740 



TABLE 839.— CHARACTERISTICS OF EARTH'S INTERIOR (concluded) 

 Part 2. — Elastic constants of earth's interior 



Part 3. — Velocities of earthquake waves 



V P is the velocity in km/sec of the primary or condensational wave, V,, of the secondary 

 or distortional wave. Turner speaks of them as the push and shake waves. 



Layer 

 to 20 ± 10 km depth, depending on 



locality 

 20 ± 10 to 45 ± 10 km depth, depend- 

 ing on locality 

 Between 45 ± 10 and 2900 km depth : 



45 ± 10 



1300 



2400 



<2900 

 Core, 2700 to 6370 km (center) : 



>2900 



6000 



V P< km/sec 



V«, km/sec 



TABLE 840.— BULK MODULI OF ROCK-FORMING MINERALS* 



The bulk modulus, K, of a compact holocrystalline rock can be obtained with a fair 

 degree of accuracy except for low pressures by adding the proportionate bulk moduli of 

 the constituent minerals. 



Pressure, P, and K X 10"° are in bars. 



Mineral 1 



Feldspar : Orthoclase 527 



Oligoclase, Ab7xAn 2 2 582 



Labradorite, Ab <s An 5 2 654 



Pyroxene : Orthorhombic 1.00 



Diopside 935 



Augite 981 



Hornblende : Actinolite 769 



Mica : Phlogopite 431 



Quartz 373 



Calcite 736 



Magnetite 1.818 



Corundum 2.44 



Tourmaline 1.22 



Rutile 1.72 



1.852 



Compiled by R. W. Goranson. 



SMITHSONIAN PHYSICAL TABLES 



