The Halifax County complex: Oceanic lithosphere in the eastern North Carolina Piedmont

Abstract

Research Article| April 01, 1984 The Halifax County complex: Oceanic lithosphere in the eastern North Carolina Piedmont LUCILLE E. KITE; LUCILLE E. KITE 1Department of Marine, Earth, and Atmospheric Sciences, North Carolina State University, Raleigh, North Carolina 27695 Search for other works by this author on: GSW Google Scholar EDWARD F. STODDARD EDWARD F. STODDARD 1Department of Marine, Earth, and Atmospheric Sciences, North Carolina State University, Raleigh, North Carolina 27695 Search for other works by this author on: GSW Google Scholar Author and Article Information LUCILLE E. KITE 1Department of Marine, Earth, and Atmospheric Sciences, North Carolina State University, Raleigh, North Carolina 27695 EDWARD F. STODDARD 1Department of Marine, Earth, and Atmospheric Sciences, North Carolina State University, Raleigh, North Carolina 27695 Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (1984) 95 (4): 422–432. https://doi.org/10.1130/0016-7606(1984)95<422:THCCOL>2.0.CO;2 Article history First Online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation LUCILLE E. KITE, EDWARD F. STODDARD; The Halifax County complex: Oceanic lithosphere in the eastern North Carolina Piedmont. GSA Bulletin 1984;; 95 (4): 422–432. doi: https://doi.org/10.1130/0016-7606(1984)95<422:THCCOL>2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract The Halifax County complex, in the Eastern Slate Belt of North Carolina, consists of the low-grade metamorphic equivalents of the following lithologic groups: (1) an ultramafic group composed of peridotite, pyroxenite, and dunite, locally preserving cumulate textures; (2) gabbroids consisting of leucogabbro, anorthosite, and gabbro; (3) local quartz diorite and plagiogranite; and (4) a relatively large volume of porphyritic and massive basaltic rocks. Within the complex, the lithologies conform approximately, from west to east, to the sequence: peridotite and dunite-pyroxenite-anorthosite and leucogabbro-gabbro–diorite-basaltic rocks. On its west side, the complex is separated from metavolcanic rocks and metagraywackes of the Eastern Slate Belt by the late Paleozoic Hollister mylonite zone; to the east, the complex disappears beneath sediments of the Atlantic Coastal Plain. Relict primary silicate and oxide minerals include olivine of Fo79, clinopyroxene with compositional range of Wo44–49 En44–49 Fs5–9 in the ultramafic rocks and Wo34–49 En42–48 Fs8–21 in the gabbroids, plagioclase of as much as An93 in the leucogabbros, Cr-rich magnetite, and ilmenite. Major- and trace-element analyses of samples from each of the rock groups show an Fe-enrichment trend extending through the mafic sequence of gabbroids and basaltic rocks. The chemical characteristics of the basaltic rocks compare favorably with those of tholeiitic ocean-floor basalts and still more favorably with island-arc tholeiites. Field relationships, plus lithologic, geochemical, and mineralogical evidence, suggest that the complex originated as (early Paleozoic?) oceanic material. Either it represents the lower portions of a lithospheric section produced at a mid-ocean ridge or in a marginal basin, or, perhaps more likely, it was formed in the early stages of the development of an intraoceanic volcanic arc. We believe the Halifax complex is representative of the underpinnings of the Eastern Slate Belt volcanic arc. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.