Cynthia Dusel-Bacon (Former Employee)
Science and Products
Filter Total Items: 51
Paleozoic magmatism and crustal recycling along the ancient Pacific margin of North America, northern Cordillera
No abstract available.
Authors
Stephen Piercey, JoAnne L. Nelson, Maurice Colpron, Cynthia Dusel-Bacon, Renée-Luce Simard, Charlie Roots
U-Pb zircon and geochemical evidence for bimodal mid-Paleozoic magmatism and syngenetic base-metal mineralization in the Yukon-Tanana terrane, Alaska
New SHRIMP (sensitive, high-resolution ion microprobe) U-Pb zircon ages and trace element geochemical data for mafic and felsic metaigneous rocks of the pericratonic Yukon-Tanana terrane in east-central Alaska help define the tectonic setting of mid-Paleo-zoic magmatism and syngenetic hydrothermal Zn-Pb-Ag mineralization along the ancient Pacific margin of North America. We compare data...
Authors
Cynthia Dusel-Bacon, J. L. Wooden, M.J. Hopkins
Mesozoic thermal history and timing of structural events for the Yukon-Tanana Upland, east-central Alaska: 40Ar/39Ar data from metamorphic and plutonic rocks
We present new 40Ar/39Ar ages for hornblende, muscovite, and biotite from metamorphic and plutonic rocks from the YukonTanana 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...
Authors
Cynthia Dusel-Bacon, Marvin A. Lanphere, W.D. Sharp, P.W. Layer, V. L. Hansen
Apatite fission-track evidence of widespread Eocene heating and exhumation in the Yukon-Tanana Upland, interior Alaska
We present an apatite fission-track (AFT) study of five plutonic rocks and seven metamorphic rocks across 310 km of the YukonTanana Upland in east-central Alaska. Samples yielding ~40 Ma AFT ages and mean confined track lengths > 14 µm with low standard deviations cooled rapidly from >120°C to 40 Ma sugge
Authors
Cynthia Dusel-Bacon, J.M. Murphy
Trace-element geochemistry of metabasaltic rocks from the Yukon-Tanana Upland and implications for the origin of tectonic assemblages in east-central Alaska
We present major- and trace- element geochemical data for 27 amphibolites and six greenstones from three structural packages in the Yukon-Tanana Upland of east-central Alaska: the Lake George assemblage (LG) of Devono-Mississippian augen gneiss, quartz-mica schist, quartzite, and amphibolite; the Taylor Mountain assemblage (TM) of mafic schist and gneiss, marble, quartzite, and metachert...
Authors
Cynthia Dusel-Bacon, K.M. Cooper
Structural and kinematic evolution of the Yukon-Tanana upland tectonites, east-central Alaska: A record of late Paleozoic to Mesozoic crustal assembly
The Yukon-Tanana terrane, the largest tectonostratigraphic terrane in the northern North American Cordillera, is polygenetic and not a single terrane. Lineated and foliated (L-S) tectonites, which characterize the Yukon-Tanana terrane, record multiple deformations and formed at different times. We document the polyphase history recorded by L-S tectonites within the Yukon-Tanana upland...
Authors
V. L. Hansen, Cynthia Dusel-Bacon
Stratiform zinc-lead mineralization in Nasina assemblage rocks of the Yukon-Tanana Upland in east-central Alaska
The Yukon-Tanana Upland of east-central Alaska and Yukon comprises thrust sheets of ductilely deformed metasedimentary and metaigneous rocks of uncertain age and origin that are overlain by klippen of weakly metamorphosed oceanic rocks of the Seventymile-Slide Mountain terrane, and intruded by post-kinematic Early Jurassic, Cretaceous and Tertiary granitoids. Metamorphosed continental...
Authors
Cynthia Dusel-Bacon, Jason R. Bressler, Hidetoshi Takaoka, James K. Mortensen, Douglas H. Oliver, Joel S. Leventhal, Rainer J. Newberry, Thomas K. Bundtzen
Metamorphic facies map of southeastern Alaska: Distribution, facies, and ages of regionally metamorphosed rocks
Nearly all of the bedrock in Southeastern Alaska has been metamorphosed, much of it under medium-grade conditions during metamorphic episodes that were associated with widespread plutonism. The oldest metamorphisms affected probable arc rocks near southern Prince of Wales Island and occurred during early and middle Paleozoic orogenies. The predominant period of metamorphism and...
Authors
Cynthia Dusel-Bacon, D. A. Brew, S. L. Douglass
Distribution, facies, ages, and proposed tectonic associations of regionally metamorphosed rocks in Southwestern Alaska and the Alaska Peninsula
The oldest dated metamorphic sequence in Alaska, the fault-bounded Kilbuck Terrane, consists of continental rocks that were metamorphosed under amphibolite-facies conditions during early Proterozoic (1.77 Ga) time. Proterozoic or early Paleozoic metamorphic ages are also possible for greenschist- and amphibolite-facies continental rocks in interior Alaska (Ruby and Nixon Fork terranes)...
Authors
Cynthia Dusel-Bacon, Elizabeth O. Doyle, Stephen E. Box
Hot-side-up aureole in southwest Yukon and limits on terrane assembly of the northern Canadian Cordillera: Comment and Reply
No abstract available.
Authors
V. L. Hansen, D.H. Oliver, Cynthia Dusel-Bacon, Stephen T. Johnston, Philippe Erdmer
Metamorphic and structural history of continental crust at a Mesozoic collisional margin, the Ruby terrane, central Alaska
The Ruby terrane is an elongate fragment of continental crustal rocks that is structurally overlain by thrust slices of oceanic crust. Our results from the Kokrines Hills, in the south‐central part of the Ruby terrane, demonstrate that the low‐angle schistose fabric formed under high‐P/low‐T conditions, at peak conditions of 10.8‐13.2 kbar and 425‐550° C, consistent with the rare...
Authors
S. M. Roeske, Cynthia Dusel-Bacon, John N. Aleinikoff, L.W. Snee, Marvin A. Lanphere
High-pressure amphibolite facies dynamic metamorphism and the Mesozoic tectonic evolution of an ancient continental margin, east- central Alaska
Ductilely deformed amphibolite facies tectonites comprise two adjacent terranes in east-central Alaska: the northern, structurally higher Taylor Mountain terrane and the southern, structurally lower Lake George subterrane of the Yukon-Tanana terrane. The pressure, temperature, kinematic and age data are interpreted to indicate that the metamorphism of the Taylor Mountain terrane and Lake...
Authors
Cynthia Dusel-Bacon, V. L. Hansen, J.A. Scala
Science and Products
Filter Total Items: 51
Paleozoic magmatism and crustal recycling along the ancient Pacific margin of North America, northern Cordillera
No abstract available.
Authors
Stephen Piercey, JoAnne L. Nelson, Maurice Colpron, Cynthia Dusel-Bacon, Renée-Luce Simard, Charlie Roots
U-Pb zircon and geochemical evidence for bimodal mid-Paleozoic magmatism and syngenetic base-metal mineralization in the Yukon-Tanana terrane, Alaska
New SHRIMP (sensitive, high-resolution ion microprobe) U-Pb zircon ages and trace element geochemical data for mafic and felsic metaigneous rocks of the pericratonic Yukon-Tanana terrane in east-central Alaska help define the tectonic setting of mid-Paleo-zoic magmatism and syngenetic hydrothermal Zn-Pb-Ag mineralization along the ancient Pacific margin of North America. We compare data...
Authors
Cynthia Dusel-Bacon, J. L. Wooden, M.J. Hopkins
Mesozoic thermal history and timing of structural events for the Yukon-Tanana Upland, east-central Alaska: 40Ar/39Ar data from metamorphic and plutonic rocks
We present new 40Ar/39Ar ages for hornblende, muscovite, and biotite from metamorphic and plutonic rocks from the YukonTanana 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...
Authors
Cynthia Dusel-Bacon, Marvin A. Lanphere, W.D. Sharp, P.W. Layer, V. L. Hansen
Apatite fission-track evidence of widespread Eocene heating and exhumation in the Yukon-Tanana Upland, interior Alaska
We present an apatite fission-track (AFT) study of five plutonic rocks and seven metamorphic rocks across 310 km of the YukonTanana Upland in east-central Alaska. Samples yielding ~40 Ma AFT ages and mean confined track lengths > 14 µm with low standard deviations cooled rapidly from >120°C to 40 Ma sugge
Authors
Cynthia Dusel-Bacon, J.M. Murphy
Trace-element geochemistry of metabasaltic rocks from the Yukon-Tanana Upland and implications for the origin of tectonic assemblages in east-central Alaska
We present major- and trace- element geochemical data for 27 amphibolites and six greenstones from three structural packages in the Yukon-Tanana Upland of east-central Alaska: the Lake George assemblage (LG) of Devono-Mississippian augen gneiss, quartz-mica schist, quartzite, and amphibolite; the Taylor Mountain assemblage (TM) of mafic schist and gneiss, marble, quartzite, and metachert...
Authors
Cynthia Dusel-Bacon, K.M. Cooper
Structural and kinematic evolution of the Yukon-Tanana upland tectonites, east-central Alaska: A record of late Paleozoic to Mesozoic crustal assembly
The Yukon-Tanana terrane, the largest tectonostratigraphic terrane in the northern North American Cordillera, is polygenetic and not a single terrane. Lineated and foliated (L-S) tectonites, which characterize the Yukon-Tanana terrane, record multiple deformations and formed at different times. We document the polyphase history recorded by L-S tectonites within the Yukon-Tanana upland...
Authors
V. L. Hansen, Cynthia Dusel-Bacon
Stratiform zinc-lead mineralization in Nasina assemblage rocks of the Yukon-Tanana Upland in east-central Alaska
The Yukon-Tanana Upland of east-central Alaska and Yukon comprises thrust sheets of ductilely deformed metasedimentary and metaigneous rocks of uncertain age and origin that are overlain by klippen of weakly metamorphosed oceanic rocks of the Seventymile-Slide Mountain terrane, and intruded by post-kinematic Early Jurassic, Cretaceous and Tertiary granitoids. Metamorphosed continental...
Authors
Cynthia Dusel-Bacon, Jason R. Bressler, Hidetoshi Takaoka, James K. Mortensen, Douglas H. Oliver, Joel S. Leventhal, Rainer J. Newberry, Thomas K. Bundtzen
Metamorphic facies map of southeastern Alaska: Distribution, facies, and ages of regionally metamorphosed rocks
Nearly all of the bedrock in Southeastern Alaska has been metamorphosed, much of it under medium-grade conditions during metamorphic episodes that were associated with widespread plutonism. The oldest metamorphisms affected probable arc rocks near southern Prince of Wales Island and occurred during early and middle Paleozoic orogenies. The predominant period of metamorphism and...
Authors
Cynthia Dusel-Bacon, D. A. Brew, S. L. Douglass
Distribution, facies, ages, and proposed tectonic associations of regionally metamorphosed rocks in Southwestern Alaska and the Alaska Peninsula
The oldest dated metamorphic sequence in Alaska, the fault-bounded Kilbuck Terrane, consists of continental rocks that were metamorphosed under amphibolite-facies conditions during early Proterozoic (1.77 Ga) time. Proterozoic or early Paleozoic metamorphic ages are also possible for greenschist- and amphibolite-facies continental rocks in interior Alaska (Ruby and Nixon Fork terranes)...
Authors
Cynthia Dusel-Bacon, Elizabeth O. Doyle, Stephen E. Box
Hot-side-up aureole in southwest Yukon and limits on terrane assembly of the northern Canadian Cordillera: Comment and Reply
No abstract available.
Authors
V. L. Hansen, D.H. Oliver, Cynthia Dusel-Bacon, Stephen T. Johnston, Philippe Erdmer
Metamorphic and structural history of continental crust at a Mesozoic collisional margin, the Ruby terrane, central Alaska
The Ruby terrane is an elongate fragment of continental crustal rocks that is structurally overlain by thrust slices of oceanic crust. Our results from the Kokrines Hills, in the south‐central part of the Ruby terrane, demonstrate that the low‐angle schistose fabric formed under high‐P/low‐T conditions, at peak conditions of 10.8‐13.2 kbar and 425‐550° C, consistent with the rare...
Authors
S. M. Roeske, Cynthia Dusel-Bacon, John N. Aleinikoff, L.W. Snee, Marvin A. Lanphere
High-pressure amphibolite facies dynamic metamorphism and the Mesozoic tectonic evolution of an ancient continental margin, east- central Alaska
Ductilely deformed amphibolite facies tectonites comprise two adjacent terranes in east-central Alaska: the northern, structurally higher Taylor Mountain terrane and the southern, structurally lower Lake George subterrane of the Yukon-Tanana terrane. The pressure, temperature, kinematic and age data are interpreted to indicate that the metamorphism of the Taylor Mountain terrane and Lake...
Authors
Cynthia Dusel-Bacon, V. L. Hansen, J.A. Scala