Abstract
Despite extensive studies on Pleistocene human activities in the Zagros and Alborz regions, as well as significant progress in the study of areas such as foothills, plains, and desert margins in recent years, some of these marginal and foothill areas have still received less attention and limited information has been obtained about the Paleolithic period from them. Among these areas, we can mention Khuzestan province, especially the northern areas of this province (northern heights of the Shushan plain), which despite the limited paleolithic studies conducted in recent years, the information obtained from this area seems interesting. The Khervali site is one of the few known paleolithic sites in recent years, located in the west of the Zagros highlands, in the northern heights of Shush city, and near the western bank of the Karkheh River. This site was identified and systematically investigated in 2012. Given the size of the site and the distribution of the tools, sampling the entire site was not possible, so only four areas of the entire site were selected for sampling, and a total of 330 stone tool fragments were collected from these areas. The results of the analysis of the tools from this site indicate an assemblage probably related to the Middle Paleolithic period with the prevalence of chipping techniques, along with the presence of Loval elements and scraping types, and with significant access to local raw materials.
Keywords: Khervali, Middle Paleolithic, North of the Shushan Plain, Conglomerate Formation, Access to raw materials.
Introduction
Despite extensive studies on Pleistocene human activities in the Zagros and Alborz regions, as well as significant progress in the study of areas such as foothills, plains, and desert margins in recent years, some of these marginal and foothill areas have still received less attention and limited information has been obtained about the Paleolithic period from them. Among these areas, we can mention Khuzestan Province, especially the northern areas of this province (northern heights of the Shushan Plain), which despite the limited paleolithic studies conducted in recent years, the information obtained from this area seems interesting. The Khervali site is one of the few known paleolithic sites in recent years, located in the west of the Zagros highlands, in the northern heights of Shush County, and near the western bank of the Karkheh River. Topographically, this area is an open valley with a relatively flat surface and a gentle northwest-southeast slope, located in an area consisting of several prominent hills known as the Khervali Hills on the geological maps of the Iranian Oil Company. From a geological perspective, it seems that this area, due to its higher elevation above the plain, was spared from the sedimentation process prevailing in the Khuzestan Plain and the Holocene sedimentary deposits and was formed directly on the Bakhtiari Conglomerate Formation, and its bed is covered with rounded sandstone cobbles of various sizes and abundant pieces of chert. Given the importance of the subject and the unknown status of the Paleolithic period in this area, a systematic study of this area was the main focus of the work. In order to investigate this area, due to the vastness of the area, the damage done to the area, and the time constraints, it was not possible to map and grid the area with mapping cameras. Accordingly, after surveying the entire area and carefully assessing the density and distribution of artifacts, four locations in sections with an altitude higher than the dry river bed that were protected from the natural sedimentation process and also from the damage caused by excavation operations were selected for sampling. To facilitate the recording and processing of samples taken from different collections, after recording the geographical coordinates of each point using GPS, a number was assigned to each collection, which ultimately created four circular areas with a diameter of 20 meters, named Locus 1, 3, 4, and 5. A total of 330 pieces of stone tools, including the mother rock and pieces separated from it (Core/Core Fragment), blank debitage, tools, and debris, were collected from the aforementioned loci.

Discussion
After examining the stone tools, it was determined that the raw materials used in the Khervali Valley area include flint (pieces of chert, flint, jasper, opal) and rarely river rocks of sandstone and quartz. Most of the tools in the area are made of light brown, liver, and in some cases green and red, gray and cream flint. This type of raw material is the most important petrological feature of the Bakhtiari Conglomerate Formation, which mainly belongs to the Cretaceous, Eocene and Oligocene and its outcrops have been reported so far in the western Zagros regions, especially the northern areas of the Khuzestan plains of Dehloran and Mehran. As mentioned earlier, the aforementioned site is located on the Bakhtiari Conglomerate Formation and clearly indicates the direct access of the toolmakers to the raw stone material in the area itself and its easy exploitation for the production of tools. In terms of the chronology of the site, with the exception of the presence of cleavers/mother stones among the assemblage, due to the absence of the elements of the Old Paleolithic such as hand axes and adzes, and considering the very high frequency of the use of chipping technology, the presence of the Loval technique, the presence of scrapers and serrated/crested tools, and also the absence of the new Paleolithic industries such as end scrapers, chisels, numerous retouched blades, end scrapers and DuFour micro blades, it seems more logical to attribute this site to the Middle Paleolithic period. As mentioned, the foothill areas of the northern low plains of western and southwestern Iran have remained unknown or have received less attention compared to areas such as the Zagros and Alborz. Among these unknown areas, we can mention Khuzestan province. This province in general and its northern regions (Shushan Plain) in particular, despite their importance and special place in Iranian archaeological research. Unfortunately, information about the Paleolithic period of these areas is very scanty compared to later periods and is related to nascent research of the last few years. So far, sites related to different Paleolithic periods have been reported in this region (the buffer heights between the Shushan Plain and the western foothills of the Zagros), and the information obtained from them is interesting. The important point about these sites, in addition to their proximity to permanent rivers, is their location on the Bakhtiari Conglomerate Formation located in this intermediate region, which somehow indicates the connection of these sites with raw stone sources with high density and easy access

Conclusion
The newly discovered Khervali site is one of the few identified Paleolithic sites in the north of the Shushan Plain, which is important in two respects: first, its specific geographical location, i.e., its location between the Zagros Mountains and the Khuzestan Lowland as an intermediate site for which little information is available about its Paleolithic status; second, the direct and undoubted connection of this site with the raw stone resources in the region, which was formed directly on the Bakhtiari Conglomerate Formation with a dense concentration of raw stone. It seems that conducting specialized and targeted surveys in these areas to identify Paleolithic sites and analyze their settlement patterns in the overall landscape (upland and lowland areas) can provide interesting information about the distribution and adaptation of Pleistocene populations to their environment, the patterns used in the stone economy and the exploitation of raw material resources, as well as the possible role that these areas played between the highlands and the lowlands.