Layered remnant deposits in Hellas Planitia, Mars as the remains of ancient ice mounds

Hellas Planitia is the site of many icy features in craters whose formation mechanisms offer insights into the climate processes of Mars. Layered remnant deposits (LRD) appear as crater deposits with distinct layers and have an unclear formation because of their frequent existence in the southern half of craters. We create an inventory of LRDs within Hellas Planitia using Thermal Emission Imaging System (THEMIS), Context Camera (CTX), and HiRISE images when available to measure key characteristics of LRDs and their host crater. We find 245 LRDs. Based on trends in our inventory, we propose LRDs result from old, crater-filling ice mounds that had preferential sublimation on the northern side leaving the present-day remnant in the southern portion of the crater. Understanding the formation of LRDs provides valuable insights into the broader narrative of Mars' climatic history, offering clues about past environmental conditions in the planet's Amazonian era. • We create an inventory of layered remnant deposits (LRDs) in Hellas Planitia • We compare THEMIS, CTX, and HiRISE images to analyze LRDs • We discuss an icy formation mechanism based on our findings and climate context