Influences of structure on Jurassic depositional patterns and uranium occurrences, northwestern New Mexico
— Huffman, A. Curtis, Jr. and R. D. Lupe

A study of the stratigraphy of Middle and Upper Jurassic rocks in northwest New Mexico reveals depositional patterns that strongly reflect a pronounced change in tectonic activity at the close of San Rafael deposition. Deposition of the upper San Rafael Group in northwest New Mexico took place in a quiescent environment, and only broad regional movements were taking place. Depositional patterns and stratigraphy of the Morrison Formation, however, indicate that on the Four Corners platform and Red Rock bench a number of small structures were intermittently active during Morrison time. Strobell (1958, p. 73) recognized that ". . . much of the structural configuration now visible is inherited from a tectonic pattern established in Pennsylvanian or even earlier time," in the Four Corners region, and pre-Dakota deformation has been documented in the southern San Juan Basin by Hilpert and Moench (1960) and Moench and Schlee (1967).

 

This report discusses the relationship of both regional and local structures to depositional patterns in the Jurassic rocks of northwest New Mexico. It further suggests that some of the smaller structures played a large role in the distribution of sediments favorable to uranium deposition. Such knowledge may provide an additional tool in the search for uranium in the San Juan Basin and surrounding areas.