Miocene stratigraphic relations and problems between the Abiquiu, Los Pinos, and Tesuque Formations near Ojo Caliente, northern Espanola Basin
— S. Judson May

The complex stratigraphic relations of the Abiquiu Formation, the mid-Miocene part of the Los Pinos Formation, and the Tesuque Formation are locally well exposed in the northern Espanola Basin near Ojo Caliente (Fig. 1). Exposures in this area show that much of the Los Pinos in the Ojo Caliente—Petaca area is equivalent in stratigraphic level and age to the Chama El Rito Member of the Tesuque Formation (Fig. 2) and most or all of the Abiquiu Formation in the Espanola Basin. In the Ojo Caliente area the Abiquiu and Los Pinos represent a large southwest-sloping fan complex of volcaniclastic conglomerate and sandstone derived from rhyolitic and andesitic terranes to the north and northeast (Manley, 1981). The Tesuque Formation records a large arkosic accumulation of sand carried mainly west and south from Precambrian rocks of the Sangre de Cristo uplift. In the Ojo Caliente area these two alluvial systems merged and intertongued in a complex manner, producing the Chama—El Rito Member of the Tesuque Formation which contains interbedded volcaniclastic gravels and arkosic sandstones of the two systems.