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Grand Canyon lies on the southern end of the Intermountain West seismic belt. [84] At least 35 earthquakes larger than 3.0 on the Richter Scale occurred in the Grand Canyon region in the 20th century. [85] Of these, five registered over 5.0 on the Richter Scale and the largest was a 6.2 quake that occurred in January 1906. [85]
Figure 1. A geologic cross section of the Grand Canyon. [5]The Tonto Group is a name for an assemblage of related sedimentary strata, collectively known by geologists as a Group, that comprises the basal sequence Paleozoic strata exposed in the sides of the Grand Canyon.
The Cardenas Basalt and Dox Formation are found mostly in the eastern region of Grand Canyon. The Shinumo Quartzite, Hakatai Shale, and Bass Formation are found in central Grand Canyon. The Unkar Group accumulated approximately between 1250 and 1104 Ma (1,104 million years ago, 1.1 billion).
East of the Grand Wash fault and in the Grand Canyon region, its thickness decreases abruptly to 52 m (171 ft) at Quartermaster Canyon, 106 m (348 ft) at 269-Mile Canyon, and 70 m (230 ft) near Diamond Bar Ranch. Further eastward in the Grand Canyon region, the thickness of the Frenchman Mountain Dolostone gradually decreases to 52 m (171 ft ...
Grand Canyon Association, Grand Canyon Village, Arizona. 176 pp. ISBN 978-1934656037 Chronic, H (1983) Roadside Geology of Arizona. 23rd printing, Mountain Press Publishing Company, Missoula, Montana. 332 pp. ISBN 978-0-87842-147-3
The largest uranium producer in the United States is ramping up work just south of Grand Canyon National Park on a long-contested project that largely has sat dormant since the 1980s. The Biden ...
The Neoproterozoic Chuar Group consists of 1,600 m (5,200 ft) of exceptionally well-preserved, unmetamorphosed sedimentary strata that is composed of about 85% mudrock.The Group is the approximate upper half of the Grand Canyon Supergroup, overlain by the thin, in comparison, Sixtymile Formation, the top member of the multi-membered Grand Canyon Supergroup.
Blakey, Ron and Wayne Ranney, Ancient Landscapes of the Colorado Plateau, Grand Canyon Association (publisher), 2008, 176 pages, ISBN 978-1934656037 Chronic, Halka. Roadside Geology of Arizona, Mountain Press Publishing Co., 1983, 23rd printing, pp. 229–232, ISBN 978-0878421473