|
|
 |
|||||||||||||||||
|
|||||||||||||||||
 |
|||||||||||||||||
| JOURNAL HOME | HELP | CONTACT PUBLISHER | SUBSCRIBE | ARCHIVE | SEARCH | TABLE OF CONTENTS |
1 Woods Hole Oceanographic Institution–Massachusetts Institute of Technology Joint Program in Oceanography, Woods Hole, Massachusetts 02543, USA
2 Department of Geology and Geophysics, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, USA
The Lough Nafooey arc, in the western Irish Caledonides, collided with Laurentia during the Early Ordovician. This event is recorded in the stratigraphy of the South Mayo trough, the preserved forearc basin of this system. Lavas at the base of the oldest Lough Nafooey Group show intraoceanic arc composition. 
Nd(t) decreases and light rare earth elements (REEs) become more enriched upsection in the Lough Nafooey Group (ca. 495– 481 Ma), reflecting early collision with Laurentia. The subsequent Tourmakeady Group (ca. 481–470 Ma) is rhyolitic, light REE enriched, and has strongly negative Nd(t). These rocks were erupted during the Grampian orogeny. The Rosroe and Mweelrea Formations (<470 Ma) show wide scatter of La/Sm and Nb/Zr values, suggesting mixed mantle sources. This correlates with rapid exhumation of the adjacent Connemara metamorphic terrane. The chemical evolution of the arc supports models of collision, orogeny, and tectonic unroofing within 
15 m.y., and shows that genesis of magmas more enriched than continental crust can occur during arc-continent collision, clarifying the potential role of arc volcanism in continental crust formation.
Key Words: Caledonides • Iapetus • Ireland • subduction • geochemistry
This article has been cited by other articles:
|
|
 |
|
  B. McConnell, N. Riggs, and Q. G. Crowley Detrital zircon provenance and Ordovician terrane amalgamation, western Ireland Journal of the Geological Society, May 1, 2009; 166(3): 473 - 484. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. E. Draut, P. D. Clift, J. M. Amato, J. Blusztajn, and H. Schouten Arc-continent collision and the formation of continental crust: a new geochemical and isotopic record from the Ordovician Tyrone Igneous Complex, Ireland Journal of the Geological Society, May 1, 2009; 166(3): 485 - 500. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 P. D. Ryan Preservation of forearc basins during island arc-continent collision: Some insights from the Ordovician of western Ireland Geological Society of America Special Papers, January 1, 2008; 436(0): 1 - 9. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. R. Smyth, R. Hall, and G. J. Nichols Cenozoic volcanic arc history of East Java, Indonesia: The stratigraphic record of eruptions on an active continental margin Geological Society of America Special Papers, January 1, 2008; 436(0): 199 - 222. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. J. Dorais, J. Workman, and J. Aggarwal The petrogenesis of the Highlandcroft and Oliverian Plutonic Suites, New Hampshire: Implications for the structure of the Bronson Hill terrane Am J Sci, January 1, 2008; 308(1): 73 - 99. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. G. Barnes, C. D. Frost, A. S. Yoshinobu, K. McArthur, M. A. Barnes, C. M. Allen, O. Nordgulen, and T. Prestvik Timing of sedimentation, metamorphism, and plutonism in the Helgeland Nappe Complex, north-central Norwegian Caledonides Geosphere, December 1, 2007; 3(6): 683 - 703. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. M. Chew, J. R. Graham, and M. J. Whitehouse U-Pb zircon geochronology of plagiogranites from the Lough Nafooey (= Midland Valley) arc in western Ireland: constraints on the onset of the Grampian orogeny Journal of the Geological Society, July 1, 2007; 164(4): 747 - 750. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. J. ROBERTS, F. CORFU, T. H. TORSVIK, L. D. ASHWAL, and D. M. RAMSAY Short-lived mafic magmatism at 560-570 Ma in the northern Norwegian Caledonides: U-Pb zircon ages from the Seiland Igneous Province Geological Magazine, November 1, 2006; 143(6): 887 - 903. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. F. Dewey Inaugural Article: Orogeny can be very short PNAS, October 25, 2005; 102(43): 15286 - 15293. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 P. D. Clift, A. E. Draut, P. B. Kelemen, J. Blusztajn, and A. Greene Stratigraphic and geochemical evolution of an oceanic arc upper crustal section: The Jurassic Talkeetna Volcanic Formation, south-central Alaska Geological Society of America Bulletin, July 1, 2005; 117(7-8): 902 - 925. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
MichaelJ. Flowerdew, J.S. Daly, and MartinJ. Whitehouse 470 Ma granitoid magmatism associated with the Grampian Orogeny in the Slishwood Division, NW Ireland Journal of the Geological Society, May 1, 2005; 162(3): 563 - 575. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Draut, A. E. DRAUT, P. D. CLIFT, D. M. CHEW, M. J. COOPER, R. N. TAYLOR, and R. E. HANNIGAN Laurentian crustal recycling in the Ordovician Grampian Orogeny: Nd isotopic evidence from western Ireland Geological Magazine, March 1, 2004; 141(2): 195 - 207. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. A. Mange, M. A. MANGE, J. F. DEWEY, and D. T. WRIGHT Heavy minerals solve structural and stratigraphic problems in Ordovician strata of the western Irish Caledonides Geological Magazine, January 1, 2003; 140(1): 25 - 30. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 P. D. Clift, H. Schouten, and A. E. Draut A general model of arc-continent collision and subduction polarity reversal from Taiwan and the Irish Caledonides Geological Society, London, Special Publications, January 1, 2003; 219(1): 81 - 98. [Abstract] [PDF]
|
|
| JOURNAL HOME | HELP | CONTACT PUBLISHER | SUBSCRIBE | ARCHIVE | SEARCH | TABLE OF CONTENTS |
