Mode of igneous intrusion in La Plata Mountains, Colorado
The La Plata Mountains, in southwestern Colorado, have long been known as an example of a mountain group of the laccolithic type, although it has been recognized that the igneous geology was much more complex than that of typical laccoliths. A restudy of the ore‐deposits of the District, now in progress, has thrown new light on the mode of intrusion of the igneous rocks (E. B. Eckel, Resurvey of the geology and ore‐deposits of the La Plata Mining District, Colorado, Proc. Colorado Sci. Soc, v. 13, No. 9, pp. 508–546, 1936). The Mountains, which include parts of La Plata and Montezuma Counties, are 8 to 18 miles northwest of Durango and occupy an oval area 10 to 15 miles in diameter. The altitude ranges from about 8000 to 13,225 feet above sea‐level. ©1937. American Geophysical Union. All Rights Reserved.