Earth and Planetary Sciences ETDs

Publication Date

Spring 5-22-1956


Canjilon Hill is located on the west side of the Rio Grande, about 2 3/4 miles north-northwest of Bernalillo. Exposed on the hill is a local unit of breccia, conglomerate, and sandstone, which forms an elongate saucer-shaped body 4100 feet long, 2200 feet wide and 280 to 500+ feet thick. Unlike the underlying Santa Fe formation these strata contain an abundance of large angular basalt pebbles, cobbles, and boulders. In this paper these strata are termed the Canjilon formation of the Santa Fe group. Structural and sedimentological evidence suggest that the Canjilon formation was deposited in a subsidence depression initiated on the Pleistocene (?) Ortiz surface. The subsidence was probably due to the withdrawal of support in an underlying magma chamber. The basalt fragments in the Canjilon strata may have been derived in either or both of ways: (1) explosion debris; (2) erosion of a basalt flow surrounding the subsidence depression. Continued subsidence during deposition of the Canjilon formation is suggested by unconformities and inward dips exceeding the angle of repose. The total subsidence was at least 300 feet. Normal faults along with subsidence occurred are exposed along the periphery of the hill. A later period of igneous activity is represented by a large funnel-shaped basaltic plug, a cone sheet, a plug (?), and numerous dikes and sills cutting the Canjilon formation.

Degree Name

Earth and Planetary Sciences

Level of Degree


Department Name

Department of Earth and Planetary Sciences

First Committee Member (Chair)

Vincent Cooper Kelley

Second Committee Member

J. Paul Fitzsimmons

Third Committee Member

Abraham Rosenzweig




Canjilon Formation, Canjilon Hill, Stratigraphy

Document Type