Skip to Main Content
Book Chapter

The tectono-thermal evolution of the Waterbury dome, western Connecticut, based on U-Pb and 40Ar/39Ar ages

By
Craig Dietsch
Craig Dietsch
Department of Geology, University of Cincinnati, P.O. Box 0013, Cincinnati, Ohio 45221-0013, USA
Search for other works by this author on:
;
Michael J. Kunk
Michael J. Kunk
U.S. Geological Survey, 12201 Sunrise Valley Drive, Reston, Virginia 20192, USA
Search for other works by this author on:
;
John Aleinikoff
John Aleinikoff
U.S. Geological Survey, MS 963, Denver, Colorado 80225, USA
Search for other works by this author on:
;
John F. Sutter
John F. Sutter
U.S. Geological Survey, 12201 Sunrise Valley Drive, Reston, Virginia 20192, USA
Search for other works by this author on:
Published:
September 01, 2010

The Waterbury dome, located in the Rowe-Hawley zone in western Connecticut, is a triple window exposing three terranes: parautochthonous or allochthonous peri-Laurentian rocks in its lowest level 1, allochthonous rocks of the Rowe-Hawley zone in its middle level 2, and allochthonous cover rocks, including Silurian-Devonian rocks of the Connecticut Valley Gaspé trough, in its highest level 3. Levels 1 and 2 are separated by the Waterbury thrust, a fault equivalent to Cameron's Line, the Taconic suture in southwestern New England. Relict mesoscopic folds and foliation in levels 1 and 2 are truncated by a dominant D2 migmatitic layering and are likely Taconic. U-Pb zircon crystallization ages of felsic orthogneiss and tonalite, syntectonic with respect to the formation of S2, and a biotite quartz diorite that crosscuts level 2 paragneiss are 437 ± 4 Ma, 434 ± 4 Ma, and 437 ± 4 Ma, respectively.

Level 3 nappes were emplaced over the Waterbury dome along an Acadian décollement synchronous with the formation of a D3 thrust duplex in the dome. The décollement truncates the Ky + Kfs-in (migmatite) isograd in the dome core and a St-in isograd in level 3 nappes, indicating that peak metamorphic conditions in the dome core and nappe cover rocks formed in different places at different times. Metamorphic overgrowths on zircon from the felsic orthogneiss in the Waterbury dome have an age of 387 ± 5 Ma. Rocks of all levels and the décollement are folded by D4 folds that have a strongly developed, regional crenulation cleavage and D5 folds. The Waterbury dome was formed by thrust duplexing followed by fold interference during the Acadian orogeny. The 40Ar/39Ar ages of amphibole, muscovite, biotite, and K-feldspar from above and below the décollement are ca. 378 Ma, 355 Ma, 360 Ma (above) and 340 (below), and 288 Ma, respectively. Any kilometer-scale vertical movements between dome and nappe rocks were over by ca. 378 Ma. Core and cover rocks of the Waterbury dome record synchronous, post-Acadian cooling.

You do not currently have access to this article.

Figures & Tables

Contents

GSA Memoirs

From Rodinia to Pangea: The Lithotectonic Record of the Appalachian Region

Richard P. Tollo
Richard P. Tollo
Geological Sciences Program, George Washington University, Washington, D.C., USA
Search for other works by this author on:
;
Mervin J. Bartholomew
Mervin J. Bartholomew
Department of Earth Sciences, University of Memphis, Memphis, Tennessee, USA
Search for other works by this author on:
;
James P. Hibbard
James P. Hibbard
Department of Marine, Earth and Atmospheric Sciences, North Carolina State University, Raleigh, North Carolina, USA
Search for other works by this author on:
;
Paul M. Karabinos
Paul M. Karabinos
Department of Geosciences, Williams College, Williamstown, Massachusetts, USA
Search for other works by this author on:
Geological Society of America
Volume
206
ISBN print:
9780813712062
Publication date:
September 01, 2010

References

Related

Citing Books via

Related Articles
Close Modal
This Feature Is Available To Subscribers Only

Sign In or Create an Account

Close Modal
Close Modal