THE GREATER CAUCASUS MOUNTAINS: A COMPLETE TRANSECT FROM ACTIVE SUBDUCTION TO CONTINENTAL COLLISION IN A SINGLE OROGENIC SYSTEM

2020 ◽  
Author(s):  
Nathan A. Niemi ◽  
◽  
Eric Cowgill ◽  
Dylan Vasey
Keyword(s):  
Continental Collision ◽  
Greater Caucasus ◽  
Caucasus Mountains

scholarly journals Supraglacial debris cover assessment in the Caucasus Mountains, 1986-2000-2014

2017 ◽  
Author(s):  
Levan G. Tielidze ◽  
Roger D. Wheate ◽  
Stanislav S. Kutuzov ◽  
Kate Doyle ◽  
Ivan I. Lavrentiev
Keyword(s):  
Morphological Type ◽  
Ice Age ◽  
Landsat 8 ◽  
Glacier Area ◽  
Greater Caucasus ◽  
Rock Structure ◽  
Debris Cover ◽  
Landsat 7 ◽  
Caucasus Mountains ◽  
Elevation Model

Abstract. Surpaglacial debris cover plays an increasingly important role impacting on glacier ablation, while there have been limited recent studies for the assessment of debris covered glaciers in the Greater Caucasus mountains. We selected 559 glaciers according to the sections and macroslopes in the Greater Caucasus main watershed range and the Elbrus massif to assess supraglacial debris cover (SDC) for the years 1986, 2000 and 2014. Landsat (Landsat 5 TM, Landsat 7 ETM+, Landsat 8 OLI) and SPOT satellite imagery were analysed to generate glacier outlines using manual and semi-automated methods, along with slope information from a Digital Elevation Model. The study shows there is greater SDC area on the northern than the southern macroslope, and more in the eastern section than the western and central. In 1986-2000-2014, the SDC area increased from 6.4 %-8.2 %-19.4 % on the northern macroslope (apart from the eastern Greater Caucasus section), while on the southern macroslope, SDC increased from 4.0 %-4.9 %-9.2 %. Overall, debris covered glacier numbers increased from 122-143-172 (1986-2000-2014) for 559 selected glaciers. Despite the total glacier area decrease, the SDC glacier area and numbers increased as a function of slope inclination, aspect, glacier morphological type, Little Ice Age (LIA) moraines, rock structure and elevation. The datasets are available for public download at https://doi.pangaea.de/10.1594/PANGAEA.880147.

Structural geometries and magnitude of shortening in the eastern Kura fold-thrust belt, Azerbaijan: Implications for the development of the Greater Caucasus Mountains

Tectonics ◽  
2013 ◽  
Vol 32 (3) ◽  
pp. 688-717 ◽  
Author(s):  
Adam M. Forte ◽  
Eric Cowgill ◽  
Ibrahim Murtuzayev ◽  
Talat Kangarli ◽  
Marius Stoica
Keyword(s):  
Thrust Belt ◽  
Greater Caucasus ◽  
Caucasus Mountains

scholarly journals Active deformation and Plio-Pleistocene fluvial reorganization of the western Kura fold–thrust belt, Georgia: implications for the evolution of the Greater Caucasus Mountains

2020 ◽  
pp. 1-15
Author(s):  
Lasha Sukhishvili ◽  
Adam M. Forte ◽  
Giorgi Merebashvili ◽  
Joel Leonard ◽  
Kelin X. Whipple ◽  
...  
Keyword(s):  
Foreland Basin ◽  
Drainage Network ◽  
Thrust Belt ◽  
Directed Flow ◽  
Active Deformation ◽  
Greater Caucasus ◽  
Geological Maps ◽  
Piggyback Basin ◽  
Caucasus Mountains ◽  
Southward Migration

Abstract Since Plio-Pleistocene time, southward migration of shortening in the eastern part of the Greater Caucasus into the Kura foreland basin has progressively formed the Kura fold–thrust belt and Alazani piggyback basin, which separates the Kura fold–thrust belt from the Greater Caucasus. Previous work argued for an eastward propagation of the Kura fold–thrust belt, but this hypothesis was based on coarse geological maps and speculative ages for units within the Kura fold–thrust belt. Here we investigate the initiation of deformation within the Gombori range in the western Kura fold–thrust belt and evaluate this eastward propagation hypothesis. Sediments exposed in the Gombori range have a Greater Caucasus source, despite the modern drainage network in the NE Gombori range, which is dominated by NE-flowing rivers. Palaeocurrent analyses of the oldest and youngest syntectonic units indicate a switch happened between ~2.7 Ma and 1 Ma from dominantly SW-directed flow to palaeocurrents more similar to the modern drainage network. A single successful 26Al–10Be burial date indicates the youngest syntectonic sediments are 1.0 ± 1.0 Ma, which, while not a precise age, is consistent with original mapping suggesting these sediments are of Akchagylian–Apsheronian (2.7–0.88 Ma) age. These results, along with recent updated dating of thrust initiation in the eastern Kura fold–thrust belt, suggest that deformation within the Kura fold–thrust belt initiated synchronously or nearly synchronously along-strike. We additionally use topographic analyses to show that the Gombori range continues to be a zone of active deformation.

scholarly journals Tectonostratigraphy and major structures of the Georgian Greater Caucasus: Implications for structural architecture, along-strike continuity, and orogen evolution

Geosphere ◽  
2022 ◽  
Author(s):  
Charles C. Trexler ◽  
Eric Cowgill ◽  
Nathan A. Niemi ◽  
Dylan A. Vasey ◽  
Tea Godoladze
Keyword(s):  
Fault System ◽  
Thrust Faults ◽  
Geologic Mapping ◽  
Greater Caucasus ◽  
The Core ◽  
The North ◽  
Thrust Sheets ◽  
Southern Half ◽  
Caucasus Mountains ◽  
Structural Architecture

Although the Greater Caucasus Mountains have played a central role in absorbing late Cenozoic convergence between the Arabian and Eurasian plates, the orogenic architecture and the ways in which it accommodates modern shortening remain debated. Here, we addressed this problem using geologic mapping along two transects across the southern half of the western Greater Caucasus to reveal a suite of regionally coherent stratigraphic packages that are juxtaposed across a series of thrust faults, which we call the North Georgia fault system. From south to north within this system, stratigraphically repeated ~5–10-km-thick thrust sheets show systematically increasing bedding dip angles (<30° in the south to subvertical in the core of the range). Likewise, exhumation depth increases toward the core of the range, based on low-temperature thermochronologic data and metamorphic grade of exposed rocks. In contrast, active shortening in the modern system is accommodated, at least in part, by thrust faults along the southern margin of the orogen. Facilitated by the North Georgia fault system, the western Greater Caucasus Mountains broadly behave as an in-sequence, southward-propagating imbricate thrust fan, with older faults within the range progressively abandoned and new structures forming to accommodate shortening as the thrust propagates southward. We suggest that the single-fault-centric “Main Caucasus thrust” paradigm is no longer appropriate, as it is a system of faults, the North Georgia fault system, that dominates the architecture of the western Greater Caucasus Mountains.

scholarly journals Brief communication: Supraglacial debris-cover changes in the Caucasus Mountains

2019 ◽  
Author(s):  
Levan G. Tielidze ◽  
Tobias Bolch ◽  
Roger D. Wheate ◽  
Stanislav S. Kutuzov ◽  
Ivan I. Lavrentiev ◽  
...  
Keyword(s):  
Morphological Type ◽  
Ice Age ◽  
Slope Aspect ◽  
Glacier Mass Balance ◽  
The Caucasus ◽  
Greater Caucasus ◽  
Time Period ◽  
Covered Area ◽  
Debris Cover ◽  
Caucasus Mountains

Abstract. Debris cover on glaciers can significantly alter melt, and hence, glacier mass balance and runoff. Debris coverage typically increases with shrinking glaciers. Here, we present data on debris cover and its changes for 559 glaciers located in different regions of the Greater Caucasus mountains based on 1986, 2000 and 2014 Landsat and SPOT images. Over this time period, the total glacier area decreased from 691.5 km2 to 590.0 km2 (0.52 % yr−1). Thereby, the debris covered area increased from ~ 11 to ~ 24 % on the northern, and from ~ 4 to 10 % on the southern macro-slope between 1986 and 2014. Overall, we found 18 % debris cover for the year 2014. With the glacier shrinkage, debris-covered area and the number of debris-covered glaciers increased as a function of elevation, slope, aspect, glacier morphological type, Little Ice Age moraines, and lithology.

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