269-9 A Revised Geologic Map of the South Polar Layered Deposits, Mars: Year 3 Updates.

Session: Planetary Geologic Mapping Across the Solar System (Posters)

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Abstract:

The south polar region of Mars contains a rich and enigmatic geologic record, which may encompass at least three timescales of ice evolution in the form of large ice-rich deposits. The region is dominated by the 4 km-thick South Polar Layered Deposits (SPLD), which are composed of layers of mixed water ice and dust and are perhaps 10s of Myr old. The SPLD are capped by the CO₂-ice-dominated South Polar Residual Cap (SPRC), which is thought to record the most recent ~100 years of climate history. Below and surrounding the SPLD lies remnants of an extensive ancient ice sheet, the Dosa Argentea Formation (DAF), that may contain ice from >3 Gya.

To provide necessary context for understanding the complex evolutionary history of these terrains and the climate record they represent, we are completing a USGS Science Investigation Map (SIM) of the south polar region of Mars poleward of 70ºS at a scale of 1:2,000,000. Here we present year 3 updates and planned next steps as the map nears completion. Since our last update, we have mapped 6 additional ROIs, resulting in a complete draft map covering 100% of the mapping area. At this meeting, we will present the full draft map, with contacts and units reconciled from the two mappers, as well as the draft description of map units (DOMU) and correlation of map units (COMU).

In the third year of this effort, we have continued and refined the team mapping strategy employed in the first two years with great success, as seen by the significant increase in mapping rate from year 2 (mapped an additional 22% of SIM extent) to year 3 (an additional 78% of SIM extent). This increased pace can be largely attributed to the higher cadence of progress meetings within the mapping team, allowing for the two mappers to more rapidly identify and address areas where refinement is necessary to either the map or map units. Next steps for this map product are revising and finalizing the map products for USGS submission.

Geological Society of America Abstracts with Programs. Vol. 57, No. 6, 2025

doi: 10.1130/abs/2025AM-10730

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