000 02475nab a2200205 4500
005 20260520000314.0
008 260224s2012 xxu
245 0 0 _aTectonic geomorphological investigations of antiforms using differential geometry
_bPermam anticline, northern Iraq
260 _a
_b
_cfeb. 2012
270 _a07/05/2012 ; 07/05/2012
300 _a13 p. ; 301-314
520 _aTranscripción del resumen del autor: Modern differential geometric methods are applied to compute and analyze curvature quantities of the Permam anticline, which is part of the Zagros fold and thrust belt in northern Iraq, northeast of the city of Erbil. Because this particular anticline is composed of, among others, weathering-resistant limestones, the surface topography strongly resembles the antiformal fold shape. This makes it an ideal area where numerical curvature analysis, applied to Shuttle Radar Topography Mission digital elevation models (DEMs), allows drawing not only geomorphological, but also tectonic, conclusions. The curvature analysis is based on the computation of the Gaussian and mean curvatures and is used to classify the folded surface into eight geologically relevant shapes (antiform, synform, plane, dome, basin, and three types of saddles). The performed curvature analysis investigates in detail the effects of two adaptable parameters: the cutoff wavelength of the low-pass filter that is applied to the DEM before curvature calculation and the curvature threshold that is applied to the principal curvature values before the calculation of the Gaussian and mean curvatures. The analysis demonstrates that these two parameters strongly influence each other, and that they together determine the information content and interpretability of the results. By choosing appropriate parameter combinations, geomorphological-oriented studies and tectonic-oriented studies are viable using the same DEM. How tectonic-oriented studies can be used to determine fracture patterns or densities in folded layers is discussed. Further suggestions are made to combine curvature analysis of DEMs with similar studies applied to seismically mapped surfaces in three-dimensional seismic data sets where erosion is absent.
581 _a2
773 0 _tAAPG Bulletin
_g96
942 _cARTICULO
100 1 _aBurtscher, Annegret
_952552
100 1 _aFrehner, Marcel
_952553
100 1 _aGrasemann, Bernhard
_950735
999 _c187142
_d187142