The carbonate aquifers of the Appalachian Valley and Ridge Province, formed during Appalachian mountain building, have highly variable karst aquifer characteristics. The Valley and Ridge, Piedmont, and Blue Ridge Aquifers demonstrate karst features such as caves, sinkholes, sinking streams, and conduits.
The carbonate aquifers of the Appalachian Valley and Ridge Province are formed within a thick Paleozoic sequence of layered carbonate and siliciclastic rocks that were highly folded and faulted during Appalachian mountain building. Fluid flow thus has been through complex geologic structures, resulting in highly variable karst aquifer characteristics with a wide range of groundwater residence times, geochemical characteristics, and aquifer compartmentalization. Cave geometries likewise are variable, ranging from small, isolated caves of limited extent to some of the longest and deepest caves known in the United States.
The Great Valley aquifer is the primary carbonate aquifer in the Valley and Ridge Province, formed within a sequence of Cambrian and Ordovician rocks over 10,000 feet (3,048 meters) thick. This aquifer is an important water resource for numerous cities and towns along the Interstate 81 corridor from Tennessee to Pennsylvania.
The northern extent of the Great Valley in Virginia, West Virginia, and Maryland has been particularly well studied, especially within the drainage basin of the Shenandoah River. Larger springs typical of the Shenandoah Valley karst aquifer are 4th and 5th magnitude (10-500 gal/min; 0.6 to 28 L/sec) artesian springs, most with relatively muted discharge variability. Geologic structure strongly influences spring locations, discharge and geochemistry. Spring discharge accounts for more than 85% of stream flow in the Shenandoah River basin. As a result, surface-water quantity and quality is highly dependent on groundwater use and management. Circulation of groundwater through conduits exceeds depths of 2000 feet (610 meters) as evidenced by a small number of high-yield deep wells. Most wells are finished less than 300 feet (100 meters) below land surface and may yield between 1-150 gal/min (0.063-9.45 L/s). While the majority of springs have ambient water temperatures, many mildly thermal springs have been identified.
The Shenandoah Valley karst hosts a number of unique endemic species. Of note is the Madison Cave Isopod (Antrolana lira), a crustacean of originally marine ancestry found only caves containing fresh groundwater in the Shenandoah Valley region.
Sinkholes
Featured Studies and Datasets
Aquifer-scale studies and the datasets they produce are a key component to understanding how karst aquifers behave, and the quality of water within them.
- Assessment of the Northern Shenandoah Valley karst aquifer — Hydrogeologic assessment and simulation of groundwater flow.
Additional Information
The following websites are additional sources of information about this aquifer:
Below are other science projects associated with karst aquifers.
Karst Aquifers
Karst Aquifers: Arbuckle-Simpson Aquifer
Karst Aquifers: Basin and Range and Bear River Range Carbonate Aquifers
Karst Aquifers: Colorado Plateau Karst
Karst Aquifers: Edwards Balcones Fault Zone Aquifer
Karst Aquifers: Edwards-Trinity Plateau Aquifer
Karst Aquifers: Upper Floridan and Biscayne Aquifers
Karst Aquifers: Madison Aquifer
Karst Aquifers: Midwest Paleozoic Carbonate Aquifers
Karst Aquifers: New England Karst Aquifers
Karst Aquifers: Ozark Plateau Karst Aquifers
Karst Aquifers: Roswell Basin Aquifer
Karst Aquifers: Pacific Northwest Pseudokarst Aquifers
- Overview
The carbonate aquifers of the Appalachian Valley and Ridge Province, formed during Appalachian mountain building, have highly variable karst aquifer characteristics. The Valley and Ridge, Piedmont, and Blue Ridge Aquifers demonstrate karst features such as caves, sinkholes, sinking streams, and conduits.
The carbonate aquifers of the Appalachian Valley and Ridge Province are formed within a thick Paleozoic sequence of layered carbonate and siliciclastic rocks that were highly folded and faulted during Appalachian mountain building. Fluid flow thus has been through complex geologic structures, resulting in highly variable karst aquifer characteristics with a wide range of groundwater residence times, geochemical characteristics, and aquifer compartmentalization. Cave geometries likewise are variable, ranging from small, isolated caves of limited extent to some of the longest and deepest caves known in the United States.
The Great Valley aquifer is the primary carbonate aquifer in the Valley and Ridge Province, formed within a sequence of Cambrian and Ordovician rocks over 10,000 feet (3,048 meters) thick. This aquifer is an important water resource for numerous cities and towns along the Interstate 81 corridor from Tennessee to Pennsylvania.
The northern extent of the Great Valley in Virginia, West Virginia, and Maryland has been particularly well studied, especially within the drainage basin of the Shenandoah River. Larger springs typical of the Shenandoah Valley karst aquifer are 4th and 5th magnitude (10-500 gal/min; 0.6 to 28 L/sec) artesian springs, most with relatively muted discharge variability. Geologic structure strongly influences spring locations, discharge and geochemistry. Spring discharge accounts for more than 85% of stream flow in the Shenandoah River basin. As a result, surface-water quantity and quality is highly dependent on groundwater use and management. Circulation of groundwater through conduits exceeds depths of 2000 feet (610 meters) as evidenced by a small number of high-yield deep wells. Most wells are finished less than 300 feet (100 meters) below land surface and may yield between 1-150 gal/min (0.063-9.45 L/s). While the majority of springs have ambient water temperatures, many mildly thermal springs have been identified.
The Shenandoah Valley karst hosts a number of unique endemic species. Of note is the Madison Cave Isopod (Antrolana lira), a crustacean of originally marine ancestry found only caves containing fresh groundwater in the Shenandoah Valley region.
Sinkholes
Sources/Usage: Public Domain.Flourescent tracer is injected into a sinkhole as part of intensive investigations of the hydrogeology, water quality, and groundwater flow of the karst aquifer in the Hopewell Run Watershed, northern Shenandoah Valley, near Leetown, West Virginia. (Credit: Mark Kozar, USGS.) Featured Studies and Datasets
Aquifer-scale studies and the datasets they produce are a key component to understanding how karst aquifers behave, and the quality of water within them.
- Assessment of the Northern Shenandoah Valley karst aquifer — Hydrogeologic assessment and simulation of groundwater flow.
Additional Information
The following websites are additional sources of information about this aquifer:
- Science
Below are other science projects associated with karst aquifers.
Karst Aquifers
Karst terrain is created from the dissolution of soluble rocks, principally limestone and dolomite. Karst areas are characterized by distinctive landforms (like springs, caves, sinkholes) and a unique hydrogeology that results in aquifers that are highly productive but extremely vulnerable to contamination.Filter Total Items: 13Karst Aquifers: Arbuckle-Simpson Aquifer
The Arbuckle-Simpson aquifer, which underlies more than 500 square miles in south central Oklahoma, is the principal water source for approximately 39,000 people in several cities in the region. The U.S. Environmental Protection Agency has designated the aquifer's eastern portion as a Sole Source Aquifer, a mechanism to protect drinking water supplies in areas with limited water supply.Karst Aquifers: Basin and Range and Bear River Range Carbonate Aquifers
In the Basin and Range, bedrock is present in the uplifted blocks of the mountain ranges and beneath fill in the valleys. While some of this bedrock is relatively impermeable, fracturing may enable groundwater to circulate through the rock, enlarging and increasing the size and number of pathways for water movement. This can ultimately produce a permeable water-yielding unit.Karst Aquifers: Colorado Plateau Karst
In northern and central Arizona, the Kaibab Limestone and its equivalents are karstic. North of the Grand Canyon, subterranean openings are primarily widely spaced fissures, while south of the Grand Canyon, fissures are more closely spaced and a few shallow caves are present.Karst Aquifers: Edwards Balcones Fault Zone Aquifer
The Edwards aquifer is the most transmissive of all the aquifers in Texas and Oklahoma, with large discharges from springs and from flowing and pumped wells. This aquifer demonstrates karst features such as springs and in-stream sinkholes, as well as endangered species.Karst Aquifers: Edwards-Trinity Plateau Aquifer
The Edwards-Trinity aquifer, located in the Trans-Pecos and the Edwards Plateau areas, is composed of relatively flat-lying rocks that are generally exposed at the land surface. This aquifer is generally recharged by precipitation; water is mostly unconfined in the shallow parts of the aquifer and is confined in the deeper zones.Karst Aquifers: Upper Floridan and Biscayne Aquifers
Covering approximately 100,000 square miles of the southeastern United States, the Floridan aquifer system (FAS) is one of the most productive aquifers in the world. The FAS is the primary source of drinking water for almost 10 million people, with nearly 50 percent of all water withdrawals being used for industrial purposes and agricultural irrigation.Karst Aquifers: Madison Aquifer
The Madison aquifer underlies eight states in the U.S. and Canada. It is an important water resource in the northern plains states where surface water supplies are limited and population is increasing. Declining water levels are a major issue for many of the communities that rely on this aquifer.Karst Aquifers: Midwest Paleozoic Carbonate Aquifers
The porosity of carbonate and dolomitic units in Midwest Paleozoic rocks has been enhanced by dissolution, and in many areas these rocks have undergone extensive karst development. This aquifer demonstrates karst features such as disappearing streams, springs, and caves.Karst Aquifers: New England Karst Aquifers
The New England Karst Aquifers feature crystalline limestones and marbles, narrow fissures, and some small caves.Karst Aquifers: Ozark Plateau Karst Aquifers
The Ozark Plateaus aquifer system consists of two aquifers, the Springfield Plateau aquifer and the Ozark aquifer, and an intervening confining unit. The system consists of mostly of carbonate rocks that are Cambrian through Mississippian in age.Karst Aquifers: Roswell Basin Aquifer
The Roswell Artesian Basin consists of an eastward-dipping carbonate aquifer overlain by a leaky evaporitic confining unit, overlain in turn by an unconfined alluvial aquifer. This aquifer provides habitat for several federally listed endangered invertebrate species. Decades of intensive pumping have caused substantial declines in hydraulic head in the aquifer.Karst Aquifers: Pacific Northwest Pseudokarst Aquifers
Pseudokarst features such as lava tubes, fissures, open sinkholes, and caves, are extensive in some regions of the west. Some of the largest regions with this type of pseudokarst are located in the Pacific Northwest, including the Snake River area of Idaho, part of the Columbia Basalt Plateau in Washington and Oregon, and in the lava fields of northeastern California. - Publications