Skip to Main Content
Book Chapter

Regional Exposure Events and Platform Evolution of Zhujiang Formation Carbonates, Pearl River Mouth Basin: Evidence from Primary and Diagenetic Seismic Facies

By
Eva P. Moldovanyi
Eva P. Moldovanyi
Amoco Production Company Houston, Texas, U.S.A.
Search for other works by this author on:
F. M. Wall
F. M. Wall
Amoco Norway Oil Company Stavanger, Norway
Search for other works by this author on:
Zhang Jun Yan
Zhang Jun Yan
China Offshore Oil Nanhai East Corporation Guangzhou, Peoples Republic of China
Search for other works by this author on:
Published:
January 01, 1995

Abstract

The concept of chaotic or “diagenetic” seismic facies is introduced as a tool for understanding factors controlling the evolution of Miocene Zhujiang Formation carbonate platforms in the Pearl River Mouth Basin, South China Sea. Seismic data from this basin contain a continuum of chaotic seismic facies, which are present only within the carbonate interval and range in appearance from simple concave-shaped reflectors to highly irregular, high-amplitude chaotic reflectors. Diagenetic seismic facies are significant because they are overprinted on depositional (primary) seismic facies. The common association between chaotic seismic facies and other features, such as truncated zones and hummocky carbonate surfaces, supports a model involving karstification of Zhujiang Formation carbonates.

Two contrasting stages of carbonate platform development are recognized from seismic stratigraphic relationships within the Zhujiang Formation interval: (1) the “lower” platform, a broad and areally extensive low-relief ramp, and (2) the “upper” platform, a narrow and high-relief feature. A regional episode of subaerial diagenesis separating the two stages of platform development is inferred from the distribution of chaotic seismic facies and from the presence on seismic of erosional carbonate surfaces. The magnitude of sea level fluctuation is thought to have been on the order of a few 100 m and was likely eustatically controlled. Numerous backstepping events in the upper Zhujiang carbonate suggest this stage of platform development was characterized by continually rising sea level. Smaller-scale exposure events, not resolvable on seismic, are recognized in cores of upper Zhujiang carbonates in the Liuhua 11–1 field and are seemingly at odds with the drowning model. These exposure events are interpreted to be sudden brief excursions in an otherwise continuously drowning sequence.

You do not currently have access to this article.

Figures & Tables

Contents

AAPG Memoir

Unconformities and Porosity in Carbonate Strata

David A. Budd
David A. Budd
Search for other works by this author on:
Arthur H. Saller
Arthur H. Saller
Search for other works by this author on:
Paul M. Harris
Paul M. Harris
Search for other works by this author on:
American Association of Petroleum Geologists
Volume
63
ISBN electronic:
9781629810843
Publication date:
January 01, 1995

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