DOCSLIB.ORG

Rock Glaciers of the Beartooth and Northern Absaroka Ranges, Montana, USA Zachary M

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Rock Glaciers of the Beartooth and Northern Absaroka Ranges, Montana, USA Zachary M University of Montana ScholarWorks at University of Montana Geography Faculty Publications Geography 9-2019 Rock glaciers of the Beartooth and northern Absaroka ranges, Montana, USA Zachary M. Seligman University of Montana, Missoula Anna E. Klene University of Montana - Missoula Frederick E. Nelson Michigan State University Let us know how access to this document benefits ouy . Follow this and additional works at: https://scholarworks.umt.edu/geography_pubs Part of the Geography Commons Recommended Citation Seligman, ZM, Klene, AE, Nelson, FE. Rock glaciers of the Beartooth and northern Absaroka ranges, Montana, USA. Permafrost and Periglac Process. 2019; 1– 11. https://doi.org/10.1002/ppp.2019 This Article is brought to you for free and open access by the Geography at ScholarWorks at University of Montana. It has been accepted for inclusion in Geography Faculty Publications by an authorized administrator of ScholarWorks at University of Montana. For more information, please contact [email protected]. Permafrost and Periglacial Processes Rock glaciers of the Beartooth and northern Absaroka ranges, Montana, USA Journal: Permafrost and Periglacial Processes Manuscript ID PPP-19-0010.R1 Wiley - Manuscript type:ForSpecial Peer Issue Paper Review Date Submitted by the 14-Jun-2019 Author: Complete List of Authors: Nelson, Frederick; Michigan State University, Department of Geography, Environment, and Spatial Sciences; Northern Michigan University, Department of Earth, Environmental, and Geographical Sciences Klene, Anna; University of Montana, Department of Geography Seligman, Zachary; University of Montana, Geography mapping, Montana, periglacial, rock glacier, Rocky Mountains, climate Keywords: change http://mc.manuscriptcentral.com/ppp Page 1 of 42 Permafrost and Periglacial Processes 1 2 3 1 4 5 6 2 7 8 3 9 4 10 11 5 12 13 6 Rock glaciers of the Beartooth and northern Absaroka ranges, Montana, USA 14 15 7 16 8 17 18 9 19 10 For Peer Review 20 11 21 12 22 23 13 24 14 1 1 2,3 25 15 Zachary M. Seligman, Anna E. Klene, and Frederick E. Nelson 26 16 27 17 1Department of Geography, University of Montana, Missoula MT 59812, USA 28 29 18 30 19 2Department of Geography, Environment, and Spatial Sciences, Michigan State University, East 31 20 Lansing MI 48824, USA 32 21 33 3 34 22 Department of Earth, Environmental, and Geographical Sciences, Northern Michigan 35 23 University, Marquette MI 49855, USA 36 24 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 http://mc.manuscriptcentral.com/ppp Permafrost and Periglacial Processes Page 2 of 42 1 2 3 25 4 5 26 6 27 Abstract 7 8 28 Six-hundred and sixty rock glaciers in the northern Absaroka and Beartooth Ranges of south- 9 10 29 central Montana were digitized and evaluated using geographic information systems 11 12 13 30 technology and an array of topographic and environmental parameters. Beartooth rock glaciers 14 15 31 are larger, occur at higher elevations, receive more precipitation, and are subject to colder 16 17 18 32 temperatures than northern Absaroka rock glaciers. Elevation is strongly correlated with rock 19 For Peer Review 20 33 glacier activity. Comparative analysis of these adjacent mountain ranges indicates that 21 22 23 34 Beartooth geomorphic landscapes are shifting from predominantly glacial to periglacial 24 25 35 regimes, and that the northern Absarokas have largely completed this transition. Because 26 27 36 glaciers are declining in response to climatic warming, rock glaciers could soon become the 28 29 30 37 most important source of ice in the region. 31 32 38 33 34 35 39 KEYWORDS 36 37 40 climate change, ground ice, mapping, Montana, periglacial, rock glacier, northern Absaroka 38 39 41 Range, Beartooth Range, Rocky Mountains, water resources 40 41 42 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 2 60 http://mc.manuscriptcentral.com/ppp Page 3 of 42 Permafrost and Periglacial Processes 1 2 3 43 4 5 44 1. INTRODUCTION 6 7 45 As global warming proceeds, water resources derived from glaciers and mountain snowpacks 8 9 46 are increasingly threatened. Although rock glaciers have been studied for more than a century,1 10 11 12 47 looming water deficits in many arid and semi-arid mountainous regions have intensified 13 14 48 interest in these features. Because most rock glaciers are well insulated by a veneer of earth 15 16 17 49 materials, the substantial ice volumes contained in them are being considered as alternative, 18 19 50 longer-term sources of water.For2 Accompanying Peer Reviewthis increased interest is a burgeoning scientific 20 21 22 51 literature concerned with rock glaciers, including a large number of regional inventories (e.g. 23 24 52 3,4,5,6,7,8,9. Further evidence of the increasing scientific and societal importance of rock glaciers is 25 26 53 27 the International Permafrost Association’s recently established “Action Group on Rock Glacier 28 29 54 Inventories and Kinematics”.10 30 31 55 Basic mapping of periglacial landforms in the Middle and Northern Rocky Mountain 32 33 34 56 physiographic provinces (pp. 365-404)11 has not been carried out extensively, despite the 35 36 57 widespread occurrence of periglacial features and recent technological advances that make 37 38 39 58 such undertakings feasible. Although several localized rock-glacier studies have been conducted 40 41 59 in parts of the U.S. states of Montana12,13 and Wyoming,14,15,16 there have been very few 42 43 17 44 60 exhaustive inventories over extensive areas of this region. Johnson et al. produced an 45 46 61 inventory in the Lemhi Range in the adjacent state of Idaho, Legg18 worked in Glacier National 47 48 62 19 49 Park in Montana, and Florentine documented a series of rock glaciers in southwest Montana 50 51 63 that partially overlaps Seligman’s20 earlier study, albeit using highly divergent methods of data 52 53 64 collection (cf. Section 3.1 below and Florentine (pp. 11-12)19. 54 55 56 57 58 59 3 60 http://mc.manuscriptcentral.com/ppp Permafrost and Periglacial Processes Page 4 of 42 1 2 3 65 This paper represents the first such survey conducted in the northern Absaroka and 4 5 6 66 Beartooth Ranges of Montana. Here, we summarize the differences between rock glaciers in 7 8 67 the two ranges with respect to several topographic and environmental parameters based upon 9 10 20 11 68 a survey by Seligman, report similarities and differences in these parameters between the two 12 13 69 ranges, and explore how the results can be interpreted in the context of Quaternary and 14 15 16 70 contemporary climatic changes. 17 18 71 19 For Peer Review 20 21 72 2. STUDY AREA 22 23 73 The Absaroka and Beartooth ranges span the border between the U.S. states of 24 25 74 Montana and Wyoming (Figure 1), near Yellowstone National Park. These adjacent mountain 26 27 75 ranges are among the highest in the region, and prominently display the effects of both glacial 28 29 30 76 and periglacial processes. The Beartooth and northern Absaroka ranges are, respectively, the 31 32 77 first and fourth highest mountain ranges in Montana. 33 34 35 78 36 37 79 [Figure 1 near here] 38 39 40 80 41 42 81 The Absaroka Mountains form part of the Absaroka-Gallatin volcanic field, the largest 43 44 45 82 such field in the Middle and Northern Rocky Mountains. Volcanism in this region occurred along 46 47 83 two subparallel, northwest trending belts defined by hypabyssal plutons that extend for roughly 48 49 84 150 km.21 Topography developed in the Absarokas consists of the remnants of a highly 50 51 52 85 dissected plateau displaying the rugged, sculpted results of extensive glaciation, including 53 54 86 cirques, horn peaks, arêtes, U-shaped valleys, and prominent moraines. In this study we focus 55 56 57 58 59 4 60 http://mc.manuscriptcentral.com/ppp Page 5 of 42 Permafrost and Periglacial Processes 1 2 3 87 on the “Northern Absaroka Range” (hereafter “northern Absarokas”), which lies almost entirely 4 5 22 6 88 within the state of Montana. Of the many peaks rising above 3000 m.a.s.l. in the northern 7 8 89 Absarokas, Tumble Mountain (3449 m) is the tallest; at least 10 peaks in the range exceed 9 10 11 90 3300 m. Rock glaciers are the most prominent periglacial landforms in the northern Absarokas. 12 13 91 One feature at Galena Creek, south of the present study area, has played a prominent role in 14 15 14-16, 23 16 92 the history of rock-glacier research. 17 18 93 The Beartooth Mountains are dominated by metamorphosed Precambrian granite 19 For Peer Review 20 94 uplifted roughly 50 million years ago.24 Granite Peak, at 3904 m.a.s.l., forms the highest 21 22 23 95 topographic point in Montana, and several other peaks exceed 3800 m. Glaciated terrain on the 24 25 96 northeast side of the Beartooths consists of deeply eroded glacial valleys (Figure 2A). Moraines 26 27 28 97 occur in all valleys above 2750 m.a.s.l. In some major valleys they extend to below 1500 m and 29 30 98 are considered to be of early to late Pinedale (Late Pleistocene) age. Younger moraines of Late 31 32 33 99 Holocene age occur at the foot of existing glaciers and in cirques that were deglaciated recently 34 35 100 (pp.
Load more

Recommended publications
  • Custer Gallatin National Forest Beartooth Ranger District Information Packet
    CUSTER GALLATIN NATIONAL FOREST BEARTOOTH RANGER DISTRICT INFORMATION PACKET www.fs.usda.gov/custergallatin Did You Know? • The highest 41 peaks in Montana are in the Beartooth Mountains. 22 of these are over 12,000ft. • Granite Peak is Montana’s highest peak, at 12,799ft. It is known for its remoteness and extreme weather. • The Absaroka- Beartooth Wilderness is the 6th largest wilderness area in the lower 48 states. • There are over 300 lakes and 10 major sub-alpine tundra plateaus in the Beartooths, with even more lakes across the Absaroka-Beartooth Wilderness. • At 3.96 billion years old, rock samples from the Beartooths are some of the oldest rocks on Earth. • The Beartooth Highway reaches an altitude of 10, 947 ft. and is often considered one of the most beautiful roads in America. 406-446-2103 ∙ 6811 Hwy 212, Red Lodge, MT 59068 You are camping in bear country. Wilderness Restrictions and Regulations The Beartooth Ranger District has an area of 587,000 acres. Of this, 345,000 acres are within the Absaroka-Beartooth Wilderness. The boundary of the Absaroka-Beartooth Wilderness continues west into the Gallatin National Forest (in all, the Absaroka-Beartooth Wilderness is 943,626 acres). General Use 15 people is the maximum group size 16 days at a camp site is the maximum camp stay limit No camping/campfires within 200 feet of a lake No camping/campfires within 100 feet of flowing water No use/possession of motorized vehicles, motorboats, chainsaws and other mechanized equipment Bicycles, wagons, carts, hang gliders or other mechanized equipment cannot be possessed or used Dispose of human waste properly.
    [Show full text]
  • Geologic Map of the Red Lodge Area, Carbon
    GEOLOGIC MAP OF THE RED LODGE AREA, CARBON COUNTY, MONTANA by David A. Lopez Montana Bureau of Mines and Geology Open-File Report MBMG 524 2005 This map has been reviewed for conformity with technical and editorial standards of the Montana Bureau of Mines and Geology. Partial support has been provided by the STATEMAP component of the National Cooperative Geologic Mapping Program of the U.S. Geological Survey under Contract Number 04HQAG0079. Kalispell MONTANA 15 Great Falls 90 Missoula Helena 94 Butte Billings Bozeman 90 90 15 110° 109° Big Timber YELLOWSTONE CO 94 Y Billings r 90 e r e l SWEET GRASS CO v l owsto e i n v R e Riv i r e 90 R e r ld u ne o to B ws STILLWATER CO lo Columbus el Y 45°30' e 78 n o r t ive 212 s R w r o te l a l w e ll Y ti S e h CARBON CO t BIG HORN CO f o Luther k STUDY r o Red Lodge 72 F AREA s rk la C 310 N PARK CO 212 45° 10 0 10 20 Miles Figure 1. Location map of the study area. 1 2 DESCRIPTION OF MAP UNITS SURFICIAL DEPOSITS af Artificial fill—Mine tailings and fill in the Rock Creek valley in northern part of the town of Red Lodge. Qal Alluvium (Holocene)—Gravel, sand, silt, and clay along active stream channels. Qc Colluvium (Holocene and Pleistocene)—Locally derived slope-wash depositsmainly of sand, silt, and clay. Typically thin veneer concealing bedrock, but locally as thick as 30 ft (9 m).
    [Show full text]
  • High-Mountain Permafrost in the Austrian Alps (Europe)
    HIGH-MOUNTAIN PERMAFROST IN THE AUSTRIAN ALPS (EUROPE) Gerhard Karl Lieb Institute of Geography University of Graz Heinrichstrasse 36 A-8010 Graz e-mail: [email protected] Abstract Permafrost research in the Austrian Alps (Eastern Alps) is based on a variety of methods, including at large scales, the measurement of the temperature of springs and of the base of winter snow cover, and at small scales, mainly an inventory of some 1450 rock glaciers. Taking all the information available into consideration, the lower limit of discontinuous permafrost is situated near 2500 m in most of the Austrian Alps. These results can be used for modelling the permafrost distribution within a geographical information system. Detailed investi- gations were carried out in the Doesen Valley (Hohe Tauern range) using additional methods, including several geophysical soundings. In this way, realistic estimates of certain permafrost characteristics and the volume of a large active rock glacier (some 15x106m3) were possible. This rock glacier has been chosen as a monitoring site to observe the effects of past and future climatic change. Introduction snow cover (BTS) and geophysical soundings, such as seismic, geoelectric, electromagnetic and ground pene- Although mountain permafrost in the Austrian Alps trating radar surveys have been published (survey and has caused construction problems and damage to buil- references in Lieb, 1996). The best results for mapping dings at several high-altitude locations, specific investi- the mere existence of permafrost were obtained by mea- gations of permafrost did not start until 1980. Since suring spring temperatures and BTS, both procedures then, studies of the distribution and certain characteris- being easily applicable and providing quite accurate tics of permafrost have been carried out at a number of interpretation.
    [Show full text]
  • Late Wisconsin Climate Inferences from Rock Glaciers in South-Central
    LateWisconsin climatic inlerences from rock glaciers in south-centraland west-central New Mexico andeast-central Arizona byJohn W. Blagbrough, P0 Box8063, Albuquerque, NewMexico 87198 Abstract Inactive rock glaciersof late Wisconsin age occur at seven sites in south-central and west-central New Mexico and in east-centralArizona. They are at the base of steep talus in the heads of canyons and ravines and have surfacefeatures indicating they are ice-cemented (permafrost) forms that moved by the flow of interstitial ice. The rock glaciersindicate zones of alpine permafrost with lower levels that rise from approximately 2,400m in the east region to 2,950 m in the west. Within the zones the mean annual temperaturewas below freezing, and the climatewas marked by much diurnal freezing and thawing resulting in the production of large volumes of talus in favorableterrain. The snow cover was thin and of short duration, which fa- vored ground freezing and cryofraction. The rock glaciers in the east region occur near the late Wisconsin 0'C air isotherm and implv that the mean annual temperature was depressedapproximately 7 to 8'C during a periglacial episodein the late Wisconsin.A dry continental climate with a seasonaldistribution of precipitation similar to that of the present probably prevailed, and timberline former timberlines. may have been depresseda minimum of 1,240m. The rise in elevation of the rock glaciersfrom east to west acrossthe region is attributed to greater snowfall in west-centralNew Mexico and east-centralArizona, which reducedthe inten- sity and depth of ground freezing near the late Wisconsin 0"C air isotherm.
    [Show full text]
  • Mesoproterozoic Frost Action at the Base of the Svinsaga Formation 291
    NORWEGIAN JOURNAL OF GEOLOGY Mesoproterozoic frost action at the base of the Svinsaga Formation 291 Mesoproterozoic frost action at the base of the Svinsaga Formation, central Telemark, South Norway Juha Köykkä & Kauko Laajoki Köykkä, J. & Laajoki, K. 2009: Mesoproterozoic frost action ath the base of the Svinsaga Formation, central telemark, South Norway. Norwegain Journal of Geology, vol 89, pp 291-303. Trondheim 2009, ISSN 029-196X. The Mesoproterozoic Svinsaga Formation (SF) in central Telemark, South Norway, was unconformably deposited after ca. 1.347 Ga on the quartz arenite of the upper member of the Brattefjell Formation (UB), which is part of the Vindeggen Group. The unconformity is marked by a fracture zone a few meters thick developed in the UB quartz arenite. The lower part of the fracture zone, which contains sparse and closed fractures, and microfractures, grades upwards into a system of wider and mostly random oriented fractures and fracture patterns. The fractures are filled with mudstone. The fracture zone is overlain by several meters of in situ SF breccia, in which the fragments consist solely of the UB quartz arenite. The in situ breccia gradually grades into a basal breccia and clast- or matrix-supported conglomerates. The SF conglomerate beds contain solitary quartz arenite fragments and blocks up to 9.0 m3 that were derived from the UB. The fractures, fracture patterns, and microfractures in the UB quartz arenite and shattered quartz arenite fragments in the in situ SF breccia are ascribed to in situ fracturing, brecciation, and the accumulation of slightly moved blocks in a cold climate.
    [Show full text]
  • Sess Report 2018
    SESS REPORT 2018 The State of Environmental Science in Svalbard – an annual report Xxx 1 SESS report 2018 The State of Environmental Science in Svalbard – an annual report ISSN 2535-6321 ISBN 978-82-691528-0-7 Publisher: Svalbard Integrated Arctic Earth Observing System (SIOS) Editors: Elizabeth Orr, Georg Hansen, Hanna Lappalainen, Christiane Hübner, Heikki Lihavainen Editor popular science summaries: Janet Holmén Layout: Melkeveien designkontor, Oslo Citation: Orr et al (eds) 2019: SESS report 2018, Longyearbyen, Svalbard Integrated Arctic Earth Observing System The report is published as electronic document, available from SIOS web site www.sios-svalbard.org/SESSreport Contents Foreword .................................................................................................................................................4 Authors from following institutions contributed to this report ...................................................6 Summaries for stakeholders ................................................................................................................8 Permafrost thermal snapshot and active-layer thickness in Svalbard 2016–2017 .................................................................................................................... 26 Microbial activity monitoring by the Integrated Arctic Earth Observing System (MamSIOS) .................................................................................. 48 Snow research in Svalbard: current status and knowledge gaps ............................................
    [Show full text]
  • Quaternary Deposits and Landscape Evolution of the Central Blue Ridge of Virginia
    Geomorphology 56 (2003) 139–154 www.elsevier.com/locate/geomorph Quaternary deposits and landscape evolution of the central Blue Ridge of Virginia L. Scott Eatona,*, Benjamin A. Morganb, R. Craig Kochelc, Alan D. Howardd a Department of Geology and Environmental Science, James Madison University, Harrisonburg, VA 22807, USA b U.S. Geological Survey, Reston, VA 20192, USA c Department of Geology, Bucknell University, Lewisburg, PA 17837, USA d Department of Environmental Sciences, University of Virginia, Charlottesville, VA 22904, USA Received 30 August 2002; received in revised form 15 December 2002; accepted 15 January 2003 Abstract A catastrophic storm that struck the central Virginia Blue Ridge Mountains in June 1995 delivered over 775 mm (30.5 in) of rain in 16 h. The deluge triggered more than 1000 slope failures; and stream channels and debris fans were deeply incised, exposing the stratigraphy of earlier mass movement and fluvial deposits. The synthesis of data obtained from detailed pollen studies and 39 radiometrically dated surficial deposits in the Rapidan basin gives new insights into Quaternary climatic change and landscape evolution of the central Blue Ridge Mountains. The oldest depositional landforms in the study area are fluvial terraces. Their deposits have weathering characteristics similar to both early Pleistocene and late Tertiary terrace surfaces located near the Fall Zone of Virginia. Terraces of similar ages are also present in nearby basins and suggest regional incision of streams in the area since early Pleistocene–late Tertiary time. The oldest debris-flow deposits in the study area are much older than Wisconsinan glaciation as indicated by 2.5YR colors, thick argillic horizons, and fully disintegrated granitic cobbles.
    [Show full text]
  • Glacier Mass Balance Bulletin No. 11 (2008–2009)
    GLACIER MASS BALANCE BULLETIN Bulletin No. 11 (2008–2009) A contribution to the Global Terrestrial Network for Glaciers (GTN-G) as part of the Global Terrestrial/Climate Observing System (GTOS/GCOS), the Division of Early Warning and Assessment and the Global Environment Outlook as part of the United Nations Environment Programme (DEWA and GEO, UNEP) and the International Hydrological Programme (IHP, UNESCO) Compiled by the World Glacier Monitoring Service (WGMS) ICSU (WDS) – IUGG (IACS) – UNEP – UNESCO – WMO 2011 GLACIER MASS BALANCE BULLETIN Bulletin No. 11 (2008–2009) A contribution to the Global Terrestrial Network for Glaciers (GTN-G) as part of the Global Terrestrial/Climate Observing System (GTOS/GCOS), the Division of Early Warning and Assessment and the Global Environment Outlook as part of the United Nations Environment Programme (DEWA and GEO, UNEP) and the International Hydrological Programme (IHP, UNESCO) Compiled by the World Glacier Monitoring Service (WGMS) Edited by Michael Zemp, Samuel U. Nussbaumer, Isabelle Gärtner-Roer, Martin Hoelzle, Frank Paul, Wilfried Haeberli World Glacier Monitoring Service Department of Geography University of Zurich Switzerland ICSU (WDS) – IUGG (IACS) – UNEP – UNESCO – WMO 2011 Imprint World Glacier Monitoring Service c/o Department of Geography University of Zurich Winterthurerstrasse 190 CH-8057 Zurich Switzerland http://www.wgms.ch [email protected] Editorial Board Michael Zemp Department of Geography, University of Zurich Samuel U. Nussbaumer Department of Geography, University of Zurich
    [Show full text]
  • Colluvial Deposit
    Encyclopedia of Planetary Landforms DOI 10.1007/978-1-4614-9213-9_55-1 # Springer Science+Business Media New York 2014 Colluvial Deposit Susan W. S. Millar* Department of Geography, Syracuse University, Syracuse, NY, USA Synonyms Colluvial depositional system; Colluvial mantle; Colluvial soil; Colluvium; Debris slope; Hillslope (or hillside) deposits; Scree (UK); Slope mantle; Slope-waste deposits; Talus (US) Definition A sedimentary deposit composed of surface mantle that has accumulated toward the base of a slope as a result of transport by gravity and non-channelized flow. Description The International Geomorphological Association recognizes colluvium as a hillslope deposit resulting from two general nonexclusive processes (Goudie 2004). Rainwash, sheetwash, or creep can generate sediment accumulations at the base of gentle slopes; or non-channelized flow can initiate sheet erosion and toe-slope sediment accumulation. The term “colluvium” is frequently applied broadly to include mass wasting deposits in a variety of topographic and climatic settings. For example, Blikra and Nemec (1998) describe colluvium as any “clastic slope-waste material, typically coarse grained and immature, deposited in the lower part and foot zone of a mountain slope or other topographic escarpment, and brought there chiefly by sediment-gravity processes.” Lang and Honscheidt (1999) describe colluvium as “slope wash and tillage sediments, resulting from soil erosion....” The composition of a colluvial deposit can therefore be coarse-grained, eroded bedrock, with an open-work structure and several meters thick (Blikra and Nemec 1998), to fine-grained soil, ranging from a few millimeters to meters in thickness (e.g., Lang and Hönscheidt 1999). Some deposits may exhibit distinct macro- and micro-fabric development, bedding structures, and evi- dence of distinct periods of accumulation (e.g., Bertran et al.
    [Show full text]
  • Inventory and Distribution of Rock Glaciers in Northeastern Yakutia
    land Article Inventory and Distribution of Rock Glaciers in Northeastern Yakutia Vasylii Lytkin Melnikov Permafrost Institute, Siberian Branch of the Russian Academy of Sciences, Yakutsk 677010, Russia; [email protected] Received: 2 September 2020; Accepted: 8 October 2020; Published: 10 October 2020 Abstract: Rock glaciers are common forms of relief of the periglacial belt of many mountain structures in the world. They are potential sources of water in arid and semi-arid regions, and therefore their analysis is important in assessing water reserves. Mountain structures in the north-east of Yakutia have optimal conditions for the formation of rock glaciers, but they have not yet been studied in this regard. In this article, for the first time, we present a detailed list of rock glaciers in this region. Based on geoinformation mapping using remote sensing data and field studies within the Chersky, Verkhoyansk, Momsky and Suntar-Khayata ranges, 4503 rock glaciers with a total area of 224.6 km2 were discovered. They are located within absolute altitudes, from 503 to 2496 m. Their average minimum altitude was at 1456 m above sea level, and the maximum at 1527 m. Most of these formations are located on the sides of the trough valleys, and form extended sloping types of rock glaciers. An assessment of the exposure of the slopes where the rock glaciers are located showed that most of the rock glaciers are facing north and south. Keywords: rock glacier; permafrost; inventory; northeastern Yakutia; remote sensing 1. Introduction The geography of distribution of rock glaciers is quite extensive. They are found in many mountainous regions of Europe, North and South America and Asia, including some circumpolar regions [1–18].
    [Show full text]
  • The Archean Geology of Montana
    THE ARCHEAN GEOLOGY OF MONTANA David W. Mogk,1 Paul A. Mueller,2 and Darrell J. Henry3 1Department of Earth Sciences, Montana State University, Bozeman, Montana 2Department of Geological Sciences, University of Florida, Gainesville, Florida 3Department of Geology and Geophysics, Louisiana State University, Baton Rouge, Louisiana ABSTRACT in a subduction tectonic setting. Jackson (2005) char- acterized cratons as areas of thick, stable continental The Archean rocks in the northern Wyoming crust that have experienced little deformation over Province of Montana provide fundamental evidence long (Ga) periods of time. In the Wyoming Province, related to the evolution of the early Earth. This exten- the process of cratonization included the establishment sive record provides insight into some of the major, of a thick tectosphere (subcontinental mantle litho- unanswered questions of Earth history and Earth-sys- sphere). The thick, stable crust–lithosphere system tem processes: Crustal genesis—when and how did permitted deposition of mature, passive-margin-type the continental crust separate from the mantle? Crustal sediments immediately prior to and during a period of evolution—to what extent are Earth materials cycled tectonic quiescence from 3.1 to 2.9 Ga. These compo- from mantle to crust and back again? Continental sitionally mature sediments, together with subordinate growth—how do continents grow, vertically through mafi c rocks that could have been basaltic fl ows, char- magmatic accretion of plutons and volcanic rocks, acterize this period. A second major magmatic event laterally through tectonic accretion of crustal blocks generated the Beartooth–Bighorn magmatic zone assembled at continental margins, or both? Structural at ~2.9–2.8 Ga.
    [Show full text]
  • Fluctuations of Tidewater Glaciers in Hornsund Fjord (Southern Svalbard) Since the Beginning of the 20Th Century
    Title: Fluctuations of tidewater glaciers in Hornsund Fjord (Southern Svalbard) since the beginning of the 20th century Author: Małgorzata Błaszczyk, Jacek A. Jania, Leszek Kolondra Citation style: Błaszczyk Małgorzata, Jania Jacek A., Kolondra Leszek. (2013). Fluctuations of tidewater glaciers in Hornsund Fjord (Southern Svalbard) since the beginning of the 20th century. “Polish Polar Research” (vol. 34, no. 4 (2013), s. 327-352), doi 10.2478/popore-2013-0024 vol. 34, no. 4, pp. 327–352, 2013 doi: 10.2478/popore−2013−0024 Fluctuations of tidewater glaciers in Hornsund Fjord (Southern Svalbard) since the beginning of the 20th century Małgorzata BŁASZCZYK, Jacek A. JANIA and Leszek KOLONDRA Wydział Nauk o Ziemi, Uniwersytet Śląski, ul. Będzińska 60, 41−200 Sosnowiec, Poland <[email protected]> <[email protected]> <[email protected]> Abstract: Significant retreat of glaciers terminating in Hornsund Fjord (Southern Spits− bergen, Svalbard) has been observed during the 20th century and in the first decade of the 21st century. The objective of this paper is to present, as complete as possible, a record of front positions changes of 14 tidewater glaciers during this period and to distinguish the main factors influencing their fluctuations. Results are based on a GIS analysis of archival maps, field measurements, and aerial and satellite images. Accuracy was based on an as− sessment of seasonal fluctuations of a glacier’s ice cliff position with respect to its mini− mum length in winter (November–December) and its maximum advance position in June or July. Morphometric features and the environmental setting of each glacier are also pre− sented.
    [Show full text]