Skip to Main Content
Book Chapter

The Geometric Interrelationships of Outcrops and Rock Bodies: Setting Up and Testing Quantitative Hypotheses

By
John C. Tipper
John C. Tipper
Search for other works by this author on:
Published:
January 01, 2011

Abstract

An outcrop’s geometry will always have an effect on how data from that outcrop are interpreted; therefore those data should be used only when the implications of that geometry have been taken fully into account. Problems inevitably arise whenever the geologist attempts to do this, the greatest of which stems from the uncertainty that necessarily exists in the position and orientation of the outcrop relative to the underlying rock body. This problem is best handled by means of a hypothesis-based approach for outcrop interpretation, for instance by using one of the three techniques outlined in this paper. The first of these techniques—the use of geometric probability arguments—is illustrated here in the context of recognizing clinoforms in outcrop. It is shown that clinoforms will rarely be seen as sigmoid-shaped curves on randomly positioned and randomly oriented outcrop faces; they are more likely to be seen as simple convex-up or concave-up curves. The second technique—the use of Monte Carlo methods—is illustrated in the context of interpreting dog-legged outcrops in flat-lying sedimentary successions. It is shown that the probability of failing to recognize simple features on the face of dog-legged outcrops can be high, and that this failure probability is highest for relatively long and sinuous outcrops with relatively many segments. This result conflicts totally with conventional geological wisdom. The third technique—the use of standard statistical tests—is illustrated by showing how isolated outcrops can be used to test correlation hypotheses in areas of broken exposure. The paper warns of the danger of conflating rock body and outcrop, then finally offers guidance on hypothesis selection.

Key words: stratigraphy, correlation, model, hypothesis, Monte Carlo

You do not currently have access to this article.

Figures & Tables

Contents

SEPM Concepts in Sedimentology and Paleontology

Outcrops Revitalized: Tools, Techniques and Applications

Ole J. Martinsen
Ole J. Martinsen
Statoil Exploration
Search for other works by this author on:
Andrew J. Pulham
Andrew J. Pulham
ESACT
Search for other works by this author on:
Peter D.W. Haughton
Peter D.W. Haughton
University College Dublin
Search for other works by this author on:
Morgan D. Sullivan
Morgan D. Sullivan
Chevron Energy Technology Company
Search for other works by this author on:
SEPM Society for Sedimentary Geology
Volume
10
ISBN electronic:
9781565763067
Publication date:
January 01, 2011

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