地震暗点

地震暗点（dim spot）是指地震波屬性在局部顯示的低振幅异常，一般可指碳氢化合物的存在^[1]。起因是含碳氢化合物的砂岩其声阻抗比同層含水的声阻抗低的。如果在深層，上層被低声阻抗页岩覆蓋，砂岩頂界反射系数在含碳氢化合物地區會減低。因而造成局部暗点^[2] 。在淺部地層，页岩和砂岩声阻抗会交叉相反，反而造成亮点（bright spot）^[3].

参考文献

^ Sheriff, R. E.; Geldart, L. P. (1995). Exploration Seismology (2nd ed.). Cambridge University Press. p. 415. ISBN 0521468264
^ Hilterman, Fred J., (2001), “Seismic Amplitude Interpretation”, SEG.
^ Brown, Alistar. R., (2010), “Dim Spots in Seismic Images as Hydrocarbon Indicators”, AAPG Search and Discovery Article #40514

[”Sheriff”-1] Sheriff, R. E.; Geldart, L. P. (1995). Exploration Seismology (2nd ed.). Cambridge University Press. p. 415. ISBN 0521468264

[Hilterman”-2] Hilterman, Fred J., (2001), “Seismic Amplitude Interpretation”, SEG.

[”Brown”-3] Brown, Alistar. R., (2010), “Dim Spots in Seismic Images as Hydrocarbon Indicators”, AAPG Search and Discovery Article #40514

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