Skip to Main Content
Book Chapter

Sediments of Laguna Madre, Texas1

By
Gene A. Rusnak
Gene A. Rusnak
Miami, FloridaThe Marine Laboratory, University of Miami. Numerous individuals from the Scripps Institution of Oceanography have assisted in the collection, processing, and discussion of data. Francis P. Shepard de serves special thanks for having initiated this study and for his continued interest in its progress. The writer also acknowledges the help of C. R. Haller, R. R. Lankford, H. W. Lusk, J. R. Moriarty, Frances L. Parker, R. H. Parker, F. B Phleger, D. M. Poole, E. Sanborn, and S. Southworth. Tjeerd H. van Andel and Joseph R. Curray have my special thanks for their many discussions of the problems associated with this study. Many organizations are gratefully acknowledged for supplying data, laboratory analyses, and assistance in the field. These include Texas Game and Fish Commission, Rockport, Texas; The California Research Corporation, La Habra, California; Shell Research and Development Corporation, Houston, Texas; Humble Oil and Refining Company, Houston, Texas; Alberta Research Council, Edmonton, Alberta; and the Jersey Production Research Company, Tulsa, Oklahoma. The U. S. Army Corps of Engineers; Cur-nutte Engineering Company, Raymondville, Texas; Houston Engineering Service, Corpus Christi, Texas; and the Atlantic Gulf and Pacific Dredging Company, Houston, Texas, provided data from shallow borings in the area.
Search for other works by this author on:
Published:
January 01, 1960

Abstract

Laguna Madre is a linear coastal lagoon, developed on the pre-Holocene3

3

Throughout the paper the age of transgressive de posits following the last glaciation is referred to as “Holocene,” in keeping with its generally accepted usage.

erosion surface by the buildup of a barrier island, resulting from the transgression brought about during the postglacial rise in sea level. The Holocene deposits average 10-20 feet in thickness, although local depressions in the pre-Holocene surface may contain a considerably thicker section. The bulk of the Holocene deposits consists of subgraywacke and subarkosic sand. Local concentrations, however, include limestones, gravels, oolites, and relatively pure clays.

Source of the clay is unknown, but heavy and light mineral analyses of the sand fraction indicate locally reworked earlier deposits. The northern Laguna sediments are derived from the pre-Holocene sediments off the Nueces delta province and the southern Laguna sediments are derived from the Holocene and pre-Holocene deposits of the Rio Grande distributary province.

The immediate source of the lagoonal fill is the barrier island sand, which is believed to be derived from the earlier deposits of the nearshore gulf. During and after sea-level rise, the near-shore gulf floor was actively eroded by wave action to establish an equilibrium profile. The eroded material was sorted and the sand fraction was transported landward. Wind action piled the new beach sands into coastal dunes on the barrier. Where the earlier deposits were relatively un-consolidated, as offshore northern Padre Island, thick dune deposits could form because of large supply. Where the earlier deposits were more consolidated, and consequently less easily eroded, as in the vicinity of the Rio Grande delta, the dunes are lower and the barrier narrower.

Subsequent to the formation of the lagoon about 5,000 years ago, partial filling was accomplished by washover storm waves, wind transport, and tidal activity.

You do not currently have access to this article.

Figures & Tables

Contents

AAPG Special Publication

Recent Sediments, Northwest Gulf of Mexico

Francis P. Shepard
Francis P. Shepard
Scripps Institution of OceanographyUniversity of CaliforniaLa Jolla
Search for other works by this author on:
Fred B Phleger
Fred B Phleger
Scripps Institution of OceanographyUniversity of CaliforniaLa Jolla
Search for other works by this author on:
Tjeerd H. Van Andel
Tjeerd H. Van Andel
Scripps Institution of OceanographyUniversity of CaliforniaLa Jolla
Search for other works by this author on:
American Association of Petroleum Geologists
ISBN electronic:
9781629812403
Publication date:
January 01, 1960

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