This discovery shows that these #sediments were formed in a river, a delta or near the shore of an ancient lake. It raises questions about #oxydation processes on Mars... and reinforces the hypothesis of past #habitability...
Those waters brought fine-grained sand and mud known for preserving fossilized life in comparable environments on Earth. The Martian crater's lake grew as wide as 35 km in diameter and as deep as 30 m.