Premium
Construction and destruction of volcanic knobs at the Cocos‐Nazca Spreading System near 95°W
Author(s) -
Kleinrock Martin C.,
Brooks Benjamin A.
Publication year - 1994
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/94gl01597
Subject(s) - geology , lithosphere , volcano , crust , tectonics , magma , ridge , seamount , mid ocean ridge , mantle (geology) , seismology , geophysics , paleontology
Characterization of volcanic knobs observed in Sea Beam bathymetry near the 95°W Galapagos propagator system on the Cocos‐Nazca spreading axis provides insight into volcanic and tectonic processes at propagators and mid‐ocean ridges. Despite evidence suggesting a higher magma supply rate at the propagator axis, crust accreted there contains fewer knobs than crust created at the failing or doomed spreading axes. Fissure‐fed flows rather than seamount construction are more important along the propagator. The process of transferring lithosphere from one plate to another as this ridge offset migrates through a region destroys about half of the preexisting knobs. Data tentatively suggest that on‐axis volcanic cones increase in size and contribution to crustal construction but decrease in abundance with decreasing spreading rate, possibly reflecting the magma plumbing systems in differing thermal regimes.