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Marquenas Formation
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. Description The Marquenas Formation was first believed to be over 80% quartzite, with the rest mostly metaconglomerate. The metaconglomerate lenses are found throughout the formation but particularly towards its top, and it was designated the Marquenas Quartzite. However, Bauer and Williams noted that the unit is about equally divided between quartzite and metaconglomerate, which led them to redesignate it as the Marquenas Formation. It can be divided into a lower, highly strained, poorly sorted boulder conglomerate; a middle quartzite member; and an upper, highly strained, pebble-to-cobble conglomerate. Cross stratification shows that the layering is overturned, and this supported the interpretation of the formation as part of the Vadito Group, likely ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Picuris Mountains
The Picuris Mountains are a mountain range in northern New Mexico. They are considered a subrange of the Sangre de Cristo Mountains. Geography The mountains are located to the east of Dixon and surround Picuris Pueblo to the west, north, and east. The range resembles a triangle with its base to the east, along the valley of the Rio Grande del Rancho. The northwest face lies along the valley of the Rio Grande and the southern face lies along Rio Pueblo and Embudo Creek. History The area was first visited by Europeans on July 13, 1598, when Juan de Oñate visited Picuris Pueblo. Geology The range is underlain by Precambrian rock beds of the Hondo Group and Vadito Group. It is the namesake for the Picuris orogeny. Economy Mining has been historically important in the Picuris Mountains. The Harding Pegmatite Mine was operated off and on from about 1900 to 1958, when it was donated to the University of New Mexico as an outdoor geological laboratory. At one time, the mine made ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Big Rock Formation
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. Description The Big Rock Formation consists of a lower conglomerate member with minor micaceous quartzite and an upper quartzite member. The conglomerate is a medium to dark gray quartz pebble metaconglomerate with minor quartzite beds, interpreted as braided alluvial deposits. The pebbles are mostly of light gray quartz but with some ferruginous chert. Pebble sizes are from 1 to 20 cm and the pebbles are systematically elongated. Crossbedding is pervasive. Flattened felsic clasts may be metamorphosed pumice.Simmons ''et al.'' 2011, p.360 It is exposed in the central Tusas Mountains, where it is distinctive enough to be an important stratigraphic marker bed. Its thickness is typically . Detrital zircon geochronology yields a minimum age for the source regions of 1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Precambrian Formations Of New Mexico
The Precambrian (or Pre-Cambrian, sometimes abbreviated pꞒ, or Cryptozoic) is the earliest part of Earth's history, set before the current Phanerozoic Eon. The Precambrian is so named because it preceded the Cambrian, the first period of the Phanerozoic Eon, which is named after Cambria, the Latinised name for Wales, where rocks from this age were first studied. The Precambrian accounts for 88% of the Earth's geologic time. The Precambrian is an informal unit of geologic time, subdivided into three eons ( Hadean, Archean, Proterozoic) of the geologic time scale. It spans from the formation of Earth about 4.6 billion years ago ( Ga) to the beginning of the Cambrian Period, about million years ago ( Ma), when hard-shelled creatures first appeared in abundance. Overview Relatively little is known about the Precambrian, despite it making up roughly seven-eighths of the Earth's history, and what is known has largely been discovered from the 1960s onwards. The Precambrian fossi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Precambrian
The Precambrian (or Pre-Cambrian, sometimes abbreviated pꞒ, or Cryptozoic) is the earliest part of Earth's history, set before the current Phanerozoic Eon. The Precambrian is so named because it preceded the Cambrian, the first period of the Phanerozoic Eon, which is named after Cambria, the Latinised name for Wales, where rocks from this age were first studied. The Precambrian accounts for 88% of the Earth's geologic time. The Precambrian is an informal unit of geologic time, subdivided into three eons ( Hadean, Archean, Proterozoic) of the geologic time scale. It spans from the formation of Earth about 4.6 billion years ago ( Ga) to the beginning of the Cambrian Period, about million years ago ( Ma), when hard-shelled creatures first appeared in abundance. Overview Relatively little is known about the Precambrian, despite it making up roughly seven-eighths of the Earth's history, and what is known has largely been discovered from the 1960s onwards. The Precambrian fos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Picuris Orogeny
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. Description Age and isotope data show that southern North America is composed of a series of northeast-trending provinces representing island arc terranes accreted onto the 1800 Mya core of La ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hondo Group
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. Geology The Hondo Group consists of a lower very clean quartzite (the Ortega Formation) and upper schists, quartzites, and slates. The total thickness is about .Montgomery 1953 The upper section is absent in the Tusas Mountains, where the Hondo Group is essentially synonymous with the Ortega Formation. The upper section is assigned to the Rinconada Formation in the Picuris Mountains. The most complete section is in the northern Picuris Mountains, where the Hondo Group fills an overturned syncline. Detrital zircon geochronology establishes an age for the lower Hondo Group of 1765 to 1704 Mya.Jones ''et al.'' 2011 The Pilar and Piedra Lumbre Formations were originally included in the Hondo Group ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mya (unit)
Mya may refer to: Brands and product names * Mya (program), an intelligent personal assistant created by Motorola * Mya (TV channel), an Italian Television channel * Midwest Young Artists, a comprehensive youth music program Codes * Burmese language, ISO 639-3 code is * Moruya Airport's IATA code * The IOC, license plate, and UNDP country code for Myanmar Myanmar, ; UK pronunciations: US pronunciations incl. . Note: Wikipedia's IPA conventions require indicating /r/ even in British English although only some British English speakers pronounce r at the end of syllables. As John Wells explai ... ("MYA") People * Mya (given name) * Mya (singer) (Mya Marie Harrison, born 1979), an American R&B singer-songwriter and actress * Bo Mya (1927–2006), nom de guerre of a Myanmar rebel leader, chief rapist of the Karen National Union Other uses * ''Mýa'' (album), a 1998 album by Mýa * ''Mya'' (bivalve), a genus of soft-shell clams * MYA (unit) for "million ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pilar Formation
The Pilar Formation is a geologic formation that crops out in the Picuris Mountains of northern New Mexico. It has a radiometric age of 1488 ± 6 million years, corresponding to the Calymmian period. Description The Pilar Formation consists of a dense gray-black to black hard carbonaceous phyllite or schist with thin white schistose layers that are interpreted as a metatuff. The rock has very irregular slaty cleavage, with tiny muscovite flakes visible in the hand lens. It contains many quartz veins and some limonite augens. Its composition is 50% to 75% quartz and 15% to 30% muscovite with carbonaceous material finely disseminated throughout the quartz and muscovite grains. Montgomery rejected its designation as a slate, as it has undergone middle-grade metarmophism along with the underlying staurolite-bearing Rinconada Formation. A metamorphosed tuff bed in the Pilar Formation yields an age of 1488 ± 6 Mya, considerably younger than the Rinconada Formation. This suggests t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Manzano Group
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 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. However, the name was abandoned after 1920. Description 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 thick. The group records deformation attributed to the Mazatzal orogeny, and the quartzites of the group may be the provenance of the lower conglomerates of the Marquena ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ortega Formation
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. Jones ''et al.'' 2011 Description The Ortega Formation consists of a very clean (98% modal quartzBauer 2004, p.198), typically bluish-white, quartzite, with some beds near the base of the formation composed of metaconglomerate. Crossbedding is found throughout the formation, and aluminosilicate minerals are abundant within the formation. These show that its lower beds were buried deeply enough to be metamorphosed to the sillimanite facies, at temperatures of over . The Ortega Formation is the principal ridge-forming formation of the Picuris Mountains and is a uniform thick. The contact between the Ortega Formation and the underlying Vadito Group is fairly easy to trace using a regional manganese-rich marker bed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tusas Mountains
The Tusas Mountains are a mountain range in northern New Mexico, extending slightly into southern Colorado. They are considered the southeasternmost part of the San Juan Mountains. Grouse Mesa, , is the highest peak in the range. The mountains are located to the west of Taos and northwest of Santa Fe. The Tusas Mountains are a wide region of upland mesas and gently sloping mountains, dissected in places by deep canyons. Geography The eastern part of the range is primarily located in the Carson National Forest, bordered by the Taos Plateau volcanic field and Rio Grande del Norte National Monument to the east. It provides the headwaters for the Rio San Antonio, a tributary of the Conejos River (which flows into the Rio Grande in Colorado), and further south the Rio Tusas and Rio Vallecito, which form the Rio Ojo Caliente, a tributary of the Rio Chama (also a Rio Grande tributary). Numerous volcanic features are located along the eastern edge of the range bordering the Taos plateau ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vadito Group
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. Description The Vadito Group is an extensive sequence of supracrustal rocks dominated by feldspathic gneisses, feldspathic schists, and metamorphosed sandstones and conglomerates. Its lower section includes amphibolites, though mafic beds make up less than 10% of the unit. It is found in the Picuris Mountains, the Tusas Mountains, the Truchas Range, the Mora River area, the Rincon Mountains (), the northern Taos Range, and in the Cimarron Range. Detrital zircon geochronology establishes that the principal source regions for the sediments that became the Vadito Group had ages of 1765 to 1704 Mya. The absolute age of the Burned Mountain Formation constituting the upper part of the Vadito Group in the Tusas Mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
