Geological and petrologic evolution of seamounts near the EPR based on submersible and camera study |
| |
Authors: | Rodey Batiza Terri L. Smith Yaoling Niu |
| |
Affiliation: | (1) Department of Geological Sciences, Northwestern University, 60208 Evanston, IL, USA;(2) 2427 Cherokee Dr. NW, 72L 0X6 Calgary, Alberta, Canada;(3) Present address: Hawaii Institute of Geophyscis, University of Hawaii, 2525 Correa Rd, 96822 Honolulu, HI, USA |
| |
Abstract: | Observations from 17 ALVIN dives and 14 ANGUS runs plus laboratory study of basalt samples collected with ALVIN help to constrain the morphologic, volcanic and petrologic evolution of four seamounts near the East Pacific Rise (EPR). Comparison among the four volcanoes provides evidence for a general pattern of near-EPR seamount evolution and shows the importance of sedimentation, mass wasting, hydrothermal activity and other geologic processes that occur on submerged oceanic volcanoes. Seamount 5, closest to the EPR (1.0 Ma) is the youngest seamount and may still be active. Its summit is covered by fresh lavas, recent faults and hydrothermal deposits. Seamount D is on crust 1.55 Ma and is inactive; like seamount 5, it has a breached caldera and is composed exclusively of N-MORB. Seamounts 5 and D represent the last stages of growth of typical N-MORB-only seamounts near the EPR axis. Seamounts 6 and 7 have bumpy, flattish summits composed of transitional and alkalic lavas. These lavas probably represent caldera fillings and caps overlying an edifice composed of N-MORB. Evolution from N-MORB-only cratered edifices to the alkalic stage does not occur on all near-EPR seamounts and may be favored by location on structures with relative-motion-parallel orientation. |
| |
Keywords: | seamounts East Pacific Rise submersible studies basalt geochemistry |
本文献已被 SpringerLink 等数据库收录! |
|