Origin and Diagenesis of Lacustrine Sediments of the Late Oligocene Creede Formation, Southwestern Colorado

Finkelstein, David Barry

Permalink

https://hdl.handle.net/2142/86547 Copy

Description

Title

Origin and Diagenesis of Lacustrine Sediments of the Late Oligocene Creede Formation, Southwestern Colorado

Author(s)

Finkelstein, David Barry

Issue Date

1997

Doctoral Committee Chair(s)

Altaner, Stephen P.

Department of Study

Geology

Discipline

Geology

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

Ph.D.

Degree Level

Dissertation

Keyword(s)

Geology

Language

eng

Abstract

Vertically-zoned sequences of authigenic silicates in tuffs reflect alteration of silicic-intermediate vitric tuff within an elevated geothermal gradient (90$\sp\circ$-150$\sp\circ$C/km). The abundance of clinoptilolite - Al-smectite in drillcore CCM-2 is consistent with diagenetic waters having low to moderate salinity and a pH of 7-9. The higher-grade mineral assemblage (analcime, K-feldspar, quartz, interstratified illite/smectite and chlorite/smectite in CCM-1) is due to hotter fluids migrating through the more permeable strata. Alteration occurred in a relatively closed system. On the basis of studies of zeolite formation in other burial diagenetic systems, the observed authigenic silicate assemblage in tuffs of the Creede Formation must have formed within $\sim$3-4 m.y. of deposition.

Graduation Semester

1997

Type of Resource

text

Permalink

http://hdl.handle.net/2142/86547

Owning Collections