Detrital-zircon fission-track ages for the “Hoh Formation”: Implications for late Cenozoic evolution of the Cascadia subduction wedge

2004 ◽  
Vol 116 (1) ◽  
pp. 60 ◽  
Author(s):  
Richard J. Stewart ◽  
Mark T. Brandon
Keyword(s):  
Detrital Zircon ◽  
Fission Track ◽  
Late Cenozoic ◽  
Zircon Fission Track ◽  
Fission Track Ages ◽  
Subduction Wedge

scholarly journals Resolution of the age structure of the detrital zircon populations of two Lower Cretaceous sandstones from the Weald of England by fission track dating

1984 ◽  
Vol 121 (4) ◽  
pp. 269-277 ◽  
Author(s):  
A. J. Hurford ◽  
F. J. Fitch ◽  
A. Clarke
Keyword(s):  
Detrital Zircon ◽  
Lower Cretaceous ◽  
Fission Track ◽  
Age Distribution ◽  
The Other ◽  
Fission Track Dating ◽  
Zircon Age ◽  
Zircon Fission Track ◽  
Geological Implications ◽  
Fission Track Ages

AbstractModes in the frequency of distribution of fission track ages obtained from detrital zircon grains may prove characteristic of individual sandstone bodies, supporting the identification of the sources from which a particular flow of sedimentary detritus was derived and thus allowing new inferences to be made concerning palaeogeography. A computer program has been written and used to identify modes in the zircon fission track age distribution within two Lower Cretaceous sandstone samples from the Weald of southern England. Pronounced modes appear in one rock around 119 Ma, 160 Ma, 243 Ma and 309 Ma and in the other around 141 Ma, 175 Ma, 257 to 277 Ma and 394 to 453 Ma. The geological implications of these quite dissimilar zircon age spectra are discussed. It is concluded that they support the palaeogeographical models of Allen (1981) and indicate that the provenance of the first sample, from the Top Ashdown Sandstone member at Dallington in East Sussex, was almost entirely southerly, while that of the second, from the Netherside Sand member at Northchapel in West Sussex, was more varied, but predominantly westerly and northerly.

Downstream Changes of Alpine Zircon Fission-Track Ages in the Rhone and Rhine Rivers

2004 ◽  
Vol 74 (1) ◽  
pp. 82-94 ◽  
Author(s):  
M. Bernet ◽  
M. T. Brandon ◽  
J. I. Garver ◽  
B. Molitor
Keyword(s):  
Fission Track ◽  
Zircon Fission Track ◽  
Fission Track Ages

Fission-Track Ages of Tuff Layers Related to the Pliocene-Pleistocene Boundary on the Boso Peninsula, Japan

1990 ◽  
Vol 33 (1) ◽  
pp. 86-93 ◽  
Author(s):  
Masao Kasuya
Keyword(s):  
Fission Track ◽  
Middle Part ◽  
Late Cenozoic ◽  
Boso Peninsula ◽  
Normal Polarity ◽  
Fission Track Ages ◽  
Age Constraints

AbstractFission-track ages of zircon crystals from four tuff layers in the late Cenozoic sediment sequence of the Boso Peninsula,.Japan, are 1.6 ± 0.2 myr (the Kurotaki Formation), 5.5 ± 0.6 and 5.2 ± 0.5 myr (the uppermost part of the Amatsu Formation), and 11.5 ± 0.8 myr (the middle part of the Amatsu Formation). These ages provide numerical age constraints on magneto-biostratigraphy. The normal polarity interval in the lower part of the Kiwada Formation corresponds to the Olduvai polarity subzone. The boundary between the Pliocene and Pleistocene lies slightly above the Olduvai polarity subzone.

Low-temperature thermal history of the Gilmore Dome area, Fairbanks Mining District, Alaska

1993 ◽  
Vol 30 (4) ◽  
pp. 764-768 ◽  
Author(s):  
John M. Murphy ◽  
Arne Bakke
Keyword(s):  
Gold Deposit ◽  
Fission Track ◽  
Hydrothermal Fluids ◽  
Mining District ◽  
Cooling Path ◽  
Alteration Assemblage ◽  
Zircon Fission Track ◽  
History Of ◽  
Maximum Temperatures ◽  
Fission Track Ages

Eight apatite and two zircon fission-track ages provide evidence of complex Tertiary thermal overprinting by hydrothermal fluids in the Gilmore Dome area. Five ages on apatite from the Fort Knox gold deposit average 41 Ma, one from the Stepovich prospect is 80 Ma, and two from Pedro Dome average 67 Ma. Elevations of these samples overlap but their ages do not, indicating that each area experienced a different thermal history.Ages of apatite from the Fort Knox gold deposit decrease with elevation from 42 to 36 Ma but have data trends indicative of complex cooling. Two ~51 Ma ages on zircon indicate that maximum temperatures approached or exceeded ~180 °C. An alteration assemblage of chalcedony + zeolite + calcite + clay in the deposit resulted from deposition by a paleo-hydrothermal system. The data suggest that the system followed a complex cooling path from > 180 to < 110 °C between 51 and 36 Ma, and that final cooling to below 60 °C occurred after ~25 Ma.The 80 Ma age from Stepovich prospect either resulted from cooling after intrusion of the underlying pluton (~90 Ma) or records postintrusion thermal overprinting sometime after ~50 Ma. The 67 Ma samples from Pedro Dome may also have experienced partial age reduction during later heating. The differences in the data from the different areas and the presence of a late alteration assemblage at Fort Knox suggest that the fluids responsible for heating were largely confined to the highly fractured and porous Fort Knox pluton.

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