|
|
|
|||||||||||||||||
| JOURNAL HOME | HELP | CONTACT PUBLISHER | SUBSCRIBE | ARCHIVE | SEARCH | TABLE OF CONTENTS |
1 School of Geosciences, University of Aberdeen, Aberdeen AB24 3UE, UK
2 Department of Geology and Geophysics, University of New Orleans, New Orleans, Louisiana 70148, USA
3 Department of Geology, Western Washington University, Bellingham, Washington 98225, USA
4 University of CaliforniaSanta Cruz, Santa Cruz, California 95060,USA, and U.S. Geological Survey, 400 Natural Bridges Drive, Santa Cruz, California 95060, USA
5 Department of Geological Sciences, University of CaliforniaSanta Barbara, Santa Barbara, California 93106, USA
6 Lamont-Doherty Earth Observatory, Columbia University, P.O. Box 1000, 61 Route 9W, Palisades, New York 10964, USA
The Jurassic Talkeetna volcanic arc of south-central Alaska is an oceanic island arc that formed far from the North American margin. Geochronological, geochemical, and structural data indicate that the arc formed above a north-dipping subduction zone after ca. 201 Ma. Magmatism migrated northward into the region of the Talkeetna Mountains ca. 180 Ma. We interpret this magmatism as the product of removal of the original forearc while the arc was active, mainly by tectonic erosion. Rapid exhumation of the arc after ca. 160 Ma coincided with the sedimentation of the coarse clastic Naknek Formation. This exhumation event is interpreted to reflect collision of the Talkeetna arc with either the active margin of North America or the Wrangellia composite terrane to the north along a second north-dipping subduction zone. The juxtaposition of accreted trench sedimentary rocks (Chugach terrane) against the base of the Talkeetna arc sequence requires a change from a state of tectonic erosion to accretion, probably during the Late Jurassic (before 150 Ma), and definitely before the Early Cretaceous (ca. 125 Ma). The change from erosion to accretion probably reflects increasing sediment flux to the trench due to collision ca. 160 Ma.
Key Words: Alaska terrane accretion subduction tectonic erosion collision
This article has been cited by other articles:
![]() |
P. D. Clift, H. Schouten, and P. Vannucchi Arc-continent collisions, sediment recycling and the maintenance of the continental crust Geological Society, London, Special Publications, January 1, 2009; 318(1): 75 - 103. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. W. Scholl and R. von Huene Implications of estimated magmatic additions and recycling losses at the subduction zones of accretionary (non-collisional) and collisional (suturing) orogens Geological Society, London, Special Publications, January 1, 2009; 318(1): 105 - 125. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. M. Amato, A. O. Boullion, A. M. Serna, A. E. Sanders, G. L. Farmer, G. E. Gehrels, and J. L. Wooden Evolution of the Mazatzal province and the timing of the Mazatzal orogeny: Insights from U-Pb geochronology and geochemistry of igneous and metasedimentary rocks in southern New Mexico Geological Society of America Bulletin, March 1, 2008; 120(3-4): 328 - 346. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. M. Trop Latest Cretaceous forearc basin development along an accretionary convergent margin: South-central Alaska Geological Society of America Bulletin, January 1, 2008; 120(1-2): 207 - 224. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. E. Draut, P. D. Clift, and D. W. Scholl Preface Geological Society of America Special Papers, January 1, 2008; 436(0): v - vii. [Full Text] [PDF] |
||||
![]() |
M. Rioux, B. Hacker, J. Mattinson, P. Kelemen, J. Blusztajn, and G. Gehrels Magmatic development of an intra-oceanic arc: High-precision U-Pb zircon and whole-rock isotopic analyses from the accreted Talkeetna arc, south-central Alaska Geological Society of America Bulletin, September 1, 2007; 119(9-10): 1168 - 1184. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. W. Scholl and R. von Huene Crustal recycling at modern subduction zones applied to the past--Issues of growth and preservation of continental basement crust, mantle geochemistry, and supercontinent reconstruction Geological Society of America Memoirs, January 1, 2007; 200(0): 9 - 32. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. M. Trop and K. D. Ridgway Mesozoic and Cenozoic tectonic growth of southern Alaska: A sedimentary basin perspective Geological Society of America Special Papers, January 1, 2007; 431(0): 55 - 94. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. L. Pavlis and S. M. Roeske The Border Ranges fault system, southern Alaska Geological Society of America Special Papers, January 1, 2007; 431(0): 95 - 127. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. M. Amato, M. E. Rioux, P. B. Kelemen, G. E. Gehrels, P. D. Clift, T. L. Pavlis, and A. E. Draut U-Pb geochronology of volcanic rocks from the Jurassic Talkeetna Formation and detrital zircons from prearc and postarc sequences: Implications for the age of magmatism and inheritance in the Talkeetna arc Geological Society of America Special Papers, January 1, 2007; 431(0): 253 - 271. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. D. Manuszak, K. D. Ridgway, J. M. Trop, and G. E. Gehrels Sedimentary record of the tectonic growth of a collisional continental margin: Upper Jurassic-Lower Cretaceous Nutzotin Mountains sequence, eastern Alaska Range, Alaska Geological Society of America Special Papers, January 1, 2007; 431(0): 345 - 377. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. E. Draut and P. D. Clift Sedimentary Processes in Modern and Ancient Oceanic Arc Settings: Evidence from the Jurassic Talkeetna Formation of Alaska and the Mariana and Tonga Arcs, Western Pacific Journal of Sedimentary Research, March 1, 2006; 76(3): 493 - 514. [Abstract] [Full Text] [PDF] |
||||
| JOURNAL HOME | HELP | CONTACT PUBLISHER | SUBSCRIBE | ARCHIVE | SEARCH | TABLE OF CONTENTS |