Which peninsula marks the southern end of the Gulf of Mexico?
Gulf of Mexico origin for the Gulf of Mexico at the close of the Permian, which could have caused the Permian–Triassic extinction event. However, Gulf Coast geologists do not regard this hypothesis as having any credibility. Instead they overwhelmingly accept plate tectonics, not an asteroid impact, as having created the Gulf of Mexico as illustrated by papers authored by Kevin Mickus and others. This hypothesis is not to be confused with the Chicxulub Crater, a large impact crater on the coast of the Gulf of Mexico on the Yucatán Peninsula. Increasingly, the Gulf of Mexico is regarded as a backarc basin behind the
Gulf of Mexico to the latitude of the South point of the Dry Tortugas (24°35'N), along this parallel Eastward to Rebecca Shoal (82°35'W) thence through the shoals and Florida Keys to the mainland at eastern end of Florida Bay, all the narrow waters between the Dry Tortugas and the mainland being considered to be within the Gulf. The consensus among geologists who have studied the geology of the Gulf of Mexico is that before the Late Triassic, the Gulf of Mexico did not exist. Before the Late Triassic, the area now occupied by the Gulf of Mexico consisted of dry land, which included