Zonal biochronological method for solving long-living problems of general stratigraphy

Abstract

Research subject. Problematic issues of general stratigraphy are considered, including the Karpinsky principle, the unification of autonomous zonal biochronological scales (BCS), the basics of stratigraphic classification, the relation of zonal biostratigraphic and chronostratigraphic units. Materials and methods. The existing standard solutions to the above issues are analyzed. An attempt is made to reveal the logical sources of contradictions and to pave ways for a consistent synthesis. Results. The necessity for a successful solution of these issues to abandon the identification of the biochronological scale and the geological section is shown. From the recognition of the zone as the smallest subdivision of the biochronological scale, the linearity of the zonal subdivisions of the scale follows, which makes it a correct tool for performing basic stratigraphic operations – section subdivision and correlation of the boundaries of stratigraphic units. Strict differentiation of the scale from a section studied using this scale makes it possible to fulfill all the requirements of the Karpinsky principle regarding dividing horizons with mixed fauna. The same condition underlies the creation of a stratigraphic classification, which must be preceded by a clear separation of the material (“mapped”) stratigraphic units of the Earth’s crust and units of chronological scales, which are used for their correlation. Placing them in a single “dualistic” stratigraphic classification cannot give a satisfactory result. The creation of autonomous zonal scales should be preceded by the definition of the biozones of the species used to build these scales, according to the normative (standard) zonal scale for a given stratigraphic interval. Taking into account the minimum dimension of the zonal subdivisions of the standard scale, the zones of autonomous scales distinguished by this method correspond to a whole number of normative zones, and, therefore, the boundaries of the stratozones established on the autonomous scales, in this case, will certainly coincide with any boundaries of the stratozones, distinguished on the normative scale. This procedure makes it possible to perform the unification of autonomous zonal BCSs based on different groups of fossils. Zonal BCS performs correlation functions, zonal units are a tool for chronological identification of remote geological objects, including the boundaries of chronostratigraphic units, although not being included in their hierarchy. Conclusions. A biochronological scale is a model of the biochronological calculation of geological time and cannot be identical to what it models. Differentiation of the scale from a section studied using this scale is an indispensable condition that precedes and ensures the successful solution of long-living problems of general stratigraphy.