CONDITIONALLY OBJECTIVE COLOUR AND ASSESSMENT OF THE POSSIBILITY OF CHROMOSTRATIGRAPHIC CORRELATION OF THE UPPER MORAINES OF THE YAROSLAVL VOLGA REGION
Introduction: The colour of moraines is a good stratigraphic marker, therefore its diagnostic requires a description based on a quantitative approach. However, in the practice of the lithostratigraphic correlation of moraines, only the subjective colour is used. This increases the probability of erroneous dating of the Quaternary beds. Therefore, the development and use of a new colorimetric methodology is highly demanded in the practice of lithostratigraphic studies. Methodology'. The methodology for determining the objective colour of a moraine and chromostratigraphic correlation of sedimentary strata was developed using relative colorimetric analysis. Based on the example of the upper moraines of the Yaroslavl Volga region of the conditionally Dnieper and Moscow ages, based on 16 sections, the scale and boundaries of the variability of their colour parameters and the correlation potential of objective colour were shown. Results and discussion: The brightness, saturation, and nature of the relationship of colour parameters had the highest diagnostic value for determining the stratigraphic type of moraine. The study of samples from reference sections with two moraine horizons (Dolgopolka and Rykusha) showed the same scale of differences between the Moscow and Dnieper moraines in terms of objective colour parameters. Conditionally, the Moscow moraine differs from the conditionally Dnieper in the Yaroslavl Volga region by a large shift of the colour tone into the red region and increased brightness, while the saturation was not statistically different or geographically irregularly changed. The colour distribution of sediments from sections with one moraine horizon was discrete, the average colour distance between two moraines coincided with the colour difference between two moraines in the reference sections. Conclusions: The accuracy of diagnostics of the relative age of moraines by objective colour and, accordingly, the chromostratigraphic correlation of moraines from sections with the only preserved moraine horizon, according to the available material, was about 90%. This allowed us to consider the method for the determination of objective colour as being promising for solving the problem of matching moraine horizons within the local region.