Abstract
The discovery of three outstanding Achaemenid buildings in Borazdjan Plain territory, such as “Charkhab”, “Sang-Siyah” and “Bardak-Siyah”, unveiled a new domain in the archaeological study of the Persian Gulf hinterlands and in the Achaemenid era. Excavation in the surrounding areas of these three buildings in two courses in the years of the decades 1350s and 1380s, led to the expsition of their different parts and architectural details. The presence of remarkable Achaemenid architectural elements including the central columned hall, lateral pillared porches and stone column pedestals, as well as the locality situations of the palaces on the plain and peripheral areas of the permanent “Dalaki” and “Shapur” and the seasonal “Ardu”rivers, made new theories possible about the quality and the reason of choosing the location and the erection of a government edifice in the Achaemenid era, while putting forward some general questions about the spatial structure of each palace. Because of the roughcast excavations, our information about the spatial extent of the unearthed collections is quite incomplete. In “Charkhab” site, for being in the vicinity of the seasonal “Ardu” river, there has been more than 1.5 meters of sedimentation which makes it difficult to access Achaemenid findings. So we decided to use new archaeological methods especially archeo-geophysical survey to study around the site and then continue the excavation around the palace according to the results obtained. So, in the first step, the western and north-western fronts with the extent of 13 hectares were surveyed archeo-geophysically using a magnetometric method and according to the outputs and the final produced map and the scatteration of exposed anomalies, some locations were determined for trenches and excavation. According to the maps obtained through magnetometry, some trenches were selected in zones where the abundance of anomalies was evident. In total, two trenches CH II and CH III, each with the dimension of 10×10 were excavated, while most findings were obtained from an Achaemenid leyer in trench CH III in the depth of 153 cm, where items such as baked bricks with the dimension 32×32×8 with bitumen mortar similar to those of Charkhab Palace, gate-pivot stones and pillar foundations worked with raw stone, pieces of cream colored pedestal stones and the most important of all, pieces of cornoture with horizontal strings similar to that of “Bardak-Siyah” Palace and  the specific palace of Cyrus at Pasargadae, can be mentioned
Keywords: Borazjan, Charkhab Palace, Archaeogeophysical Survey, Magnetometry, Excavation of Charkhab Site.

Introduction
Describing the importance of the Persian Gulf and its geopolitical role in the Achaemenid period, Herodotus describes the actions of “Scyllax Cariandi” and the order of Darius II to identify a sea route from the Indus River in India to Egypt, which was used by Indians and Iranians (Herodoutus, 1828: 289). 
In addition, other well-known historians and geographers of the early Christian centuries, such as Strabo, Arian, and Ptolemy, mentioned the Persian Gulf with titles such as “Persicon Kitas” and “Sinus Persicus”. 
The commercial prosperity of its shores is described in interaction with the West and the East. (Bayat, 1988: 28). 
Generally speaking, it can be inferred that the northern shores of the Persian Gulf inspecial, were of great importance during the Achaemenid period and later, and the construction of magnificent architectural works and government landmarks have not been unexpected.
The discovery of the remains of three outstanding Achaemenid landmarks in Borazjan plain titled “Charkhab”, “Sang-e Siah” and “Bardak-Siah”, opened a new chapter in the archaeological studies of the Persian Gulf and the Achaemenid history as well.
Excavation of these buildings during two seasons in the 1350s and 1380s, led to the discovery of various sections and their architectural components. 
Considering the presence of prominent elements of Achaemenid architecture, including the central columned hall, the side columned porches and stone pillars, along with the location of these palaces in the plains and the banks of Dalki and Shapur rivers and the seasonal Ardo valley, it has been tried to provide a definitive answer to existing questions and hypotheses based on current studies in this article. 
Asking general questions about the spatial structure of each of these palaces, provided new insights into how and why to choose a location and build a government building during the Achaemenid period. 
An important question in this field is whether these palaces were only used as summer accommodation facilities or they have been used as government seats.
Hypotheses in this study, basically suggest that the development of maritime trade, offshore communication routes, as well as suitable environmental structures and facilities, have led to the Achaemenid settlements in Borazjan plain. 
Achaemenid palaces discovered in Borazjan plain are part of the urban structures in that period. Some Achaemenid relics discovered, such as the Charkhab Palace, might have been left incomplete due to improper site selection and unsuitable location.
Architectural structures and spatial analyzes of the sites discovered in the Borazjan plain, are probably modeled on the architecture of the earlier Achaemenid culture in Pasargadae.
Studies of the surroundings of these sites show that there are other spaces related to the palaces. Based on geophysical studies as well as archaeological surveys around the sites, it can be imagined that these palaces were a collection. Further information on this subject, needs further archeological excavations and research.
One of the most important Achaemenid buildings on the northern hinterlands of the Persian Gulf is Charkhab Palace, which was accidentally discovered in 1350, during the bulldozing operations of water transfer pipeline from Borazjan to Bushehr, through the date palm groves on the western suburb outskirts of Borazjan and in the so-called “Charkhab area”.  
After preliminary investigations and the similarity of the discovered structure with the stone columns used in Pasargadae, it was decided to explore the place of discovery. The result of this excavation led to the appearance of different parts of the remains of a magnificent Achaemenid building (Sarfaraz, 1350 and 1351; Ebrahimi, 1391). Simultaneously with the excavation of Charkhab site and following the public reports that similar relics were found close a nearby village called Jatut / Jatal; Sarfaraz was able to discover another building on the banks of Dalaki River called Sang-e Siyah, about nine kilometers north of Charkhab. 
This site was excavated in 1977 by Ismail (Ehsan) Yaghmaei (Yaghmaei, 2005: 9-11; 2018: 191-196; Ebrahimi, 2012). 
During the exploration of the Sang-e Siyah remains and in the surrounding areas and palm groves, the excavations led to the discovery of another building called “Bardak Siyah” which means “the black stone”, among the palm groves of Dorudgah village. 
Yaghmaei explored the building and continued his excavations during the winter and the spring of 1978 (Yaghmaei, 2005; 1397; Ebrahimi, 2012). 
In the 2001s, with the resumption of archeological activities in Bushehr province, the Charkhab building, which had been buried under the flood deposits after the first exploration period, was excavated again by Sarfaraz in five consecutive seasons. 
In addition to the sections that were appeared earlier, some other new parts of the building became visible again. (Sarfaraz, 2001; 2003; 2004; 2005; 2006).
Due to unfinished excavations, our knowledge of the spatial extent of these collections is very limited. 
In the Charkhab area, the settled sediments are more than 1.5 meters high, due to its proximity to the Ardo seasonal river. This has made it difficult to obtain necessary findings from the Achaemenid period.
The study of archeogeophysics today, plays a crucial role in identifying the points and structures of ancient layers.
Using this methodology, saves time and also achieves the desired results much faster, much easier and much more accurately.
Therefore, we decided to use these new archeological methods, especially archaeogeophysical surveys, to conduct research around this area, and based on the results of these studies, to continue exploring around the palace.
Therefore, in the first place, the western and northwestern fronts of the palace, with an area of 13 hectares, were examined by magnetometric archeogeophysics, which revealed the dispersion of anomalies according to the output and finalized maps, and places for trenches and excavations were determined.
According to magnetic output maps, trenches were selected in areas where the abundance of anomalies was apparent.
Totally, two trenches ChII and ChIII with dimensions of 10 x 10 were excavated and most findings were obtained in trench ChIII at a depth of 153 cm and in an Achaemenid layer. 
In the cultural findings of the recent excavation in Charkhab, paddy parts of the columns with cream-colored strings are important.
Examples found in Bardak Siyah and Sang-e Siyah, are also comparable to the example of the private palace of Cyrus the Great in Pasargadae.
These paddy parts are quite different from the paddy parts obtained in Charkhab Palace (ChI), which are round and black without any carvings.
It seems that this collection (ChIII) is similar in architectural elements to those of Bardak Siyah and Sang-e Siyah palaces and those of the private palace of Cyrus the Great in Pasargadae.
The cream-colored base stone of the gateway as well as the foundations of the columns found in the ChIII trench are similar to those of Charkhab(ChI) and Bardak Siyah palaces.
The bricks obtained with  the dimensions of 33 x 33 x 8 cm and bitumen mortar in this trench are comparable to those found in the palaces discovered in Borazjan.
Given the architectural elements obtained, it is possible that this complex had been built earlier than the Charkhab Palace (ChI) itself.
Undoubtedly, more studies and more extensive research are needed to answer all the hypotheses and questions.

Abstract
In premodern societies, cemeteries were formed next to human settlements. The distribution of graves in these cemeteries depended on the size of the population and the use of these settlements. One of the difficulties in modern archaeological research in identifying cemeteries is determining their core and buffer zones. Due to the dispersion of graves, the density of graves in cemeteries can sometimes vary considerably. Determining the core and buffer zone in these areas is therefore always done with great caution. With the advancement of science and various new methods in archaeological fieldwork, the core and buffer zones of archaeological sites can now be done more precisely. One of the more efficient and effective methods in identifying, and consequently, determining the core and buffer zone of sites, is the geophysical survey. A geophysical survey with the magnetic method in the archeological site of Mehdiabad-e Olia in the cultural landscape of Bam was carried out to determine the distribution of archaeological graves and determine the core zone of this ancient cemetery in 2018.
Keywords: Archaeological Cemetery, Geophysical Survey, Core Zone, Buffer Zone, Mehdiabad-e Olia Cultural Landscape of Bam.

Introduction
Archaeological sites are spaces where physical and material artifacts of past human life entangle. These sites can be investigated by various types of archaeological fieldwork. Archaeologists identify the ancient sites by using remote sensing studies, aerial photography and satellite imagery, and pedestrian surveys. Most of the time, when we move from the center to the outside of the sites, the density of cultural finds such as sherds of pottery, artifacts, stone tools, bones, or architectural remains decreases. Sometimes, around the ancient sites, the topography, geomorphology, and landform, as well as sediments during different periods, cause cultural materials and artifacts to remain under these sediments and be hidden from view. Therefore, archaeologists often need to excavate to determine the presence or absence of materials below the surface. Areas, where the remains of ancient materials are present and can be reached with confidence by survey and excavation, are called the core zones of an archaeological site. From a legal point of view, it is forbidden to do any modern changes in the core zone of an archaeological site. A buffer zone is often added to protect ancient sites. The buffer zone is defined concerning the core zone and depends on the topography, geomorphology, environmental conditions, and elements related to the site. One field where the density of artifacts is very uncertain is the ancient cemeteries, which were generally built next to the settlements. The graves were mostly solitary and sometimes included secondary burial or mass burials.
Sometimes, due to the lack of obvious evidence of these graves, it is difficult and impossible to identify them, and determining their density and dispersion and the core zone of the cemetery. Determining the core zone and suggestion of the buffer zone traditionally is by using archaeological surveys and digging experimental sondages around the ancient site with special methods. Sometimes in ancient cemeteries, determine the core zone is not accurate, because maybe the archaeologist dig the experimental sondages between two graves and he doesn’t identify the graves, and due to the lack of awareness of the existence of graves, he doesn’t put this sections in the core zone, and this part should be outside the scope of the laws of the core zone of the archaeological site, and due to the lack of awareness of the existence of graves, this section not be included in the core zone of the site and will be outside the scope of the laws of the core zone of the archaeological site. But by geophysical methods, archaeologists can identify the location of all the graves and determine exactly the core zone of the ancient cemetery.
 

The ancient cemetery of Mehdiabad-e Olia is located 3 km south of the village of Mehdiabad-e Olia. The cemetery expands on both sides of a branch of the seasonal River of Bandenesa, 90 km from the city of Bam. In winter 2016, after a flood event, several pits with ancient pottery fragments were found. Based on a preliminary analysis of the ceramics by the archaeologists of the research center of the citadel of Bam they were able to identify these to be of Achaemenid or Parthian date. Most of the graves are rectangular and they are only about 90 to 120 cm below the surface. The large extent of the site is ideal for geophysical studies to determine the distribution of graves and identify the core zone of this ancient cemetery. A magnetic survey is a fast and efficient method for the first approach of an archaeological site. The principle of the magnetic method is to measure the local variations of the Earth magnetic field due to the presence of iron oxides in the soils and the archeological structures. Surface soil is magnetically stronger than underground soils. Its properties are further enhanced by human activities. This makes identification of different archaeological structures possible: graves, pits, and holes prove a higher magnetic record after they were filled with soil and surface sediments. The difference in the intensity of the magnetic field causes graves and pits can be identified as point anomalies with the surrounding context on magnetic maps.
The magnetic survey on the site was carried out with a cesium gradiometer G858 with a mesh grid of 1 m x 0.10 m interpolated at 0.50 m. Our survey covered an area of 8 hectares and focused on both sides of the road and the river by which several graves had been found. The magnetic map showed several anomalies: linear anomalies and positive and bipolar point anomalies. The strong linear anomaly on the south of the map was linked to the recently made modern canal. Another linear anomaly corresponding to the road in the southwestern part of this area. Other linear anomalies were related to artificial water passages. The majority of point anomalies are related to the graves, however. Our magnetic map identified approximately 800 graves. Some of these point anomalies are located on the surface graves that were found in the flood. 

Conclusion
According to the magnetic map, the density of point anomalies decreases in the east, south, and southeast of the area surveyed. This means that the limit of the cemetery is specified in this section and the core zone line of the site can be well defined here. The highest density of cemetery graves is in the central part of the studied area. The anomalies of graves continue in the north and west of the section, but the density of these anomalies decreases, and the line of the core zone of the cemetery can be identified in this part of the area. Our magnetic survey shows that the core zone of the ancient cemetery is well recognizable without actual excavation. Any excavation and opening of sondages in this region are dangerous and would pave the way for the looting of these sites. A geophysical survey, however, will protect this ancient cemetery. After our survey, an Iranian archaeological mission directed by Shahram Zare found a large Achaemenid building near 650 m west of the cemetery. Archaeological research on this site is continuing.