LATE CHALCOLITHIC SOLAR-CHTHONIC ROCK-CUT STRUCTURES FOR TIME MEASURING IN THE EASTERN RHODOPES, BULGARIA

Abstract

Our paper is focused on Late Chalcolithic solar-chthonic rock-cut structures for time measuring. Here we present two objects from the Eastern Rhodopes, Bulgaria – two additionally processed natural caves, which can be used for determining of the winter solstice – the beginning of one calendar cycle. Tangarduk Kaya cave sanctuary is situated near the village of Ilinitsa, Kardgali district. The different parts of the cave are formed after natural processes of Karst formation and human activity. At the level of the cave gallery floor the entrance aperture is widened and its vertical section is in a special form if they see from the inside outwards. The end of the gallery is obviously formed as altar. Archaeoastronomical investigations show that Tangarduk Kaya cave sanctuary could be connected with the cult of the Great Mother-Goddess. In the period between 3000 - 2000 B.C. the projection of the entrance aperture during the winter solstice reached 0.4 m from the base of the altar. Besides, this cave sanctuary could be used for determining of the year's duration and its beginning, with enough accuracy. The other rock–cut object Parmakla Kaya cave sanctuary near the village of Nochevo, Asenovgrad Municipality is in the same category. In the bedrock there is a natural cave, which is additionally processed. Orientation of the main axis of the cave is also in the meridian. Solar projection of the entrance on the day of the winter solstice is with a maximum length along the central axis. This also allows determining the dura- tion of the solar tropical year. On the vertical part of the rock massif, whose front is south oriented about 40 trapezoidal niches are carved. They are divided into two groups around the entrance of the cave. Probably, they are integrally related to the monument and their orientation allows observation of different shade effects during the movement of the sun on the celestial sphere.