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<oai_dc:dc xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd">
  <dc:contributor>A.A. Drake</dc:contributor>
  <dc:contributor>D.W. Rankin</dc:contributor>
  <dc:creator>J. Wright Horton, Jr.</dc:creator>
  <dc:date>1989</dc:date>
  <dc:description>&lt;p&gt;&lt;span&gt;Parts of the&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;central&lt;/span&gt;&lt;span&gt;&amp;nbsp;and&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;southern&lt;/span&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;Appalachian&lt;/span&gt;&lt;span&gt;&amp;nbsp;orogen appear to have evolved away from Proterozoic North America (Laurentia) and to have been accreted to it during the&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;Paleozoic&lt;/span&gt;&lt;span&gt;&amp;nbsp;orogenies that collectively formed the orogen. Identifying each&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;tectonostratigraphic&lt;/span&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;terrane&lt;/span&gt;&lt;span&gt;&amp;nbsp;is a necessary step&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;in&lt;/span&gt;&lt;span&gt;&amp;nbsp;understanding the evolution of the orogen. The&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;terranes&lt;/span&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;in&lt;/span&gt;&lt;span&gt;&amp;nbsp;the&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;central&lt;/span&gt;&lt;span&gt;&amp;nbsp;and&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;southern&lt;/span&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;Appalachians&lt;/span&gt;&lt;span&gt;&amp;nbsp;are delineated, interpreted, and classified with varying degrees of confidence as: (1) Laurentian native&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;terranes&lt;/span&gt;&lt;span&gt;, (2) internal continental&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;terranes&lt;/span&gt;&lt;span&gt;&amp;nbsp;of the&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;Appalachian&lt;/span&gt;&lt;span&gt;&amp;nbsp;orogen, (3) disrupted&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;terranes&lt;/span&gt;&lt;span&gt;, (4) possible oceanic crustal remnants, (5) volcanic-arc&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;terranes&lt;/span&gt;&lt;span&gt;, (6) a continental&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;terrane&lt;/span&gt;&lt;span&gt;&amp;nbsp;of Gondwanaland affinity, and (7) metamorphic complexes of undetermined affinity. The Laurentian native&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;terranes&lt;/span&gt;&lt;span&gt;&amp;nbsp;consist of external massifs of Laurentian basement (Grenvillian and older), their rift- and shelf-facies cover rocks, and slope-rise prism deposits. External massifs are present&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;in&lt;/span&gt;&lt;span&gt;&amp;nbsp;the Blue Ridge tectonic province, Reading Prong, and Honey Brook Upland. Rocks of the Talladega block are stratigraphically tied to Laurentia and, with the possible exception of the Hillabee greenstone, are also considered native. Offshore, deep-water, post-rift deposits of the Hamburg and Westminster&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;terranes&lt;/span&gt;&lt;span&gt;&amp;nbsp;have no direct stratigraphic ties to Laurentia and are considered discrete native (not suspect)&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;terranes&lt;/span&gt;&lt;span&gt;. The internal continental&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;terranes&lt;/span&gt;&lt;span&gt;&amp;nbsp;of the&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;Appalachian&lt;/span&gt;&lt;span&gt;&amp;nbsp;orogen are isolated massifs of Middle Proterozoic (Grenvillian) continental basement and their cover sequences that occur within the metamorphic core of the orogen. These&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;terranes&lt;/span&gt;&lt;span&gt;, the Baltimore, Sauratown, and Pine Mountain&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;terranes&lt;/span&gt;&lt;span&gt;, could be either structurally isolated outliers of Laurentia or microcontinental fragments of Laurentian crust displaced by rifting or transcurrent faulting and later reassembled. Disrupted&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;terranes&lt;/span&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;in&lt;/span&gt;&lt;span&gt;&amp;nbsp;the&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;central&lt;/span&gt;&lt;span&gt;&amp;nbsp;and&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;southern&lt;/span&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;Appalachians&lt;/span&gt;&lt;span&gt;&amp;nbsp;contain mélange complexes as well as more coherent&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;terrane&lt;/span&gt;&lt;span&gt;&amp;nbsp;fragments (volcanic, ophiolitic, or continental) intermingled with the mélange complexes. Those identified include the Jefferson, Potomac, Smith River, Inner Piedmont, Falls Lake, Juliette, and Sussex&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;terranes&lt;/span&gt;&lt;span&gt;. The Bel Air-Rising Sun&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;terrane&lt;/span&gt;&lt;span&gt;&amp;nbsp;(Baltimore Complex)&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;in&lt;/span&gt;&lt;span&gt;&amp;nbsp;Maryland and Pennsylvania is the only&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;terrane&lt;/span&gt;&lt;span&gt;&amp;nbsp;named separately as a possible oceanic crustal remnant. Similar mafic and ultramafic complexes are present&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;in&lt;/span&gt;&lt;span&gt;&amp;nbsp;all of the disrupted&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;terranes&lt;/span&gt;&lt;span&gt;, but are too small to consider as separate&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;terranes&lt;/span&gt;&lt;span&gt;. Volcanic-arc&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;terranes&lt;/span&gt;&lt;span&gt;&amp;nbsp;include the Chopawamsic, Carolina, Spring Hope, Roanoke Rapids, and Charleston&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;terranes&lt;/span&gt;&lt;span&gt;. The only&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;terrane&lt;/span&gt;&lt;span&gt;&amp;nbsp;recognized as a continental&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;terrane&lt;/span&gt;&lt;span&gt;&amp;nbsp;of Gondwanaland affinity is the Suwannee&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;terrane&lt;/span&gt;&lt;span&gt;, which contains rocks believed to correlate with those now exposed&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;in&lt;/span&gt;&lt;span&gt;&amp;nbsp;west Africa. Metamorphic complexes of undetermined affinity are&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;terranes&lt;/span&gt;&lt;span&gt;&amp;nbsp;that could not be clearly classified on the basis of available data. These include the Milton, Gaffney, Uchee, Crabtree, Goochland, Wilmington, and Hatteras&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;terranes&lt;/span&gt;&lt;span&gt;. The Penobscottian, Taconian, Acadian, and Alleghanian&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;Paleozoic&lt;/span&gt;&lt;span&gt;&amp;nbsp;compressional events collectively assembled the various&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;terranes&lt;/span&gt;&lt;span&gt;&amp;nbsp;into what is now the&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;Appalachian&lt;/span&gt;&lt;span&gt;&amp;nbsp;orogen. Only the&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;central&lt;/span&gt;&lt;span&gt;&amp;nbsp;and&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;southern&lt;/span&gt;&lt;span&gt;&amp;nbsp;parts of the U.S.&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;Appalachians&lt;/span&gt;&lt;span&gt;&amp;nbsp;are considered here. The Penobscottian orogeny, about 550 to 490 Ma, amalgamated the Potomac, the Chopawamsic, probably the Bel Air-Rising Sun, and possibly other exotic&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;terranes&lt;/span&gt;&lt;span&gt;&amp;nbsp;at some unknown distance from Laurentia. This was followed by the Taconian orogeny, about 470 to 440 Ma, which accreted the previously amalgamated&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;terranes&lt;/span&gt;&lt;span&gt;&amp;nbsp;and probably other&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;terranes&lt;/span&gt;&lt;span&gt;&amp;nbsp;such as the Carolina&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;terrane&lt;/span&gt;&lt;span&gt;&amp;nbsp;to Laurentia. The younger age limit for the Taconian event is partly constrained by Middle and Late Ordovician faunal assemblages&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;in&lt;/span&gt;&lt;span&gt;&amp;nbsp;successor basin deposits of the Arvonia Slate and Quantico Formation. The significance of the Acadian orogeny, dated about 400 to 380 Ma&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;in&lt;/span&gt;&lt;span&gt;&amp;nbsp;New England, is unclear&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;in&lt;/span&gt;&lt;span&gt;&amp;nbsp;the&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;central&lt;/span&gt;&lt;span&gt;&amp;nbsp;and&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;southern&lt;/span&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;Appalachians&lt;/span&gt;&lt;span&gt;.&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;In&lt;/span&gt;&lt;span&gt;&amp;nbsp;the Talladega block of Alabama and Georgia, an Early to Middle Devonian dynamothermal event is firmly bracketed between Early Devonian fossils and K-Ar ages that indicate a thermal peak no later than Middle Devonian time. A regional tectonothermal event and faulting of approximately this age are also suggested by isotopic studies&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;in&lt;/span&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;terranes&lt;/span&gt;&lt;span&gt;&amp;nbsp;to the east. The late&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;Paleozoic&lt;/span&gt;&lt;span&gt;&amp;nbsp;(Alleghanian) continental collision between Laurentia and Gondwanaland, which formed the supercontinent Pangea, marks the final stage of accretionary history&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;in&lt;/span&gt;&lt;span&gt;&amp;nbsp;the&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;Appalachian&lt;/span&gt;&lt;span&gt;-Caledonide orogen. Effects evident&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;in&lt;/span&gt;&lt;span&gt;&amp;nbsp;the&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;central&lt;/span&gt;&lt;span&gt;&amp;nbsp;and&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;southern&lt;/span&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;Appalachian&lt;/span&gt;&lt;span&gt;&amp;nbsp;region include: (1) the accretion of the Suwannee&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;terrane&lt;/span&gt;&lt;span&gt;&amp;nbsp;and perhaps the Charleston&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;terrane&lt;/span&gt;&lt;span&gt;&amp;nbsp;to what is now North America, (2) slicing and shifting of&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;terranes&lt;/span&gt;&lt;span&gt;&amp;nbsp;along dextral strike-slip faults, particularly&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;in&lt;/span&gt;&lt;span&gt;&amp;nbsp;the eastern Piedmont, (3) westward transport of native and previously accreted&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;terranes&lt;/span&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;in&lt;/span&gt;&lt;span&gt;&amp;nbsp;the western Piedmont and Blue Ridge as part of a composite crystalline thrust sheet, (4) deposition of clastic wedges&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;in&lt;/span&gt;&lt;span&gt;&amp;nbsp;the&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;Appalachian&lt;/span&gt;&lt;span&gt;&amp;nbsp;foreland, and (5) imbricate thrusting and folding of the resultant strata&amp;nbsp;&lt;/span&gt;&lt;span class="ScopusTermHighlight"&gt;in&lt;/span&gt;&lt;span&gt;&amp;nbsp;the Valley and Ridge Province.&lt;/span&gt;&lt;/p&gt;</dc:description>
  <dc:format>application/pdf</dc:format>
  <dc:identifier>10.1130/SPE230-p213</dc:identifier>
  <dc:language>en</dc:language>
  <dc:publisher>Geological Society of America</dc:publisher>
  <dc:title>Tectonostratigraphic terranes and their Paleozoic boundaries in the central and southern Appalachians</dc:title>
  <dc:type>article</dc:type>
</oai_dc:dc>