Neoproterozoic
Paleogeography and Paleoclimate Implications from the Red Pine Shale,
Myer, Caroline A.1, Carol M.
Dehler1 (1)
The Red Pine Shale, Uinta Mountain Group,
(625 to >1200 m thick) is an organic-rich sedimentary succession that
indicates a south-trending marine deltaic system in the
Six measured sections have been described
(type section in northwestern part of range and Hades section in southwestern
part of range) for facies analysis and were sampled for C-isotope and TOC
analyses, and sandstone petrography. Five facies have been identified
including: shale facies (distal prodelta), slump-fold facies (distal to
proximal prodelta), concretion facies (distal to proximal prodelta),
shale-and-sandstone facies (distal delta front), and sandstone facies (proximal
delta front to delta plain). Concretions contain vase-shaped microfossils,
which are used for correlation and the ~750 Ma age constraint.
Measured sections in the Hades area were
correlated using marker beds and facies intervals. Correlations show a thinning
of sandstone bodies southward, suggesting a delta system feeding the basin from
the north. Correlations also indicate a minimum measured composite thickness of
880m, and a minimum mapped thickness of >1200m (basal contact not exposed).
The type section is ~625m thick, the lower contact with the underlying
formation of
Initial C-isotope values from the overall
composite section range from -28.93 to -16.91 PDB (~3 to 20 m sample spacing)
and display anomalies that have potential to be used as fingerprints for local
and regional correlation, as well as potential climate proxies.
AAPG Search and Discover Article #90063©2007 AAPG Annual Convention, Long Beach, California