Stratigraphic and paleoenvironmental variations in Rare Earth Element (REE) composition and crystallography of fossil bioapatite

2006 2006

Other formats: Order a copy

Abstract (summary)

Rare Earth Elements (REE) and unit cell dimension (UCDA) analyses of fossil bioapatite from Cretaceous, Tertiary and Pleistocene age vertebrates were used to identify and interpret changes occurring in the paleoenvironment over time and for stratigraphic correlation. REE composition and the UCD in bioapatite are dependent upon the composition of diagenetic waters, concentrations of REE and other species incorporated into bioapatite during permineralization. REE signature and UCD differences in bioapatite identify distinct intervals in lithologic units. These differences reflect changes in the depositional environment, and can be used to interpret paleoenvironments. Because these distinct intervals represent an averaging of periods of certain depositional environments, they can be correlated over significant areas.

Fossil vertebrate samples were obtained from the Upper Cretaceous, Campanian and Maastrictian deposits of the Pierre Shale, from the Sharon Springs, Gregory, Crow Creek, DeGrey and Verendrye members. These samples were collected in an area between Chamberlain and Pierre, South Dakota, at localities along the banks of the Missouri River. REE signatures and UCD variations were found to be consistent within individual lithostratigraphic units, but are significantly different between these units. Variations in REE signatures and UCD in the Pierre Shale represent changes in the depositional environment and have been used successfully to interpret events during diagenesis. Specific REE signatures and UCD have been shown to extend laterally and act as markers for their units. These markers can be used to discriminate among units for purposes of stratigraphic correlation in the Pierre Shale.

Analysis of REE in fossils from the Pleistocene Fossil Lake, Oregon, also revealed that REE signatures are laterally constant over many km, but differ among the thin lithostratigraphic units. Paleoenvironmental interpretations from REE analysis were consistent with those from other geologic data.

Preliminary research was conducted in the fluvial deposits of the Upper Cretaceous Judith River and Lance Formations and the Tertiary deposits of the Fort Union Formation in Wyoming. Unique REE signatures and UCD variations were found for each tested lithostratigraphic unit.

REE and UCD analyses resulting from this research provides a finer scale of resolution for stratigraphic correlation and a proxy for paleoenvironmental interpretation.

Indexing (details)

0996: Geochemistry
0372: Geology
0418: Paleontology
Identifier / keyword
Earth sciences; Bioapatite; Composition; Fossil; Paleoenvironmental; Rare earth; Stratigraphic
Stratigraphic and paleoenvironmental variations in Rare Earth Element (REE) composition and crystallography of fossil bioapatite
Patrick, Doreena M.
Number of pages
Publication year
Degree date
School code
DAI-B 67/03, Dissertation Abstracts International
Place of publication
Ann Arbor
Country of publication
United States
9780542597398, 054259739X
Giegengack, Robert
University of Pennsylvania
University location
United States -- Pennsylvania
Source type
Dissertations & Theses
Document type
Dissertation/thesis number
ProQuest document ID
Database copyright ProQuest LLC; ProQuest does not claim copyright in the individual underlying works.
Document URL
Access the complete full text

You can get the full text of this document if it is part of your institution's ProQuest subscription.

Try one of the following:

  • Connect to ProQuest through your library network and search for the document from there.
  • Request the document from your library.
  • Go to the ProQuest login page and enter a ProQuest or My Research username / password.