The investigations of Tolbor 21 multilayered Paleolithic site (Northern Mongolia)

The site of Tolbor 21 (49°15 ’47”N., 102° 57’28” E) is located on the west bank of the Ikh-Tulberiin-gol river (right side tributary of Selenga River, North-Central Mongolia) at 1 089 m a.s.l. It is exposed to the South-East along a gentle-slope hill side. It was discovered and tested in 2011. This initial test revealed the presence of preserved Paleolithic assemblages. Two 14C-AMS dates were obtained on bone samples from the test pits: 44,640 ± 690 (MAMS-14933) from Pit 1 (ca.150 cm below modern surface) and 39,240 ± 360 (MAMS-14936) from Pit 2 (ca.115 cm below modern surface). Primary outcrops of raw material (silicified argillites and rhyolites) were identified near the site (ca. 100 m). In 2014, a third test pit of 4 x 1 m was opened to document the stratigraphy. In 2015 the investigation of site was resumed. Nearby the test pit of 2014 were opened the excavation pit of 4 x 2 m. A 3.1 m high section was exposed along the slope. The Tolbor-21 section comprises a packet of fine grained loess-like sediments and bedded gravels and sands, much of which is affected by solifluction, subdivided here into 5 stratigraphic units, this section formed through a combination of aeolian and slope processes, along with pedogenesis. As result of analysis of artifacts distribution 6 cultural horizons were recognized. The small assemblage (n=8) of lowermost cultural horizon 6 lacks the diagnostic artifacts. Horizon 5 artifacts (n=45) are tentatively assigned to the early stages of the UP by the occurrence of tool types such as borer and retouched point on blade. Horizon 4 (n= 691) and 3 (n=863) situated in lithological layer 3 would roughly correspond to the radiocarbon determinations of 39 kauncal BP. These assemblages fit to regional definition of Early Upper Paleolithic. They characterizes the domination of unidirectional reduction of subprismatic cores and production of blade and bladelets and sporadic microblades. Along with stone artifacts in the horizon 4 was founded ostrich shell bead. The assemblages of horizons 2 and 1 are identified as Late Upper Paleolithic/Early Holocene.