Physical Sciences and Mathematics Commons^™

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 …

Mineralogy And Petrology Of Lava Flows (Tertiary-Quaternary) In Southeastern Idaho And At Black Mountain, Rich County, Utah, Barbara J. Puchy

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Lava flows of Tertiary-Quaternary age occur in Enoch Valley, Upper Valley, and Slug Valley in southeastern Idaho. The basalts in Upper Valley and Enoch Valley contain olivine (Fo₆₉ to Fo₃₇), plagioclase (An₆₂ to An₃₉), augite and Fe-Ti oxides. The lava in Slug Valley lacks plagioclase, but contains sanidine (Or₇₀ to Or₅₆) with a trace of biotite and amphibole, and thus, has been termed alkali trachyte.

Black Mountain, on the eastern side of Bear Lake, northeastern Utah, is capped by basalt. Minerals present include olivine (Fo₈₃ to Fo₇₂), plagioclase …

Geology For The Layman, James O. Staggs

Annual of the Arkansas Natural Resources Law Institute

The first thing that an individual must thoroughly understand, is that geology is not an exact science. This may be strange for a geologist to say, but it is very similar to the profession of law in that any set of data may be and is usually interpreted differently by individual lawyers. We geologist start with some known facts (sometime geological), make assumptions, and then intrepret into the unknown. It is this interpretation that separates a successful geologist from a geologist. A successful oil finding geologist is a geologist that has developed this interpretation of geological facts into an art. …

Geologic Map And Coal Sections Of The Red Point Quadrangle, Eugene G. Elllis, U.S. Forest Service, U.S. Geological Survey, Joseph R. Frank

All U.S. Government Documents (Utah Regional Depository)

Red Point quadrangle, in Emery County in central Utah, was mapped in 1979 as a part of the U.S. Geological Survey's progress to evaluate lands in the public domain for potential coal leasing. Mapping was done using U.S. Forest Service color aerial photographs at a scale of 1:15,640 and U.S. Geological Survey black-and-white aerial photographs at a scale of 1:30,000. The quadrangle was mapped previously by Spicker (1931) at a scale of 1:62,500.

Stratigraphy And Depositional Environments Of The Wilcox Group (Paleocene) At The Oxbow Mine Site, Northwestern Louisiana, Richard E. Halle

Theses and Dissertations

The stratigraphy, structure, and depositional environments of the Naborton, Do let Hills, and part of the Cow Bayou Formations (Wilcox Group, Paleocene) at the Oxbow Mine site, Red River, De Soto, and Natchitoches Parishes,. Louisiana, were evaluated from a study of four continuous cores and 466 geophysical logs.

Overlying 40 feet {12 m) of silty Porters Creek shale is the Naborton Formation composed of 130-195 feet (40-59 m) of sand, silt, clay, and lignite. There are three lignites in this formation and their average total thickness is 13.5 feet (4. l m), or about 10% of the formation thickness. The …

Stratigraphy And Sedimentology Of The Sentinel Butte Formation (Paleocene) Near Lost Bridge, Dunn County, West-Central North Dakota, Bradley D. Nesemeier

Theses and Dissertations

The Sentinel Butte Formation (Paleocene) near Lost Bridge, Dunn County, west-central North Dakota, is 190 meters thick, and is charac terized by four main lithologies: sand, silt, clay, and lignite. The study interval is ISO meters thick, and lies between the basal sand of the formation and the Bullion Butte lignite bed, neither of which are exposed in the immediate study area. Sand, gray to yellow, makes up about 3S% of the interval studied. It occurs in tabular beds 2-18 meters thick. It is fine to very-fine, angular, and composed largely of quartz, feldspar, rock fragments, with minor amounts of …