UNDERWATER GEOPHYSICAL SURVEY OF THE SUBMERGED SETTLEMENT IN FRONT OF THE MOUTH OF THE RIVER OF ROPOTAMO (Lyudmil Vagalinski – lvagalin@techno-link.com, Kalin Dimitrov) Geophysical survey in the maritime aquatory in front of the mouth of the River of Ropotamo were carried out, in the gulf to the south of St. Demetrius Cape. The aim was to identify promising locations for the underwater archaeological excavations and preliminary information on the stratigraphy of the site to be collected. An area of 38 ha was explored with a multi-beam echo sounder. An area of c. 40 ha was scanned with lateral scanning sonar. Vertical electric underwater drilling was performed at 471 points with a depth of penetration into the sea bottom of 5 m to 25 m. Visualizations and 3D models were built to support the archaeological explorations. The positioning of the archeological trenches according to data from the geophysical surveys has led to successful subsequent archeological excavations. The ancient mouth of the River of Ropotamo was located at c. 700 – 800 m to the northwest of the present-day one. During the Early Bronze Age when the sea level was 8 – 10 m lower than today, the gulf between the mouth of the river and St. Demetrius Cape was a coastal terrace. A settlement existed on that terrace during the Early Bronze Age, situated on the banks of small right tributaries of the River of Ropotamo.

UNDERWATER ARCHAEOLOGICAL EXCAVATIONS IN FRONT OF THE MOUTH OF THE RIVER OF ROPOTAMO (Lyudmil Vagalinski – lvagalin@techno-link.com, Jonathan Adams, Kalin Dimitrov) In 1976, finds from Late Antiquity and the Middle Ages were occasionally discovered in front of the mouth of the River of Ropotamo during dredging works. In 1982 – 1989, underwater archaeological expeditions were carried out. In 1989, finds were discovered, interpreted as remains from a settlement of the Early Bronze Age, submerged during the sea level rise. In 2017, Trenches T1 and T2 were explored in Zone KV-2. In Stratum II from –3.60 m to –4.30 m in depth, sherds from Late Antiquity, the Middle Ages and the Ottoman period, pieces of wood, fragmentary mortar and stones with traces from fire were discovered. A Mediaeval anchor was found, too. In Stratum III from –4.50 m to –5.10 m in depth, sherds from the beginning of the Early Bronze Age were found. In Stratum IV from –5.10 m to –5.60 m in depth, a wooden post vertically driven into the ground and part of an oven or a hearth were discovered. A ceramic vessel of the beginning of the Early Bronze Age was also found. The strata of Late Antiquity, the Middle Ages and the Ottoman period indicated the existence of a harbor, at least from the Middle Ages onwards. The stratum of the beginning of the Early Bronze Age was related to a settlement situated on a terrace on the right bank of a small river that was a right tributary of the River of Ropotamo. Judging from the pottery, the settlement dated to the First Phase or the beginning of the Second Phase of the Early Bronze Age. The radiocarbon dating of the wooden post showed 4474±21 BP or 3335–3031 cal BC.

EXPLORATIONS NEAR THE MOUTH OF THE RIVER OF ROPOTAMO (Kalin Dimitrov – kalin.d@abv.bg, Daniel Pantov) Geophysical surveys were carried out in the area of St. Demetrius (Skombolito) Cape and the mouth of the River of Ropotamo. A drone survey with recording was also carried out to make orthophoto mosaics and create a DEM by aerial photogrammetry. During a field survey, rock-cut structures, probably cisterns, and a stratum with sherds were documented on St. Demetrius Cape. The maps obtained from geomagnetic and LiDAR measurements indicated areas with anomalies, including remains from rectangular buildings.

UNDERWATER ARCHAEOLOGICAL EXPLORATIONS AT THE MOUTH OF THE RIVER OF ROPOTAMO (Kalin Dimitrov – kalin.d@abv.bg, Nayden Prahov, Jonathan Adams) The site was located between Cape St. Demetrius (Skombolito) and the mouth of the River of Ropotamo. It was discovered in 1976 and explored during the 1980s. In 2018, the explorations continued in Trenches T2 and T3. Stratum I was the present-day sea bottom at 3.20 m in depth and the ground beneath down to 60 cm in depth. It contained finds of the Ottoman period, the Middle Ages and single sherds of Late Antiquity. Stratum II was 30 – 40 cm thick and contained Roman and Late Antique finds: imported and local amphorae, kitchenware, red-gloss pottery, glass vessels, terracotta lamps, sherds from terra sigillata, carbonized branches and trunks. Stratum III contained single finds of the pre-Roman period: a Late Archaic Ionian kylix discovered in 1988, black-gloss sherds of the Hellenistic period, single sherds of Thracian greyware. Strata I, II and III were accumulated in a bay that was used as a harbor and constituted a port accumulation. Stratum IV was a _hiatus_. Stratum V contained finds of the Early Bronze Age: sherds, intact ceramic vessels, wooden posts and fragmentary burned wattle-and-daub. In 2017 and 2018, 12 vertical wooden posts were discovered stuck into the ground, 15 – 25 cm in diameter. The lower end of the posts is pointed, showing traces of chopping with axes. The calibrated C14 dates from nine samples of wooden posts dated to the beginning of the first phase of the Early Bronze Age in 3080 – 2970 cal. BC. The settlement was situated along the right bank of a small stream, a right tributary of the River of Ropotamo. The settlement seemed to have been abandoned by its inhabitants.

UNDERWATER ARCHAEOLOGICAL EXCAVATIONS IN FRONT OF THE MOUTH OF THE RIVER OF ROPOTAMO (Kalin Dimitrov – kalin.d@abv.bg, Jonathan Adams, Johan Rönnby) The archaeological site in the gulf between St. Demetrius (Skombolito) Cape and the mouth of the River of Ropotamo was explored during the 1980s. The excavations in 2017 and 2018 revealed that the gulf was used as a harbor during the Ottoman period, Late Antiquity and Roman period. A layer of sediments without any archaeological finds was situated beneath the harbor accumulations and the remains of a settlement of the First Phase of the Early Bronze Age (dated with 14C samples to 3080 – 2970 cal. BC) were situated beneath. In 2019, the excavations continued in three sectors: Т1, Т2–Т3 and Т4. In Trenches Т2–Т3, no archaeological material was discovered in Strata VI and VII, situated beneath Stratum V of the Early Bronze Age. The explorations of wooden posts Nos. 10 and 14 showed that they were driven in a terrestrial environment just above the level of the ancient coastline. During the construction of the settlement at the end of the 4th millennium BC, the sea level was c. 5.80 m beneath the present-day sea level. In 2017, 2018 and 2019, 18 wooden posts were discovered in Trenches Т2–Т3. The harbor accumulations were documented in the upper strata of Trench T4 and finds from all the relevant periods were discovered, while the archaeological material of the Roman period prevailed. Finds from the Archaic and the Hellenistic period were discovered as well. Fifty-five wooden posts of the Early Bronze Age were documented beneath Stratum IV consisting of sediments without archaeological finds. Fragmentary burned wattle-and-daub, fragments from an oven, five horn tools, flint tools, querns and pestles, and at least 14 ceramic vessels were discovered. The Early Bronze Age settlement was built on land and was later flooded when the sea level rose. The Black Sea level has risen by c. 5.80 meters in the last 5,000 years.

EXPLORATIONS ON ST. DEMETRIUS CAPE (Kalin Dimitrov – kalin.d@abv.bg, Daniel Pantov) Geophysical surveys were carried out in the area of St. Demetrius (Skombolito) Cape, related to the underwater archaeological explorations in the bay. A geomagnetic survey and a LiDAR scanning were performed. The geomagnetic survey was carried out with two proton magnetometers (gradientometers) model GSM-19TGW. The measurement grid consisted of parallel profiles situated 1 m apart. The LiDAR scanning was carried out with a GPR system of type UtilityScan. Anomalies were documented during the surveys, but they are not related to human activities.