Rock Run is a

tributary A tributary, or an ''affluent'', is a stream or river that flows into a larger stream (''main stem'' or ''"parent"''), river, or a lake. A tributary does not flow directly into a sea or ocean. Tributaries, and the main stem river into which they ...

of Martins Creek in Lower Makefield Township in

Bucks County Bucks County is a county in the Commonwealth of Pennsylvania. As of the 2020 census, the population was 646,538, making it the fourth-most populous county in Pennsylvania. Its county seat is Doylestown. The county is named after the English ...

Pennsylvania Pennsylvania, officially the Commonwealth of Pennsylvania, is a U.S. state, state spanning the Mid-Atlantic (United States), Mid-Atlantic, Northeastern United States, Northeastern, Appalachian, and Great Lakes region, Great Lakes regions o ...

in the

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

Statistics

Rock Run was entered into the

Geographic Names Information System The Geographic Names Information System (GNIS) is a database of name and location information about more than two million physical and cultural features, encompassing the United States and its territories; the Compact of Free Association, asso ...

of the

U.S. Geological Survey The United States Geological Survey (USGS), founded as the Geological Survey, is an agency of the U.S. Department of the Interior whose work spans the disciplines of biology, geography, geology, and hydrology. The agency was founded on March ...

on 2 August 1979 as identification number 1185276. It is also listed in the Pennsylvania Gazatteer of Streams as identification number 02922.

Course

Rock Run rises near Big Oak Road and Stony Hill Road in the southern portion of Lower Makefield Township at an elevation of approximately and is generally east oriented until

river mile A river mile is a measure of distance in miles along a river from its river mouth, mouth. River mile numbers begin at zero and increase further upstream. The corresponding metric unit using kilometre, kilometers is the river kilometer. They are an ...

2.87 where it makes a 90° turn to the right flowing south as it receives a tributary from the left. After about a mile it then turns east, then south and southwest until it discharges at Martins Creek's 3.20 river mile.

Geology

Atlantic Plain The Atlantic Plain is one of eight distinct physiographic regions of the United States, physiographic divisions of the contiguous United States. Using the USGS physiographic classification system, the Atlantic Plain division comprises two provinc ...

Atlantic Coastal Plain The Atlantic Ocean is the second largest of the world's five borders of the oceans, oceanic divisions, with an area of about . It covers approximately 17% of Earth#Surface, Earth's surface and about 24% of its water surface area. During the ...

Province ***Lowland and Intermediate Upland Section **** Trenton Gravel ****Pensauken and Bridgeton Formations Rock Run rises in the

Felsic In geology, felsic is a grammatical modifier, modifier describing igneous rocks that are relatively rich in elements that form feldspar and quartz.Marshak, Stephen, 2009, ''Essentials of Geology,'' W. W. Norton & Company, 3rd ed. It is contrasted ...

Gneiss Gneiss (pronounced ) is a common and widely distributed type of metamorphic rock. It is formed by high-temperature and high-pressure metamorphic processes acting on formations composed of igneous or sedimentary rocks. This rock is formed under p ...

formation laid during the

Precambrian The Precambrian ( ; or pre-Cambrian, sometimes abbreviated pC, or Cryptozoic) is the earliest part of Earth's history, set before the current Phanerozoic Eon. The Precambrian is so named because it preceded the Cambrian, the first period of t ...

, light buff to pink and medium to fine grained rock,

mineralogy Mineralogy is a subject of geology specializing in the scientific study of the chemistry, crystal structure, and physical (including optical mineralogy, optical) properties of minerals and mineralized artifact (archaeology), artifacts. Specific s ...

includes

quartz Quartz is a hard, crystalline mineral composed of silica (silicon dioxide). The Atom, atoms are linked in a continuous framework of SiO4 silicon–oxygen Tetrahedral molecular geometry, tetrahedra, with each oxygen being shared between two tet ...

microcline Microcline (KAlSi3O8) is an important igneous rock-forming tectosilicate mineral. It is a potassium-rich alkali feldspar. Microcline typically contains minor amounts of sodium. It is common in granite and pegmatites. Microcline forms during s ...

pyroxene The pyroxenes (commonly abbreviated Px) are a group of important rock-forming inosilicate minerals found in many igneous and metamorphic rocks. Pyroxenes have the general formula , where X represents ions of calcium (Ca), sodium (Na), iron ( ...

, and

biotite Biotite is a common group of phyllosilicate minerals within the mica group, with the approximate chemical formula . It is primarily a solid-solution series between the iron- endmember annite, and the magnesium-endmember phlogopite; more al ...

. As it flows east, it runs into the Pensauken and Bridgeton Formations laid down during the

Tertiary Tertiary (from Latin, meaning 'third' or 'of the third degree/order..') may refer to: * Tertiary period, an obsolete geologic period spanning from 66 to 2.6 million years ago * Tertiary (chemistry), a term describing bonding patterns in organic ch ...

period, yellow to reddish brown feldspathic quartz

sand Sand is a granular material composed of finely divided mineral particles. Sand has various compositions but is usually defined by its grain size. Sand grains are smaller than gravel and coarser than silt. Sand can also refer to a textural ...

, coarse

gravel Gravel () is a loose aggregation of rock fragments. Gravel occurs naturally on Earth as a result of sedimentation, sedimentary and erosion, erosive geological processes; it is also produced in large quantities commercially as crushed stone. Gr ...

, and

boulder In geology, a boulder (or rarely bowlder) is a rock fragment with size greater than in diameter. Smaller pieces are called cobbles and pebbles. While a boulder may be small enough to move or roll manually, others are extremely massive. In ...

. Then it finally flows into the Trenton Gravel Formation from the Quaternary, consisting of feldspathic quartz sand which is reddish brown, yellow, and white, with some beds of gravel.

Crossings and Bridges

References

{{authority control Rivers of Bucks County, Pennsylvania Rivers of Pennsylvania Tributaries of the Delaware River

Statistics

Course

Geology

Crossings and Bridges

See also

References