The head of the project: Ilya G. Shorkunov
The title of the project: Memory of interfluve landscapes at the last Middle Pleistocene glacial area of the Russian Plain: structure, methodology, and reconstruction
Key words: uplands, paleo record, paleoarchive, soil memory, buried topography, cover beds, mantle loams, glacial till, cryogenic horizons, Saalian, Eemian, Weichselian, Holocene, paleosol, hierarchical morphogenetic research
The proposed project aims at developing and testing a universal methodological system for deciphering the complex memory of the interfluvial landscapes. Despite the fact that interfluvial areas occupy a larger part of the entire land surface [Rychagov, 2006], the sedimentary series of sea and ocean floor, deposits infilling river and lake basins, as well as glacial ice cores and tree rings are the main case study objects for global paleogeographic reconstructions. The obligatory property of these archives of paleogeographic information is rhythmic and hierarchically multi-scale horizontal stratification, where each successive layer (laminaset, bed, unit) has a characteristic accumulation (growth, exposure) time and is a successive element of the chronosequence. This type of memory is usually attributed as book-wise [Targulian, 1983, 2008]. Resembling in the first approximation type of record is also characteristic of a specific archive – the loess-soil formation of the Northern Hemisphere, which construct a significant part of interfluvial areas of accumulative plains in temperate and subtropical latitudes [Kukla & An, 1989; Velichko, 1990, 1997; Dodonov, 1991, 2001; Bronger et al., 1995; Bronger, 2003, etc.].However, the stratification of the loess-soil series has usually only one scale corresponding to the general rhythm of the climatically conditioned evolutionary stages of the “cold” biosphere [Makeev, 2009]. Deciphering soil and sedimentary memory in an increasing series of temporal resolutions inevitably encounters the problems of long-term subaerial exposure of soil and loess; repeatedly superimposed and destroyed records during the successive evolution of the interfluvial landscape, manifesting in soil polygenesis and deep diagenetic transformation of the entire sedimentary sequence. Such a paleoarchive has a low temporal, but significantly higher spatial resolution, which makes it crucial for restoring the parameters of a particular landscape in situ. Encountering such type of record usually referred to as palimpsest [Targulian, 1983, 2008] and typical for vast interfluvial areas, a problem of perusal of a unique history of continuous subaerial exogenesis arises especially acute.
As the object for this Project, region of the last Middle Pleistocene glaciation at the Russian Plain center is chosen. The modern landscape is represented there by a complex and poorly studied in terms of spatial relations combination of the moraine, glaciofluvial, and limnoglacial plains, to varying degrees modified by superimposed, primarily erosion-accumulative and cryogenic, processes. Therefore, its glacial topography is morphologically much less clearly expressed than at the Valdai (Weichselian) glaciation zone northward. Although, concepts of glacial and postglacial processes contribution into the modern geomorphological landscape are developed only in the most generalized way. Moreover, the questionable age of a number of end-moraine formations, attributed to the Early Valdai (Early Weichselian) ice cover distribution by certain researchers, has not yet been finally established. The discordance between completeness of a stratified geological, soil and cryogenic chronicle in valley, gully and lake basins - on the one hand, and palimpsest paleopedogenic record of interfluves - on the other, remains unresolved, which makes it difficult to correlate events and depict the evolution of the landscape as a whole. The range of inheritance, the ratio of depth and density of the modern and ancient erosion networks penetrating the interfluves, the relationship of fluvial and cryogenic processes, especially during the relatively rapid cryolithozone degradation at the end of the Valdai (Weichselian) time, have not been sufficiently studied. Reconstruction of the interfluvial landscapes transformation is based on an integrated approach to study relief and land forming processes, sedimentary sequences and incorporated cryostructures and cryogenic horizons, as well as soil formation features to restore the relic landscapes for different time intervals, - in a unified system of approaches and methods, in a successive series of spatial scales and for different types of landscape memory.
The original methodology of hierarchical morphogenetic research includes a complex application of morphological, physiochemical, and (radio)isotopic instrumental methods for the solid-phase organization investigation involving biomorphs associations determination techniques and detailed morphological and morphometric topography analysis using modern geodetic and remote sensing technologies for several key and control objects in a range of morphological resolutions from macro to micro and submicroscale. This will allow for the first time identifying the succession of stages of uplands landscape transformation during the Postglacial in its connection with the evolution of the Late Pleistocene soil and vegetation cover,
the pulsatory history of the Valdai (Weichselian) cryolithozone, the incision-infill cycles of fluvial network and depressions of the initial glacial topography. In addition, a conceptual model of interfluvial morpho-, litho-, and pedogenesis for the last 150 kyr will be developed, implemented as a series of large-scale morphogenetic maps and schemes of the actual and buried surfaces for key areas.
In the course of the Project, the creative team will compile and publish a database of radioisotope (14С – scintillation technique and acceleration mass spectrometry) and optically stimulated luminescent (OSL) estimated ages for various types of records and its carriers at the key sites of the interfluvial complex of the Moscow glaciation terminal zone.
The results will be published in peer-reviewed periodics indexed in the RISC, Scopus and WoS systems, including the first quartile (Q1) journals. According to the work results (outside the implementation of this Project), the creative team plans to develop software – an application for mobile devices with online access to the created database allowing any user to work independently with organized information both remotely and directly in the field. Visualization and presentation system of he integrated interdisciplinary research data, including a database structure, a web-portal design, and a mobile application, is a universal product and can be used to organize the work results of research groups of a broad profile, conduct educational training, and popularize scientific knowledge.
The expected results
1. Diagnostic features of modern and buried landforms and associated deposits will be highlighted, allowing reliably determining their origin, age and stratigraphic position at the key and control sites based on the integrated analysis of morphology, morphometric characteristics, lithostratigraphic and post-cryogenic sedimentary strata organization and their pedogenic reworking.
2. The leading morpholithogenic mechanisms will be determined in a successive series of formation and transformation stages of interfluvial topography, stages and chronology of active denudation and accumulation processes will be established, as well as the longest exposure phases of stable surfaces associated with changes in landscape and climatic conditions and recorded in a detailed record of diagenesis, soil formation and cryogenesis at the interfluves.
3. The chronosequence of incision-infill cycles within small erosion forms will be distinguished; the volumes and rates of sedimentation at the erosion network chains of different-order will be linked with the exogenous dynamics at their water and sediment catchments; sets of pedo- and cryogenic features typical for the hilltops and small valley and gully bottoms will be correlated.
4. Thus, it will become possible to evaluate the contribution as actual (Holocene), incl. modern, reproducible processes, and relict (glacial and postglacial) components in the formation of the interfluves of the last Middle Pleistocene glaciation marginal zone at the Russian Plain center and to restore the corresponding typical landscape conditions – at different time scales in a series of increasing spatial resolution.
5. This will allow developing a detailed scenario for the modern relief formation of uplands, starting with the glacial cover degradation phases and fluvio-limno-glacial transformations during the Late Moscow (Late Saalian), in the Late Pleistocene and Holocene followed by the morpholithogenic stages and superimposed periods of cryogenesis, and continuous polygenetic soil formation. It will be illustrated by a series of large-scale morphogenetic maps of modern and paleotopography for the key sites, as well as smaller-scale final chronomorphogenetic maps of the key and control sites uplands. For the first time, based on the results of interdisciplinary hierarchical research, a conceptual model of morpho-, litho-, and pedogenesis will be created for the interfluves of the Central Russian Plain over the past 150 kyr.
6. The developed models and original approaches will make it possible to consider the sets of lithostratotypical, (paleo)topological, cryo- and pedogenic features as a unified ensemble of memory features of the interfluvial landscapes.
We expect to typify the landscape memory concerning a characteristic set of paleogeographic information carriers, their spatial and temporal resolution, as well as the duration and continuity of records, successive or superimposed arrangement and preservation degree of particular features. For key sites, thematic maps of landscape memory types will be created, which will allow assessing the degree of reliability of paleogeographic reconstructions carried out previously on the basis of a limited set of case study objects (sections, pits, cores, etc.) within landscape positions with varying memory capacities.
Preliminary clasterization of the control site territories of this study according to the types of landscape memory will allow selecting the necessary and sufficient number of objects at the reconnaissance stage of investigation and testing the approach with higher spatial accuracy and a more reasonable set of methodological approaches.
7. In the course of the Project, the creative team will compile and publish a database of radioisotope (14С – scintillation technique and acceleration mass spectrometry) and optically stimulated luminescent (OSL) estimated ages for various types of records and its carriers at the key sites of the interfluvial complex of the Moscow glaciation terminal zone, which will allow considering the key sites as unique reference objects (areas) for regional lithostratotypical correlations and paleogeographic reconstructions.
8. The results will be published in peer-reviewed periodics indexed in the RISC, Scopus and WoS systems, including the first quartile (Q1) journals. The main research results will be organized into a database and published on the creative team’s web portal as an interactive GIS project. According to the work results (outside the implementation of this Project), the creative team plans to develop software – an application for mobile devices with online access to the created database allowing any user to work independently with organized information both remotely and directly in the field. Visualization and presentation system of the integrated interdisciplinary research data, including a database structure, a web-portal design, and a mobile application, is a universal product and can be used to organize the work results of research groups of a broad profile, conduct educational training, and popularize scientific knowledge.
Comprehensive application of the original methodological approach and modern instrumentall and technical base in the study will allow to accomplishing the proposed Project goals in full and obtain the results with a high degree of reliability and verifiability. Presence of the recent publication compiled by the creative team on preliminary research results of the key site “Poklony” in an international journal from the top 25 (Q1) already confirms the world level of the study and indicates the relevance of the issues being addressed to the world stage.