scholarly journals Exhumation of ultrahigh-pressure continental crust in east central China: Late Triassic-Early Jurassic tectonic unroofing

2000 ◽  
Vol 105 (B6) ◽  
pp. 13339-13364 ◽  
Author(s):  
Bradley R. Hacker ◽  
Lothar Ratschbacher ◽  
Laura Webb ◽  
Michael O. McWilliams ◽  
Trevor Ireland ◽  
...  
Keyword(s):  
Continental Crust ◽  
Early Jurassic ◽  
Central China ◽  
Ultrahigh Pressure ◽  
Late Triassic ◽  
East Central

scholarly journals Exhumation of the ultrahigh-pressure continental crust in east central China: Cretaceous and Cenozoic unroofing and the Tan-Lu fault

2000 ◽  
Vol 105 (B6) ◽  
pp. 13303-13338 ◽  
Author(s):  
Lothar Ratschbacher ◽  
Bradley R. Hacker ◽  
Laura E. Webb ◽  
Michael McWilliams ◽  
Trevor Ireland ◽  
...  
Keyword(s):  
Continental Crust ◽  
Central China ◽  
Ultrahigh Pressure ◽  
East Central

A refractory mantle protolith in younger continental crust, east-central China: Age and composition of zircon in the Sulu ultrahigh-pressure peridotite

Geology ◽  
2006 ◽  
Vol 34 (9) ◽  
pp. 705 ◽  
Author(s):  
Jianping Zheng ◽  
W.L. Griffin ◽  
Suzanne Y. O'Reilly ◽  
J.S. Yang ◽  
R.Y. Zhang
Keyword(s):  
Continental Crust ◽  
Central China ◽  
Ultrahigh Pressure ◽  
East Central

Ultrahigh-pressure eclogite transformed from mafic granulite in the Dabie orogen, east-central China

2007 ◽  
Vol 25 (9) ◽  
pp. 975-989 ◽  
Author(s):  
Y.-C. LIU ◽  
S.-G. LI ◽  
X.-F. GU ◽  
S.-T. XU ◽  
G.-B. CHEN
Keyword(s):  
Central China ◽  
Mafic Granulite ◽  
Ultrahigh Pressure ◽  
Dabie Orogen ◽  
East Central

Mesozoic thermal history and timing of structural events for the Yukon-Tanana Upland, east-central Alaska: 40Ar/39Ar data from metamorphic and plutonic rocks

2002 ◽  
Vol 39 (6) ◽  
pp. 1013-1051 ◽  
Author(s):  
Cynthia Dusel-Bacon ◽  
Marvin A Lanphere ◽  
Warren D Sharp ◽  
Paul W Layer ◽  
Vicki L Hansen
Keyword(s):  
Early Cretaceous ◽  
Final Stage ◽  
Complex Interaction ◽  
Early Jurassic ◽  
Crustal Thickening ◽  
Late Triassic ◽  
East Central ◽  
The North ◽  
Plutonic Rocks ◽  
Lake George

We present new 40Ar/39Ar ages for hornblende, muscovite, and biotite from metamorphic and plutonic rocks from the Yukon–Tanana Upland, Alaska. Integration of our data with published 40Ar/39Ar, kinematic, and metamorphic pressure (P) and temperature (T) data confirms and refines the complex interaction of metamorphism and tectonism proposed for the region. The oldest metamorphic episode(s) postdates Middle Permian magmatism and predates the intrusion of Late Triassic (215–212 Ma) granitoids into the Fortymile River assemblage (Taylor Mountain assemblage of previous papers). In the eastern Eagle quadrangle, rapid and widespread Early Jurassic cooling is indicated by ~188–186 Ma 40Ar/39Ar plateau ages for hornblende from plutons that intrude the Fortymile River assemblage, and for metamorphic minerals from the Fortymile River assemblage and the structurally underlying Nasina assemblage. We interpret these Early Jurassic ages to represent cooling resulting from northwest-directed contraction that emplaced the Fortymile River assemblage onto the Nasina assemblage to the north as well as the Lake George assemblage to the south. This cooling was the final stage of a continuum of subduction-related contraction that produced crustal thickening, intermediate- to high-P metamorphism within both the Fortymile River assemblage and the structurally underlying Lake George assemblage, and Late Triassic and Early Jurassic plutonism in the Fortymile River and Nasina assemblages. Although a few metamorphic samples from the Lake George assemblage yield Jurassic 40Ar/39Ar cooling ages, most yield Early Cretaceous 40Ar/39Ar ages: hornblende ~135–115 Ma, and muscovite and biotite ~110–108 Ma. We interpret the Early Cretaceous metamorphic cooling, in most areas, to have resulted from regional extension and exhumation of the lower plate, previously tectonically thickened during Early Jurassic and older convergence.

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