Open AccessElasticity of Mafic Rocks from the Mid‐Atlantic Ridge
Author(s) -
Christensen Nikolas I.,
Shaw George H.
Publication year - 1970
Publication title -
geophysical journal of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.302
H-Index - 168
eISSN - 1365-246X
pISSN - 0016-8009
DOI - 10.1111/j.1365-246x.1970.tb06070.x
Subject(s) - geology , basalt , mafic , mid atlantic ridge , ridge , oceanic crust , crest , crust , geochemistry , shear (geology) , mineralogy , petrology , seismology , subduction , paleontology , tectonics , physics , quantum mechanics
Summary Compressional wave velocities are reported to pressures of 10kb for 57 cores of rock dredged from the Mid‐Atlantic Ridge at 22°N and 4°S latitude. Shear wave velocities are reported to pressures of 10 kb for 9 rock cores. The rocks studied consist of basalt, altered basalt, dolerite and chlorite‐rich greenstones. Compressional wave velocities for all of the rocks, with the possible exception of the dolerites, are similar to reported velocities of the oceanic crust over the Mid‐Atlantic Ridge crest. None of the rocks appear to be abundant constituents of the oceanic layer (Layer 3). Relationships between bulk density and velocity are given at pressures of 0.4, 1, 2, 6 and 10 kb. The least squares solution at 10kb, V p = 2.53ρ–0.76, falls between Birch's solutions for mean atomic weights 21 and 22.