Introduction

Abstract

AbstractThe alluvial fan is conical or funnel-shaped alluvium deposited at the edge of the mountains, whose thickness decreases and width increases from the mountains toward the plains (Pourmorad et al. 2021). The average slope of an alluvial fan is about 5°, but may change by more than 25° (Li et al. 2020). The radius of the alluvial fan may vary from less than a few hundred meters to more than 150 km (Tavanaei et al. 2020). Alluvial fan deposits are often red in color due to the fact that they form in an oxidizing environment (Kumar et al. 2020). The shape of these sediments depends on the tectonic and climatic conditions of the region (Bowman 2019). However, most alluvial fan sediments are formed in areas with arid and semi-arid climates with low vegetation, very low rainfall and rapid erosion. These sediments are not specific to the climate and are formed in different regions (Pourmorad and Jahan 2021). Economically, the identification of alluvial fan deposits can be of particular importance. For example, alluvial sediments can be the center of groundwater accumulation, and most groundwater reservoirs within the sedimentary basin are fed by water from alluvial sediments (Zhang et al. 2020). Most of the gold in the world is also extracted from the deposits of ancient alluvial fans in South Africa, which have remained in placer form. In addition, large amounts of uranium placer are extracted from old alluvial sediments in South African sedimentary basins (Sissakian et al. 2020). This book has a comprehensive study of alluvial fan sediments, which seeks to introduce all the sedimentary and geochemical properties of the alluvial fan. Here, an attempt has been made to study and evaluate the alluvial fan sediments of southwestern Iran as a master case with full practical application. A detailed study including sedimentology, lithology, geochemistry and morphotectonics of alluvial fans of southwestern Iran has been described in this book. These studies will contribute significantly to the identification of similar sedimentary environments and will provide a clear view of the environmental, mineral, agricultural and urban hazards of different regions.KeywordsField studiesSamplingLaboratory studiesGeochemical studies