TITAN'S SEDIMENT CYCLE (Invited Presentation)

Saturn’s moon Titan is a frozen Ocean World covered in a thick mantle of organic molecule sediments. The organic molecules originate from methane photochemistry high in the atmosphere. On the surface, Titan’s thick 1.5 bar atmosphere hosts winds that allow wind-driven material transport, while a volatile methane cycle, much like Earth’s water cycle, drives fluvial and dissolution geology. From physical and chemical processing, the surface organics are converted into mobile materials that are processed, transported, deposited, eroded, and recycled across the Titan landscape.

We are now beginning to piece together the geological story of Titan as a sedimentary world. Organic coated mountains and plateaux, hydrocarbon-filled rivers, ice-cobble alluvial fans, organic linear dunes, and vast organic plains are all testament to a landscape dominated by sedimentary processes. Mapping has revealed Titan to have latitudinal segregation of geological processes. In the mid-latitudes and equatorial regions, eolian processes dominate fluvial processes – here, Titan is a wind-driven world. In Titan’s polar regions, networks of fluvial channels and canyons, filled and dry lakes, and evidence for dissolution geology suggests that polar Titan is dominated by processes driven by the liquid hydrocarbon cycle.

In many ways Titan is like Earth, with water ice crustal materials being eroded into sediments. In other ways, Titan is very different, with atmospheric airfall originating from being the ultimate source of organic sediments. Like on Earth, the sediment layers of Titan will reveal erosion, transport, and emplacement conditions throughout Titan’s history. In addition to the geological record, Titan’s sediment record will reveal details on the chemical record of the amounts, products, and processes synthesizing organic molecules in Titan’s atmosphere. The sedimentary layers of Titan are a rich target for future exploration to understand this sophisticated world.