Skip to Main Content
Book Chapter

Recognition and Geologic Preservation of Ancient Carbonate Eolianites

By
David B. Loope
David B. Loope
Chevron USA Production Company, 935 Gravier St., New Orleans, Louisiana 70112, U.S.A.
Search for other works by this author on:
F.E. (Rick) Abegg
F.E. (Rick) Abegg
University of Nebraska, Lincoln, Nebraska 68588, U.S.A.
Search for other works by this author on:
Published:
January 01, 2001

Abstract

Eolian dunes composed of calcium carbonate grains are today widespread along subtropical shorelines. The most definitive criterion for recognizing ancient dune deposits (regardless of original mineralogy) is inversely graded lamination produced by the migration and climb of wind ripples. Additional features useful for recognition of carbonate eolianites are rare (e.g., vertebrate trackways or raindrop imprints) or nondiagnostic, but provide supporting evidence. Eolianites typically lack clasts larger than 3 to 4 mm in diameter. Absence of large-scale cross stratification should not be used to disprove an eolian origin. Calcretes occur within and immediately below many eolianites, as indicated by scattered rhizoliths, alveolar texture, and vadose pendant cements. Depleted δ13C whole-rock values in eolian strata largely result from concentration of 12C in such vadose features.

Shorelines have high wind energy, and carbonate panicles have been produced in great abundance throughout the Phanerozoic, but the pre-Quaternary record of carbonate dunes appears to be meager. Poor preservation potential of topographically high dunes would contribute to the paucity of ancient carbonate eolianites. Preservation may be enhanced by cementation of dunes or if dunes climb during migration, burying strata below interdune surfaces. If subsidence is sufficient, dune strata will escape ravinement during subsequent transgressions.

Many upper Paleozoic carbonate eolianites may not have been sourced by beaches but by deflation. Broad exposure of subtidal deposits resulting from rapid regression across flat platforms or ramps would allow deflation of carbonate sediments. Deflation may have been more widespread in the geologic past, inasmuch as rhizoliths suggest that plants may not have adapted to mobile dune substrates until the Cretaceous.

You do not currently have access to this article.

Figures & Tables

Contents

SEPM Special Publication

Modern and Ancient Carbonate Eolianites: Sedimentology, Sequence Stratigraphy, and Diagenesis

F. E. (Rick) Abegg
F. E. (Rick) Abegg
Chevron USA Production Company, 935 Gravier St., New Orleans, Louisiana 70112, U.S.A.
Search for other works by this author on:
David B. Loope
David B. Loope
University of Nebraska, Lincoln, Nebraska 68588, U.S.A.
Search for other works by this author on:
Paul M. (Mitch) Harris
Paul M. (Mitch) Harris
Chevron Petroleum Technology Company, Houston, Texas, U.S.A.
Search for other works by this author on:
SEPM Society for Sedimentary Geology
Volume
71
ISBN electronic:
9781565761933
Publication date:
January 01, 2001

GeoRef

References

Related

Citing Books via

Close Modal
This Feature Is Available To Subscribers Only

Sign In or Create an Account

Close Modal
Close Modal