Geochemical characteristics of mid-ocean ridge basalts

Sun, Shen-Su; Nesbitt, R.W.; Sharaskin, A.Ya.

doi:10.1016/0012-821x(79)90013-x

Cited by 653 publications

(278 citation statements)

References 69 publications

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“…Mid-ocean ridge basalt (MORB) glasses have, thus, been extensively used to decipher the composition of mantle-derived magmas and the composition of their sources, i.e. the upper, depleted, convecting mantle (e.g., Sun et al 1979;Hofmann 1988;O'Neill and Jenner 2012).…”

Section: Mid-ocean Ridge Basaltsmentioning

confidence: 99%

Boron Isotopes in the Ocean Floor Realm and the Mantle

Marschall

2017

Advances in Isotope Geochemistry

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This chapter reviews the boron isotopic composition of the ocean floor, including pristine igneous oceanic crust such as mid-ocean ridge basalts and ocean island basalts and their implications for the B isotopic composition of the mantle. The chapter further discusses the B isotopic effects of assimilation of altered crustal materials in mantle-derived magmas. The systematics of seawater alteration on oceanic rocks are discussed, including sediments, igneous crust and serpentinization of ultramafic rocks and the respective marine hydrothermal vent fluids. The chapter concludes with a discussion of the secular evolution of the B isotopic composition of seawater.

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Section: Mid-ocean Ridge Basaltsmentioning

confidence: 99%

Boron Isotopes in the Ocean Floor Realm and the Mantle

Marschall

2017

Advances in Isotope Geochemistry

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“…All of (Pearce et al , 1981). The order of elements is of relative incompatibility, following Sun et al (1979). 5H-1, 100-100 5H-2, 100-100 5H-3, 100-100 5H-4, 88-90 5H-4, 100-100 5H-5, 100-100 5H-6, 100-100 5H-7, 40-40 6H-1, 100-100 6H-2, 100-100 6H-3, 100-100 6H-4, 100-100 6H-5, 100-100 6H-6, 100-100 6H-7, 40-40 7H-1, 100-100 7H-2, 100-102 7H-3, 100-102 7H-4, 100-102 7H-5, 100-102 7H-6, 100-102 7H-7, 40-42 8H-1, 100-102 8H-2, 100-101 8H-3, 100-101 8H-4, 100-102 8H-5, 100-102 8H-6, 100-102 8H-7, 50-52 9H-1, 100-102 9H-2, 100-102 9H-3, 100-102 9H-4, 100-102 9H-5, 100-102 9H-6, 100-102 10H-1, 100-102 10H-2, 100-102 10H-3, 100-102 10H-4, 100-102 10H-5, 100-102 10H-6, 100-102 11H-1, 100-102 11H-2, 100-102 11H-3, 100-102 11H-4, 100-102 11H-5, 100-102 11H-6, 100-102 the physical parameters we measured are highly uniform with depth and exhibit low variability, with the exception of the grain density, which is highly variable (Table 13).…”

Section: Physical Properties Of the Sedimentary Sectionmentioning

confidence: 99%

Site 797

1990

Proceedings of the Ocean Drilling Program

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1 Tamaki, K., Pisciotto, K., Allan, J., et al., 1990. Proc. ODP, Init. Repts., 127: College Station, TX (Ocean Drilling Program). Principal results: The objectives at Site 797, located in the southern Yamato Basin, were (1) to determine the age and nature of acoustic basement, (2) to measure the direction and magnitude of the present stress field, and (3) to characterize the sedimentation, subsidence, and oceanographic evolution of the area. The results at Site 797 are summarized below and in Figure 1. The principal results at Site 797 are as follows:1. Acoustic basement and an overlying seismic interval at this site comprise basalts and dolerites and interlayered volcaniclastic sandstones, siltstones, and silty claystones. The age of the sediments which overlie the shallowest basalt layer is estimated to be about 19 Ma. Based on paleodepth estimates using microfossils within these sediments and the sedimentologic interpretation of the underlying volcaniclastic sediments, this part of the Yamato Basin probably subsided rapidly during the early Miocene. The uppermost basalts most likely represent submarine lava flows, whereas the bulk of the underlying igneous units are sills and dikes. The upper nine units are high-Al basalt in composition, consistent with generation during the early stages of arc rifting. However, the units below these are mildly alkaline basalts and enriched tholeiites, which are unrelated to the overlying basalts and were probably derived from a different mantle source.2. The in-situ stress field could not be determined, because poor hole conditions precluded packer/hydro fracture tests. A borehole televiewer log over one basalt interval showed fractures but no borehole breakouts for stress directions.3. The lithologic and paleontological data indicate at least four principal stages in the evolution of this part of the Yamato Basin: (a) an early Miocene period of submarine basaltic volcanism and concomitant deposition of gravity-flow and current-reworked volcani- 323 SITE 797clastic sandstones and siltstones on a shelf or slope, probably outboard of a delta; (b) a late early to early middle Miocene phase of diminishing submarine volcanic activity, warm surface waters, and deposition of calcareous and slightly phosphatic hemipelagic claystones at lower middle bathyal depths (1500-2000 m) in a poorly oxygenated basin; (c) a late Miocene to late Pliocene cooling period beginning with an interval of anomalously slow sedimentation (5 m/m.y.) or a hiatus and characterized by dominant but variable diatomaceous sedimentation at lower middle bathyal depths (1500-2000 m); and (d) a latest Pliocene to Holocene stage during which diatomaceous sedimentation diminished volcanic-ash production and terrigenous input increased, subsidence continued, and climate oscillated to produce a sequence of interlayered light-and dark-colored silty clays having variable organic-carbon contents. In contrast with the more northern sites drilled during Leg 127, the sediments at Site 797 contain more carbonate suggesting ...

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“…Figure 5 also shows the histogram of the ratios of the normal-type MORB, using the data in Fig. 8 in SUN et al, (1979). Figure 5 characterizes the Northeast Japan arc and the Izu-Ogasawara arc on the basis of 87 Sr/86 Sr ratios , although the ranges of the ratios in the volcanic rocks on the back-arc side of both arcs overlap each other.…”

Section: Samplesmentioning

confidence: 99%

Comprehensive strontium isotope study of Quaternary volcanic rocks from the Izu-Ogasawara arc.

1983

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In the Izu-Ogasawara arc, many Quaternary volcanoes are located in a line parallel to the Izu-Ogasawara Trench. 87Sr/86 ST ratios were determined for 65 samples of Quaternary volcanic rocks, 4 cognate inclusions and one sample of basement rock from 15 volcanic islands and 3 submarine volcanoes. In this arc, the 87 Sr/86 Sr ratios in several rocks from the same volcano agree with one another within 0 .0002, regardless of the difference of the rock types and the eruptive stages. The ratios of the volcanoes along the volcanic front in the Izu-Ogasawara arc were constant over 1,200 km and were all within the range between 0.7034 and 0.7039, which is significantly lower than those from the Northeast Japan arc (0.7038-0.7044) (NOTSU, 1983). In the northern region of the Izu-Ogasawara arc, across-arc 87Sr/86Sr ratio variation was found. The ratios decrease with increasing depth of the Wadati-Benioff zone. Even in the volcanic rocks distant from the volcanic front, the ratios (0.7033-0.7035) were slightly higher than those in normal-type MORB, so it is suggested that a small amount of oceanic sediment, altered basalt or sea water component that accompanies the subducting slab has been contributed to the source magma which originates from a partially melted, upper mantle wedge. This contribution becomes smaller with increasing distance from the volcanic front.

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Geochemical characteristics of mid-ocean ridge basalts

Cited by 653 publications

References 69 publications

Boron Isotopes in the Ocean Floor Realm and the Mantle

Boron Isotopes in the Ocean Floor Realm and the Mantle

Site 797

Comprehensive strontium isotope study of Quaternary volcanic rocks from the Izu-Ogasawara arc.

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