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Geography and Geology Faculty Publications

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Geology

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Full-Text Articles in Physical Sciences and Mathematics

Review Of Hard Road West: History And Geology Along The Gold Rush Trail By Keith Heyer Meldahl, Harmon D. Maher Jr. Jan 2009

Review Of Hard Road West: History And Geology Along The Gold Rush Trail By Keith Heyer Meldahl, Harmon D. Maher Jr.

Geography and Geology Faculty Publications

The dust jacket of Hard Road West promises familiar pleasures to John McPhee lovers, and so I picked the book up with great anticipation. McPhee’s works have greatly heightened the interest of writers and readers in the genre of creative nonfiction, and while for me, Keith Meldahl’s work does not quite reach McPhee’s stratospheric heights, for the right audience it is definitely a very good read.


U-Pb Studies Of Zircon Cores And Overgrowths, And Monazite: Implications For Age And Petrogenesis Of The Northeastern Idaho Batholith, M. E. Bickford, R. B. Chase, B. K. Nelson, Robert Duncan Shuster, E. C. Arruda Jul 1981

U-Pb Studies Of Zircon Cores And Overgrowths, And Monazite: Implications For Age And Petrogenesis Of The Northeastern Idaho Batholith, M. E. Bickford, R. B. Chase, B. K. Nelson, Robert Duncan Shuster, E. C. Arruda

Geography and Geology Faculty Publications

U/Pb isotopic studies of zircons, many containing xenocrystic cores with euhedral overgrowths, and monazite from igneous rocks and metasedimentary inclusions of the northeastern Idaho batholith yield linear arrays on concordia diagrams. We interpret these as mixing lines between an old component (cores) and a young component (overgrowths and zircons without cores). The lower intercept of such arrays with concordia may yield the minimum age of the rocks if the overgrowths and zircons without cores are discordant, or the crystallization age if they are concordant. Monazites yield apparently concordant ages either equal or less than the lower intercept zircon ages. The …