New Methods in Stratigraphic Correlation
Patrick, Doreena1, Paul N.
Wegleitner2, James E. Martin3 (1) GeoChemical
Solutions LLC, North Wales, PA (2) GeoChemical
Solutions LLC, Fort Pierre, SD (3) South Dakota School of Mines and Technology,
Rapid City, SD
Our recent research has involved new
methods for stratigraphic correlation including Rare
Earth Element (REE) and trace element (TE) analyses of both fossil bioapatite and associated sediments and unit cell dimension
(UCD) analysis of fossil bioapatite. REE and TE
analyses use variations within fossil bioapatite and
sediment fractions to identify a unique signature for stratigraphic
units. The REE composition and UCD of fossil bioapatite
are dependent upon the conditions of diagenesis and
thus dependent upon availability of TE for substitution during bioapatite per mineralization. REE and TE signatures and
UCD variations identify distinct intervals within lithologic
formations. Because these intervals represent an averaging of periods of
certain depositional environments, these distinct intervals can be correlated
over significant areas. REE and TE analyses of fossils and sediment fractions
and UCD analysis of fossil bioapatite define an
environmental package that relies on several analytical methods and more than
one variable to determine a “fingerprint” for lithologic
units. As a test, fossil vertebrates and sediment samples were obtained from
the Pierre Shale, at various localities in
AAPG Search and Discover Article #90063©2007 AAPG Annual Convention, Long Beach, California