The Ordovician

Ordovician

The Ordovician is a geologic period and system, the second of six of the Paleozoic Era, and covers the time between 488.3±1.7 to 443.7±1.5 million years ago . It follows the Cambrian Period and is followed by the Silurian Period...

 Kittatinny Formation or Kittatinny Limestone is a dolomitic limestone

Dolostone

Dolostone or dolomite rock is a sedimentary carbonate rock that contains a high percentage of the mineral dolomite. In old U.S.G.S. publications it was referred to as magnesian limestone. Most dolostone formed as a magnesium replacement of limestone or lime mud prior to lithification. It is...

 formation in New Jersey

New Jersey

New Jersey is a state in the Northeastern and Middle Atlantic regions of the United States. , its population was 8,791,894. It is bordered on the north and east by the state of New York, on the southeast and south by the Atlantic Ocean, on the west by Pennsylvania and on the southwest by Delaware...

. The Kittatiny Limestones are located primarily within the long valley running from Picatinny Arsenal

Picatinny Arsenal

The Picatinny Arsenal is an American military research and manufacturing facility located on a lot in northern New Jersey near Lake Denmark. The Arsenal is the headquarters of the United States Army Armament Research, Development and Engineering Center...

 in Rockaway Township

Rockaway Township, New Jersey

Rockaway Township is a township in Morris County, New Jersey, United States. As of the 2010 United States Census, the township population was 24,156....

, southwest toward Chester Township

Chester Township, New Jersey

Chester Township is a township in Morris County, New Jersey, United States. As of the 2010 United States Census, the township population was 7,838....

. It overlies the Cambrian

Cambrian

The Cambrian is the first geological period of the Paleozoic Era, lasting from Mya ; it is succeeded by the Ordovician. Its subdivisions, and indeed its base, are somewhat in flux. The period was established by Adam Sedgwick, who named it after Cambria, the Latin name for Wales, where Britain's...

 Hardyston Quartzite

Hardyston Quartzite

The Cambrian Hardyston Formation or Hardyston Quartzite is a mapped bedrock unit in Pennsylvania and New Jersey.It was originally described by Wolff and Brooks in 1898, where two outcrops in Hardyston Township, Sussex County, New Jersey, were described...

.

The Kittatinny is now usually considered a Supergroup, rather than a Formation, as it includes several other Groups

Group (stratigraphy)

A group in stratigraphy is a lithostratigraphic unit, a part of the geologic record or rock column that consists of defined rock strata. Groups are divided into formations and are sometimes themselves grouped into "supergroups"....

 and Formations. Drake and Lyttle made this revision in 1980. The Supergroup includes the Leithsville Formation, Allentown Dolomite, and Beekmantown Group (which in turn includes the Stonehenge Limestone, Rickenbach Dolomite, Epler Formation, and Ontelaunee Formation). Richard Dalton wrote a more recent review of the stratigraphy

Stratigraphy

Stratigraphy, a branch of geology, studies rock layers and layering . It is primarily used in the study of sedimentary and layered volcanic rocks....

 of the Kittatinny.

The Kittatinny Limestone in New Jersey locally contains hydrocarbons and numerous accessory minerals including fluorite

Fluorite

Fluorite is a halide mineral composed of calcium fluoride, CaF2. It is an isometric mineral with a cubic habit, though octahedral and more complex isometric forms are not uncommon...

, sphalerite

Sphalerite

Sphalerite is a mineral that is the chief ore of zinc. It consists largely of zinc sulfide in crystalline form but almost always contains variable iron. When iron content is high it is an opaque black variety, marmatite. It is usually found in association with galena, pyrite, and other sulfides...

, arsenopyrite

Arsenopyrite

Arsenopyrite is an iron arsenic sulfide . It is a hard metallic, opaque, steel grey to silver white mineral with a relatively high specific gravity of 6.1. When dissolved in nitric acid, it releases elemental sulfur. When arsenopyrite is heated, it becomes magnetic and gives off toxic fumes...

, galena

Galena

Galena is the natural mineral form of lead sulfide. It is the most important lead ore mineral.Galena is one of the most abundant and widely distributed sulfide minerals. It crystallizes in the cubic crystal system often showing octahedral forms...

, quartz

Quartz

Quartz is the second-most-abundant mineral in the Earth's continental crust, after feldspar. It is made up of a continuous framework of SiO4 silicon–oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall formula SiO2. There are many different varieties of quartz,...

, albite

Albite

Albite is a plagioclase feldspar mineral. It is the sodium endmember of the plagioclase solid solution series. As such it represents a plagioclase with less than 10% anorthite content. The pure albite endmember has the formula NaAlSi3O8. It is a tectosilicate. Its color is usually pure white, hence...

, and others. The Kittatiny is an exception to the general rule that Paleozoic rocks in this area are generally poor aquifers, since wells drilled into it produce relatively large flows of water.