| Description |
In 1928, Utah Construction Company completed its first project outside of the United States with the 110 mile railroad for Southern Pacific of Mexico. Over the next 30 years, UCC continued to work on projects in Mexico including dams, roads, mining, and canals. The collection contains several booklets and correspondence along with approximately 500 photographs. |
| OCR Text |
Show METALLOGENIC PROVINCES Major Tectonic Features The recently compiled Tectonic map of Mexico published by the Geological Society of America (Cserna and Heezen) depicts the major structural elements of the West Coast of Mexico in greater detail than known heretofore and on a more rational basis. From this map, we can easily trace the main tectonic and geologic elements spanning a distance of nearly 1,500 miles from Arizona to the Guatemalan border along the West Coast of Mexico. The corresponding geotectonic cycle is known to have lasted from late Jurassic until the end of Tertiary. There is sufficient correlation of Tertiary intrusives, fault alignment, folds, and graben to show that the great porphyry copper provinces of Arizona and New Mexico in fact do continue into Mexico and perhaps sporadically into Central America as well. Copper Provinces The copper mineralization of the southwest is the most important economic ore province of the entire Western Cordillera, and the detailed and broader location of copper apart from its intrusive and structural aspects has a strong bearing on the direction of pros-pecting and geologic research. Copper mineralization genetically associated with Laramide stocks of generally mon-zonitic composition is the first order of importance in the states of Sonora, Michoacan, and Guerrero, as well as in other parts of western Mexico. These intrusives contributed to the formation of ore deposits in the Paleozoic and Mesozoic host rocks, and the deposits were localized in, or controlled by, Laramide structural features particularly the north-west faults and east-west and north-south faults and folds. Furthermore, Laramide dia-tremes or breccia pipes served as important loci for hypogene mineralization of copper districts as exemplified by Cananea, La Caridad, Nacozari, and perhaps others. As was typical of Arizona, the Cenozoic era in Mexico was a time of complex geological activity. Structural movements, volcanic and igneous activity, erosion, and sedimentation all acted upon pre-existing geological features to form the present moun-tains, valleys, and drainage systems. Because of the scarcity of significant fossils in Cenozoic sediments and the lack of detailed topographic or geologic maps, however, the sequence of events is known only in a very general way. 39 |
