Kaolinization in examples of Carboniferous and Cretaceous tonsteins

Conference · Mon Mar 01 00:00:00 EST 1993 · Geological Society of America, Abstracts with Programs; (United States)

OSTI ID:7206979

McCuistion, J T; Ambers, C P ^[1]

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1. Indiana Univ., Bloomington, IN (United States). Dept. of Geological Science

Optical and electron petrography were used to test if differences of mineral textures in tonsteins offer any evidence of the alteration history of their volcanic precursors. A suspect tonstein from the Mississippian Sample fm. In Crawford County, IN, and true tonsteins from the Pennsylvanian Breathitt Fm. in Leslie County, KY; Cretaceous Adaville Fm. in Lincoln County, WY; and the Cretaceous Williams Fork Fm. in Moffat and Routt Counties, CO were studied. Optical petrography showed lack of silt or sand in the Indiana clay, minor silt/fine-sand in the Kentucky clay, and lack of mica in both. The Indiana clay is very fine grained and has a strong preferred orientation, whereas the Kentucky clay matrix is also very fine grained but is isotropic. Abundant, angular, quartzofeldspathic, medium sand abounds in the western clays. Very large kaolinite verms up to 0.5 mm in length dominate the western clays. Each large kaolinite contains evenly spaced interlayers of relict biotite extending exactly the width of each verm. Kaolinite in the western clays shows strong compactional strain including undulose extinction, kink bands, and shearing along the basal plane. Compactional fabrics show all of the samples to have altered from their parent material before significant burial.

• OSTI ID: 7206979
• Report Number(s): CONF-9303210-; CODEN: GAAPBC
• Journal Information: Geological Society of America, Abstracts with Programs; (United States), Vol. 25:3; Conference: 27. annual Geological Society of America (GSA) North-Central Section meeting, Rolla, MO (United States), 29-30 Mar 1993; ISSN 0016-7592
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
ARGILLITE
DIAGENESIS
PETROGRAPHY
COLORADO
GEOLOGIC FORMATIONS
INDIANA
KENTUCKY
WYOMING
KAOLINITE
MINERALOGY
ALUMINIUM COMPOUNDS
ALUMINIUM SILICATES
DEVELOPED COUNTRIES
GEOLOGY
MINERALS
NORTH AMERICA
OXYGEN COMPOUNDS
ROCKS
SEDIMENTARY ROCKS
SHALES
SILICATE MINERALS
SILICATES
SILICON COMPOUNDS
USA
580000* - Geosciences