extended abstracts - Geomorphic Processes and Geoarchaeology

Geomorphic processes and geoarchaeology
low-lying plain about to 10 km width, which is run up to the Chorniye Gory ridge.
Drainage system belongs to the Tesnaya, Kamyshovaya and Gladkaya rivers. The
Kraskino hillford is situated in the central part of the Kraskino depression, an isolated
tectonic structure. It was formed in the early Paleogene. Kraskino depression has nearly
oval shape with the Expeditsiya bay in the center. Its base consists of granites,
sedimentary and metamorphic rocks of the later Paleozoic. Upper layer consists of
sedimentary and volcanic rocks of the Cainozoic age. Hat of the geological cross-section
consists of Quaternary deposits up to 100 m in width: lams, detritus, gravel, coal, aleurite,
loam – alluvial and marine sedimentaries. The highest layer of Kraskino cross-section is a
«culture layer». Soft sediments of the Kraskino hillfort’s culture layer are alluvial sandy
and argillo-arenaceous deposits.
Archeological excavations allowed to locate remains of cult, residential and
support buildings, fencings and fortifications. They are represented by fragments of
various compositions of rocks. The research of Kraskino hillfort’s rocks was done. The
main purpose of geological research is to find out the sources of rocks used for
housebuilding and other activities. Researching method is benchmarking rock fragments
from hillfort and rocks from Kraskino hillfort’s surroundings. The research was
performed in macro- and microscoping (petrological slides’ analysis). Benchmarking
allowed to locate possible sources of mineral raw materials and ways of carrying.
Kraskino hillfort’s building materials are mainly represented by 14 groups of rocks: 1 –
rare-porphyritic plagiophyre andesites; 2 – short- and medium-grained gabbro (gabbrodiorites?);
3 – porphyritic pyroxene basaltic andesites (andesites?); 4 – large-porphyritic
dacite andesites; 5 – porphyritic volcanic acid and mid-acid rocks; 6 – aphyric and rareporphyritic
volcanic acid and mid-acid rocks; 7 – porphyritic leucocratic granites; 8 –
fused tuffs (including pumice tuffs); 9 – mid-grained granodiorites; 10 – psephitic crystallithoclastic
tuffs; 11 – volcanic glass; 12 – mid-grained biotite-amphibolic granites; 13 –
microgranites, aplites and quartz veins; 14 – lithified sedimentary rocks.
Geological research (visual and petrographic analysis of hillfort and surroundings’
rocks, analysis of geological maps and traverse) allows to make following conclusions:
1. Specialities of Kraskino hillfort’s geological structure (soft Quaternary deposits)
allow to confirm that all the rock fragments located into the hillfort aren’t. They were
have being brought here as a result of antropogenic activities;
2. Kraskino hillfort’s rock fragments can be divided to the 2 groups by its abrasion
degree: 1 – variously abrased alluvium, round stones and chunks; 2 – variously sized and
shaped sharp edged. 1 st group materials were carried from locations with possibility of
natural processing of rocks: river-beds and its surroundings, seashore beaches. 2 nd group
materials were selected from natural open-cut mines (bed-rock barings, bank stream
gravel). Ways of carrying building materials are mainly water: rivers, ingressive guts, the
Expeditsiya bay.
3. Magmatic (intrusive, volcanic and sub-volcanic) units prevailing among the
Kraskino hillfort’s rocks. Sedimentary and methamorphic rocks are affluent. The widest
represented are volcanic and sub-volcanic units and allied to them comagmatic and
shallow intrusive stones. They are represented by porphyritic andesites (group 1), largeporphyritic
andesites (group 9) and short- and medium-grained gabbro (group 2). These
rocks make base of wall, footing of temple and other constructions. Points of origin of the
rocks take place nearby the hillfort (Novgorodskiy peninsula, tuffet near Kraskino
239