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GEOREF RECORD

Mineralogy and geochemistry of late Eocene silicified wood from Florissant Fossil Beds National Monument, Colorado

George E. Mustoe
Mineralogy and geochemistry of late Eocene silicified wood from Florissant Fossil Beds National Monument, Colorado (in Paleontology of the upper Eocene Florissant Formation, Colorado, Herbert W. Meyer (editor) and Dena M. Smith (editor))
Special Paper - Geological Society of America (2008) 435: 127-140

Abstract

Silicified stumps preserved within a late Eocene lahar deposit have diverse mineralogy, ranging from opal-CT to chalcedony. In specimens that contain both silicapolymorphs, the minerals appear to have originated independently, rather than from diagenetic transformation of an opaline parent material. This petrifaction process is unlike the progressive transformation of opal-A-opal-CT-chalcedony that has long been accepted as a general model for wood silicification. At the Florissant fossil forest, petrifaction occurred in several stages, beginning with precipitation of amorphous silica on cell wall surfaces. Cell lumina later became filled with opal-CT and chalcedony. A final phase of silica deposition is evidenced by chalcedony-filled fractures that crosscut permineralized tissues in some specimens. Spaces between adjacent tracheids commonly remain unmineralized, causing the silicified wood to remain permeable to water, and to readily cleave radially and tangentially. To a lesser degree, the fossilized wood is subject to transverse fracturing. This combination of structural characteristics causes Florissant fossil stumps to be susceptible to damage from freeze-thaw weathering.


ISSN: 0072-1077
EISSN: 2331-219X
Coden: GSAPAZ
Serial Title: Special Paper - Geological Society of America
Serial Volume: 435
Title: Mineralogy and geochemistry of late Eocene silicified wood from Florissant Fossil Beds National Monument, Colorado
Title: Paleontology of the upper Eocene Florissant Formation, Colorado
Author(s): Mustoe, George E.
Author(s): Meyer, Herbert W.editor
Author(s): Smith, Dena M.editor
Affiliation: Western Washington University, Geology Department, Bellingham, WA, United States
Affiliation: National Park Service, Florissant Fossil Beds National Monument, Florissant, CO, United States
Pages: 127-140
Published: 2008
Text Language: English
Publisher: Geological Society of America (GSA), Boulder, CO, United States
ISBN: 978-0-8137-2435-5
References: 55
Accession Number: 2008-109810
Categories: Paleobotany
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: illus. incl. 2 plates, 1 table, geol. sketch map
N38°55'00" - N38°55'00", W105°16'00" - W105°16'00"
Secondary Affiliation: University of Colorado at Boulder, USA, United States
Country of Publication: United States
Secondary Affiliation: GeoRef, Copyright 2017, American Geosciences Institute.
Update Code: 200840
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