| Payson ophiolite | |
|---|---|
| Stratigraphic range: | |
| Underlies | Tonto Basin Supergroup |
| Overlies | Larson Spring Formation |
| Lithology | |
| Primary | basalt, gabbro |
| Location | |
| Coordinates | 34°11′N111°20′W / 34.18°N 111.34°W |
| Region |  Arizona Arizona |
| Country | United States |
| Type section | |
| Named for | Payson, Arizona |
| Named by | J.C. Dann |
| Year defined | 1991 |
  Payson ophiolite (the United States)  Payson ophiolite (Arizona) | |
The Payson ophiolite is an ophiolite of Statherian age (late Paleoproterozoic) located near Payson, Arizona, US.
The Payson ophiolite crops out south and west of the town of Payson, Arizona, in the Arizona transition zone between the Colorado Plateau and the Basin and Range. [1] It consists of a well-developed sheeted dyke complex that grades below into gabbroic rock and above into submarine volcanic rock. The whole sequence dips gently (by about 15 degrees) to the southwest. The ophiolite is exposed over a sizable area and is little deformed, with metamorphism limited to the lower greenschist facies. Much of the gabbro is essentially unaltered. [2]
The ophiolite is intruded by a sill of granitic rock, the Payson Granite, which conceals the deepest layers of the ophiolite, including the entire ultramafic mantle portion of the ophiolite. The deepest accessible layers are the gabbronorite of Round Valley. [2] Regionally, the ophiolite is thought to be overlain by the Tonto Basin Supergroup. [3]
The ophiolite is part of the Mazatzal block, a terrane 50 to 60 kilometers (31 to 37 mi) wide on the eastern end of the Arizona transition zone. The Payson ophiolite lies on a basement of granitic rock overlain by felsic volcanic and volcaniclastic rock of the Larson Spring Formation. This shows that the ophiolite was emplaced by rifting of an existing island arc, which likely produced a pull-apart basin. [2] [3]
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The Yavapai orogeny was an orogenic (mountain-building) event in what is now the Southwestern United States that occurred between 1710 and 1680 million years ago (Mya), in the Statherian Period of the Paleoproterozoic. Recorded in the rocks of New Mexico and Arizona, it is interpreted as the collision of the 1800-1700 Mya age Yavapai island arc terrane with the proto-North American continent. This was the first in a series of orogenies within a long-lived convergent boundary along southern Laurentia that ended with the ca. 1200–1000 Mya Grenville orogeny during the final assembly of the supercontinent Rodinia, which ended an 800-million-year episode of convergent boundary tectonism.
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The Alder Group is a group of geologic formations exposed in the Mazatzal Mountains of central Arizona, US. It dates to the Statherian Period of the Paleoproterozoic and records mountain-building events associated with the assembly of North America.
The White Ledges Formation is a geologic formation that crops out in central Arizona, US. Detrital zircon geochronology establishes a maximum age for the formation of 1726 million years (Mya), in the Statherian period of the Precambrian. The formation is typical of quartzites deposited around 1650 million years ago in the southwestern part of Laurentia, the ancient core of the North American continent.
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