COLD CRUST IN A HOT-SPOT

被引:50
作者
MENKE, W [1 ]
LEVIN, V [1 ]
机构
[1] COLUMBIA UNIV, DEPT GEOL SCI, PALISADES, NY 10964 USA
关键词
D O I
10.1029/94GL01896
中图分类号
P [天文学、地球科学];
学科分类号
07 ;
摘要
Shear waves from locally-recorded Icelandic earthquakes exhibit very little anelastic attenuation, even though they turn in 0-5 Ma lower (15-25 km) crust just above the Moho. Lower crustal shear wave quality factors are about Q=150-225 for paths that cross central Iceland and about Q=300 for paths in southwestern Iceland, values that indicate that the temperature of the lower crust is at least 250-325-degrees-C below the solidus of gabbro (that is, about 875-950-degrees-C, based on published experimental studies of the effect of temperature on shear wave attenuation in gabbro). These low temperatures are not consistent with existing models of crustal accretion, which predict partial melt at lower crustal depths.
引用
收藏
页码:1967 / 1970
页数:4
相关论文
共 20 条
[1]   TOPOGRAPHIC RELIEF AND SEDIMENT THICKNESS - THEIR EFFECTS ON THE THERMAL EVOLUTION OF THE OCEANIC-CRUST [J].
ABBOTT, DH ;
STEIN, CA ;
DIACHOK, O .
GEOPHYSICAL RESEARCH LETTERS, 1992, 19 (19) :1975-1978
[2]  
BEBLO M, 1978, J GEOPHYS-Z GEOPHYS, V45, P1
[3]   TOMOGRAPHIC IMAGE OF THE MID-ATLANTIC PLATE BOUNDARY IN SOUTHWESTERN ICELAND [J].
BJARNASON, IT ;
MENKE, W ;
FLOVENZ, OG ;
CARESS, D .
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH, 1993, 98 (B4) :6607-6622
[4]   SEISMIC ACTIVITY ASSOCIATED WITH THE SEPTEMBER 1977 DEFLATION OF THE KRAFLA CENTRAL VOLCANO IN NORTHEASTERN ICELAND [J].
BRANDSDOTTIR, B ;
EINARSSON, P .
JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH, 1979, 6 (3-4) :197-212
[5]   EVIDENCE FROM BOREHOLE SAMPLES FOR THE ROLE OF ACCESSORY MINERALS IN LOWER-CRUSTAL CONDUCTIVITY [J].
DUBA, A ;
HEIKAMP, S ;
MEURER, W ;
NOVER, G ;
WILL, G .
NATURE, 1994, 367 (6458) :59-61
[6]  
EINARSSON P, 1989, NATO ADV SCI I C-MAT, V266, P329
[7]  
EINARSSON P, 1986, MAP EARTHQUAKE EPICE
[8]  
GEBRANDE H, 1980, J GEOPHYS-Z GEOPHYS, V47, P239
[9]  
GUDMUNDSSON O, 1994, IN PRESS GEOPHYS J I