Comparison of Morphometric Characteristics of Anticlines and its Application in Oil Exploration (Case study: Male-Koh and Noa-Koh Anticlines)

 
Malehkoh anticline in Lorestan province and Noakoh anticline in Kermanshah province are parts of Folded Zagros structural zone. The purpose of this research is to evaluate and compare the morphometry of oil-rich Malehkoh and oil-less Noakoh anticlines and to assess the application of these studies in the exploration of oil resources. To achieve the purpose of this study, at first topographic maps at a scale of 1:50000 and geologic maps of the study area at scales of 1:250000 and 1/1000000 were digitized in ILWIS software and then geologic and topographic data were obtained. Morphometric characteristics of anticlines were extracted based on Quickbird imagery as well as field works. The morphometric indexes of anticlines such as Fold Symmetry Index (FSI), Fold Front Sinuosity (FFS), Anticline Divide (AD) Aspect Ratio (AR), Bifurcation Ratio (Rb), Drainage Frequency (Fs), Drainage Density (Dd)  and characteristics of triangular facets such areas and base lengths were obtained. Results of this study represent that the high rates of FFS, AD and Ar, and low rates of Rb, Dd and Fs indexes as well as large triangular facts in Noakoh anticline are indicators of oldness, tightness and more erosion  and therefore of escapement of oil of  mentioned anticline. On the other hand, in the oil- rich Malehkoh anticline, smaller triangular facets, lower rates of  FFS, AD, and Ar and higher rates of Rb, Dd and Fs indexes reveal the  youthfulness, less erosion and  therefore preservation of oil resources  in mentioned anticline. This study represents that development and compression of Noakoh anticline have resulted in the downward movement of neutral surface and thereby progress and connection of extensional to compressional fractures, and then has allowed migration and escapement of oil recourses of anticline. Overall, results of this study reveal that mentioned morphometric parameters are appropriate indexes for distinguishing oil- rich and oil- less anticlines.