Book contents
- Frontmatter
- Contents
- Preface
- Part A Problem of effectiveness
- Part B Proposed solution
- Part C Applications for information-handling
- 9 Earth and biologic evolution
- 10 Proposed new Period Classification of fossils of past organisms
- 11 Paleoenvironment investigation
- 12 General stratigraphic procedures
- 13 Limitations of the use of zones
- 14 Event-Correlation
- Part D Further considerations
- Appendices 1 and 2: Worked examples of GOR and PTR forms
- Glossary
- References
- Index
14 - Event-Correlation
Published online by Cambridge University Press: 02 February 2010
- Frontmatter
- Contents
- Preface
- Part A Problem of effectiveness
- Part B Proposed solution
- Part C Applications for information-handling
- 9 Earth and biologic evolution
- 10 Proposed new Period Classification of fossils of past organisms
- 11 Paleoenvironment investigation
- 12 General stratigraphic procedures
- 13 Limitations of the use of zones
- 14 Event-Correlation
- Part D Further considerations
- Appendices 1 and 2: Worked examples of GOR and PTR forms
- Glossary
- References
- Index
Summary
Preference for use of events rather than zones. In describing successions in order to compare them and thus to achieve correlation, each item of description should be based on as small a thickness of rock as possible, the single sample. This smallness makes it at least theoretically possible to discriminate parts of successions of the same order of magnitude as these samples. When a zone is used the information from many samples is aggregated into a fairly large unit (the zone), below the size of which no further discrimination is possible.
When these events are erected and recognised from single samples, it is possible to order the events from two or more successions in such a way as to reveal at once changes of depositional rate or hiatuses of deposition in the successions. As all such successions have in general more gap than deposition, it is then possible to achieve correlation to the detail permitted by the nature of the succession rather than by the coarseness of the zonal scheme.
Definition of ‘event’. The term ‘event’ has been used in stratigraphy over the last 20 years although it is not used or even indexed by the International Stratigraphic Guide (Hedberg 1976); for definition an event can be said to refer to ‘an interpretation raised by an observer from a single rock sample of any stated size’, and may involve information on biological, chemical or physical phenomena. This definition can include, if desired, the concept of an event having long duration (e.g. a glaciation, an orogeny), although this must be with reference to the extent of the samples specified in the definition which would be correspondingly broad.
- Type
- Chapter
- Information
- Fossils as InformationNew Recording and Stratal Correlation Techniques, pp. 90 - 98Publisher: Cambridge University PressPrint publication year: 1989