Caballo Mountains: Difference between revisions
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The Rio Grande Rift is a continental rift zone, which extends approximately 680 miles (~1,100 km) from central [[Colorado]] in the north to the state of [[Chihuahua]], [[Mexico]] in the south. It is the product of [[extensional]], (or divergent) [[tectonic]] forces that formed a series of [[basins]] between the [[Colorado Plateau]] and the North American [[craton]]<ref name=chapin 1994>{{cite book|last=Chapin |first=C. |last2=Cather |first2=S. |year=1994 |title=Tectonic setting of the axial basins of the northern and central Rio Grande rift |book=Geological Society of America Special Paper 291 |pages=1–3 |ISBN=0-8137-2291-8</ref> Thin continental [[crust]], [[normal fault]] block topography, high regional elevation, and [[volcanism]] is found over the course of the rift. <ref name=seager 2003>{{cite book|last=Seager |first=William R.|last2=Mack |first2=Greg H. |year=2003 |title=Geology of the Caballo Mountains, New Mexico|publisher=New Mexico Bureau of Geology and Mineral Resources|pages=106-112|isbn=1-883905-15-X</ref> |
The Rio Grande Rift is a continental rift zone, which extends approximately 680 miles (~1,100 km) from central [[Colorado]] in the north to the state of [[Chihuahua]], [[Mexico]] in the south. It is the product of [[extensional]], (or divergent) [[tectonic]] forces that formed a series of [[basins]] between the [[Colorado Plateau]] and the North American [[craton]]<ref name=chapin 1994>{{cite book|last=Chapin |first=C. |last2=Cather |first2=S. |year=1994 |title=Tectonic setting of the axial basins of the northern and central Rio Grande rift |book=Geological Society of America Special Paper 291 |pages=1–3 |ISBN=0-8137-2291-8</ref> Thin continental [[crust]], [[normal fault]] block topography, high regional elevation, and [[volcanism]] is found over the course of the rift. <ref name=seager 2003>{{cite book|last=Seager |first=William R.|last2=Mack |first2=Greg H. |year=2003 |title=Geology of the Caballo Mountains, New Mexico|publisher=New Mexico Bureau of Geology and Mineral Resources|pages=106-112|isbn=1-883905-15-X</ref> |
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{{Timeline Geological Timescale}} |
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The history of movement along the rift has been divided into three separate stages: an initial stage during the late [[Eocene]] to early [[Oligocene]], a second stage during the late Oligocene to late [[Miocene]], and a third stage beginning in the late Miocene or early [[Pliocene]] and continuing to the recent past. <ref name=seager 2003 />. Activity in the vicinity of the Caballos during the first stage included explosive [[rhyolitic]] eruptions from [[cauldrons]] located in two different parts of the [[San Mateo Mountains|Socorro County]], in the [[Black Range]], in the [[Dona Ana Mountains]], and in the [[Organ Mountains]]. <ref name=seager 2003 /> The subsiding of the basin appears to have begun around 34.9 Ma <ref name=seager 2003 />The Caballo Mountains began to rise in the late Oligocene, and throughout the Miocene. Approximately 9.6 Ma, the eruption of [[basalts]] near [[Fort Selden]] signaled the renewal of crustal extension and volcanism in the southern part of the rift. Activity along both older and new faults increased the number, but decreased the width of basins along this portion of the rift. <ref name=seager 2003 /> |
The history of movement along the rift has been divided into three separate stages: an initial stage during the late [[Eocene]] to early [[Oligocene]], a second stage during the late Oligocene to late [[Miocene]], and a third stage beginning in the late Miocene or early [[Pliocene]] and continuing to the recent past. <ref name=seager 2003 />. Activity in the vicinity of the Caballos during the first stage included explosive [[rhyolitic]] eruptions from [[cauldrons]] located in two different parts of the [[San Mateo Mountains|Socorro County]], in the [[Black Range]], in the [[Dona Ana Mountains]], and in the [[Organ Mountains]]. <ref name=seager 2003 /> The subsiding of the basin appears to have begun around 34.9 Ma <ref name=seager 2003 />The Caballo Mountains began to rise in the late Oligocene, and throughout the Miocene. Approximately 9.6 Ma, the eruption of [[basalts]] near [[Fort Selden]] signaled the renewal of crustal extension and volcanism in the southern part of the rift. Activity along both older and new faults increased the number, but decreased the width of basins along this portion of the rift. <ref name=seager 2003 /> |
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Revision as of 06:51, 20 February 2011
Caballo Mountains (New Mexico) new article content ...
Template:Geobox
The Caballo Mountains are a mountain range located in Dona Ana County and Sierra County, New Mexico, United States. The range is located east of the Rio Grande and Caballo Lake, and west of the Jornada del Muerto. The nearest towns are Truth or Consequences and Hatch. Most of the range is located on land owned by the Bureau of Land Management. The mountains are unusual, and perhaps unique in New Mexico, for the relatively complete geologic history revealed by their rocks. Vehicular access to the range is by Interstate 25 from the west, by New Mexico Highway 51 from the north, and by several dirt roads from the east.
Geography
The Caballo Mountains trend north and south, with a length of approximately 32 miles (50 km). The width of the range varies from 3-6 miles (5-10 km). The highest point on the range, Timber Mountain (7,565 feet), has a topographic prominence of approximately 3,400 feet.
The types, sizes, and profiles of the Caballo watersheds vary significantly according to the part of the range that they drain. No perennial streams flow through the mountains, although the Rio Grande flows westward around their northern end, parallel to their main axis, and eastward around their southern end. The northern part of the Caballos drains into the Rio Grande through Ash Canyon and Mescal Canyon. The confluences of those two intermittent streams are just below Elephant Butte Dam, east of the main axis of the mountains, and northwest (upstream) of Truth or Consequences. Water falling on the precipitous west face of the range drains directly into the Rio Grande by means of numerous first order canyons with high gradients. Most of these canyons are several miles south (downstream) of Truth or Consequences, and all are ephemeral.
In contrast, the eastern side has only two primary drainages, each with a much lower gradient. Water falling on the southern half of the east side flows into Barbee Draw. After joining another tributary near Point of Rocks to form Rincon Arroyo, this ephemeral drainage flows into the Rio Grande near Rincon, New Mexico. The north portion of the east side flows into Jornada Draw. This part of the Jornada del Muerto, however, is endorheic and has no surface connection to the Rio Grande.
Geology
The Rio Grande Rift is a continental rift zone, which extends approximately 680 miles (~1,100 km) from central Colorado in the north to the state of Chihuahua, Mexico in the south. It is the product of extensional, (or divergent) tectonic forces that formed a series of basins between the Colorado Plateau and the North American cratonCite error: The <ref> tag has too many names (see the help page). Thin continental crust, normal fault block topography, high regional elevation, and volcanism is found over the course of the rift. Cite error: The <ref> tag has too many names (see the help page).
The following five timelines show the geologic time scale to scale. The first shows the entire time from the formation of the Earth to the present, but this gives little space for the most recent eon. The second timeline shows an expanded view of the most recent eon. In a similar way, the most recent era is expanded in the third timeline, the most recent period is expanded in the fourth timeline, and the most recent epoch is expanded in the fifth timeline.
(Horizontal scale is millions of years for the above timelines; thousands of years for the timeline below)
The history of movement along the rift has been divided into three separate stages: an initial stage during the late Eocene to early Oligocene, a second stage during the late Oligocene to late Miocene, and a third stage beginning in the late Miocene or early Pliocene and continuing to the recent past. Cite error: The <ref> tag has too many names (see the help page).. Activity in the vicinity of the Caballos during the first stage included explosive rhyolitic eruptions from cauldrons located in two different parts of the Socorro County, in the Black Range, in the Dona Ana Mountains, and in the Organ Mountains. Cite error: The <ref> tag has too many names (see the help page). The subsiding of the basin appears to have begun around 34.9 Ma Cite error: The <ref> tag has too many names (see the help page).The Caballo Mountains began to rise in the late Oligocene, and throughout the Miocene. Approximately 9.6 Ma, the eruption of basalts near Fort Selden signaled the renewal of crustal extension and volcanism in the southern part of the rift. Activity along both older and new faults increased the number, but decreased the width of basins along this portion of the rift. Cite error: The <ref> tag has too many names (see the help page).
Ecology
References
Hawley, J.W. Guidebook to Rio Grande rift in New Mexico and Colorado New Mexico Bureau of Mines and Mineral Resources, Socorro 1978. Mack, Greg J.,The Geology of Southern New Mexico, University of New Mexico Press, Albuquerque 1997 Seager, William R. and Greg H. Mack, Geology of the Caballo Mountains, New Mexico New Mexico Bureau of Geology and Mineral Resources, Socorro 2003