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The AAPG/Datapages Combined Publications Database

AAPG Bulletin


Volume: 65 (1981)

Issue: 5. (May)

First Page: 951

Last Page: 951

Title: Basin Evolution and Present Faulting Patterns Within Isthmus of Panama Volcanic Arc: ABSTRACT

Author(s): Allen Lowrie, Robert Stewart

Article Type: Meeting abstract


The present foundation of Panama consists of a raised block of Upper Cretaceous or older oceanic crust within a plate convergence zone. The trend of the Panamanian volcanic arc is east-west. Although broken laterally, the structural pattern from the Pacific to the Caribbean includes a subduction complex crested by a coastal range, a fore-arc basin, followed by a volcanic arc, and a back-arc fold-thrust belt and retro-arc basin along the Caribbean margin. Plate interactions have been a prime mechanism in causing trans-isthmian faulting. The present boundary between Nazca (Panama basin) and Cocos plates is the Panama fracture zone. Faulting within this fracture zone partly cuts the fore-arc basin. Due north, in the Gulf of Mosquitos, there is morphologic evidence of faultin along the continental margin. The southeastward trend of eastern Panama is contrary to the convexity, relative to the underthrusting plates, of volcanic island arcs; thus, eastern Panama should trend toward the northeast and all of eastern Panama may have rotated up to 90°, from northeast to southeast. The Darien-Atrato basin is a fore-arc basin. East-west compression in eastern Panama is suggested by fault patterns lying perpendicular to the trend of the San Blas-Darien cordillera. There, inferred faults change trend from roughly north-south in the west to northeast-southwest in the east. Extension of these faults into adjacent basins is not known. Thus, one consideration in hydrocarbon exploration in Panama is the locating of faults.

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