塔北隆起二叠纪岩浆岩产状的地震解释及其侵位模式     

程海艳  李江海  赵星  潘赟 《岩石学报》2010,26(1):283-290

塔北隆起西部发育大面积岩浆岩,岩浆岩发育产状的研究不仅对岩浆岩油气藏勘探具有重要意义,而且对塔北隆起碳酸盐岩油气藏研究具有重要意义。本文利用钻井和地震资料,提出塔北隆起二叠纪岩浆岩岩性主要为玄武岩、流纹岩、辉绿岩、正长岩、花岗岩和凝灰岩。岩浆岩发育模式与构造作用密切相关,在英买力低凸起北部地区,主要发育一条逆冲断层,地层受构造作用扰动较少,岩浆岩主要为玄武岩,通过近于垂直的通道到达地表; 英买2地区,构造挤压作用在盐上形成大量的构造裂缝,岩浆岩侵入其中,形成辉绿岩侵入体; 哈拉哈塘地区构造变形微弱,岩浆岩通过垂直的火山通道到达地表,在地表形成了一层平行分布的喷发岩; 而在塔北隆起的中部,由于受拉张作用的影响,地壳发育一定的减压熔融,形成中酸性岩浆,岩浆侵位产生了大量的中酸性侵入体和喷出岩。  相似文献   

Surface wave ray tracing and azimuthal anisotropy: a generalized spherical harmonic approach     

Lapo Boschi  John H. Woodhouse 《Geophysical Journal International》2006,164(3):569-578

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On high-frequency spheroidal modes and the structure of the upper mantle     

B. L. N. Kennett  J. H. Woodhouse 《Geophysical Journal International》1978,55(2):333-350

Summary. The asymptotic properties of spheroidal mode dispersion at high frequency for fixed phase velocity are related to the intercept times τ_β( p ) for P and S waves. If the mode eigenfrequency and the ratio of horizontal to vertical displacement at the surface for the mode are known τ_α( p ) and τ_β( p ) may be separately estimated. If discontinuities exist in the velocity model then 'solotone' effects occur, in frequency at fixed slowness, and in τ_α( p ), τ_β( p ) estimated from the mode dispersion as a function of slowness. The coupling of P and S waves in the spheroidal modes means that the interaction of P waves with upper-mantle discontinuities affects also the estimates of the S wave τ_β( p ) values for which the corresponding turning points lie in the lower mantle. The asymptotic formalism also shows that sharp pulses formed by superposition of spheroidal modes correspond to multiple PS reflections.
A study of τ_α( p ), τ_β( p ) estimates derived from spheroidal modes with periods from 45–50s, calculated for model 1066B, shows that even in the presence of strong upper-mantle discontinuities the errors in intercept time are only about one-tenth of a period. The asymptotic properties may there-for provide a useful means of estimating intercept times from modes with a few seconds period as a supplement to travel-time methods.  相似文献   

Diffraction by Anomalous Regions in the Earth's Mantle     

J. H. Woodhouse 《Geophysical Journal International》1973,32(3):295-324

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Centroid-moment tensor solutions for October–December, 1983     

A.M. Dziewonski  J.E. Franzen  J.H. Woodhouse 《Physics of the Earth and Planetary Interiors》1984,34(3):129-136

Centroid-moment tensor solutions are presented for 133 earthquakes that occurred during the fourth quarter of 1983.  相似文献   

Observations of long period Rayleigh wave ellipticity     

Ana M. G. Ferreira  John H. Woodhouse 《Geophysical Journal International》2007,169(1):161-169

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Surface wave tomography: global membrane waves and adjoint methods     

D. Peter  C. Tape  L. Boschi  J. H. Woodhouse 《Geophysical Journal International》2007,171(3):1098-1117

We implement the wave equation on a spherical membrane, with a finite-difference algorithm that accounts for finite-frequency effects in the smooth-Earth approximation, and use the resulting 'membrane waves' as an analogue for surface wave propagation in the Earth. In this formulation, we derive fully numerical 2-D sensitivity kernels for phase anomaly measurements, and employ them in a preliminary tomographic application. To speed up the computation of kernels, so that it is practical to formulate the inverse problem also with respect to a laterally heterogeneous starting model, we calculate them via the adjoint method, based on backpropagation, and parallelize our software on a Linux cluster. Our method is a step forward from ray theory, as it surpasses the inherent infinite-frequency approximation. It differs from analytical Born theory in that it does not involve a far-field approximation, and accounts, in principle, for non-linear effects like multiple scattering and wave front healing. It is much cheaper than the more accurate, fully 3-D numerical solution of the Earth's equations of motion, which has not yet been applied to large-scale tomography. Our tomographic results and trade-off analysis are compatible with those found in the ray- and analytical-Born-theory approaches.  相似文献   

A geochemical reconstruction of oil generation in the Barrow Sub-basin of Western Australia     

John K. Volkman  Robert Alexander  Robert Ian Kagi  Rohinton A. Noble  Carry Wayne Woodhouse 《Geochimica et cosmochimica acta》1983,47(12):2091-2105

A suite of crude oils and petroleum source rock extracts from the Barrow Sub-basin of Western Australia have been analysed for biological marker compounds by capillary GC-MS, and for volatile hydrocarbons by whole oil capillary GC. These analyses were used to calculate values for twenty-three biomarker parameters in order to assess aspects of source type, maturity, migration and biodegradation of the hydrocarbons.The crude oils had a source in the Upper Jurassic Dingo Claystone formation. These hydrocarbons accumulated in the reservoir sands and in some cases were biodegraded. Several accumulation and biodegradation episodes have been recognised while the basin continued to subside, which resulted in a suite of oils showing marked differences in composition.  相似文献   

Centroid-moment tensor solutions for July–September, 1984     

A.M. Dziewonski  J.E. Franzen  J.H. Woodhouse 《Physics of the Earth and Planetary Interiors》1985,38(4):203-213

Centroid-moment tensor solutions are presented for 197 earthquakes that occurred during the third quarter of 1984. The solutions are obtained using corrections for aspherical Earth structure.  相似文献   

Coupled normal-mode sensitivity to inner-core shear velocity and attenuation     

J. Andrews  A. Deuss  J. Woodhouse 《Geophysical Journal International》2006,167(1):204-212

We have studied the response of normal modes to perturbations in inner-core shear velocity and attenuation, using fully coupled mode synthetics. Our results indicate that (i) mode pairs   _n S _l – _{n ±1} S _l   are strongly coupled by anelasticity, (ii) this coupling causes shear velocity perturbations to strongly affect the Q values of modes through exchange of inner-core characteristics, (iii) there is no evidence for a weakly attenuating inner core in shear, and (iv) the discrepancy between attenuation models returned from normal modes and body waves is small. These results suggest that inversions for inner-core attenuation and shear velocity should be performed simultaneously and should take account of the strong cross-coupling due to attenuation.  相似文献