Discrimination of inland and coastal dunes in Eastern Saudi Arabia desert system: An approach from particle size and textural parameter variations Ardiansyah Koeshidayatullah * , Septriandi Asmaidi Chan, Majed Al-Ghamdi, Tariq Akif, Khalid Al-Ramadan Geosciences Department, King Fahd University of Petroleum and Minerals, P.O Box 31261, Dhahran, Saudi Arabia article info Article history: Received 23 May 2015 Received in revised form 21 December 2015 Accepted 4 January 2016 Available online 5 January 2016 Keywords: Particle size Dunes Inland Coastal ANOVA Saudi Arabia abstract Different particle size parameters have been investigated in this study in order to distinguish the characteristics of different dune morphologies in the Eastern Saudi Arabia. Sand samples were collected from various environments including: the stoss, lee, crest and interdune sides of the inland dunes and foreshore; berm; backshore and backdune of the coastal dunes. Statistical parameters reveal that the majority of inland dune samples are dominated by well sorted fine sand whereas coastal dune samples are mainly dominated by very coarse to medium sand, ranging from well sorted to moderately sorted with a low percentage of silt and clay. The presence of relatively coarser grains in the coastal dunes might be explained by continuous wind deflation along the coast together with wave and tidal activities that concentrate coarser grains. Cross-plots from four statistical parameters and supported by the ANOVA test clearly distinguish the particle variations between these dunes. The log-probability analysis suggest that the main transport mechanism in inland and coastal dunes is dominated by the saltation population, comprising up to 80 percent of the distribution. However, the coastal dunes suspension population is mostly belonging to coarser grained material, whereas the inland dunes population is finer. In com- parison with particle size characteristics of dunes in the region, the current study shows a close rela- tionship to mean particle size in Iraq, but is relatively finer compared to the Kuwait dunes. This similarity and difference in particle size variation is mostly controlled by the proximity to the coast and also the wind energy and variation in the wind direction. © 2016 Elsevier Ltd. All rights reserved. 1. Introduction Over the last decades, various studies on sand dunes have been conducted in order to understand their transport mechanisms and provenance (i.e. Watson, 1986; El-Sayed et al., 1996; Livingstone et al., 1999; Ellis et al., 2012; Garzanti et al., 2013). Most of studies have employed particle size characteristics and variations to recognize depositional environments (Folk, 1971; Lancaster, 1995a, 1995b; Abuodha, 2003; Duran et al., 2011). The desert dunes and sand seas have been the most frequently studied because they constitute important information about the ancient and modern environments (Lancaster, 1988b). The particle size distribution of the sand dunes has been greatly influenced by many controlling factors such as; inland and marine transport dynamic processes, the availability and types of source, proximity to the source zone, and vegetation (Folk, 1971; Pye and Tsoar, 1990; Al-Dousari et al., 2008; Jackson and Nordstorm, 2011). Different statistical approaches have been used in the particle size studies. Visher (1969) proposed useful relationships between cumulative subpopulation and mean (F) of particle size in un- derstanding different transport processes. In addition, scatter di- agrams of textural parameters and graphical measurement of shape and spread have been made to distinguish different grain populations within the dune profile (Folk, 1971; Friedman, 1979). Many previous studies have been done in other parts of the world in order to characterize the different morphology of dunes, including: Kuwait (Al-Dousari et al., 2008, 2013), UAE (El-Sayed et al., 1996), Qatar (Al-Sheeb, 1998), Kalahari Desert (Lancaster, 1988a; Thomas, 1988; Livingstone et al., 1999), China (Wang et al., 2003), Mexico (Kasper and Edwards, 2005), Namib Desert * Corresponding author. E-mail address: ardiansyah.ik@gmail.com (A. Koeshidayatullah). Contents lists available at ScienceDirect Journal of African Earth Sciences journal homepage: www.elsevier.com/locate/jafrearsci http://dx.doi.org/10.1016/j.jafrearsci.2016.01.003 1464-343X/© 2016 Elsevier Ltd. All rights reserved. Journal of African Earth Sciences 117 (2016) 102e113