Petrology and geochemistry of the lower ocean crust formed at the East Pacific Rise and exposed at Hess Deep: A synthesis and new results

2002 ◽  
Vol 3 (11) ◽  
pp. 1-30 ◽  
Author(s):  
L. A. Coogan ◽  
K. M. Gillis ◽  
C. J. MacLeod ◽  
G. M. Thompson ◽  
R. Hékinian
Keyword(s):  
East Pacific Rise ◽  
Ocean Crust ◽  
East Pacific ◽  
Petrology And Geochemistry

scholarly journals Subsurface structure of a submarine hydrothermal system in ocean crust formed at the East Pacific Rise, ODP/IODP Site 1256

2010 ◽  
Vol 11 (10) ◽  
pp. n/a-n/a ◽  
Author(s):  
Jeffrey C. Alt ◽  
Christine Laverne ◽  
Rosalind M. Coggon ◽  
Damon A. H. Teagle ◽  
Neil R. Banerjee ◽  
...  
Keyword(s):  
Hydrothermal System ◽  
East Pacific Rise ◽  
Subsurface Structure ◽  
Ocean Crust ◽  
East Pacific

scholarly journals Origin of the sheeted dike complex at superfast spread East Pacific Rise revealed by deep ocean crust drilling at Ocean Drilling Program Hole 1256D

2008 ◽  
Vol 9 (6) ◽  
pp. n/a-n/a ◽  
Author(s):  
Susumu Umino ◽  
Laura Crispini ◽  
Paola Tartarotti ◽  
Damon A. H. Teagle ◽  
Jeffery C. Alt ◽  
...  
Keyword(s):  
East Pacific Rise ◽  
Deep Ocean ◽  
Ocean Crust ◽  
Ocean Drilling Program ◽  
Ocean Drilling ◽  
East Pacific ◽  
Dike Complex ◽  
Sheeted Dike Complex

On‐bottom gravity profile across the East Pacific Rise crest at 21° north

Geophysics ◽  
1984 ◽  
Vol 49 (12) ◽  
pp. 2166-2177 ◽  
Author(s):  
Bruce P. Luyendyk
Keyword(s):  
East Pacific Rise ◽  
The Body ◽  
Density Contrast ◽  
Spreading Center ◽  
Upper Ocean ◽  
Ocean Crust ◽  
Sea Floor ◽  
East Pacific ◽  
Ideal Body ◽  
The Ideal

Twenty on‐bottom gravity stations were taken with a LaCoste‐Romberg model G gravity meter inside the submersible Alvin, over a 6 km long cross‐strike profile which straddles the East Pacific Rise spreading center at 21°N. The residual Bouguer anomaly shows a 1.5 mGal low with a total half‐width of 1.7 km centered about the spreading axis and hydrothermal vents. Uncertainties in the ocean depth are believed to contribute a standard error of about 0.3 to 0.4 mGal for the gravity data. The observed elevation factor of 0.1552 mGal/m indicates that the upper ocean crust bulk density is [Formula: see text]. On the other hand, 90 rock samples give a density of [Formula: see text]. This suggests that the largescale porosity of the upper crust is 14 percent. The gravity anomaly was inverted to find the ideal body with the smallest maximum density contrast which satisfies the data and their associated errors. This body extends from the sea floor to 2 500 m depth and has a density contrast of [Formula: see text]. If the density contrast is allowed to be as large as [Formula: see text], the top of the ideal body can be as deep as 300 m and its bottom as deep as 1 300 m; alternatively with the body top at the sea floor, the bottom of the body can be no shallower than 500 m. The ideal body is, therefore, restricted to the dikes and flows of the upper ocean crust. The body is not thought to represent magma in the shallow crust, but rather fractured crust filled with heated seawater.

Sign in / Sign up

Export Citation Format

Share Document