New Albany Shale
Encyclopedia
The New Albany Shale is an organic-rich geologic formation of Devonian
and Mississippian age in the Illinois Basin
of the United States
. It is a major source of hydrocarbons.
with minor beds of dolomite
and sandstone
. It was deposited under anoxic marine conditions. Pyrite
is a common accessory mineral, and parts of the shale have greater than 4% by weight of organic carbon. The black shale layers have anomalously high radioactivity (due to uranium
), phosphorus
, and heavy metals. The formation was named for outcrops near New Albany, Indiana
. It is one of a number of organic-rich shales of upper Devonian
and lower Mississippian age in North America. It is correlative with the Antrim Shale
of the Michigan Basin
, the Ohio Shale of Ohio
and eastern Kentucky
, and the Chattanooga Shale of Tennessee
and central Kentucky.
The formation is composed of six members. These members in ascending stratigraphic order are the Blocher, the Selmier, the Morgan Trail, the Camp Run, the Clegg Creek and the Ellsworth. The Blocher consists of brownish-black to grayish-black, slightly calcareous pyritic shale. The Selmier is a greenish-gray to olive-gray shale. The Morgan Trail is a brownish-black to olive-black fissile siliceous pyritic shale. The Camp Run is a greenish-gray to olive-gray shale interbedded with brownish-black shale. The Clegg Creek is a brownish black pyritic shale that is rich in organic matter. The Ellsworth is composed of a lower part of interbedded brownish-black shale and an upper part of greenish-gray shale.
is produced from wells completed in the New Albany Shale in the southern part of the basin in Indiana
and western Kentucky. As of 2001, technically recoverable shale gas
in the New Albany was estimated to be between 1.9 and 19.2 trillion cubic feet. More recently reserves have been estimated as high as 160 trillion cubic feet.
The New Albany Shale is also a major deposit of oil shale
. The Eastern Devonian shale has been estimated to contain 189,000 106 bbls of oil.
The formation is also thought to be the source rock
of petroleum
found in Devonian and Silurian
formations in the basin. It is hypothesized that the long distance migration of oil from the New Albany Shale into surrounding sandstones was caused by orogenies occurring to the east. These orogenies caused periods of uplift and subsidence that influenced movement of the hydrocarbons in the Illinois Basin.
Devonian
The Devonian is a geologic period and system of the Paleozoic Era spanning from the end of the Silurian Period, about 416.0 ± 2.8 Mya , to the beginning of the Carboniferous Period, about 359.2 ± 2.5 Mya...
and Mississippian age in the Illinois Basin
Illinois Basin
The Illinois Basin is a Paleozoic depositional and structural basin in the United States, centered in and underlying most of the state of Illinois, and extending into southwestern Indiana and western Kentucky...
of the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
. It is a major source of hydrocarbons.
Stratigraphy
The New Albany formation consists of brown, black, and green shaleShale
Shale is a fine-grained, clastic sedimentary rock composed of mud that is a mix of flakes of clay minerals and tiny fragments of other minerals, especially quartz and calcite. The ratio of clay to other minerals is variable. Shale is characterized by breaks along thin laminae or parallel layering...
with minor beds of dolomite
Dolomite
Dolomite is a carbonate mineral composed of calcium magnesium carbonate CaMg2. The term is also used to describe the sedimentary carbonate rock dolostone....
and sandstone
Sandstone
Sandstone is a sedimentary rock composed mainly of sand-sized minerals or rock grains.Most sandstone is composed of quartz and/or feldspar because these are the most common minerals in the Earth's crust. Like sand, sandstone may be any colour, but the most common colours are tan, brown, yellow,...
. It was deposited under anoxic marine conditions. Pyrite
Pyrite
The mineral pyrite, or iron pyrite, is an iron sulfide with the formula FeS2. This mineral's metallic luster and pale-to-normal, brass-yellow hue have earned it the nickname fool's gold because of its resemblance to gold...
is a common accessory mineral, and parts of the shale have greater than 4% by weight of organic carbon. The black shale layers have anomalously high radioactivity (due to uranium
Uranium
Uranium is a silvery-white metallic chemical element in the actinide series of the periodic table, with atomic number 92. It is assigned the chemical symbol U. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons...
), phosphorus
Phosphorus
Phosphorus is the chemical element that has the symbol P and atomic number 15. A multivalent nonmetal of the nitrogen group, phosphorus as a mineral is almost always present in its maximally oxidized state, as inorganic phosphate rocks...
, and heavy metals. The formation was named for outcrops near New Albany, Indiana
New Albany, Indiana
New Albany is a city in Floyd County, Indiana, United States, situated along the Ohio River opposite Louisville, Kentucky. In 1900, 20,628 people lived in New Albany; in 1910, 20,629; in 1920, 22,992; and in 1940, 25,414. The population was 36,372 at the 2010 census. The city is the county seat of...
. It is one of a number of organic-rich shales of upper Devonian
Devonian
The Devonian is a geologic period and system of the Paleozoic Era spanning from the end of the Silurian Period, about 416.0 ± 2.8 Mya , to the beginning of the Carboniferous Period, about 359.2 ± 2.5 Mya...
and lower Mississippian age in North America. It is correlative with the Antrim Shale
Antrim Shale
The Antrim Shale is a formation of Upper Devonian age in the Michigan Basin, in the US state of Michigan, and extending into Ohio and Indiana. It is a major source of natural gas in the northern part of the basin....
of the Michigan Basin
Michigan Basin
The Michigan Basin is a geologic basin centered on the Lower Peninsula of the US state of Michigan. The feature is represented by a nearly circular pattern of geologic sedimentary strata in the area with a nearly uniform structural dip toward the center of the peninsula.The basin is centered in...
, the Ohio Shale of Ohio
Ohio
Ohio is a Midwestern state in the United States. The 34th largest state by area in the U.S.,it is the 7th‑most populous with over 11.5 million residents, containing several major American cities and seven metropolitan areas with populations of 500,000 or more.The state's capital is Columbus...
and eastern Kentucky
Kentucky
The Commonwealth of Kentucky is a state located in the East Central United States of America. As classified by the United States Census Bureau, Kentucky is a Southern state, more specifically in the East South Central region. Kentucky is one of four U.S. states constituted as a commonwealth...
, and the Chattanooga Shale of Tennessee
Tennessee
Tennessee is a U.S. state located in the Southeastern United States. It has a population of 6,346,105, making it the nation's 17th-largest state by population, and covers , making it the 36th-largest by total land area...
and central Kentucky.
The formation is composed of six members. These members in ascending stratigraphic order are the Blocher, the Selmier, the Morgan Trail, the Camp Run, the Clegg Creek and the Ellsworth. The Blocher consists of brownish-black to grayish-black, slightly calcareous pyritic shale. The Selmier is a greenish-gray to olive-gray shale. The Morgan Trail is a brownish-black to olive-black fissile siliceous pyritic shale. The Camp Run is a greenish-gray to olive-gray shale interbedded with brownish-black shale. The Clegg Creek is a brownish black pyritic shale that is rich in organic matter. The Ellsworth is composed of a lower part of interbedded brownish-black shale and an upper part of greenish-gray shale.
Natural resources
Natural gasNatural gas
Natural gas is a naturally occurring gas mixture consisting primarily of methane, typically with 0–20% higher hydrocarbons . It is found associated with other hydrocarbon fuel, in coal beds, as methane clathrates, and is an important fuel source and a major feedstock for fertilizers.Most natural...
is produced from wells completed in the New Albany Shale in the southern part of the basin in Indiana
Indiana
Indiana is a US state, admitted to the United States as the 19th on December 11, 1816. It is located in the Midwestern United States and Great Lakes Region. With 6,483,802 residents, the state is ranked 15th in population and 16th in population density. Indiana is ranked 38th in land area and is...
and western Kentucky. As of 2001, technically recoverable shale gas
Shale gas
Shale gas is natural gas produced from shale. Shale gas has become an increasingly important source of natural gas in the United States over the past decade, and interest has spread to potential gas shales in the rest of the world...
in the New Albany was estimated to be between 1.9 and 19.2 trillion cubic feet. More recently reserves have been estimated as high as 160 trillion cubic feet.
The New Albany Shale is also a major deposit of oil shale
Oil shale
Oil shale, an organic-rich fine-grained sedimentary rock, contains significant amounts of kerogen from which liquid hydrocarbons called shale oil can be produced...
. The Eastern Devonian shale has been estimated to contain 189,000 106 bbls of oil.
The formation is also thought to be the source rock
Source rock
In petroleum geology, source rock refers to rocks from which hydrocarbons have been generated or are capable of being generated. They form one of the necessary elements of a working petroleum system. They are organic-rich sediments that may have been deposited in a variety of environments including...
of petroleum
Petroleum
Petroleum or crude oil is a naturally occurring, flammable liquid consisting of a complex mixture of hydrocarbons of various molecular weights and other liquid organic compounds, that are found in geologic formations beneath the Earth's surface. Petroleum is recovered mostly through oil drilling...
found in Devonian and Silurian
Silurian
The Silurian is a geologic period and system that extends from the end of the Ordovician Period, about 443.7 ± 1.5 Mya , to the beginning of the Devonian Period, about 416.0 ± 2.8 Mya . As with other geologic periods, the rock beds that define the period's start and end are well identified, but the...
formations in the basin. It is hypothesized that the long distance migration of oil from the New Albany Shale into surrounding sandstones was caused by orogenies occurring to the east. These orogenies caused periods of uplift and subsidence that influenced movement of the hydrocarbons in the Illinois Basin.
External links
- D.L. Stevenson, L.L. Whiting, and R.M. Cluff, 1981, Geologic structure of the base of the New Albany Shale Group in Illinois, Illinois State Geological Survey, Illinois Petroleum 121, PDF file.