Neoacadian Phase

Results shown limited to content with bounding coordinates.
Follow your search
Access your saved searches in your account

Would you like to receive an alert when new items match your search?
Close Modal
Sort by
Series: GSA Memoirs
Published: 23 January 2023
DOI: 10.1130/2022.1220(26)
EISBN: 9780813782201
... orogenic front. Orogenesis continued in the Late Devonian to Carboniferous Neoacadian orogeny. This phase was also associated with amphibolite-facies metamorphism and intrusion of I- and S-type granitoids. Widespread crustal melting and 50–60 km crustal thicknesses may have favored the development...
FIGURES | View All (11)
Journal Article
Journal: Geology
Published: 22 April 2021
Geology (2021) 49 (8): 946–951.
...Ian W. Hillenbrand; Michael L. Williams Abstract The Acadian and Neoacadian orogenies are widely recognized, yet poorly understood, tectono-thermal events in the New England Appalachian Mountains (USA). We quantified two phases of Paleozoic crustal thickening using geochemical proxies. Acadian (425...
FIGURES | View All (4)
Series: Geological Society, London, Special Publications
Published: 01 January 2009
DOI: 10.1144/SP327.13
EISBN: 9781862395756
... with accretion of these microcontinents are known as the Taconic, Salinic, Acadian and Neoacadian orogenies, respectively. The Ordovician Taconic orogeny was a composite event comprising three different phases, due to involvement of three peri-Laurentian oceanic and continental terranes. The Taconic orogeny...
FIGURES | View All (20)
Series: GSA Memoirs
Published: 11 September 2017
DOI: 10.1130/2017.1213(10)
EISBN: 9780813782133
.... Clustering within these data reveals that the Blue Ridge and Inner Piedmont terranes were affected by three tectonothermal events: (1) 462–448 Ma (Taconic); (2) 395–340 Ma (Acadian and Neoacadian); and (3) 335–322 Ma, related to the early phase of the Alleghanian orogeny. By combining zircon rim ages...
Series: GSA Field Guide
Published: 01 January 2012
DOI: 10.1130/2012.0029(11)
EISBN: 9780813756295
... orogeny, this event is now called the Neoacadian orogeny. Active deformational loading during the event initially produced the Sunbury black-shale basin, whereas subsequent relaxational phases produced the Borden-Grainger-Price-Pocono and Pennington–Mauch Chunk clastic wedges, which largely reflect...
FIGURES | View All (46)
Series: GSA Field Guide
Published: 24 September 2021
DOI: 10.1130/2021.0061(07)
EISBN: 9780813756615
... select field locations in a rough transect across the orogen from Ducktown, Tennessee, to Goldville, Alabama. Metamorphic rocks from nine locations are described and analyzed in order to construct quantitative P-T-t paths, utilizing isochemical phase diagram sections and garnet Sm-Nd ages. P-T-t...
FIGURES | View All (42)
Journal Article
Published: 01 October 2015
American Mineralogist (2015) 100 (10): 2254–2271.
... crop out in the southern end of the Central Maine Terrane and thus are a part of the Acadian/Neoacadian Orogen. The typical mineral assemblage is garnet + sillimanite + K-feldspar + plagioclase + quartz + cordierite + biotite ± spinel. The sillimanite is commonly pseudomorphous after kyanite...
FIGURES | View All (12)
Series: GSA Memoirs
Published: 01 January 2004
DOI: 10.1130/0-8137-1197-5.525
... in the core near the southwest end. The coarse augen gneiss phase constitutes a larger proportion of the Toxaway Gneiss toward the northeast. Field evidence indicates that the augen phase intruded the banded Toxaway lithology; U/Pb isotopic ages of these lithologies, however, are statistically...
Journal Article
Published: 01 November 2018
American Mineralogist (2018) 103 (11): 1851–1868.
...Duncan S. Keller; Jay J. Ague Abstract We quantify the metamorphic pressure-temperature ( P-T ) conditions for a newly discovered silica-undersaturated high-pressure granulite (HPG) from the Central Maine Terrane (CMT) in northeastern Connecticut, U.S.A. The rocks lie within the Acadian-Neoacadian...
FIGURES | View All (10)
Journal Article
Journal: Lithosphere
Publisher: GSW
Published: 01 December 2009
Lithosphere (2009) 1 (6): 337–342.
... at ca. 390 Ma and was associated with widespread migmatization. A third metamorphic event (M3) occurred during the ca. 378–371 Ma time interval and was possibly associated with the Neoacadian orogeny. Intermittent monazite growth during the 360–305 Ma interval suggests that the main phase...
FIGURES | View All (5)
Journal Article
Journal: Geology
Published: 01 October 2016
Geology (2016) 44 (10): 871–874.
... and Alleghanian tectonic phases ( Fig. 2 ). The insensitivity of the U-Pb detrital zircon system to magma-poor Neoacadian and Alleghanian orogenesis in the southern Appalachians, a region central to the Paleozoic evolution of Laurentia, highlights the incompleteness of the detrital zircon record when...
Journal Article
Journal: Geosphere
Published: 05 January 2023
Geosphere (2023) 19 (1): 19–46.
... of the southern Appalachian Acadian-Neoacadian deformational and metamorphic core. The granite occurs as disconnected concordant to semi-concordant plutons in migmatitic, sillimanite zone rocks of the Brindle Creek thrust sheet. Locally garnet-bearing, the Walker Top Granite contains blocky alkali feldspar...
FIGURES | View All (15)
Journal Article
Journal: Lithosphere
Publisher: GSW
Published: 14 August 2019
Lithosphere (2019) 11 (5): 722–749.
... geochemistry, and zircon Lu-Hf isotope data analyses were applied to six intrusions that were emplaced over a period of more than 40 m.y. during and following Neoacadian deformation in the eastern Blue Ridge of Alabama. Garnet Sm-Nd geochronology, pressure-temperature ( P - T ) phase diagram sections...
FIGURES | View All (13)
Journal Article
Published: 11 April 2022
Journal of Sedimentary Research (2022) 92 (3): 304–319.
... Ordovician Taconic and Middle Devonian Acadian ages with two discrete modes at 463 and 369 Ma, and the latter dominated by Late Ordovician Taconic, Middle Devonian Acadian, and Late Devonian Neoacadian ages with discrete modes at 445, 397, 360, and 351 Ma. The new data suggest that early Pennsylvanian...
FIGURES | View All (13)
Journal Article
Journal: Geosphere
Published: 02 November 2021
Geosphere (2021) 17 (6): 1840–1860.
... and Ridge. Both the Cambrian Chilhowee Group and Pennsylvanian Pottsville Formation exhibit (U-Th)/He dates ranging from 507 to 263 Ma with a Mississippian subset (353–329 Ma, n = 4), which indicates rapid cooling and inferred exhumation during Late Devonian–Early Mississippian Neoacadian tectonism. We...
FIGURES | View All (9)
Journal Article
Published: 21 September 2015
Canadian Journal of Earth Sciences (2015) 52 (10): 921–937.
... to the contact, the Alleghanian cleavage (S 2 ) is parallel to the contact in both units, with S 0 in the White Rock Formation metavolcanic rocks and Halifax slate parallel to and discordant to the contact. The geometry of deformed Neoacadian minor folds, quartz fringes on sulphide grains, and micro...
FIGURES | View All (17)
Journal Article
Journal: GSA Bulletin
Published: 16 May 2017
GSA Bulletin (2017) 129 (9-10): 1195–1208.
... Appalachians, is controversial in the southern Appalachians. Some researchers suggest that it occurred in the Late Devonian–Mississippian and refer to this tectonic phase as the Neoacadian ( Hatcher, 1987 ; Hatcher et al., 2007 ). Others consider the Acadian orogeny to be largely absent in this region aside...
FIGURES | View All (5)
Journal Article
Published: 01 July 2016
The Canadian Mineralogist (2016) 54 (4): 945–969.
... to Mississippian Neoacadian orogeny and the Pennsylvanian to Permian Alleghanian orogeny. Thus the New England LCT pegmatites were emplaced during the latter stages of the assembly of Pangea. 40 Ar/ 39 Ar muscovite ages from 11 LCT and one NYF pegmatites range from ca . 339 to ca . 243 Ma and are interpreted...
FIGURES | View All (10)
Journal Article
Published: 11 November 2014
Geological Magazine (2015) 152 (5): 767–787.
... to directly date mineral reactions and hence metamorphic equilibrium assemblages, but also ductile deformation in white mica-bearing rocks. Deformation-induced recrystallization of white mica and associated phases will generally lead to complete Sr-isotopic re-equilibration...
FIGURES | View All (6)
Journal Article
Published: 19 June 2012
Canadian Journal of Earth Sciences (2012) 49 (7): 781–795.
...- and northeast-trending folds with associated axial planar cleavage during the Middle Devonian ( Hicks et al. 1999 ), an event referred to here as the Neoacadian orogeny following van Staal (2007) and White et al. (2007) . They were intruded by abundant 385–357 Ma peraluminous granitoid rocks (e.g., Clarke...