Mars once had water=confirmed!
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Started by metmike - Oct. 12, 2021, 12:31 p.m.
By metmike - Oct. 12, 2021, 12:36 p.m.
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 Observations from orbital spacecraft have shown that Jezero crater, Mars, contains a prominent fan-shaped body of sedimentary rock deposited at its western margin. The Perseverance rover landed in Jezero crater in February 2021. We analyze images taken by the rover in the three months after landing. The fan has outcrop faces that were invisible from orbit, which record the hydrological evolution of Jezero crater. We interpret the presence of inclined strata in these outcrops as evidence of deltas that advanced into a lake. In contrast, the uppermost fan strata are composed of boulder conglomerates, which imply deposition by episodic high-energy floods. This sedimentary succession indicates a transition, from a sustained hydrologic activity in a persistent lake environment, to highly energetic short-duration fluvial flows.

“Fig. 2 Stratigraphy of Kodiak butte.(A and D) Zoomed images of the two scarps of Kodiak (see fig. S2 for wider context). Elevation scales were inferred from a HiRISE DEM (14) and have systematic uncertainties of ±2 m. White boxes indicate regions shown in more detail in other panels. (B and E) Interpreted line drawings of the main visible beds (blue lines for individual beds and red lines for discontinuities), overlain on the same images. Units k1 to k5 are labeled and discussed in the text. (C) Zoomed image of k1 showing the change in dip from subhorizontal beds (topsets) to inclined beds (foresets). (F) Zoomed image of the foresets in k3. This unit has a coarse texture with several cobble-size clasts (white arrow). The erosional truncation of k3 by k4 is labeled.” Mangold et al., 2021

For comparison, here is a schematic diagram of a Gilbert-type delta depositional sequence: