R_o差值法恢复地层剥蚀量的不合理性  

IRRATIONALITY OF CALCULATING DENUDATION THICKNESS OF STRATA WITH R_o-DIFFERENCE METHOD

作　　者：佟彦明[1] 吴冲龙[1] 

机构地区：[1]中国地质大学

出　　处：《天然气工业》2006年第5期21-23,共3页Natural Gas Industry

摘　　要：Dow(1977)利用不整合面处上下构造层Ro的差值来估算地层剥蚀量的方法,在国内仍有广泛的应用。求取了实例剖面中两构造层的最高古地温和古地温梯度,发现该方法从多方面都表现出不合理性。该方法的结果不能解释该剖面下构造层实际的Ro值和所经历过的最高古地温;用该方法的结果和原理还可推导出其它一些不合理的结论;该方法的原理和真柄钦次泥岩声波时差法的原理在本质上是相互矛盾的。认为将实际上存在剥蚀地层的Ro剖面外推可以得到无剥蚀情况下的结果是该方法在原理上的不足之处。由此提出了利用Ro恢复地层剥蚀量的新方法。Dow (1977) proposed to calculate denuded thickness of strata by using the difference of vitrinite reflectance (R_o) between the upper and lower structural layers at an unconformity and this method is still extensively applied in China at present. The maximum palaeotemperature and palaeogeothermal gradients of two structural layers on a case profile are calculated to exemplify the irrationality of this method. It is found that this method is irrational in many aspects. Its results cannot explain the real R_o value and the maximum palaeotemperature of the lower structural layer on the profile. Some other irrational conclusions can be deducted by using its results and principles. Its principles essentially contradict the principles of Magara's mudstone SDT method. The shortcoming of this method is that it calculates R_o profile of strata without denudation by extrapolating the R_o profile of denudated strata. A new method is presented here to calculate denudation thickness of strata by using R_o.

关 键 词：不整合面 剥蚀量 Ro差值法 不合理性 新方法 

分 类 号：P512.2[天文地球—地质学]