Quantitative Structural Analysis Based On Corona Imagery

Widely spaced seismic reflection profiles caused by steep strata are a common problem in structural interpretation of foreland fold-and-thrust belt, particularly in remote areas with sparse surface and well data. High-resolution remote sensing imagery is an effective approach for measurement of surface parameters and for constraint of seismic profile interpretation. In this paper, the surface structural parameters of the foreland fold-and-thrust belt in the southern Tianshan Mountain were extracted and analyzed on the basis of CORONA KH-4B high-resolution satellite stereo pairs of 1960s-1970s, which were declassified by USA, as well as QuickBird and Landsat 7 ETM+ multi-spectral imageries. The results and the novel implications are highlighted as follows:Methodologically, an accurate method for ground control point (GCP) selection are built by a gradual mathematical approach in mark-deficient areas, which are achieved in the JX4C digital photogrammetric system, based on the characteristics of the CORONA KH-4B satellite stereo pairs after combining with 1:50000 topographic map. A rational function model (RFM) was founded to rectify the panoramic deformation of CORONA imagery. The corona imageries are then initially supported by the JX4C digital photogrammetric system, meanwhile, large scale digital elevation model (DEM) and digital orthphoto mapping (DOM) are formed using stereo pairs.Triangular faces exposed by eroded drainages are identified to determine the spatial coordinate of the identified point in the JX4C digital photogrammetric system using the CORONA stereo pairs covering the foreland belt of the southern Tianshan Mountain. The strike and dip of bedding are programming calculated in the Matlab system. Field survey by OZIExplore software which is embedded in GPS shows that the measurement error of surface bedding attitude in the Qiulitag Belt of the southern Tianshan Mountain is less than 3°, which reaches the accuracy for quantitative structural analysis. This method is favorable for geological survey in large areas, especially for remote areas with rare vegetation coverage, distinct stratum outcrop, and complex structure.A lot of surface parameters in the Kuqa fold-and-thrust belt of the southern Tianshan Mountain are obtained after application of these method stated above, which fill up the surface data in these complex areas. Some parameters for deformation of river terrace, fault and fold scarp are identified and measured, which are helpful to reveal the characters of neotectonics. The surface deformation of the Qiulitag Belt of the southern Tianshan Mountain has been built based on the surface parameters obtained from remote sensing measurement together with field survey and seismic and well data. Seimic and well data reveal that three sets of detachments of Jurassic coal bed (J), Paleogene Kumugeliemu Formation (E_1-2km), and Miocene Jidike Formation (N₁j) developed in the structural intersection. The strata developed in various detachments folded, overlapped and interfered, forming complex structural in the middle segment of the Qiutag Belt. The strata of the Jidike (N₁j) and Kangcun (N₁k) formations formed several folds and faults. The strata of the Kuqa (N₂k) formation twisted yet continued with attenuated deformation from old to young stratum, reflecting consecutive structural formation together with durative sedimentation from the Upper Neogene. The growing strata developed in Kuqa Formation and Quaternary also indicate its active duration.