Digital structural-lithological model and geological-genetic characteristics of Kopytkovsky phosphorite deposit

Abstract

Introduction. The relevance of this publication is associated with the problem of foundation and developing a raw material base of phosphate raw material in accordance with the demand of the national agro-industrial complex. The purpose of the publication is to develop a preliminary digital structural-lithological model (DSLM) of the Kopytkivsky deposit, as a tool for information support of its development, as well as geological and genetic characteristics of the object as a basis for specifying the criteria for predicting deposits of this type. This goal covers the following tasks: - presentation of methodology and research methods; - presentation of the database; - demonstration of derivatives of the created digital structural-lithological model (DSLM) and their interpretation;- representation of functional and cognitive characteristics of the object (Kopytkivsky phosphorite deposit). Materials and Metodology. The studies are based on two methodological principles: traditional lithological, paleofacial, paleogeographic studies and the author's development - digital structural and lithological modeling, dialectically combined in the form of a single predictive-paleoreconstructive retrospective-static model. Main Results. Kopytkivsky deposit belongs to the Zdolbunovskiy district of the Zdolbunovskiy-Ternopil zone of the Volyn-Podolsk Cretaceous basin of the phosphorite-bearing province of the East European platform. The indicated zone refers to the Volyno-Podilllya plate, i.e the western slope of the Ukrainian shield. In the area of the Kopytkivsky deposit, layers of inoceramic limestones represent the lower stratigraphic subdivision of the Cretaceous system, lying directly on the pre-Mesozoic basement. The DSLM of the Kopytkivsky field has been developed, intended for information support for further work on its development (detailed exploration and operation). The DSLM database is represented by a description of 567 geological exploration wells. Conclusions. Based on the constructed DSLM, a number of derivatives (including visualizations) were obtained that reflect the structural and material - industrial characteristics of the field - a number of maps, profiles, as well as a block diagram of the central part of the field. The description of the most informative visualizations are given: Map of the hypsometry of the bottom of the "productive horizon", Map of the hypsometry of the roof of the "productive horizon", Map of specific reserves and others. The model derivatives reflect the spatial (areal and hypsometric) configuration of phosphorites ore bodies and the distribution of specific reserves of P2O5. Based on the methodological principles of formation analysis and the methodological approaches adopted by us for predictive-paleoreconstructive retrospective-static modeling of the object, a geological and genetic characteristic of the stage of formation of layers of inoceramic limestones has been obtained. The mechanism of phosphorite formation is considered. The presented DSLM is intended for information support of detailed and operational exploration, with the prospect of the current development of the model (as a permanent one) with the addition of new data during exploration and operational work.