Named for Florida Mesa (the type locality) in the San Juan Mountains, south side of the San Juan Range, between Animas and Florida Rivers, La Plata Co, CO in the San Juan basin. The more or less extensive deposits of boulder and gravel cap this Florida Mesa. Occurs on all sides of the San Juan Mountains, in foothills and in each of the larger valleys radiating from the mountain core. Descriptions given for occurrence in Ignacio quad; La Plata, Red Mesa, and Soda Canyon quads; Montrose quad; Uncompahgre quad; Creede quad; Del Norte quad; Conejos quad; Summitville and Pagosa Springs quads; Rio Arriba Co, NM; and San Luis Valley. Ranges from coarse sand or grit to large cobbles and boulders. Most of the deposit consists of rounded and waterworn pebbles and cobblestones with a major diameter between 3 and 6 inches. Characterized by abundant diorite and monzonite porphyry from sills and laccoliths in the La Plata area. Fragments of Vallecito conglomerate from southeast part of Needle Mountain quad found in gravels in Los Pinos River area. Farther east and north is composed mostly of volcanic material. Has a known maximum thickness of 50+ ft; ordinarily forms a thin veneer only 10-20 ft thick. In the Conejos quad, south of Alamosa Creek, overlies Hinsdale basalt or rests directly upon Los Pinos gravel (named). Geologic maps. Of Pleistocene age. Deposited after Cerro till.

Source: GNU records (USGS DDS-6; Denver GNULEX).

Is a unit of the Durango area, southwest CO in the San Juan basin that is shown as ranging in age from 788,000 to about 650,000 yrs, or of early middle Pleistocene, pre-Illinoian age.

Source: GNU records (USGS DDS-6; Denver GNULEX).