ABSTRACT
A Permo-Triassic reconstruction of western Pangea (North America,
South
America, Africa) is proposed that is characterized by: 1)
definition of
the North Atlantic fit by matching of marginal offsets (fracture
zones)
along the opposing margins, 2) a South Atlantic fit that is
tighter than
the Bullard fit and that is achieved by treating Africa as two
plates astride
the Benue Trough and related structures during the Cretaceous, 3)
complete
closure of the Proto-Atlantic Ocean between North and South
America, accomplished
by placing the Yucatan block between the Ouachita Mountains and
Venezuela,
4) a proposed Hercynian suture zone that separates zones of
foreland thrusting
from zones of arc-related magmatic activity; to the northwest of
this suture
lie the Chortis block and Mexico and most of North America, and to
the
southeast of this suture lie South America, the Yucatan block,
Florida
and Africa, and 5) satisfaction of paleomagnetic data from North
America,
South America and Africa. Beginning with the proposed
reconstruction, the
relative motion history of South America with respect to North
America
is defined using the finite difference method. Within the
framework provided
by the proposed relative motion history, an evolutionary model for
the
development of the Gulf of Mexico and Caribbean region is outlined
in a
series of 13 plate boundary reconstructions at various time
intervals from
the Jurassic to the present. The model includes: 1) formation of
the Gulf
of Mexico by 140ma, 2) Pacific provenance of the Caribbean plate
through
the North America-South America gap during Cretaceous time, 3)
Paleocene-Early
Eocene back-arc spreading origin for the Yucatan Basin, whereby
Cuba is
the frontal arc and the Nicaragua Rise-Jamaica is the remnant arc,
and
4) 1400 km of post-Eocene cumulative offset along both the
Northern and
Southern Caribbean Plate Boundary Zones, allowing grandiose
eastward migration
of the Caribbean plate with respect to the North and South
American plates.
Pindell, J.L., 1981. Permo-Triassic reconstruction of Western
Pangea
and the evolution of the Gulf of Mexico-Caribbean region.
Unpublished MSc.
thesis, State University of New York at Albany. 121 pp., +xi
University at Albany Science Library call number: SCIENCE
Oversize
(*) QE 40 Z899 1981 P56
thesis (scanned
text) - 4.6MB pdf file
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