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This version is available at https://strathprints.strath.ac.uk/43272/ Strathprints is designed to allow users to access the research output of the University of Strathclyde. Unless otherwise explicitly stated on the manuscript, Copyright © and Moral Rights for the papers on this site are retained by the individual authors and/or other copyright owners. Please check the manuscript for details of any other licences that may have been applied. You may not engage in further distribution of the material for any profitmaking activities or any commercial gain. You may freely distribute both the url (https://strathprints.strath.ac.uk/) and the content of this paper for research or private study, educational, or not-for-profit purposes without prior permission or charge.Any correspondence concerning this service should be sent to the Strathprints administrator: strathprints@strath.ac.ukThe Strathprints institutional repository (https://strathprints.strath.ac.uk) is a digital archive of University of Strathclyde research outputs. It has been developed to disseminate open access research outputs, expose data about those outputs, and enable the management and persistent access to Strathclyde's intellectual output.Journal of the Geological Society, London, Vol. 170, 2013, pp. 237 -247. doi: 10.1144 Rifting in intra-continental areas will commonly interact with a framework of pre-existing deformed zones. Although new structures form, structural inheritance may influence the location and geometry of tectonic deformation because strained rocks can act as weak zones localizing subsequent deformation (e.g. Watterson 1975;Sykes 1978;Handy 1989;Holdsworth et al. 2001). In particular, basins along rift margins are often inferred to be influenced by pre-existing structures (e.g. Daly et al. 1989;Lee & Hwang 1993;van Wees & Beekman 2000;Scheck-Wenderoth & Lamarche 2005). The connection between basins and pre-existing structures is frequently based on the similarity of the trends of seismically imaged rift faults to basement tectonic trends observed onshore (e.g. Roberts & Holdsworth 1999;Wilson et al. 2006). However, assessing the direct relationship between rift faults and pre-existing structures is often difficult because the basement is overlain by syn-to post-rift formations. The effect of pre-existing structures on fault architecture at scales of tens to hundreds of metres is less clear. Some studies suggest that pre-existing foliations resulting from crystal-plastic deformation exert a strong influence on fault zone architecture during later deformation (e.g. Beacom et al. 2001;Butler et al. 2008). Experimental work indicates that foliated rocks are mechanically anisotropic (Donath 1964;Shea & Kronenberg 1993), suggesting that foliations impart mechanical anisotropy or planes of weakness into the country rock that may be exploited by subsequent fracturing. However, analogues for the deeper sections of rift faults are rarely exposed, and the specific impacts of mechanical anisotropy for fault structures at exposure scale are con...

UAVs have been used in engineering for at least two decades, mainly focusing on structural health monitoring, geological surveys and site inspections, especially at cases where a rapid assessment is required, for example after a natural disaster. While there is a wide range of recognition algorithms for the automatic identification of structural damage, structural geological features etc. from the acquired images, the parameters affecting the resolution of these images are often overlooked. As a result, the UAV technology is not used at its full potential and at times, it is even regarded as leading to poor outcomes. This paper discusses the main parameters affecting the resolution of the images acquired by a UAV. We present a case study of the structural geological mapping of a coastal area carried out using two types of UAVs: a fixed wing and a hexacopter. A comparison between the structural geological maps based on the orthophotos and one produced using conventional techniques shows that the level of detail is the same and the time spent is at least 5 times less when using a UAV. The fixed wing is faster and therefore, can cover large areas while the copter gives better resolution images as it can fly at lower heights. The latter is cost and time effective only if it is used for surveys limited to small areas. The characterization of some structural geological features has not been possible based solely on the orthophotos. We show that in order to achieve the desired accuracy, a ground sample distance of at least half that value is required. We discuss technical aspects, such as the effect of topography and UAV orientation on the overlap value, the camera calibration, number of control points and lighting conditions, that should be taken into account prior to flying a UAV and provide recommendations on how to obtain optimum results, i.e. orthophotos that suit the needs of the project.

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