Continent-ocean transition on the Voring Plateau, NE Atlantic, derived from densely sampled ocean bottom seismometer data -: art. no. B05101

被引:83
作者
Mjelde, R
Raum, T
Myhren, B
Shimamura, H
Murai, Y
Takanami, T
Karpuz, R
Næss, U
机构
[1] Univ Bergen, Dept Earth Sci, N-5007 Bergen, Norway
[2] Hokkaido Univ, Inst Seismol & Volcanol, Sapporo, Hokkaido 060, Japan
[3] Norsk Hydro AS, N-5020 Bergen, Norway
[4] Norwegian Petr Directorate, Stavanger, Norway
关键词
D O I
10.1029/2004JB003026
中图分类号
P3 [地球物理学]; P59 [地球化学];
学科分类号
0708 ; 070902 ;
摘要
[1] A 180 km long seismic wide-angle profile was acquired across the Voring Plateau, NE Atlantic, using a tuned air gun array and three-component ocean bottom seismometers deployed with similar to 5 km spacing. The seismic P wave data have been modeled by ray tracing/inversion, and the model has been constrained by S wave and gravity modeling. The data and modeling have allowed us to depict the crustal structure and nature of the continent-ocean transition ( COT) in a classical volcanic margin case. The P wave velocity near the top of the main crustal layer is estimated to similar to 6.0 km/s landward of the similar to 25 km wide COT. The seaward increase to similar to 6.5 km/s in the COT is conformable with heavily intruded continental crust within this zone. Farther seaward, the velocity increase to similar to 6.9 km/s in the same layer suggests the presence of oceanic crust. The abundant magmatism landward of, and within, the COT is primarily observed as extrusives forming wedges of seaward dipping reflectors and mafic lower crustal intrusions/underplating. The maximum thickness of the oceanic crust is measured to similar to 23.5 km at the seaward termination of the COT.
引用
收藏
页码:1 / 19
页数:19
相关论文
共 81 条
[1]  
ANDERSON DL, 1994, GEOLOGY, V22, P39, DOI 10.1130/0091-7613(1994)022<0039:SOS>2.3.CO
[2]  
2
[3]  
[Anonymous], 1996, GLOBAL TECTONICS
[4]  
[Anonymous], 1984, PETROLEUM GEOLOGY N
[5]   VELOCITY OF COMPRESSIONAL WAVES IN ROCKS TO 10 KILOBARS, .2. [J].
BIRCH, F .
JOURNAL OF GEOPHYSICAL RESEARCH, 1961, 66 (07) :2199-+
[6]  
Blystad P., 1995, The Norwegian Petroleum Directorate, V8
[7]   Effect of thermal contrasts on gravity modeling at passive margins: Results from the western Barents Sea [J].
Breivik, AJ ;
Verhoef, J ;
Faleide, JI .
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH, 1999, 104 (B7) :15293-15311
[8]  
Brekke H, 2000, GEOL SOC SPEC PUBL, V167, P327, DOI 10.1144/GSL.SP.2000.167.01.13
[9]  
BREKKE H, 1987, NORSK GEOL TIDSSKR, V67, P295
[10]   SEDIMENT SHEAR Q FROM AIRGUN OBS DATA [J].
BROMIRSKI, PD ;
FRAZER, LN ;
DUENNEBIER, FK .
GEOPHYSICAL JOURNAL INTERNATIONAL, 1992, 110 (03) :465-485