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Bibliographic Details
Main Authors: Bellon, Herve, Maury, R C, Stephan, J F
Format: Dataset Open Access
Language:en
Published: PANGAEA 1982
Subjects:
Online Access:https://doi.org/10.1594/PANGAEA.817821
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author Bellon, Herve
Maury, R C
Stephan, J F
author_facet Bellon, Herve
Maury, R C
Stephan, J F
collection Datos científicos de ciencias marinas y ambientales
contents At Site 493, DSDP Leg 66, dioritic basement was reached below lower Miocene (NN1 Zone, 22-24 Ma) terrigenous sediments. Petrographical, mineralogical (including microprobe analyses), and chemical features of the dioritic rocks reveal their magmatic affinity with the calc-alkaline series. Furthermore, their radiometric age (35.3 m.y.) links the basement to the Sierra Madre Occidental in Mexico and to mid-Tertiary volcanic arcs in Central America. The presence of Oligocene diorite 50 km from the trench axis confirms the truncation of the south Mexico margin, which we explain as the result of a 650 to 800 km left-lateral displacement of Central America relative to North America. Truncation must have occurred in the late Miocene, after the diorite intrusion and prior to the present subduction.
format Dataset Open Access
id pangaea_https___doi_org_10_1594_PANGAEA_817821
institution PANGAEA
language en
publishDate 1982
publisher PANGAEA
record_format pangaea
spellingShingle Petrology, geochemistry, and geodynamics at DSDP Hole 66-493
Bellon, Herve
Maury, R C
Stephan, J F
66-493; Deep Sea Drilling Project; DRILL; Drilling/drill rig; DSDP; Glomar Challenger; Leg66; North Pacific Ocean
At Site 493, DSDP Leg 66, dioritic basement was reached below lower Miocene (NN1 Zone, 22-24 Ma) terrigenous sediments. Petrographical, mineralogical (including microprobe analyses), and chemical features of the dioritic rocks reveal their magmatic affinity with the calc-alkaline series. Furthermore, their radiometric age (35.3 m.y.) links the basement to the Sierra Madre Occidental in Mexico and to mid-Tertiary volcanic arcs in Central America. The presence of Oligocene diorite 50 km from the trench axis confirms the truncation of the south Mexico margin, which we explain as the result of a 650 to 800 km left-lateral displacement of Central America relative to North America. Truncation must have occurred in the late Miocene, after the diorite intrusion and prior to the present subduction.
title Petrology, geochemistry, and geodynamics at DSDP Hole 66-493
topic 66-493; Deep Sea Drilling Project; DRILL; Drilling/drill rig; DSDP; Glomar Challenger; Leg66; North Pacific Ocean
url https://doi.org/10.1594/PANGAEA.817821