Features of the Ecological-geological System of the Tuff Massif of the Pauzhetsky Geothermal Region (Kamchatka)
Authors
Violetta Shanina
DOI
Abstract
The purpose of the study is to fully characterize the ecological-geological system (EGS) of the tuff massif of the Pauzhetsky geothermal region (Kamchatka), compiled on the basis of the author’s own field research (six field seasons) and published literature data. Features of the lithotope: an outcrop of andesite-dacitic tuffs of the Upper Pauzhetian subformation (N2-Q1) was studied. According to their properties, the rocks are divided into groups: 1) silty tuffs: density 1.40-1.57 g/cm3, density of the solid component 2.70-2.72 g/cm3, porosity 42.2-48.2% , open porosity 31.2-40.3%, hygroscopic humidity 0.7-3.6%, water absorption 20.5-27.1%, longitudinal wave speed 2.00-2.40 km/s, magnetic susceptibility 2.9-11.4*10-3 SI, uniaxial compressive strength 8-11 MPa; 2) fine psephitic tuffs are dense (ρ = 1.59-1.80 g/cm3), density of the solid component is 2.72-2.78 g/cm3, porous (33.8-42.7%); 3) pumice tuffs are characterized by the lowest density (ρ=0.98-1.35 g/cm3) and the highest porosity (n=49.8-63.5%). Features of the edaphotope: on the tuffs under consideration, volcanic layered ocher soils are developed; they have a low density (0.6-0.8 g/cm3), crumbly, with high water permeability and a predominance in the composition of humic acids of free and associated with mobile sesquioxides of humic acids and fulvic acids. Features of the phytocenosis: forest and dwarf altitudinal zones occur. Features of the zoocoenosis: invertebrates include extensive complexes of arachnids, the diversity of the animal world is represented by species of mammals characteristic of Kamchatka. The ecological and geological system formed on the tuff massif of the Pauzhetsky geothermal region is a complex formation. The most important features of the EGS are mainly determined by its lithogenic base - rocks soils (andesite-dacite tuffs), which have specific properties. The composition and properties of the lithotope largely determine the properties of the edaphotope and the species composition of phytocenoses and have less influence on the zoocenosis.