Similarities in the Deep-seated Controls of Mineralization between the United States and China
published: Jan 1, 1982
ArtNo. ESP136000201007, Price: 19.00 €
The lithosphere of both the United States and China is penetrated by major fracture zones trending east-west and north-south. These deep-seated structural boundaries define major lithospheric blocks several hundred kilometers in size. Also, zones having other trends participate in the delineation of some of these blocks. The "root" of the blocks apparently extend very deep, probably to the base of the lithosphere, guiding magmatism and playing a crucial role in the concentration of metals. The east-west trending structural zones are very well expressed in the morphology of China but require a special approach, including analysis of geophysical data, to be recognized in the United States. The author reviews the main criteria suggesting the presence of major east-west fracture zones or structural boundaries in the U.S. territory, adding supporting criteria from the digital colored residual Bouguer gravity map by Hildenbrand et al. (1982). The main E-W trending structural boundaries so far known or proposed in the United States are compared with the spacing of the known east-west structural zones in China. The role of the deep block structure in the concentration of metals is illustrated by examples of structural boundaries related to the Colorado Plateau and the Yishan platform in northern China. The dimensions of the two respective structural blocks appear to be significantly similar. Major deposits or clusters of ore deposits tend to concentrate near the corners and boundaries of both these lithospheric blocks. The author indicates new target areas for mineral exploration in the vicinity of the Yishan block, referring to a success from a similar approach in the Western United States. The author assumes that the similarity between the deep structures of the United States and China is based on a global regularity in the structure of the upper mantle.