How do silt and clay reach the surface of a playa?

Silt and clay reach the surface of a playa primarily through the action of surface floodwaters. When occasional flow events occur, these waters enter closed basins and deposit fine-grained sediments, such as silt and clay, across the playa surface.1

In addition to these flood-driven processes, the presence of these materials can be linked to the history of the basin. Many playas are formed by the desiccation of former lakes, where fine-grained lacustrine sediments—including silts and clays—were originally deposited in standing water. Over time, as these ancient lakes dried, these sediments were left behind to form the modern playa surface.23

While these sediments are deposited by water, they are also subject to redistribution by wind. Once deposited, clays and salts on the playa surface can dry, curl, and flake, making them susceptible to deflation. These wind-eroded sediments are then transported and deposited in surrounding areas, sometimes forming features like clay dunes or lunettes.4