Skip to Main Content
Book Chapter

Chapter 17: Atlantic and Gulf of Mexico continental margins

By
A. M. Trehu
A. M. Trehu
Search for other works by this author on:
K. D. Klitgord
K. D. Klitgord
Search for other works by this author on:
D. S. Sawyer
D. S. Sawyer
Search for other works by this author on:
R. T. Buffler
R. T. Buffler
Search for other works by this author on:
Published:
January 01, 1989

The U.S. Atlantic and Gulf of Mexico continental margins are thickly sedimented passive margins that formed when Pangea split apart during Middle Jurassic time to create the Atlantic Ocean and Gulf of Mexico. Keys to understanding the process of continental breakup and its relation to preexisting structure are found in the structure of the crust beneath the sediment-filled basins and adjacent platforms and embayments that outline the margins. Because of the great thickness of post-rift sedimentary rock in the basins and the presence of massive reef carbonates and salt layers and diapirs, the crustal structure beneath the basins in the region of the transition between oceanic and continental crust is poorly known at present. Recent advances in seismic reflection and refraction data collection techniques (both sources and receivers), however, are just beginning to yield new data to look at the crustal structure in this important region. One of the most important results on the deep structure of continental margins obtained in recent years is recognition of a thick, high-velocity (7.2 to 7.5 km/sec) layer at the base of the crust beneath the U.S. Atlantic continental margin as well as beneath several other margins worldwide. This layer is observed beneath both extended continental crust and early oceanic crust and has been interpreted to indicate that extensive intrusive magmatism was associated with the late stage of rifting and early sea-floor spreading. Only a weak suggestion of such a layer has been observed beneath the Gulf of Mexico margin, although this may be in part due to the difficulty of observing lower crustal arrivals because of the extensive presence of salt in the shallow section.

You do not currently have access to this article.

Figures & Tables

Contents

GSA Memoirs

Geophysical Framework of the Continental United States

L. C. Pakiser
L. C. Pakiser
Search for other works by this author on:
Walter D. Mooney
Walter D. Mooney
Search for other works by this author on:
Geological Society of America
Volume
172
ISBN print:
9780813711720
Publication date:
January 01, 1989

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