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Linking Native Lithologies to a Bigger Panorama

A color photo from the Martian surface shows a landscape of sandy, rocky terrain. What looks like a pair of light orange-brown sand dunes rise in the background. Four or five large, sharp-edged rocks are strewn among the sand on the left side of the image. But a clear vertical dividing line extends from the center of the image to the right side, where the sand is covered by similar rocks of all sizes. A pale yellow sky is visible above the scene.

This picture from NASA’s Mars Perseverance rover, taken by the Mastcam-Z instrument’s proper eye, reveals a group of ridge-forming boulders. The rover acquired this picture trying south alongside the ridge whereas exploring the “Westport” area of the outer crater rim on July 18, 2025 — Sol 1568, or Martian day 1,568 of the Mars 2020 mission — on the native imply photo voltaic time of 11:53:04.

NASA/JPL-Caltech/ASU

Written by Margaret Deahn, Ph.D. Scholar at Purdue College

NASA’s Mars 2020 rover is constant to discover a boundary seen from orbit dividing vibrant, fractured outcrop from darker, smoother regolith (often known as a contact). The crew has referred to as this area “Westport,” (a becoming title, because the rover is exploring the western-most rim of Jezero), which hosts a contact between the smoother, clay-bearing “Krokodillen” unit and an outcrop of olivine-bearing boulders that converge to kind a ridge on the outer Jezero crater rim. To be taught extra concerning the nature of this contact, see this blog post by Dr. Melissa Rice. Piecing collectively geologic occasions just like the formation of this olivine-bearing materials on Jezero’s crater rim might permit us to raised perceive Mars’ most historical historical past.

The rover has encountered a number of olivine-bearing rocks whereas traversing the rim, however it’s unclear if, and the way these rocks are all linked. Jezero crater is in a area of Mars often called Northeast Syrtis, which hosts the biggest contiguous publicity (greater than 113,000 sq. kilometers, or greater than 43,600 sq. miles) of olivine-rich materials recognized from orbit on Mars (about the identical sq. mileage because the state of Ohio!). The olivine-rich supplies are sometimes discovered draping over older rocks, usually infilling depressions, which can present clues to their origins. Attainable origins for the olivine-rich supplies in Northeast Syrtis might embrace (however should not restricted to): (1) intrusive igneous rocks (rocks that cool from magma underground), (2) soften shaped and deposited throughout an influence occasion, or (3) pyroclastic ash fall or circulation from a volcanic eruption.

The Perseverance rover’s investigation of the olivine-bearing supplies on the rim of Jezero crater might permit us to raised constrain the historical past of the broader volcanic models current within the Northeast Syrtis area. Olivine-rich materials in Northeast Syrtis is constantly sandwiched between older, clay-rich rock and youthful, extra olivine-poor materials (generally known as the “mafic capping” unit), and should act as an necessary marker for recording early alteration by water, which may assist us perceive early liveable environments on Mars. We see potential proof of all of those models on Jezero crater’s rim based mostly on orbital mapping. If the olivine-bearing rocks the Perseverance rover is encountering on the rim are associated to those supplies, we could possibly higher constrain the age of this widespread geologic unit on Mars.