Detachment faulting, mantle serpentinization, and serpentinite-mud volcanism beneath the Porcupine Basin, southwest of Ireland

Citation
Tj. Reston et al., Detachment faulting, mantle serpentinization, and serpentinite-mud volcanism beneath the Porcupine Basin, southwest of Ireland, GEOLOGY, 29(7), 2001, pp. 587-590
Citations number
20
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Earth Sciences
Journal title
GEOLOGY
ISSN journal
0091-7613 → ACNP
Volume
29
Issue
7
Year of publication
2001
Pages
587 - 590
Database
ISI
SICI code
0091-7613(200107)29:7<587:DFMSAS>2.0.ZU;2-B
Abstract
The Porcupine Basin southwest of Ireland provides an opportunity to study t he symmetry of rifting at stretching factors approaching continental breaku p. Profiles across the basin image a bright reflection that appears to repr esent a detachment fault, and may in part be a decollement at the top of pa rtially serpentinized mantle. Although overall the basin appears symmetric, the consistent westward structural dip of the detachment implies that, at high stretching factors, extension was asymmetric. Farther south, the Porcu pine median high appears in cross section to be a triangular construction o verlying tilted fault blocks and onlapped by postrift sediment, Despite no evidence for synrift magmatism, this high has previously been interpreted a s a basaltic structure. However, it may represent a serpentinite-mud volcan o or diapir: we suggest that such structures produce the serpentinite brecc ias found within the rifted continent-ocean transition of nonvolcanic margi ns.