Linear island and seamount chains, aseismic ridges and intraplate volcanism; results from DSDP

Author(s): Clague, David A.
Author Affiliation(s): Primary:
U. S. Geol. Surv., Menlo Park, CA, United States
Univ. South. Calif., United States
Scripps Inst. Oceanogr., United States
Volume Title: Deep Sea Drilling Project; a decade of progress
Volume Author(s): Warme, John E., editor; Douglas, Robert G.; Winterer, Edward L.
Source: Special Publication - Society of Economic Paleontologists and Mineralogists, 32, p.7-22; The Deep Sea Drilling Project; a decade of progress, Houston, TX, April 4, 1979, edited by John E. Warme, Robert G. Douglas and Edward L. Winterer. Publisher: SEPM (Society for Sedimentary Geology), Tulsa, OK, United States. ISSN: 0097-3270 CODEN: SPMIAF
Note: In English. 76 refs.; sketch maps
Summary: The Deep Sea Drilling Project drilled a substantial number of sites that bear on the origin of linear island and seamount chains, aseismic ridges and other more regional expressions of intraplate volcanism. Drilling in the Emperor Seamounts during Leg 55 was particularly successful. Results from this leg include: 1) the volcanoes of the Hawaiian-Emperor chain continue to increase in age away from Kilauea as predicted. 2) Suiko Seamount formed at a paleolatitude of 26.9±3.5°N, 7° north of present-day Hawaii, but far south of its present latitude of 44.8°N. 3) the volcanic rock types recovered include hawaiite, mugearite, alkalic basalt and tholeiitic basalt in the sequence and relative volume expected for Hawaiian volcanoes. 4) the tholeiitic and alkalic basalts recovered are geochemically similar to those in the Hawaiian Islands, only the ratio of 87Sr/86Sr appears to change through time. All the lavas appear to be derived from a source that has small-scale heterogeneities, but is homogeneous on a large scale. 4) The Emperor Seamounts were once volcanic islands that underwent subaerial and shallow marine erosion, and deposition of shallow-water biogenic carbonate sediments that capped all or most of each volcano. Drilling in other regions has yielded less conclusive results. For example, it is uncertain if the Line Islands are an age progressive chain (hot-spot trace) or result from some other type of intraplate volcanism. The mid-Pacific Mountains also show evidence of originating from a regional episode of volcanism in the mid-Cretaceous. Drilling in the Nauru Basin encountered a voluminous mid-Cretaceous volcanic flow-sill complex that overlies Jurassic magnetic anomalies, yet is composed of depleted tholeiite. In the Indian Ocean, drilling on the Ninety-East Ridge established that it 1) is volcanic in origin; 2) is older to the north; 3) formed in shallow water, and 4) formed further south and has moved northward. It appears that the Ninety-East Ridge, like the Hawaiian-Emperor chain, is a hot spot trace. In the Atlantic Ocean, drilling on the Iceland-Faeroe Ridge and the Rio Grande Rise-Walvis Ridge suggests that all these aseismic ridges are hot spot traces generated by the Iceland and Tristan de Cunha hot-spots.
Year of Publication: 1981
Research Program: DSDP Deep Sea Drilling Project
Key Words: 07 Marine Geology and Oceanography; 18 Geophysics, Solid-Earth; Aseismic ridges; Atlantic Ocean; Deep Sea Drilling Project; East Pacific Ocean Islands; Emperor Seamounts; Genesis; Hawaii; Hot spots; Iceland-Faeroe Ridge; Indian Ocean; Intraplate tectonics; Islands; Line Islands; Mid-Pacific Mountains; Nauru Basin; Nintyeast Ridge; North Atlantic; North Pacific; Northwest Pacific; Ocean floors; Oceania; Oceanography; Pacific Ocean; Plate tectonics; Polynesia; Processes; Progress report; Report; Research; Rio Grande Rise; Seamounts; South Atlantic; United States; Volcanism; Volcanology; Walvis Ridge; West Pacific
Record ID: 1982040037
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from U. S. Geological Survey, Hawaiian Volcano Observatory, United States

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