Sedimentation on a ramp type lake margin: Paleocene–Eocene Maı́z Gordo Formation, northwestern Argentina

The Maı́z Gordo Formation was deposited in a sag basin during late Paleocene to early Eocene time and formed by rocks deposited in a lacustrine basin of mixed carbonate-clastic sedimentation. Percentages of carbonate rocks decrease from the inner lake zones to the margins. Several different subenvironments were identified which were either spatially related or occurred during a time of varied climatic conditions. The paleontologic record used as an environmental indicator reveals that the climate varied from arid conditions at the base of the sequence to more humid conditions toward the top. Temperatures were moderate to warm throughout. Sag basin formation was characterized by a slowly subsiding basin with low surrounding relief, which produced a lacustrine basin characterized by ramp margins with sedimentation of low/high energy type.