The Hillsboro district, in central New Mexico, is an example of the typical geologic style of the development of Laramide porphyry copper deposits in southwestern United States. Porphyry copper deposits form from hydrothermal fluids that come from a magmatic source, generally a volcano. The copper is concentrated first by magmatic-hydrothermal processes, then copper can be further concentrated by later supergene fluids, typically meteoric waters. Porphyry copper deposits typically are large deposits and are mined mostly by open pit methods and can have by-product production of gold, silver, molybdenum, and other metals. Other types of deposits, such as skarns and polymetallic veins can occur near the porphyry copper deposits. Much of the world's copper is produced from porphyry copper deposits.
The hydrogeology studies group (known as the Aquifer Mapping Program), at the New Mexico Bureau of Geology and Mineral Resources, received an important gift in 2016 from the Healy Foundation to benefit the New Mexico’s water and natural resources. The funds will be used to support two new water-focused, multi-year programs for the state.
In 2012, our Aquifer Mapping Program at the Bureau of Geology initiated a paleohydrogeology study in the area of El Camino Real De Tierra Adentro, which is a National Historic Trail designated by Congress. This study is part of the Mitigation Plan that is being implemented by Spaceport America, with funding from New Mexico Spaceport Authority.
The Albuquerque Basin is one of the largest (8,000 km2, 3,060 mi2) and deepest basins (4,407-6,592 m, 14,500-21,600 ft) of the Rio Grande rift. This basin contains the largest metropolitan area in New Mexico. Until 2008, this region relied entirely on groundwater for its water supply. This sole reliance on groundwater resulted from an earlier view that Albuquerque lay on top of the subterranean equivalent of a vast underground lake that would take centuries to exploit. Since the 1960s, the City of Albuquerque had little reason to be concerned about its water supply because wells drilled in the northeast and southeast heights yielded large quantities of potable groundwater. The view of plentiful groundwater was essentially unchallenged until the late 1980s, when water level declines near Coronado Center provoked exploration of the deeper aquifer. Results of the deep aquifer test wells led to reassessment of the regional aquifer and the Middle Rio Grande Basin Project of the late 1990s.
New Mexico is home to many hundreds of volcanoes that erupted during the last several million years. However, the exact timing of these eruptions has proven difficult to determine by many previous studies. An ongoing NSF-funded project, led by NM Bureau of Geology researcher Matthew Zimmerer, examines the timing of eruptions during the last 500,000 years in order to understand the patterns of volcanism in space and time. This information provides the foundation for an assessment of volcanic hazards in New Mexico.
It is surprising that New Mexico does not have a detailed map of all of the productive and accessible aquifers across the state. In a state with as little as 0.24% of our land surface covered with water (the least in the country!), having detailed maps of our groundwater resources and aquifers, is essential. Some of our neighboring states, like Texas and Colorado, have these maps already available, and are successfully being used to administer and conserve water. We have started a new multi-year project to develop 3D maps of aquifers.
Bruce D. Allen, Bureau of Geology field geologist, is studying the hydrology of the playa lakes in the Estancia basin in order to reconstruct major changes in climate that have affected this region in the past. Dr. Allen and researchers from the University of New Mexico have instrumented the playas with a network of meteorological stations and piezometers to track seasonal changes in climate and groundwater flow systems.
The population centers in Alamogordo, Carrizozo, La Luz, and numerous other small communities, are largely supported by groundwater resources. With few perennial streams in this closed basin, water is sparse. Fresh water resources are limited, and recharge to these areas originates within the high elevation watersheds in the Sacramento Mountains, as precipitation, stream and spring flow. This goal of this study was to improve understanding of the groundwater resources in this region by identifying recharge areas and quantities, determining groundwater flow rates and direction, and to interpret the groundwater/surface water interactions that exist in the region. Methods used in this effort included geologic mapping, groundwater level measurements, and geochemical analyses of the groundwater, springs and streams.
The bureau has been involved for many years in studying the geologic framework and petroleum geology of the Mancos Shale, in the San Juan Basin of northwest New Mexico. Development of resources within the Mancos Shale are likely to constitute a large portion of future oil and natural gas production in the state.
Building on its basin-scale hydrogeologic studies of the Española Basin (2003-2010), in 2010-2013 the Aquifer Mapping Program helped develop a better understanding of the groundwater contribution to the wetlands around La Cienega. This work was completed with collaboration and support from NMED, NMOSE, Santa Fe County, and USF&WS.
