Greetings: I am attempting to identify a 100km long linear structure near Algarrobo,Argentina. The feature "starts" with a sea-level lake within a depression 10 km across that is cut into a plateau of 70 to 90 m elevation, and runs slightly up hill for the first 70 km, with a mazimum width of 25 km. The "outwash" featues of the structure are quite evident in the GE record, which suggest debris washed out along the west-to-east axis.

Possibilities include a volcanic structure, but lava usually does not flow up hill. It seems to resemble a flash-flood outwash valley, what with all the debris downrange (shown as "slider" placemarks), but again, the run seems uphill. The lakes could fill up and "overflow" down towards the Atalantic, but there does not seem to be any indications of terraces left during level changes. Any suggestions?

This fits my generic PZ fan structure, but they are usually not this narrow. I am having trouble assigning it as a priary impact structure or an ejecta structure. My initial assignment is to have it be the manifestation of the impact of a large piece of ejecta from the St Luis crater. i.e., a crater from impacting ejecta! I have included the St. Luis Series keyhole file, a folder with various fields of oriented structures, and a folder with other nearby small depressions similar to the subject, but who mostly lack the outwash fan.