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褶皱逆冲带的几何学研究是造山带研究的热点,但是无论是传统构造地质学方法还是地球物理学方法都在研究褶皱逆冲带几何特征时存在多解性.为了制约这种多解性,本文以天山北麓的呼图壁河剖面为列,介绍一种地质与地球物理相结合的研究方法.该方法首先沿呼图壁河剖面进行详细的地表观测,获取地表的构造地质数据形成初步的地质模型,其次结合地表构造和钻井分层数据,对收集到的石油地震剖面进行重新解释.然而,地震反射数据只分布在盆地内部,在盆山结合带缺失或者不清晰,因此对该剖面进行了重力测量并计算出布格重力异常.结合盆地各沉积地层和基底密度值,用重力正演方法模拟呼图壁河剖面的密度结构.研究结果显示沿呼图壁河剖面并不存在天山北缘断裂,盆地的沉积盖层可以从准噶尔盆地连续过度到天山内部并不整合覆盖在天山古生代基底之上.这一结果与西段金钩河剖面的天山基底逆冲到准噶尔盆地显然不同,说明了天山北缘盆山结合带构造的多样性.利用平衡剖面技术,恢复的呼图壁河平衡剖面缩短量约为4.8km,对比前人研究,说明了天山北缘的缩短量沿东西方向存在显著的不均一性.本研究也说明这种构造地质与地震及非震地球物理相结合的方法可以广泛地被应用于褶皱逆冲带.
Geometrical study of fold-thrust belts is a hotspot in orogenic belt research, however, both the traditional tectonic geophysical methods and geophysical methods are multi-solvable when studying the geometric characteristics of the folded-thrust belts.In order to restrain this multi-solution , This paper takes the Hutubi River profile in the northern foot of Tianshan Mountain as an example to introduce a research method combining geology and geophysics.The method first performs detailed surface observation along the Hutubi River profile to obtain the formation of tectonic geological data of the surface The initial geological models are followed by a re-interpretation of the collected petroleum seismic profiles in combination with surface texture and drilling stratification data.However, seismic reflection data are only distributed within the basin and are missing or unclear in the basin-mountain junction, The gravimetric measurements were carried out and the Bouguer gravity anomalies were calculated.According to the sedimentary strata and basement densities in the basin, the density structure of the Hutubi River section was simulated by gravity forward method.The results show that there is no Tianshan The northern margin of the fault, the basin sedimentary cover from the Junggar Basin over the continuous to the interior of Tianshan does not integrate the cover of the Tianshan Paleozoic basement This result is obviously different from that of the Tianshan basement in the west section of the Jinouhe section to the Junggar Basin, indicating the diversity of the basin-mountain belt structure in the northern margin of the Tianshan Mountains. With the balanced section technique, the recovered Hutubi River balance section is shortened Compared with the previous studies, it shows that the shortening along the northern Tianshan Mountains has significant heterogeneity along the east-west direction.The study also shows that the method of combining tectonic geology with earthquakes and non-seismic geophysics can be widely used Ground is applied to fold the thrust belt.