Lithochemistry (PIXL), a micro-focus X-ray fluorescence (XRF) microscope [2]. Data were collected from two sections at Cape Nukshak and Hawksbill Gap; outcrop and member names are from [3]. Lithologies are described here in order from base to top of each section

Provenance and Diagenesis of Martian Sedimentary Rocks in the Jezero Crater Delta Front from Microscale Observations by the Mars 2020 PIXL Instrument

International audienceOn ~sol 370 of the Perseverance rover mission, the Mars 2020 Science Team completed its investigation of igneous units of the Jezero crater floor [1] and directed Perseverance to drive towards the topographic scarp that marks the interface between the crater floor and Jezero’s western delta. The “Delta Front Campaign” consisted of close-up investigation and sampling of lithologies located there.Here, we report on the major findings relevant to the provenance and diagenetic history of these lithologies deduced from measurements made by the Planetary Instrument for X-ray Lithochemistry (PIXL), a micro-focus X-ray fluorescence (XRF) microscope [2]. Data were collected from the Shenandoah formation at two stratigraphic sections: Cape Nukshak and Hawksbill Gap [3].Sediment provenance ranges from relatively homogeneous, altered olivine-dominated sources at the base of the section at Cape Nukshak in the Amalik member, to highly heterogeneous and altered (likely serpentinized) mafic to ultramafic sources at the top of the section at Hawksbill Gap in the Rockytop member. The presence of Fe-bearing carbonate at both locations indicates precipitation from anoxic, alkaline waters of moderate pH. The Yori Pass member (Cape Nukshak), and the Hogwallow Flats and Devils Tanyard members (Hawksbill Gap) contain abundant Fe-Mg sulfates and phyllosilicates, with compositions that indicate at least one period of deposition under anoxic, hypersaline conditions. The preservation of the Fe-Mg sulfate component of these rocks is remarkable, given its extreme solubility and susceptibility to oxidation. Fluids that precipitated later cross-cutting anhydrite apparently had little effect on rock bulk compositions. At present, it is uncertain whether observed evidence for oxidation, including ferric-sulfate, results from ~syn-depositional variability in atmospheric and aquatic redox state, or later diagenesis or weathering. A major finding of this investigation is that the Shenandoah formation contains compositionally and mineralogically diverse sedimentary rocks, which bodes well for sample return science, and indicates that paleo-environmental conditions were variable in space and/or time during delta deposition and diagenesis

THE PETROGENETIC HISTORY OF THE JEZERO CRATER DELTA FRONT FROM MICROSCALE OBSERVATIONS BY THE MARS 2020 PIXL INSTRUMENT

International audienceOn ~sol 370 of the Perseverance rover mission, the Mars 2020 Science Team completed its investigation of igneous units of the Jezero crater floor [1] and directed Perseverance to drive towards the topographic scarp that marks the interface between the crater floor and Jezero’s western delta. The “Delta Front Campaign” consisted of close-up investigation and sampling of lithologies located there.Here, we report on the major findings relevant to the provenance and diagenetic history of these lithologies deduced from measurements made by the Planetary Instrument for X-ray Lithochemistry (PIXL), a micro-focus X-ray fluorescence (XRF) microscope [2]. Data were collected from two sections at Cape Nukshak and Hawksbill Gap; outcrop and member names are from [3]. Lithologies are described here in order from base to top of each section

The SuperCam Instrument onboard Perseverance: Overview of efforts compiled for Mars X conference

International audienceThe Perseverance rover landed at Jezero crater on February 18th, 2021. The choice of this landing site for the Mars2020 mission was motivated by its geological significance and the potential insights into Mars’ past habitability and search for past life. Indeed, Jezero crater once contained a lake, with a very well preserved delta on the west, making it an ideal location to search for signs of ancient microbial life. The Perseverance rover has four main objectives: 1. Search for traces of past microbial life 2. Characterize Mars’s climate and geology in the landing site 3. Collect samples for later return to Earth 4.Test technologies for future missions. Perseverance is equipped with seven scientific instruments, including the SuperCam suite [1,2]. SuperCam combines several remote-sensing techniques in order tostudy both the Martian surface and its atmosphere: 1. the LIBS (Laser-Induced Breakdown Spectroscopy) technique gives access to the chemical composition of the targets (up to 15m). All major elements are quantified (Si, Ti, Al, Fe, Mg, Ca, Na, K [3]) and the quantification of some minor elements is under progress [4]; 2. The Raman spectroscopy enables the identification of major mineral phases via the use of a 532nm pulsed laser, for Raman shifts between 150 and >4000cm-1; 3. The VISIR spectroscopy gives access to the mineralogy, via the reflection of sunlight to access the frequency of molecule bond vibrations of the targets. The VIS range covers the 379-464nm and 535-855nm range, and the IRS part is comprised in the 1.3-2.6 microns range using an Acousto-Optic Tunable Filter spectrometer [5]; 4. The Remote Micro Imager (RMI) uses a CMOS camera of 2048x2048 pixels, with an angular size of 10 microradians and a resolution of 50 microradians; 5. The microphone records air pressure fluctuations from 20 Hz to 12.5 or 50 KHz, at sampling rates of 25 or 100 KHz, respectively

Sedimentology and Stratigraphy of the Shenandoah Formation, Western Fan, Jezero Crater, Mars

International audienceAbstract Sedimentary fans are key targets of exploration on Mars because they record the history of surface aqueous activity and habitability. The sedimentary fan extending from the Neretva Vallis breach of Jezero crater's western rim is one of the Mars 2020 Perseverance rover's main exploration targets. Perseverance spent ∼250 sols exploring and collecting seven rock cores from the lower ∼25 m of sedimentary rock exposed within the fan's eastern scarp, a sequence informally named the “Shenandoah” formation. This study describes the sedimentology and stratigraphy of the Shenandoah formation at two areas, “Cape Nukshak” and “Hawksbill Gap,” including a characterization, interpretation, and depositional framework for the facies that comprise it. The five main facies of the Shenandoah formation include: laminated mudstone, laminated sandstone, low‐angle cross stratified sandstone, thin‐bedded granule sandstone, and thick‐bedded granule‐pebble sandstone and conglomerate. These facies are organized into three facies associations (FA): FA1, comprised of laminated and soft sediment‐deformed sandstone interbedded with broad, unconfined coarser‐grained granule and pebbly sandstone intervals; FA2, comprised predominantly of laterally extensive, soft‐sediment deformed laminated, sulfate‐bearing mudstone with lenses of low‐angle cross‐stratified and scoured sandstone; and FA3, comprised of dipping planar, thin‐bedded sand‐gravel couplets. The depositional model favored for the Shenandoah formation involves the transition from a sand‐dominated distal alluvial fan setting (FA1) to a stable, widespread saline lake (FA2), followed by the progradation of a river delta system (FA3) into the lake basin. This sequence records the initiation of a relatively long‐lived, habitable lacustrine and deltaic environment within Jezero crater