New Mexico Geology

Algal mounds are common in late Paleozoic sedimentary successions, particularly in Late Carboniferous (Pennsylvanian) and Early Permian carbonates deposited in tropical, shallow marine environments. Most of these organic buildups are skeletal mounds formed by phylloid algae. These algae grew leaf-like blades that baffled carbonate sediment. During the late Paleozoic, phylloid algae grew in dense meadows and, in some places, their dense growths trapped lime muds to form mounds. Late Paleozoic mounds in New Mexico have been described primarily from the southern part of the state. They are particularly well studied in Pennsylvanian–Permian strata in the Sacramento Mountains and San Andres Mountains, which were laid down in the late Paleozoic Orogrande basin