PULL-APART BASIN FEATURES IN 2D AND 3D

Pull-apart basins are depressions associated with geometrical irregularities of strike-slip faults. However, many uncertainties complicate the interpretations of their geometrical aspects. This study presents a review of current literature and a new data set from the pull-apart basins along the North Anatolian fault zone about the angular and scale characteristics of these basins to understand their geometries in 2-D and 3-D. Angular data in literature that attained from the natural cases, experimental and numerical studies represent a mean acute angle of 33° between the master faults and diagonal faults. Pull-apart basins along the North Anatolian fault zone also present the similar acute angles. As represented by experimental studies, this value is a result of overstep geometry. Some declinations may be observable in pull-apart basins located at zones controlled by composite regimes. Scale characteristics of pull-apart basins from all over the world indicate a good 2-D relationship between basin length and width as firstly suggested by Aydin and Nur (1982). A similar relationship between length and depth data has also been proposed by Hempton and Dunne (1983). In this study a comparison among the length, width, and depth parameters of pull-apart basins in 3-D from the well-known active and ancient pull-apart basins suggests that there may be an empirical relationship. This relationship would be most cheap and useful method to predict sediment thickness of pull-apart basins which are one of the important reservoirs for economic resources. Independent from the type of potential resource (oil, gas, ore deposits, or groundwater), sedimentary thickness is the most important parameter in understanding the attainability of the resource. The application of the proposed relationship to the pull-apart basins along the North Anatolian fault zone and some other basins around the world predicts new sediment thicknesses. By the addition of more sediment thickness data by drilling and geophysical methods to current literature, the accuracy of the regression and predicted values will increase.