Manzano Group | |
---|---|
Stratigraphic range: | |
Type | Group |
Sub-units | Blue Springs Formation Sais Quartzite Estadio Schist White Ridge Quartzite Abajo Formation Sevilleta Metarhyolite Bootleg Canyon Sequence Tijeras Greenstone |
Thickness | 2,700 meters (8,900 ft) |
Lithology | |
Primary | Metarhyolite, quartzite |
Other | Schist, amphibolite |
Location | |
Coordinates | 34°20′N106°35′W / 34.33°N 106.59°W |
Region | New Mexico |
Country | United States |
Type section | |
Named for | Manzano Mountains |
Named by | A. Luther |
Year defined | 2006 |
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. [1] [2] [3]
The name Manzano Group was previously applied to a group of sedimentary formations of Permian age in roughly the same geographical area. The original Manzano Group was historically important in the establishment of the paleontological time scale of the Permian period in western North America. [4] However, the name was abandoned after 1920. [5] [6]
The group consists of Statherian lithostratigraphic units exposed in the Los Pinos Mountains and nearby ranges of central New Mexico. These are mostly metarhyolite or quartzite units with some schist and amphibolite, and form a sequence in excess of 2,700 meters (8,900 ft) thick. [1] The group records deformation attributed to the Mazatzal orogeny, [1] [2] and the quartzites of the group may be the provenance of the lower conglomerates of the Marquenas Formation to the north, [2] which was previously problematic. [7] Study of the group also provides evidence in favor of the hypothesis that the Mazatzal Province was formed by continental arc volcanism from Yavapai crust. The group was subsequently severely folded and intruded by magma bodies during the Picuris orogeny. [3]
The group is best exposed in an overturned syncline in the Los Pinos Mountains. Here the stratigraphy is: [3]
The Estadio Schist is a garnet + staurolite + biotite schist, described as a marker bed separating the Sais Quartzite from the White Ridge Quartzite. [8]
The Manzano Series was first named by Herrick in 1900. Herrick correctly placed the Carboniferous - Permian boundary just below the base of this unit and identified Permian fossils in overlying beds, but could find no fossils within the series itself. [9] Gordon assigned the underlying beds to the (now-abandoned) Magdalena Group and added the overlying limestone beds now assigned to the San Andres Formation, and placed the Manzano Group in the upper Carboniferous [10] based on fossils reported by Lee and Girty. [4] The name continued in use at least as late as 1920, when Boese concluded from ammonite fossils that the Abo Formation was Uralian (Cisuralian?) in age. This placed the fossils in the upper Pennsylvanian as defined in western North America at that time, and Boese recommended abandonment, or at least heavy revision, of the Manzano Group. [6]
The modern units corresponding to the original Manzano Group are (in ascending stratigraphic order) the Bursum Formation, Abo Formation, Yeso Formation, Glorieta Sandstone, and San Andres Formation. [5] The Yeso Formation has itself been promoted to group rank, [11] though this has not been universally accepted. [12]
The name Manzano Group was revived in 2006 to refer to latest Statherian formations in the Manzano Mountains, [1] a usage that has since become more widely adopted. [2] [3]
The San Andres Formation is a geologic formation found in New Mexico and Texas. It contains fossils characteristic of the late Leonardian (Kungurian) Age) of the Permian Period.
The Abo Formation is a geologic formation in New Mexico. It contains fossils characteristic of the Cisuralian epoch of the Permian period.
The Yeso Group is a group of geologic formations in New Mexico. It contains fossils characteristic of the Kungurian Age of the early Permian Period.
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 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.
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 Vadito Group is a group of geologic formations that crops out in most of the Precambrian-cored uplifts of northern New Mexico. Detrital zircon geochronology and radiometric dating give a consistent age of 1700 Mya for the group, corresponding to the Statherian period.
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 Glenwoody Formation is a geological formation that is exposed in the cliffs southeast of the Rio Grande Gorge near the town of Pilar and in a few other locations in the Picuris Mountains. Its minimum age from detrital zircon geochronology is 1.693 Mya, corresponding to the Statherian period.
The Hondo Group is a group of geologic formations that crops out in most of the Precambrian-cored uplifts of northern New Mexico. Detrital zircon geochronology gives a maximum age for the lower Hondo Group of 1765 to 1704 million years (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 Los Pinos Mountains are a small mountain range in the central part of New Mexico, US. They 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 White Ridge Quartzite is a geologic formation in central New Mexico. It has a maximum age of 1650 million years (Ma), corresponding to the Statherian period.
The Blue Springs Formation is a geologic formation exposed 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 Abajo Formation is a geologic formation in the Los Pinos Mountains of central New Mexico. It was deposited about 1660 million years (Ma) ago, corresponding to the Statherian period.
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 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.