Nacimiento Formation Nacimiento Formation The Nacimiento Formation is a sedimentary rock formation found in the San Juan Basin of western New Mexico (United States) and named for the Nacimiento Mountains. It is a heterogeneous nonmarine formation composed of shale, siltstone, and sandstone, deposited in floodplain, fluvial and lacustrine settings, and made up of sediment shed from the San Juan uplift to the north and the Brazos-Sangre de Cristo uplift to the east. It was deposited mostly between ~64.5 and ~61 million years ago, during the early and middle Paleocene. The climate was humid and warm to hot. This unit interbeds with the
Hole in the Rock (rock formation) expedition, runs southeast from near the town of Escalante to a parking area just above the crevice. Alternatively, the bottom of the route can be accessed by boat, at buoy 66 on Lake Powell in the Glen Canyon National Recreation Area. The Hole in the Rock was listed on the National Register of Historic Places in 1975. Hole in the Rock (rock formation) Hole in the Rock is a narrow and steep crevice in the western rim of Glen Canyon, in southern Utah in the western United States. Together with another canyon on the eastern side of the Colorado River,