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Title: Early Cretaceous rifting and exposure of periodotite on the Galicia continental margin: preliminary results of ocean drilling program Leg 103

Abstract

Results of drilling near the ocean-continent boundary on the Galicia margin of Iberia shed new light on the timing of rifting and demonstrate the presence at the foot of the margin of a ridge of foliated, lineated, sheared and serpentinized harzburgite, probably representing oceanic mantle. Fifty km east of the periodotite ridge, on a continental fault block, the stratigraphic section sampled during Leg 103 above Hercynian basement comprises: (1) at least 250m of Upper Jurassic and possibly lowest Cretaceous limestone, dolomite and minor sandstone and claystone deposited in relatively shallow water before rifting began; (2) about 20m of Valanginian calpionellid marlstone, probably deposited in moderate depths at the onset of rifting; (3) from about 500 to 1500m of Valanginian and Hauterivian turbidite sandstone rich in terrestrial plant debris, and Barremian and Aptian( ) claystone and marlstone deposited in deeper water during rifting; and (4) about 700m of sediments deposited after Aptian time, when rifting ceased and oceanic spreading between Iberia and Newfoundland began. The lithology and seismic stratigraphy of the wedges of clastic sediments laid down during rifting show the progressive filling of basins that formed by episodic listric faulting that began very early in the Cretaceous and continued formore » about 25 my. The Lower Cretaceous turbidite sandstone cored on the Galicia margin correlates with thick Lower Cretaceous turbidites cored off Morocco during DSDP Leg 50, and with Wealden deltaic and fluviatile deposits on both sides of the Atlantic.« less

Authors:
; ; ; ; ; ; ; ; ; ;
Publication Date:
OSTI Identifier:
5892834
Report Number(s):
CONF-8510489-
Journal ID: CODEN: GAAPB
Resource Type:
Conference
Journal Name:
Geol. Soc. Am., Abstr. Programs; (United States)
Additional Journal Information:
Journal Volume: 17; Conference: 98. annual meeting of the Geological Society of America, Orlando, FL, USA, 28-31 Oct 1985
Country of Publication:
United States
Language:
English
Subject:
58 GEOSCIENCES; CONTINENTAL MARGIN; SEISMIC SURVEYS; STRATIGRAPHY; WELL DRILLING; LOUISIANA; RIFT ZONES; BOREHOLES; CONTINENTAL CRUST; CRETACEOUS PERIOD; EARTH MANTLE; GEOLOGIC FAULTS; LITHOLOGY; OCEANIC CRUST; PERIDOTITES; PLATE TECTONICS; SEDIMENTARY BASINS; SEDIMENTARY ROCKS; CAVITIES; DRILLING; EARTH CRUST; FEDERAL REGION VI; GEOLOGIC AGES; GEOLOGIC FRACTURES; GEOLOGIC STRUCTURES; GEOLOGY; GEOPHYSICAL SURVEYS; IGNEOUS ROCKS; MESOZOIC ERA; NORTH AMERICA; PLUTONIC ROCKS; ROCKS; SURVEYS; TECTONICS; USA; 580201* - Geophysics- Seismology & Tectonics- (1980-1989); 580100 - Geology & Hydrology- (-1989)

Citation Formats

Winterer, E, Boillot, G, Meyer, A, Applegate, J, Baltuck, M, Bergen, J, Comas, M, Davies, T, Dunham, K, Evans, C, and Girardeau, J. Early Cretaceous rifting and exposure of periodotite on the Galicia continental margin: preliminary results of ocean drilling program Leg 103. United States: N. p., 1985. Web.
Winterer, E, Boillot, G, Meyer, A, Applegate, J, Baltuck, M, Bergen, J, Comas, M, Davies, T, Dunham, K, Evans, C, & Girardeau, J. Early Cretaceous rifting and exposure of periodotite on the Galicia continental margin: preliminary results of ocean drilling program Leg 103. United States.
Winterer, E, Boillot, G, Meyer, A, Applegate, J, Baltuck, M, Bergen, J, Comas, M, Davies, T, Dunham, K, Evans, C, and Girardeau, J. 1985. "Early Cretaceous rifting and exposure of periodotite on the Galicia continental margin: preliminary results of ocean drilling program Leg 103". United States.
@article{osti_5892834,
title = {Early Cretaceous rifting and exposure of periodotite on the Galicia continental margin: preliminary results of ocean drilling program Leg 103},
author = {Winterer, E and Boillot, G and Meyer, A and Applegate, J and Baltuck, M and Bergen, J and Comas, M and Davies, T and Dunham, K and Evans, C and Girardeau, J},
abstractNote = {Results of drilling near the ocean-continent boundary on the Galicia margin of Iberia shed new light on the timing of rifting and demonstrate the presence at the foot of the margin of a ridge of foliated, lineated, sheared and serpentinized harzburgite, probably representing oceanic mantle. Fifty km east of the periodotite ridge, on a continental fault block, the stratigraphic section sampled during Leg 103 above Hercynian basement comprises: (1) at least 250m of Upper Jurassic and possibly lowest Cretaceous limestone, dolomite and minor sandstone and claystone deposited in relatively shallow water before rifting began; (2) about 20m of Valanginian calpionellid marlstone, probably deposited in moderate depths at the onset of rifting; (3) from about 500 to 1500m of Valanginian and Hauterivian turbidite sandstone rich in terrestrial plant debris, and Barremian and Aptian( ) claystone and marlstone deposited in deeper water during rifting; and (4) about 700m of sediments deposited after Aptian time, when rifting ceased and oceanic spreading between Iberia and Newfoundland began. The lithology and seismic stratigraphy of the wedges of clastic sediments laid down during rifting show the progressive filling of basins that formed by episodic listric faulting that began very early in the Cretaceous and continued for about 25 my. The Lower Cretaceous turbidite sandstone cored on the Galicia margin correlates with thick Lower Cretaceous turbidites cored off Morocco during DSDP Leg 50, and with Wealden deltaic and fluviatile deposits on both sides of the Atlantic.},
doi = {},
url = {https://www.osti.gov/biblio/5892834}, journal = {Geol. Soc. Am., Abstr. Programs; (United States)},
number = ,
volume = 17,
place = {United States},
year = {Tue Jan 01 00:00:00 EST 1985},
month = {Tue Jan 01 00:00:00 EST 1985}
}

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