Late Cretaceous Stratigraphy in Northern Coahuila, Mexico: GEOLOGICAL NOTES

Supplemental Material: Stratigraphy and depositional history of the Aguja Formation (Upper Cretaceous, Campanian) of West Texas, southwestern USA

“…A few outlying outcrops also identified as Aguja Formation lie beyond this region in the Providencia Carbón district in northeastern Chihuahua, Mexico (e.g., Brown et al, 2004;Westgate et al, 2006), although strata in this area have alternatively been identified as part of the San Carlos Formation (e.g., Alexandri-Rionda et al, 2008a). Isolated exposures are also found farther to the east in the Pico Etereo district in northern Coahuila (e.g., Daugherty and Powell, 1963), although strata in that area are alternatively shown as the San Miguel Formation (e.g., Alexandri-Rionda et al, 2008b).…”

“…5, section 25), and so it is inferred that it also pinches out in the intervening covered area. Isolated outcrops of Aguja Formation overlain and underlain by marine shale of the Pen Formation in northern Coahuila at Pico Etereo (Daugherty and Powell, 1963) and at La Unión (Shiller, 2017) indicate that the La Basa Sandstone likely extends south and east into those areas (Fig. 2).…”