The aim of the work is to present the interdisciplinary projects developed and funded by the Bulgarian Science Research Found. These projects are created in Departments of Archaeology, and Natural Sciences, New Bulgarian University in the period 2014–2019.

Using X-ray fluorescence and Powder X-ray diffraction analysis, the chemical and phase composition of ancient iron slags and raw iron ore were investigated. The type of raw ore was identified as self-fluxing. The operating furnace temperature was determined in the range 900–1000 °C. The results obtained are of archaeological importance. They will contribute to the chronological specification of the time of realization of the metallurgical process and the type of used furnaces.

The main objective of this paper is to present the fieldwork results ofarchaeological and geological investigations in the area of Hadjiyska river and the southern slopesof Eminska Stara Planina in Bulgaria. The area of interest is home to a large number ofarcheological findings dating back from the Late Antiquity (4-6th c.) and the Middle Ages (7-18thc.), and fewer from older periods (prehistorical, Thracian and Roman periods). Geologicalobservations show presence of alluvial, prolluvial-delluvial, and prolluvial hollocen sediments.Combining the results of archaeological and geological research allowed for (i) the verification ofthe hypothesis that older archaeological objects are covered by accumulated sediments, and (ii) anattempt to look into the livelihood in the area.

The major issue studied in this paper is a natural mineral aggregate of quartz, calcite, and fluorapatite (the raw material originated from Bulgaria) before and after high energy milling and thermal treatment, in the order to investigate the properties of natural CaO-SiO 2 -P 2 O 5 ceramic system. The activation effects are monitored by chemical analysis, X-ray powder diffraction, Fourier transformed infrared spectroscopy, and Thermal analysis (TG/DTG).The activation effect study shows: (i) change of chemical bond strength; (ii) deformation of structural polyhedrons with the formation of new isomorphic phases; (iii) the prolonged time of HEM activation leads to lower raw mineral stability and to the formation of new phases; iv) increased SiO 2 reactivity resulting in solid-phase crystallization.The obtained results can be used in the study of ceramic and cement materials (ancient and modern), soil conditioners, etc.

In the autumn of 2020 and spring of 2021, archaeological and geological field surveys were conducted within the Nessebar and Pomorie municipalities, as part of the project “Archaeology of Landscape: Patterns of Reconstruction of the Ancient Environment.” The project aims to reconstruct the landscapes of the Southern slopes of The Emine Stara Planina Mountain during Antiquity, as well as investigate human impact on the environment and archaeological sites. During the surveys, 102 new archaeological sites were discovered (see Fig. 1). Two sites date back to the Late Chalcolithic period, four to the Late Bronze Age, and nine small settlements to the Early Iron Age. These settlements were located along the banks of the Aheloy River and Hadzhiiska River. The majority of the sites (51 settlements) date back to the second half of the 1st millennium BC. Eleven settlements were dated to the Archaic and Classical periods, and ten to the Hellenistic period. Thirty sites did not yield enough diagnostic artifacts, and thus were largely dated to the second half of the 1st millennium BC. The Early and Late Roman periods, as well as Late Antiquity, were represented by a total of 54 sites, with 13 sites from the Roman period and 41 from Late Antiquity. However, this remains a conditional division, as some of the sites from Late Antiquity could potentially date back to the 2nd and 3rd centuries. The Medieval period was represented by 46 sites, with three sites dating back to the earliest part of the period (8-10th century). These sites contain pottery from the First Bulgarian Kingdom, while eleven sites belong to the 10th-12th centuries, and eighteen sites to the 13th-14th centuries.