Probably oceans, in the same way that ancient sediments bear fossils of seashells and other sea creatures that die and collect on the sea floor. Preservation of fossils on land is more iffy. Also, life seems to have originated in the waters and seas of Earth. Scientists got useful info from the Russian Luna samples of lunar soil, which were just dust grains and maybe mm sized rock chips. But it would be even better to have centimeter sized rock pieces, which give more mineralogy information.
Typical breezes are mild.
The danger for long-term operation is a dust storm or a dust devil blowing over the site. Dust devils were photographed in the distance by the Pathfinder lander. A dust storm or dust devil could blow dust into working parts and jam up a lander or robot arms or maybe wheels on a rover, or damage camera lenses. But Viking landers operated a year or more with no major damage, so I wouldn't worry much about it. The large chasmas and Valles Marineris complex are larger than many features on Earth.