Petrology and geochemistry of volcanic rocks, DSDP Leg 55, Emperor seamount chain

Online Access: Get full text
doi: 10.2973/dsdp.proc.55.120.1980
Author(s): Kirkpatrick, R. James; Clague, David A.; Freisen, Walter
Author Affiliation(s): Primary:
Univ. Ill., Geol. Dep., Urbana, IL, United States
Other:
U. S. Geol. Surv., Menlo Park, CA, United States
Volume Title: Initial reports of the Deep Sea Drilling Project covering Leg 55 of the cruises of the drilling vessel Glomar Challenger, Honolulu, Hawaii to Yokohama, Japan; July-September 1977
Volume Author(s): Shambach, James, editor; Jackson, Everett Dale; Koizumi, Itaru; Avdeiko, Gennady; Butt, Arif; Clague, David; Dalrymple, G. Brent; Greene, H. Gary; Karpoff, Anne Marie; Kirkpatrick, R. James; Kono, Masaru; Hsin Yi Ling; McKenzie, Judith; Morgan, Jason; Takayama, Toshiaki
Source: Initial reports of the Deep Sea Drilling Project covering Leg 55 of the cruises of the drilling vessel Glomar Challenger, Honolulu, Hawaii to Yokohama, Japan; July-September 1977, James Shambach, Everett Dale Jackson, Itaru Koizumi, Gennady Avdeiko, Arif Butt, David Clague, G. Brent Dalrymple, H. Gary Greene, Anne Marie Karpoff, R. James Kirkpatrick, Masaru Kono, Hsin Yi Ling, Judith McKenzie, Jason Morgan and Toshiaki Takayama. Initial Reports of the Deep Sea Drilling Project, Vol.55, p.509-557. Publisher: Texas A & M University, Ocean Drilling Program, College Station, TX, United States. ISSN: 0080-8334 CODEN: IDSDA6
Note: In English. 12 refs.; illus. incl. tables
Summary: The lack of systematic variation in the major and trace elements along the chain, discussed above and by Clague and Frey (this volume), implies that the conditions of magma genesis, the composition of the parental material, and the extent of melting at the Hawaiian hot spot have not changed significantly since Suiko was formed. There have clearly been fluctuations in at least one of these, but mostly they appear to be relatively short-lived. Kilauea and Mauna Loa lavas, for instance, are significantly different, but both volcanoes are presently active. The CaO and TiO2 anomalies for Nihoa to Daikakuji may represent a longer term fluctuation in source composition. The major problem, however, is how to account for the overall stability. If the Hawaiian hot spot is to be relatively fixed (and the magnetic evidence from Suiko [Kono, this volume] indicates that at least the change in latitude has not been great), the heat source for the igneous activity must be at least as deep as the asthenosphere and possibly deeper. It is very unlikely that it is in the lithosphere, since the lithosphere in the Pacific appears to be in motion away from the east Pacific rise. The evidence for the ultimate location of the magma's source material is considerably weaker. The lines of evidence we have are that (1) the depth of melting to produce the parental tholeiitic magma must be relatively constant and probably fairly shallow, or there would not be tholeiitic basalts (Green and Ringwood, 1967); (2) the source material must be fairly uniform through time and must be continually replenished, or the magma composition would change and igneous activity would eventually stop; and (3) on the basis of seismic activity progressing to volcanism, the magma apparently enters conduits at a depth of at least 60 km (Wright, 1971). Because this depth is in the lithosphere, the source region could be in the lower lithosphere or asthenosphere. We do not have criteria to unambiguously distinguish these possibilities.
Year of Publication: 1980
Research Program: DSDP Deep Sea Drilling Project
IPOD International Phase of Ocean Drilling
Key Words: 02 Geochemistry; Alkalic composition; Basalts; Deep Sea Drilling Project; Emperor Seamounts; Geochemistry; IPOD; Igneous rocks; Leg 55; North Pacific; Northwest Pacific; Pacific Ocean; Petrology; Site 430; Site 432; Site 433; Volcanic rocks; West Pacific
Coordinates: N350000 N500000 E1750000 E1600000
Record ID: 1981027014
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from U. S. Geological Survey, Hawaiian Volcano Observatory, United States