North Carolina Geology: North Carolina Geology Tom Shields NCST 2000 (Fall 2007)


Major Rock Types: Major Rock Types There are three major rock types: Sedimentary originate from the consolidation of sediments derived in part from living organisms but chiefly from older rocks of all classes. Examples: sandstone, shale Igneous originate from the cooling and solidification of molten matter from the earth's interior. Examples: granite Metamorphic originate from the alteration of the texture and mineral constituents of igneous, sedimentary, and older metamorphic rocks under extreme heat and pressure deep within the earth. Examples: gneiss (usually granite based), schist( basalt [igneous], shale [sedimentary], or slate [metamorphic] based) Minerals inorganic substance occurring in nature, having a characteristic and homogeneous chemical composition, definite physical properties, and, usually, a definite crystalline form. Minerals combine with each other to make up rocks, which, as distinguished from minerals, are of heterogeneous composition. Examples: Phosphate, mica, gold


A Geologic Overview of North Carolina: A Geologic Overview of North Carolina A good overview of North Carolina’s geology can be found at th U.S. Geological Survey’s 'America's Volcanic Past—North Carolina' andlt;http://vulcan.wr.usgs.gov/ LivingWith/VolcanicPast/Places/volcanic_past_north_carolina.htmlandgt;.


A Geologic Cross-Section of North Carolina: A Geologic Cross-Section of North Carolina Different rock types predominate in different regions: Coastal Plains: Sedimentary Piedmont: A mix of Metamorphic and Igneous Mountains: Metamorphic


Another Cross-Section of North Carolina: Another Cross-Section of North Carolina


The Fall Line: The Fall Line The Fall Line is marked by the shift of the soft rocks of the Coastal Plain to the harder crystalline rocks of the Piedmont.


Triassic Basin: Triassic Basin Triassic Basin long lowlands, mainly along the southeastern edge of the Piedmont where the crust of the Piedmont fractured and great blocks subsided Rivers filled these valleys with sediments from the adjacent land. Have small iron and coal deposits that were mined during the colonial era. Durham, Sanford and Wadesboro are in Triassic Basins.


Monadnocks: Monadnocks Monadnocks Areas where more resistant rock is left when softer rock around it has eroded away, leaving hills or mountains. Examples of such mountains are the Uwharries, Kings Mountain, and Pilot Mountain. Many Piedmont towns and cites are built on Monadnocks, such as Charlotte, Kannapolis, Chapel Hill, and Raleigh. Pilot Mountain, Surry and Yadkin Counties Crowders Mountain, Gaston County


Coastal Plain Aquifers: Coastal Plain Aquifers An aquifer is an underground bed or layer of earth, gravel, or porous stone that yields water. We will deal with aquifers more fully when we study water resources.


Minerals: Minerals Among North Carolina’s most important minerals are phosphate, feldspar, talc, lithium, mica, olivine, asbestos, and various gemstones. North Carolina has a greater variety of minerals than any other state—more than 300. The largest Emerald ever found in North Carolina was 1,438 carats and was found at Hiddenite, near Statesville. For information on the economic mining of North Carolina minerals and rocks, see andlt;http://minerals.usgs.gov/minerals/pubs/state/nc.htmlandgt;.