[First Hit]

Datapages, Inc.Print this page

Click to view presentation in PDF format.

 

Using Quaternary Reefs and Platforms as a Comparative Tool*

By

William F. Precht1 and Paul M. (Mitch) Harris2

 

Search and Discovery Article #50082 (2008)

Posted June 3, 2008

 

*Adapted from oral presentation at AAPG Annual Convention, Calgary, Alberta, June 16-19, 2005

Click to view list of articles adapted from presentations by P.M. (Mitch) Harris or by his co-workers and him at AAPG meetings from 2000 to 2008.

 

1PBS&J, Miami, FL

2ChevronTexaco Energy Technology Company, San Ramon, CA ([email protected])

 

Abstract 

Exposures of Quaternary reefal limestones provide an excellent opportunity to evaluate Previous HitcarbonateNext Hit platform history relative to high-frequency Previous HitseaNext Hit-Previous HitlevelNext Hit change. Detailed comparative studies of these reef systems from localities worldwide reveal a distinct and similar relationship between relative Previous HitseaNext Hit Previous HitlevelNext Hit history, sedimentary Previous HitsequencesNext Hit, internal facies mosaics, and subsequent overprinting by fabric specific diagenetic alteration.  

Reef complexes generally consist of discrete depositional stages (Previous HitcyclesNext Hit or parasequences) that can be correlated within and between complexes. The complex stacking patterns observed between the individual Previous HitcyclesNext Hit and systems tracts put facies with very different petrophysical properties in both temporal and spatial contact. Understanding the spatial context of facies within the Previous HitsequencesNext Hit is essential to predicting porosity and permeability distributions across ancient Previous HitcarbonateNext Hit platforms. Further analysis indicates that the diagenetic potential of the various facies and their position relative to sequence boundaries also control the heterogeneous reservoir properties observed throughout these reef complexes.  

The exploitation history of many hydrocarbon bearing reef complexes of various ages from around the world underscores the significance of discerning reservoir continuity relative to individual Previous HitcyclesNext Hit of deposition. Because of the ability to unravel relative Previous HitseaNext Hit Previous HitlevelNext Hit history in Quaternary reefs, their use as a counterpart for comparative studies makes them an invaluable tool for developing sound models for reefs through time and space.

 

 

uAbstract

uFigures

uConclusions

uReferences

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

uAbstract

uFigures

uConclusions

uReferences

 

 

 

Selected Figures

Plot of Previous HitseaNext Hit-Previous HitlevelNext Hit changes with respect to present Previous HitseaNext Hit Previous HitlevelNext Hit during the past 140,000 years.

Temporally, Quaternary reef systems exposed for examination are composed of numerous, parasequence-scale, shallowing-upwards packages.

Relationships of Previous HitseaNext Hit-Previous HitlevelNext Hit changes to GRIP (Greenland Ice-Core Project) data (after GRIP, 1993).

Generally, the bases of the individual Previous HitsequencesNext Hit are characterized by a transgressive surface. Vertical (temporal) changes reveal an initial rapid deepening, related to flooding of the platform.

 

Conclusions 

  • By studying reef communities through the Quaternary and their changes over time, it is possible to understand more fully the history of development, structure and function of modern reef systems.

  • Conversely, modern reefs form the foundation for understanding the multiscale processes behind the preserved sedimentary architecture and biofacies of the fossil reef Previous HitsequencesNext Hit.

  • Stage 5e consists of as many as three discrete millennial-scale parasequences.

  • These parasequences are regionally and globally coherent.

  • The exploitation history of many hydrocarbon bearing reef complexes underscores the significance of discerning reservoir continuity relative to individual Previous HitcyclesNext Hit of deposition.

  • Because of the ability to unravel relative Previous HitseaNext Hit Previous HitlevelTop history in Quaternary reefs, their use as a counterpart for comparative studies makes them an invaluable tool for developing sound models for the development of hydrocarbon resources.

 

References 

GRIP (GREENLAND ICE-CORE PROJECT) Members, 1993, Climate instability during the last interglacial recorded in the GRlP ice core: Nature, v. 364, p. 203-207.

Maslin, M., 2002, The Coming Storm: Quarto Publishing, also published by Barron's Educational Series, 144p.

Maslin, M., J. Pike, C. Stickley, and V. Ettwein, 2003, Evidence of Holocene climate variability in marine sediments: in Global Change in the Holocene, p. 185-209.

 

Return to top.