Abstract
Archaeologically, the northeast region of Iran is one of the least-known regions in the Iranian Plateau. The reasons for this situation is multifold; some of these include rarity of archaeological investigations, its vastness and the associated restrictions such as desert areas and impassable mountainous areas. The present paper deals with the chronology of and investigations at one of the key sites of the eastern Iran: Tappeh Mokhar. This is site is located to the east of the town of Torbat-e Jam, by the river of Jamroud. Archaeological finds from this site include a vast spectrum of items, including chipped-stone artefacts, ceramics, stone vessels, and clay figurines, of which ceramics are the most numerous. These finds have been recovered from delimitation soundings, and archaeological reconnaissance. The main objective of this paper is to introduce this important, multi-period site through the recovered materials before it suffers from further damage which at present made it as a depot of waster of modern construction materials. In this paper, a classification and typology of the ceramic collection from the site has been provided and then, based on comparative studies, their relative dating has been suggested. This research follows a historical approach and has been fulfilled with a descriptive-comparative method. The main queries are: which periods can be inferred from the studies of the recovered materials of Tappeh Mokhar. What are the characteristics of Mokhar ceramic assemblage and which types of ceramics of which periods can be identified in this assemblage? The preliminary studies of the ceramic assemblage, however, suggest that the site was occupied during Chalcolithic period, Bronze Age, Achaemenid and Parthian periods, and its ceramic types are comparable with sites of the northeast region, Turkmenistan and eastern region, and then with those of north, south, southwest and west of Iran.
Keywords: Tappeh Mokhar, Khorasan (Torbat-eJam), Bronze Age, Namazga 3 & 4, Achaemenid, Parthian.

Introduction
Archaeologically, the northeast region of Iran is one of the least-known regions in the Iranian Plateau. The reasons for this situation is multifold; some of these include rarity of archaeological investigations, its vastness and the associated restrictions such as desert areas and impassable mountainous areas. The present paper deals with the chronology of and investigations at one of the key sites of the eastern Iran: Tappeh Mokhar. This is site is located to the east of the town of Torbat-e Jam, by the river of Jamroud. Archaeological finds from this site include a vast spectrum of items, including chipped-stone artefacts, ceramics, stone vessels, and clay figurines, of which ceramics are the most numerous. These finds have been recovered from two types of archaeological programs: delimitation soundings, and archaeological reconnaissance. The main objective of this paper is to introduce this important, multi-period site through the recovered materials before it suffers from further damage which at present made it as a depot of waster of modern construction materials. In this paper, a classification and typology of the ceramic collection from the site has been provided and then, based on comparative studies, their relative dating has been suggested. This research follows a historical approach and has been fulfilled with a descriptive-comparative method. In addition to chronology, the regional relationship of the site has been inferred from the comparative studies. The main queries of this research are: which periods can be inferred from the studies of the recovered materials of Tappeh Mokhar. What are the characteristics of Mokhar ceramic assemblage and which types of ceramics of which periods can be identified in this assemblage? The preliminary studies of the ceramic assemblage, however, suggest that the site was occupied during Chalcolithic period, Bronze Age, Achaemenid and Parthian periods, and its ceramic types are comparable with sites within the northeast region and beyond. In fact, the ceramic studies suggest that the cultural relation of Tappeh Mokhar was mostly with the population centers of the northeast region, Turkmenistan and eastern region, and then with those of north, south, southwest and west of Iran. 
Our information on the archaeology of eastern Iran and Khorasan is limited and those few research conducted few decades ago were concentrated on the sites in northern and central parts of the province. Tappeh Mokhar with its long sequence of occupation, representing at least four periods, provides a unique opportunity to study the cultural development in this part of Iran during the late prehistoric and historic eras. This research tries to provides a reliable chronology for the site based on studies of the ceramic collection recovered from both delimitation sounding and systematic surface sampling conducted at the site. Therefore, the main objective of this paper is the quantitative and qualitative studies of the recovered collection and provides their classification and typology.  
Research Question: There are two main questions in this research: Which periods are represented by ceramic collection and cultural finds of Tappeh Mokhar; What are the main characteristics of Tappeh Mokhar ceramic collection; Which ceramic types of which periods are represented in the collection; and what they suggest about the cultural interaction of the site from an intra-regional and inter-regional perspective? 

Research Method
The nature of this research is descriptive-analytical, and is based on literature review and analysis of the archaeological materials. The main bulk of the materials studied is ceramic collection, recovered from delimitation sounding and systematic surface sampling, which are analyzed on the basis on typology, technical characteristics, decorations. Finally, a relative dating is suggested for the site based on the aforementioned studies. 

Research Background
In 1975 two geologists, Ariai and Tiboult, conducted a fieldwork in north of the Torbat-e Jam County and in the Kashaf Roud basin, resulting in discovery of an important palaeolithic locale (Jam e Al – Ahmadi, 1387; Ariai&Thibault,1975:101-103; Khodadoust & et al. 1394:109-124). In 1975 and 1987, Bernard Ekin, and in 1988 Wilber and Glombeg published their investigation on the proceedings of Sheikh Ahmad Jami (Okeane, 1979; Okeane, 1987; Wilber& Golombek, 1988; Khodadoust & et al. 1394:109-124). In 2003 a large scale excavation and stratigraphy sounding at the Architectural Complex of Torbat-e Jam has been conducted by Mohmoud Toghraei (Labbaf Khaniki,1399:147). He also conducted a delimitation sounding at Tappeh Ghar of Torbat-e Jam in 2008 (Labbaf Khaniki,1399:151). The latest research about the Islamic Period Torbat-e Jam complex is coming back to the works by Ali Zarei, as part of his PhD dissertation (Zarei,1394). 
The first archaeologist who visited Tappeh Mokhar was Gunter Kerbel. He visited this site and also the Shah Abbasi Caravansarai complex in 1980 en route his trip to Afghanistan (See: Labbaf Khaniki,1391:144; Korbel,1983;18-57). After him, the area was archaeologically surveyed by Rajab Ali Labbaf Khaniki in 1985 on behalf of Iranian Center for Archaeological Research, in which many site from prehistory to Islamic period were identified (Labbaf Khaniki,1364). The latest research at Tappeh Mokhar was conducted by Hasan Nami, of Neishabour University, in 2017 with the aim of defining the limit of the site by delimitation sounding (Nami,1394). 

Conclusion
The study area in which Tappeh Mokhar is located is part of the Qara Qum Basin, subsuming in the Jam and Hariroud Basin; Hariroud River originates from Afghanistan and the Jam Plain is very fertile because of the river sedimentation. In addition to several other environmental potentials, this factor is one of the main reasons of foundation of Tappeh Mokhar settlement. Along with natural factors, both historical and cultural factors were responsible for establishment of settlements during different periods in what is now Khorasan. Due to limitation in conducting basic, archaeological and historical research, identification and picturing the historical occupation of the study area is confronted with difficulties. Yet, thanks to increasing research during last two decades, our understanding on the ancient communities of the area is developing. The endangered site of Tappeh Mokhar was chosen in this part of Khorasan for getting a better understanding on the prehistoric and historical human developments, which proved that the site is a significant settlement during prehistoric and historic eras. 
Archaeological research at Tappeh Mokhar consisted of two approaches: a systematic surface sampling and a delimitation sounding, in which 30 small trenches were excavated around the hypothetical perimeter of the site, inferred from both topography and concentration of the surface materials. Most parts of the site have been leveled during last decades and it was used as agricultural land and also a depot for modern construction wasters. Based on our comparative studies, the site represents occupations from late Chalcolithic, Bronze Age, Achaemenid and Parthian periods; the latter is thought to be significantly represented. Future excavations at Tappeh Mokhar would potentially answer some important questions about the nature of prehistoric and historic settlements in this part of Khorasan.

Acknowledgments
My heartfelt thanks go to Dr. Kourosh Rostaei (Associate Professor of RICHT), Dr. Mohammad Esmaeil Esmaeili Jolodar (Associate Professor Depart of Archeology, University of Tehran), Reza Haidareii (M. A of Archeology, University of Tehran), Dr. Hassan Basfa, Dr. Mohsen Dana and Dr. Seyyed Javad Jafari for their insightful comments on the manuscript.
 

Abstract
Liarsang-bon ancient complex is located in Shirchak village, Rankuh section of Amlash city of Gilan province. This cemetery is located on the eastern side of the ancient complex of Liarsang-bon and at the foot of Mount Ahinbartaleh. Over 100 graves were identified and excavated in this cemetery. Based on the results of radiocarbon dating, the longevity of this cemetery has been determined simultaneously with the Parthian and Sassanid periods between the years 38 BC-123 AD and 45 BC-80 AD. The purpose of this study was to study the structure of Parthian burials in Liarsang-bon Cemetery. What has justified the necessity of the present study; Documenting and disseminating the most important achievements of the excavation is in recognizing the burial structures of the Parthian period in this region, and it is also an attempt to document the results of the excavations before the destruction of the site by natural and human factors. The authors tried to answer the following questions in the present article: What burial structures were most considered by the activists of the time in Lyarsang-bun Cemetery? Another is that these burial structures are comparable to which all-day burial structures in the region and outside the region? The result is that among the various burial methods in the Parthian era, only three types of crypts, pits and jars were identified in Liarsang-bun cemetery, which are the frequency of crypts, pits and finally jars, respectively. O indicates the variety of burials in this cemetery, which, while similar to regional burials, is reminiscent of and similar to trans-regional examples. The data of this study have been collected through information obtained from six chapters of field excavations in Liarsang-bon Cemetery and have been evaluated historically by historical descriptive analysis as well as comparison with other similar cemeteries.
Keywords: Guilan, Amlash, Cemetery, Liarsang-Bon, Parthian.

Introduction
During the six excavation seasons of Liarsang-Bon ancient cemetery between 2014, 2016, 2017, 2018 ,2019, and 2021 under the supervision of Vali Jahani a total of 130 graves were identified and excavated. In a number of pit graves and crypts, two burials have been performed simultaneously (Jahani, 2014; 2015; 2016; 2017; 2018; 2021). Based on the results of radiocarbon dating, which was extracted from the dentine collagen of two burials during the excavation of 2016 and 2017, the date of this cemetery coincides with the Parthian period between 123-38 BC and 80-45 BC. (Soltysiak & Jahani, 2019: 49). It is worth mentioning that cultural works similar to Sasanian period art have also been identified from some graves in this cemetery. It seems that this ancient site was used as a cemetery from the Parthian era to the early Islamic period. The result of five seasons of excavation of the ancient cemetery of Liarsang-Bon, many grave goods including all kinds of clay, metal and glass containers, iron and bronze weapons, personal items and accessories and a diverse number of ornaments including various types of beads, pendants, rings, bracelets, Earrings, brooches and medallions are made of various materials such as glass paste, glass, bronze, silver, gold and natural bitumen. In this research, the authors have tried to chronologically examine the frequency of burial structures and grave goods and compare these structures with contemporary examples in nearby and distant sites. Research data; It is the result of five chapters of field research in Liarsang-Bon cemetery that the authors have tried to evaluate these data by the method of historical description analysis as well as comparison with other cemeteries of the same horizon in terms of history. In the Parthian era, due to the multiplicity of religions, we see diverse and numerous ways of burial (Mohammadifar, 2014: 48). Traditionally, burial methods in this 475-year period have been considered as follows: burial in clay and stone coffins; Pithos burials; pit graves; Cellar Burials; basement graves; Well graves and temple graves.

Burial methods in Liarsang-Bon cemetery
We wrote before that about 130 graves attributable to the Parthian and Sasanian periods were excavated in this cemetery. These excavated graves have presented three types of grave structures, which included Cellar Burials, pit graves, and pit graves. Along with the dead, burial gifts such as glass, clay and metal containers (lead, bronze, gold-plated silver, etc.), metal weapons such as swords, daggers, knives and bayonets, decorative beads, bronze ornaments and seals were found. 

Cellar Burials
Among the burial methods of Liarsang-Bon cemetery, Cellar Burials have had the highest frequency. Tombs with a catacomb structure and similar to Liarsang-Bon in areas such as Khorramrud (Egami et al., 1966:4-8), Hosni Mahaleh (Sono and Fukai, 1968:27-30) located in Dilman, Vestemin area in Kiasar, Sari city (Sharifi, 2014) and also in the sites located in the steppes of southeastern Europe, Central Asia, and North Caucasus, which contain the cultural materials of the Sarmatian, Scythian, and Alani peoples. (For example, see: Moshkova, 1983: 24).

Pit Burials
The number of pit graves excavated in Liarsang-Bon cemetery is almost equal to the number of Cellar Burials. These graves were found in most of the Parthian sites, and the reasons for their creation and use are different in each site.

Pithos- Burials
14 Pithos burials for the burial of children and young people were found in the area of Liarsang-Bon. There are evidences of burials in clay Pithos in Gilan at the same time as the Parthian period, from sites such as Dilaman Qal-e Kuti (Sono and Fukai, 1968:38) and Kaloraz (Khalatbari, 2005: 35-40), Germi (Kambakhshfard, 1967) and Cheshmeh Sar Cemetery of Persepolis (Schmidt, 1953: 117-160), and Valiran Damavand cemetery (Nemati and Sadraei, 2012: 110) has been reported.

Discussion and analysis
Liarsang-Bon cemetery in Amlash region, due to its location at an important point between Marlik and Kaloraz cemeteries in the Iron Age, as well as the continuation of the burial traditions of other contemporary cemeteries such as Qal-e Kuti and Hosni Mahaleh, can indicate the total prevalence and all the methods of Burials as well as homogeneous cultures were in progress in this region from the end of the Iron Age to the end of the Sassanid period (Jahani and Babayev, 2017: 58-59). This homogeneity in the structure of graves, including Cellar Burials, which was seen in large numbers in Liarsang-Bon cemetery, was previously also observed in regional cemeteries such as Khorramrud (Egami et al., 1966: 4-8), Hosni Mohaleh cemetery (Sono and Fukai, 1968:27-30) Westmin Kiasar cemetery (Sharifi, 2014) was observed. Also, structures known as catacombs were identified in the discovered extra-regional graves, including in areas of the south and southwest of Iran, which, as a rule, due to the influence of the climate on the process of building tombs and burials, the differences between these two parts of Iran’s geography in terms of burial structures in the Parthian era, it should be assumed.
 Regarding the origin of this method of burial in the Parthian era, in addition to the cultures within the administrative geography of the Parthian era and its relatively rich background, attention is also paid to the Indo-Iranian and Indo-European peoples of the steppes of Central Asia to the northern parts of Europe (Zadenprovsky, 1997: 327 -340). The number of Cellar Burials and pit graves can be cautiously attributed to a relatively bipolar society. Economic and social conditions and the time of burial (including the urgency of battle, looting, unexpected natural disasters such as floods, earthquakes, etc.) have also been influential in creating such a burial style. Based on the type of grave goods, this type of graves has been attributed to the Parthian period to the beginning of the Sassanid period (Jahani, 2017-2021).

Conclusion
As a result of the field research conducted in Liarsang-Bon area, graves including crypt, simple pit and Pithos types were identified in the cemetery section. The absolute chronology and typology researches conducted on the grave goods from these graves show the artistic features of the Parthian and early Sasanian periods. Most of the graves are dug in the east-west direction and the bodies are often buried on the left side. Most of the burials obtained from these graves are of the squatting type and most of the bodies are on the left side. Simple pit graves and Cellar Burials have the largest number of burial structures. Burial structures known as crypts as well as their grave goods are similar to the samples discovered in the northern region of Iran, such as in Khorramroud, Westmin Kiasar and Hosni Mahaleh cemetery, and also with areas of the south and southwest of Iran and even the northern steppes in Europe is also comparable. Pit graves can also be compared with other similar burials of the Parthian era in general and only through grave goods. Graves with a Pithos structure in Liarsang-Bon cemetery are comparable to other similar burials that were identified in several cemeteries of the Parthian period, such as Sang Shir Hamadan, Germi Moghan, Cheshme Sar, Persepolis. In this way, with caution and according to the amount of data and the analysis of the four Styles tombs resulting from the excavation of the Liarsang-Bon cemetery, the burial culture related to the Parthian era and the period after that, i.e. the Sassanid era; It indicates a two-way and even direct connection with different regions, including the lands located in the northern regions of Iran and more remote lands in the south and west, which has led to the expansion of diverse burial cultures, which pay attention to the climatic conditions, customs and traditions as well reflects.