Zircon U-Pb and 40Ar/39Ar results from dikes collected within the Bruin Bay fault zone, lower Cook Inlet
Dates
Publication Date
2017
Start Date
2012
End Date
2017
File Modification Date
2017-08-30 14:32:00
Citation
Gillis, R.J., Benowitz, J.A., O'Sullivan, P.B., Layer, P.W., and Wartes, M.A., 2017, Zircon U-Pb and 40Ar/39Ar results from dikes collected within the Bruin Bay fault zone, lower Cook Inlet: Alaska Division of Geological & Geophysical Surveys, http://doi.org/10.14509/29750.
Summary
This data release presents 40Ar/39Ar step-heating geochronology results from rocks collected roughly 7 km southwest of Contact Point, Iliamna B-3 Quadrangle. Samples obtained from a felsic dike intruding the principal Bruin Bay fault plane near Contact Point produced biotite and plagioclase 40Ar/39Ar ages of 36.5 +/- 0.8 Ma and 31.5+/-0.7 Ma, respectively. The age dates inform stratigraphic, structural, and geochronologic studies along the western margin of lower Cook Inlet basin. The accompanying report also presents zircon U-Pb LA-ICP-MS geochronology results for dikes near Ursus Head.
Summary
This data release presents 40Ar/39Ar step-heating geochronology results from rocks collected roughly 7 km southwest of Contact Point, Iliamna B-3 Quadrangle. Samples obtained from a felsic dike intruding the principal Bruin Bay fault plane near Contact Point produced biotite and plagioclase 40Ar/39Ar ages of 36.5 +/- 0.8 Ma and 31.5+/-0.7 Ma, respectively. The age dates inform stratigraphic, structural, and geochronologic studies along the western margin of lower Cook Inlet basin. The accompanying report also presents zircon U-Pb LA-ICP-MS geochronology results for dikes near Ursus Head.
The Energy Resources Group from the Alaska Division of Geological & Geophysical Surveys (DGGS) has conducted topical stratigraphic, structural, and geochronologic studies along the western margin of lower Cook Inlet basin since 2009 to improve knowledge of its Mesozoic geologic framework and help spur industry interest in this under-explored region of the petroleum basin. The publicly-available geological and geochronologic data augment state- and federally-funded geologic mapping along the basin margin performed since 2013. This report presents zircon U-Pb LA-ICP-MS and 40Ar/39Ar step-heating geochronology results for one mafic and two felsic dikes in the Iliamna B-3 and C-2 quadrangles at Ursus Head and near Contact Point, lower Cook Inlet.
