Alder Group Stratigraphic range: | |
---|---|
Type | Group |
Unit of | Tonto Basin Supergroup |
Sub-units | Board Canyon Formation Houdon Formation Flying W Formation Breadpan Formation |
Underlies | Red Rock Group |
Overlies | East Verde River Formation |
Thickness | 3,000 meters (9,800 ft) |
Lithology | |
Primary | metasedimentary rock, metavolcanic rock |
Location | |
Coordinates | 33°36′N111°19′W / 33.60°N 111.32°W |
Region | Arizona |
Country | United States |
Type section | |
Named for | Alder Creek, Arizona |
Named by | E.D. Wilson |
Year defined | 1939 |
The Alder Group is a group of geologic formations exposed in the Mazatzal Mountains of central Arizona, US. [1] It dates to the Statherian Period of the Paleoproterozoic and records mountain-building events associated with the assembly of North America.
The formation consists of about 3,000 feet (910 m) of metavolcanic and metasedimentary rock [1] exposed in the Mazatzal Mountains. [2] The formation is underlain by the East Verde River Formation and overlain by the Red Rock Group. Together with the younger Mazatzal Group, these groups form the Tonto Basin Supergroup. The formation is mostly volcanic and volcaniclastic sedimentary rock, but with some sedimentary beds formed by weathering of continental rock (terrigenous beds). All have experienced metamorphism. The Alder Group is interpreted as basin fill of an intra-arc basin that formed along what was then the southern coast of Laurentia, the ancient core of North America. [1]
The formation is divided (in ascending stratigraphic order) into the Breadpan, Flying W, Houdon, and Board Cabin Formations. The Breadpan and Houdon Formations are primarily metasedimentary rock, while the Flying W and Board Cabin Formations are primarily metavolcanic rock. [1]
The unit was first designated as the Alder sedimentary series by D.H. Wilson in 1939, for exposures near Alder Creek in the Mazatzal Mountains. Wilson originally assigned the unit to the Yavapai Group and believed the beds had been metamorphosed in a single "Mazatzal Revolution". [3] In 1958, C.A. Anderson and S.C. Creasey mapped the unit into the Jerome, Arizona, area, raised it to group rank, and divided it into six formations. [4] That same year, Gordon Castil redesignated the unit as a formation and divided the unit in its original area in the Mazatzal Mountains into three unnamed members. [5]
In 1971, Anderson and coinvestigators refined the definition of the group, restricting it to the Mazatzal Mountains and reassining the beds in the Jerome area to the Big Bug Group. [2]
In 1993, Karl Karlstrom and S.A. Bowring divided the Alder Group into the Breadpan, Flying W, Houdon, and Board Cabin Formations. [6]
Granite Mountain is a 7,628-foot (2,325 m) mountain located in Yavapai County, Arizona that covers roughly 12 square miles (31 km2). It was once known as Mount Gurley, for the first governor of the Arizona Territory, John A. Gurley. Its southwest face has a sheer granite cliff approximately 500 feet high that is one of the best locations for rock climbing in the state of Arizona. It is located in the Granite Mountain Wilderness, which is managed as a part of the Prescott National Forest. The mountain stands at the northern end of the Sierra Prietas, and borders Skull Valley on the west, on the northwest by the Santa Maria Mountains, and east by the Williamson Valley.
The Vishnu Basement Rocks is the name recommended for all Early Proterozoic crystalline rocks exposed in the Grand Canyon region. They form the crystalline basement rocks that underlie the Bass Limestone of the Unkar Group of the Grand Canyon Supergroup and the Tapeats Sandstone of the Tonto Group. These basement rocks have also been called either the Vishnu Complex or Vishnu Metamorphic Complex. These Early Proterozoic crystalline rocks consist of metamorphic rocks that are collectively known as the Granite Gorge Metamorphic Suite; sections of the Vishnu Basement Rocks contain Early Paleoproterozoic granite, granitic pegmatite, aplite, and granodiorite that have intruded these metamorphic rocks, and also, intrusive Early Paleoproterozoic ultramafic rocks.
The Manzano Group is a group of geologic formations in central New Mexico. These have radiometric ages of 1601 to 1662 million years (Ma), corresponding to the late Statherian period of the Paleoproterozoic.
The Mazatzal orogeny was an orogenic event in what is now the Southwestern United States from 1650 to 1600 Mya in the Statherian Period of the Paleoproterozoic. Preserved in the rocks of New Mexico and Arizona, it is interpreted as the collision of the 1700-1600 Mya age Mazatzal island arc terrane with the proto-North American continent. This was the second 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.
The Yavapai orogeny was an orogenic (mountain-building) event in what is now the Southwestern United States that occurred between 1710 to 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.
The Picuris orogeny was an orogenic event in what is now the Southwestern United States from 1.43 to 1.3 billion years ago in the Calymmian Period of the Mesoproterozoic. The event is named for the Picuris Mountains in northern New Mexico and interpreted either as the suturing of the Granite-Rhyolite crustal province to the southern margin of the proto-North American continent Laurentia or as the final suturing of the Mazatzal crustal province onto Laurentia. According to the former hypothesis, this was the second 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.
The Moppin Complex is a Precambrian geologic complex found in the Tusas Mountains of northern New Mexico. It has not been directly dated, but is thought to be Statherian based on a minimum age of 1.755 Gya from radiometric dating of magmatic intrusions.
The Big Rock Formation is a formation that crops out in the Tusas Mountains of northern New Mexico. Detrital zircon geochronology gives a maximum age for the formation of 1665 Mya, corresponding to the Statherian period.
The Ortega Formation is a geologic formation that crops out in most of the mountain ranges of northern New Mexico. Detrital zircon geochronology establishes a maximum age for the formation of 1690-1670 million years (Mya), in the Statherian period of the Precambrian.
The Marquenas Formation is a geological formation that crops out in the Picuris Mountains of northern New Mexico. Detrital zircon geochronology gives it a maximum age of 1435 million years, corresponding to the Calymmian period.
The San Pedro quartz monzonite is a Paleoproterozoic pluton in New Mexico. It has a radiometric age of 1730 Mya, corresponding to the Statherian period.
The San Miguel gneiss is a Paleoproterozoic pluton in the Nacimiento Mountains of New Mexico. It has a radiometric age of 1.695 billion years, corresponding to the Statherian period.
The Joaquin quartz monzonite is a Mesoproterozoic pluton in northern New Mexico. Radiometric dating gives it an age of 1460 million years, corresponding to the Calymmian period.
The Los Pinos Mountains are a small mountain range in the central part of New Mexico, US. The are the southernmost part of a mountain front, running north to south, that also includes the Sandia Mountains and the Manzano Mountains. The Los Pinos Mountains are separated from the Manzano Mountains by Abo Pass, which was cut by a small tributary to the Rio Grande. The mountains run slightly west of south for 15 miles (24 km) and widen to a maximum of about 4 miles (6.4 km) across before narrowing again. The southern end of the range is ill-defined, being marked by cuestas that merge into badlands to the south.
The Blue Springs Formation is a geologic formation expoed in the Los Pinos Mountains of central New Mexico.
The Sais Quartzite is a geologic formation exposed in the Los Pinos Mountains of central New Mexico.
The Mazatzal Group is a group of geologic formations that crops out in portions of central Arizona, US. Detrital zircon geochronology establishes a maximum age for the formation of 1660 to 1630 million years (Mya), in the Statherian period of the Precambrian. The group gives its name to the Mazatzal orogeny, a mountain-building event that took place between 1695 and 1630 Mya.
The Tijeras Greenstone is a geologic formation in central New Mexico. It has a radiometric age of 1660 million years (Ma), corresponding to the Statherian period.
The Irving Formation is a Precambrian geologic formation found in the San Juan Mountains of southwest Colorado, US. It is thought to be Statherian in age
The Yavapai Supergroup is a Paleoproterozoic supergroup of metavolcanic and metasedimentary strata, partially exposed in Arizona, US. The corresponding chronostratigraphic unit is the Yavapai Series, which locally defines an interval of geologic time. The Yavapai Supergroup gives its name to the Yavapai orogeny, a major mountain-building event that took place in the U.S. Southwest in the Paleoproterozoic.