View source for Drumlin

{{Short description|Elongated hill formed by glacial action}}
[[File:Drumlins around Horicon Marsh in Wisconsin.jpg|thumb|Drumlins around [[Horicon Marsh]], Wisconsin, in an area with one of the highest concentration of drumlins in the world. The curved path of the [[Laurentide Ice Sheet]] is evident in the orientation of the various mounds.|380px]]
[[File:Puerto Williams, Chili.JPG|thumb|Elongate and [[Magellanic subpolar forests|forested]] drumlins south of [[Puerto Williams]], Chile. Flow direction here was at time of formation from west to east (left to right on picture).]]

A '''drumlin''', from the [[Irish Gaelic|Irish]] word {{Lang|ga|droimnín}} ("little ridge"), first recorded in 1833, in the classical sense is an elongated [[hill]] in the shape of an inverted spoon or half-buried egg<ref>Menzies(1979) quoted in Benn, D.I. & Evans, D.J.A. 2003 ''Glaciers & Glaciation'', Arnold, London (p431) {{ISBN|0-340-58431-9}}</ref><ref>{{cite journal |last1=Bryce |first1=James |title=On the evidences of diluvial action in the north of Ireland |journal=Journal of the Geological Society of Dublin |date=1838 |volume=1 |pages=34–44 |hdl=2027/mdp.39015035541435?urlappend=%3Bseq=108%3Bownerid=13510798883929266-84 }} Originally presented in 1833 by Irish geologist [[James Bryce (geologist)|James Bryce]] (1806–1877). From p. 37: "This peculiar form is so striking that the peasantry have appropriated an expressive name to such ridges; while ''Knock'', ''Sleive'', ''Ben'', have each their peculiar significations, the names ''Drum'' and ''Drumlin'' (Dorsum) have been applied to such hills as we have been describing."</ref> formed by [[glacier|glacial]] ice acting on underlying unconsolidated [[till]] or ground [[moraine]]. Assemblages of drumlins are referred to as fields or swarms;<ref>{{cite book |last1=Benn |first1=Douglas I. |last2=Evans |first2=David J.A. |title=Glaciers and Glaciation |date=2003 |publisher=Arnold |location=London |isbn=0340584319 |page=434 |edition=First}}</ref><ref>{{cite web |title=Glacial Landforms |url=https://www.bbc.co.uk/bitesize/guides/zg36wxs/revision/5 |website=Bitesize |publisher=BBC |access-date=28 March 2021 |archive-date=21 June 2020 |archive-url=https://web.archive.org/web/20200621221730/https://www.bbc.co.uk/bitesize/guides/zg36wxs/revision/5 |url-status=dead }}</ref> they can create a landscape which is often described as having a 'basket of eggs topography'.<ref>{{cite web |url=http://geoschol.com/counties/CAVAN_GEOLOGY.pdf |title=Cavan |website=Geoschol – Geology for schools in Ireland |archive-url=https://web.archive.org/web/20211122044434/http://geoschol.com/counties/CAVAN_GEOLOGY.pdf |archive-date=2021-11-22 |url-status=live}}</ref>

==Morphology==

Drumlins occur in various shapes and sizes,<ref>{{cite journal|title=The planar shape of drumlins|doi=10.1016/j.sedgeo.2010.01.008|volume=232|issue=3–4|pages=119–129|journal=Sedimentary Geology|bibcode=2010SedG..232..119S|year=2010|last1=Spagnolo|first1=Matteo|last2=Clark|first2=Chris D.|last3=Hughes|first3=Anna L.C.|last4=Dunlop|first4=Paul|last5=Stokes|first5=Chris R.}}</ref> including symmetrical (about the long axis), spindle, parabolic forms, and transverse asymmetrical forms. Generally, they are elongated, oval-shaped hills, with a long axis parallel to the orientation of ice flow and with an up-ice (stoss) face that is generally steeper than the down-ice (lee) face.<ref>{{Cite journal|last=Menzies|date=1979|title=A review of the literature on the formation and location of drumlins|journal=Earth-Science Reviews|volume=14|issue=4|pages=315–359|doi=10.1016/0012-8252(79)90093-X|bibcode=1979ESRv...14..315M}}</ref>

Drumlins are typically between {{convert|250 and 1,000|m|ft|abbr=on}} long and between {{convert|120 and 300|m|ft|abbr=on}} wide.<ref name="Clark Hughes Greenwood et al 2009">{{cite journal |last1=Clark |first1=Chris D. |last2=Hughes |first2=Anna L.C. |last3=Greenwood |first3=Sarah L. |last4=Spagnolo |first4=Matteo |last5=Ng |first5=Felix S.L. |title=Size and shape characteristics of drumlins, derived from a large sample, and associated scaling laws |journal=Quaternary Science Reviews |date=April 2009 |volume=28 |issue=7–8 |pages=677–692 |doi=10.1016/j.quascirev.2008.08.035 |bibcode=2009QSRv...28..677C |url=http://nora.nerc.ac.uk/id/eprint/6960/1/Drumlins.pdf }}</ref> Drumlins generally have a length to width ratio of between 1.7 and 4.1<ref name="Clark Hughes Greenwood et al 2009"/> and it has been suggested that this ratio can indicate the velocity of the glacier. That is, since ice flows in laminar flow, the resistance to flow is frictional and depends on area of contact; thus, a more elongated drumlin would indicate a lower velocity and a shorter one would indicate a higher velocity.<ref>{{Cite journal|last=Nye|first=J|date=1952|title=The Mechanics of Glacier Flow|journal=Journal of Glaciology|volume=2|issue=12|page=82|doi=10.1017/S0022143000033967|bibcode=1952JGlac...2...82N|doi-access=free}}</ref>

==Occurrence==
Drumlins and drumlin swarms are glacial landforms composed primarily of glacial [[till]]. They form near the margin of glacial systems, and within zones of fast flow deep within [[ice sheet]]s, and are commonly found with other major glacially-formed features (including [[tunnel valley]]s, [[esker]]s, scours, and exposed bedrock [[erosion]]).<ref name=shaw1984>{{Cite journal | last1 = Shaw | first1 = J. | last2 = Kvill | first2 = D. | title = A glaciofluvial origin for drumlins of the Livingstone Lake area, Saskatchewan | journal = Canadian Journal of Earth Sciences | volume = 21 | issue = 12 | pages = 1442–1459 | year = 1984 | doi = 10.1139/e84-150|bibcode = 1984CaJES..21.1442S }}</ref>

Drumlins are often encountered in drumlin fields of similarly shaped, sized and oriented hills. Many [[Pleistocene]] drumlin fields are observed to occur in a fan-like distribution.<ref>{{cite journal | last1 = Patterson | first1 = C.J. | last2 = Hooke | first2 = R.L. | year = 1995 | title = Physical environment of drumlin formation | journal = Journal of Glaciology | volume = 41 | issue = 137| pages = 30–38 | bibcode = 1995JGlac..41...30P | doi = 10.1017/S0022143000017731 | doi-access = free }}</ref> The long axis of each drumlin is parallel to the direction of movement of the glacier at the time of formation.<ref>{{cite journal|last1=Spagnolo|first1=M.|last2=Clark|first2=C.D.|last3=Hughes|first3=A.L.C.|last4=Dunlop|first4=P.|last5=Stokes|first5=C.R.|year=2010|title=The planar shape of drumlins|journal=[[Sedimentary Geology (journal)|Sedimentary Geology]]|volume=232|issue=3–4|pages=119–129|bibcode=2010SedG..232..119S|doi=10.1016/j.sedgeo.2010.01.008}}</ref> Inspection of aerial photos of these fields reveals glacier's progress through the landscape. The Múlajökull drumlins of [[Hofsjökull]] are also arrayed in a splayed fan distribution around an arc of 180°.<ref name=B/> This field surrounds the current lobe of the glacier and provide a view into the past, showing the previous extent and motion of the ice.{{Citation needed|date=July 2021}}

== Composition ==

Drumlins may comprise layers of [[clay]], [[silt]], sand, [[gravel]] and [[boulder]]s in various proportions; perhaps indicating that material was repeatedly added to a core, which may be of [[rock (geology)|rock]] or [[glacial till]]. Alternatively, drumlins may be residual, with the landforms resulting from erosion of material between the landforms. The [[Dilatancy (granular material)|dilatancy]] of glacial till was invoked as a major factor in drumlin formation.<ref>{{cite journal |last1=Smalley |first1=Ian J. |last2=Unwin |first2=David J. |title=The Formation and Shape of Drumlins and their Distribution and Orientation in Drumlin Fields |journal=Journal of Glaciology |date=1968 |volume=7 |issue=51 |pages=377–390 |doi=10.3189/S0022143000020591 |s2cid=129285660 |doi-access=free }}</ref> In other cases, drumlin fields include drumlins made up entirely of hard bedrock (e.g. [[granite]] or well-[[Limestone|lithified limestone]]).<ref name="Lesemann Brennand 2009">{{cite journal |last1=Lesemann |first1=Jerome-Etienne |last2=Brennand |first2=Tracy A. |title=Regional reconstruction of subglacial hydrology and glaciodynamic behaviour along the southern margin of the Cordilleran Ice Sheet in British Columbia, Canada and northern Washington State, USA |journal=Quaternary Science Reviews |date=November 2009 |volume=28 |issue=23–24 |pages=2420–2444 |doi=10.1016/j.quascirev.2009.04.019 |bibcode=2009QSRv...28.2420L }}</ref> These drumlins cannot be explained by the addition of soft sediment to a core. Thus, accretion and erosion of soft sediment by processes of subglacial deformation do not present unifying theories for all drumlins—some are composed of residual bedrock.{{citation needed|date=July 2018}}

== Formation ==
There are two main theories of drumlin formation.<ref>{{cite journal|title=Automated drumlin shape and volume estimation using high resolution LiDAR imagery (Curvature Based Relief Separation): A test from the Wadena Drumlin Field, Minnesota|doi=10.1016/j.geomorph.2015.07.020|volume=246|pages=589–601|journal=Geomorphology|bibcode=2015Geomo.246..589Y|year=2015|last1=Yu|first1=Peter|last2=Eyles|first2=Nick|last3=Sookhan|first3=Shane}}</ref> The first, ''constructional'', suggests that they form as sediment is deposited from subglacial waterways laden with till including gravel, clay, silt, and sand. As the drumlin forms, the scrape and flow of the glacier continues around it and the material deposited accumulates, the [[Clastic rock|clasts]]<ref>{{cite web|title=Clast Shape, Till Fabrics and Striae|url=http://www.antarcticglaciers.org/glacial-geology/techniques/clast-shape-till-fabrics-and-striae/#SECTION_2|access-date=2020-11-25|archive-date=2020-11-19|archive-url=https://web.archive.org/web/20201119102546/http://www.antarcticglaciers.org/glacial-geology/techniques/clast-shape-till-fabrics-and-striae/#SECTION_2|url-status=live}}</ref> align themselves with direction of flow.<ref>{{cite journal |last1=Hermanowski |first1=Piotr |last2=Piotrowski |first2=Jan A. |last3=Duda |first3=Piotr |title=Till kinematics in the Stargard drumlin field, NW Poland constrained by microstructural proxies |journal=Journal of Quaternary Science |date=October 2020 |volume=35 |issue=7 |pages=920–934 |doi=10.1002/jqs.3233 |bibcode=2020JQS....35..920H |s2cid=225275064 }}</ref> It is because of this process that geologists are able to determine how the drumlin formed using till fabric analysis, the study of the orientation and dip of particles within a till matrix.<ref>{{cite book |last1=Andrews |first1=John T. |title=Techniques of Till Fabric Analysis |date=1971 |publisher=Geo Abstracts |isbn=978-0-902246-04-1 }}</ref> By examining the till particles and plotting their orientation and dip on a stereonet, scientists are able to see if there is a correlation between each clast and the overall orientation of the drumlin: the more similar in orientation and dip of the clasts throughout the drumlin, the more likely it is that they had been deposited during the formation process. If the opposite is true, and there doesn't seem to be a link between the drumlin and the till, it suggests that the other main theory of formation could be true.{{Citation needed|date=July 2021}}

The second theory proposes that drumlins form by erosion of material from an unconsolidated bed. Erosion under a glacier in the immediate vicinity of a drumlin can be on the order of a meter's depth of sediment per year, depending heavily on the [[shear stress]] acting on the ground below the glacier from the weight of the glacier itself, with the eroded sediment forming a drumlin as it is repositioned and deposited.<ref name="Clark Hughes Greenwood et al 2009"/>

A hypothesis that catastrophic sub-glacial floods form drumlins by deposition or erosion challenges conventional explanations for drumlins.<ref>{{cite journal |last1=Shaw |first1=John |title=The meltwater hypothesis for subglacial bedforms |journal=Quaternary International |date=April 2002 |volume=90 |issue=1 |pages=5–22 |doi=10.1016/S1040-6182(01)00089-1 |bibcode=2002QuInt..90....5S }}</ref> It includes deposition of [[Glaciofluvial deposits|glaciofluvial sediment]] in cavities scoured into a glacier bed by subglacial meltwater, and remnant ridges left behind by erosion of soft sediment or hard rock by turbulent meltwater. This hypothesis requires huge, subglacial meltwater floods, each of which would raise sea level by tens of centimeters in a few weeks. Studies of erosional forms in bedrock at French River, Ontario, Canada, provide evidence for such floods.{{Citation needed|date=July 2021}}
[[File:Clew Bay, Ireland (ASTER).jpg|right|thumb|[[Clew Bay]] in [[County Mayo]], [[Ireland]], is a vast field of drowned drumlins, which are now [[List of islands of County Mayo|islands]].]]

The recent retreat of a marginal outlet glacier of [[Hofsjökull]] in Iceland exposed a drumlin field with more than 50 drumlins ranging from {{convert|90|to(-)|320|m|ft|abbr=on}} in length, {{convert|30|to(-)|105|m|ft|-1|abbr=on}} in width, and {{convert|5|to(-)|10|m|ft|abbr=on}} in height.<ref>A satellite image of the region of Hofsjökull where drumlin growth has been observed (see {{coord|64|39|25|N|18|41|41|W}}). The drumlins can be observed between pools of water.</ref> These formed through a progression of subglacial depositional and erosional processes, with each horizontal till bed within the drumlin created by an individual surge of the glacier.<ref name=B>{{Cite journal | doi = 10.1130/G31371.1 | last1 = Johnson | first1 = M. D. | last2 = Schomacker | first2 = A. | last3 = Benediktsson | first3 = I. O. | last4 = Geiger | first4 = A. J. | last5 = Ferguson | first5 = A. | last6 = Ingolfsson | first6 = O. | title = Active drumlin field revealed at the margin of Mulajokull, Iceland: A surge-type glacier | journal = Geology | volume = 38 | issue = 10 | pages = 943–946 | year = 2010|bibcode = 2010Geo....38..943J }}</ref> The above theory for the formation of these Icelandic drumlins best explains one type of drumlin. However, it does not provide a unifying explanation of all drumlins. For example, drumlin fields including drumlins composed entirely of hard bedrock cannot be explained by deposition and erosion of unconsolidated beds.<ref name="Lesemann Brennand 2009"/> Furthermore, hairpin scours around many drumlins are best explained by the erosive action of horseshoe vortices around obstacles in a turbulent boundary layer.<ref>{{cite journal |last1=Paik |first1=Joongcheol |last2=Escauriaza |first2=Cristian |last3=Sotiropoulos |first3=Fotis |title=On the bimodal dynamics of the turbulent horseshoe vortex system in a wing-body junction |journal=Physics of Fluids |date=1 April 2007 |volume=19 |issue=4 |pages=045107–045107–20 |doi=10.1063/1.2716813 |bibcode=2007PhFl...19d5107P }}</ref><ref>{{cite journal |last1=Shaw |first1=John |title=Hairpin erosional marks, horseshoe vortices and subglacial erosion |journal=Sedimentary Geology |date=June 1994 |volume=91 |issue=1–4 |pages=269–283 |doi=10.1016/0037-0738(94)90134-1 |bibcode=1994SedG...91..269S }}</ref>

Semi-submerged or drowned drumlins can be observed where rising sea-levels flooded the low-lying areas in between drumlin ridges. The most notable example of this is [[Clew Bay]] in the west of [[Ireland]], which contains hundreds of drumlin islands and islets. It was once a field of drumlins that was "drowned" following the [[Last Glacial Period]].<ref>{{cite web | title = Clew Bay | work = Mayo - County Geological Site Report | publisher = [[Geological Survey of Ireland]] | url = https://gsi.geodata.gov.ie/downloads/Geoheritage/Reports/MO032_Clew_Bay.pdf | date = 20 November 2020 | access-date = 29 December 2023 }}</ref>

==Soil development on drumlins==
Recently formed drumlins often incorporate a thin "A" [[soil horizon]] (often referred to as "topsoil" which accumulated after formation) and a thin "Bw" horizon (commonly referred to as "[[subsoil]]"). The "C" horizon, which shows little evidence of being affected by soil forming processes (weathering), is close to the surface, and may be at the surface on an eroded drumlin. Below the C horizon the drumlin consists of multiple beds of till deposited by lodgment and bed deformation. On drumlins with longer exposure (e.g. in the Lake Ontario drumlin field in New York State) soil development is more advanced, for example with the formation of clay-enriched "Bt" horizons.<ref name=B/>

==Examples of drumlins==
[[Image:Drumlinfield large.jpg|thumb|Drumlin field in Western New York state. The drumlins align with glacial flow.]]

===Africa===
[[Namibian drumlins]], the result of [[Paleozoic]] Era glaciation.<ref>{{citation|via=[[Science Daily]]|title=Researcher unearths an ice age in the African desert|date=February 4, 2019|publisher=West Virginia University|url=https://www.sciencedaily.com/releases/2019/02/190204114633.htm}}</ref>

===Europe===

Besides the Icelandic drumlins mentioned above, the literature also documents extensive drumlin fields in England, Scotland and Wales,<ref name="Clark Hughes Greenwood et al 2009"/> Switzerland,<ref name=Fiore2007>{{cite thesis |last1=Fiore |first1=Julien Thomas |title=Quaternary subglacial processes in Switzerland : geomorphology of the Plateau and seismic stratigraphy of Western Lake Geneva |date=2007 |publisher=Université de Genève |doi=10.13097/archive-ouverte/unige:714 }}</ref> Poland, [[Estonia]] ([[Vooremaa]]), [[Latvia]], Sweden, around [[Lake Constance]] north of the [[Alps]], in the Republic of Ireland ([[County Leitrim]], [[County Monaghan]], [[County Mayo]] and [[County Cavan]]), in Northern Ireland ([[County Fermanagh]], [[County Armagh]], and in particular [[County Down]]), Germany, [[Hindsholm]] in Denmark, Finland and [[Greenland]].<ref>{{cite journal |last1=O'Dwyer |first1=Barry |last2=Crockford |first2=Lucy |last3=Jordan |first3=Phil |last4=Hislop |first4=Lindsay |last5=Taylor |first5=David |title=A palaeolimnological investigation into nutrient impact and recovery in an agricultural catchment |journal=Journal of Environmental Management |date=July 2013 |volume=124 |pages=147–155 |doi=10.1016/j.jenvman.2013.01.034 |pmid=23490624 |bibcode=2013JEnvM.124..147O }}</ref><ref name="Clark Hughes Greenwood et al 2009"/>

===North America===

The majority of drumlins observed in North America were formed during the [[Wisconsin glaciation]].

The largest drumlin fields in the world formed beneath the [[Laurentide Ice Sheet]] and are found in [[Canada]] — Nunavut, the Northwest Territories, northern Saskatchewan, northern Manitoba, northern Ontario and northern Quebec.<ref>{{cite journal |last1=Shaw |first1=John |last2=Sharpe |first2=Davis |last3=Harris |first3=Jeff |title=A flowline map of glaciated Canada based on remote sensing data |journal=Canadian Journal of Earth Sciences |date=January 2010 |volume=47 |issue=1 |pages=89–101 |doi=10.1139/E09-068 }}</ref> Drumlins occur in every Canadian province and territory. Clusters of thousands of drumlins are found in:<ref>{{cite book |last1=Gray |first1=Charlotte |title=The Museum Called Canada: 25 Rooms of Wonder |date=2004 |publisher=Random House |isbn=978-0-679-31220-8 }}{{pn|date=January 2023}}</ref>
* [[Southern Ontario]] (along eastern end of [[Oak Ridges Moraine]] near [[Peterborough, Ontario|Peterborough]], as well as areas to the west near [[Dundas, Ontario|Dundas]] and [[Guelph, Ontario|Guelph]]<ref>{{cite web |url=http://tcc.customer.sentex.ca/GT/OD.html |title=Ontario Drumlins |website=The Creation Concept |access-date=2015-12-14 |url-status=dead |archive-url=https://web.archive.org/web/20160304131745/http://tcc.customer.sentex.ca/GT/OD.html |archive-date=2016-03-04 }}</ref>)
* Central-[[Eastern Ontario]] ([[Douro-Dummer, Ontario|Douro-Dummer]])
*Ontario – most of [[Northumberland County, Ontario|Northumberland County]] (between [[Rice Lake (Ontario)|Rice Lake]] and [[Trenton, Ontario|Trenton]], including [[Trent Hills]])
* The Thelon Plan of the [[Northwest Territories]]
* [[Alberta]] – drumlins are located on the Morley Flats in the [[Stoney Indian Reserves Nos. 142, 143, and 144|Stony Indian Reserve]] west of Calgary, as well as south of the [[Ghost Reservoir]].<ref name=":1">{{Cite book|last=Smith|first=D.G|title=Landforms of Alberta interpreted from airphotos and satellite imagery|publisher=Alberta Remote Sensing Center, Alberta Environment|year=1987|isbn=0-919975-10-0|location=Edmonton, Alberta|pages=41–43}}</ref>
*Saskatchewan – {{convert|80|km|mi|abbr=on}} south of the east end of [[Lake Athabasca]]<ref name=":1" />
*Southwest of [[Amundsen Gulf]] in [[Nunavut]]
* [[West Lawrencetown, Nova Scotia]].

In the [[United States]], drumlins are common in:
* Central New York (between the south shore of [[Lake Ontario]] and [[Cayuga Lake]])<ref name=Kerr2007>{{cite journal |last1=Kerr |first1=Michael |last2=Eyles |first2=Nick |title=Origin of drumlins on the floor of Lake Ontario and in upper New York State |journal=Sedimentary Geology |date=January 2007 |volume=193 |issue=1–4 |pages=7–20 |doi=10.1016/j.sedgeo.2005.11.025 |bibcode=2007SedG..193....7K }}</ref><ref>{{cite journal |last1=White |first1=William A. |title=Drumlins carved by rapid water-rich surges |journal=Northeastern Geology |volume=7 |date=1985 |pages=161–166 |url=https://freepages.rootsweb.com/~springport/genealogy/geology/drumlin.html }}</ref> 
* The lower [[Connecticut River|Connecticut River valley]]
* [[Manhattan]]<ref name="SandersMerguerian">{{cite conference |last1=Sanders |first1=John E. |last2=Merguerian |first2=Charles |title=The glacial geology of New York City and vicinity |pages=93–200 |editor1-first=A. I. |editor1-last=Benimoff |conference=The Geology of Staten Island, New York, Field guide and proceedings, The Geological Association of New Jersey, XI Annual Meeting |url=https://www.dukelabs.com/Publications/PubsPdf/JESCM1994b_GANJ_GlacialNYC.pdf |archive-url=https://web.archive.org/web/20170203225252/http://dukelabs.com/Publications/PubsPdf/JESCM1994b_GANJ_GlacialNYC.pdf |archive-date=2017-02-03 |url-status=live }}</ref>
* Eastern [[Massachusetts]]
* Eastern [[Connecticut]] in Windham and New London Counties
* The [[Monadnock Region]] of [[New Hampshire]]
* [[Michigan]] (central and southern [[Lower Peninsula]])<ref>{{cite journal|title=Glacial landsystems and dynamics of the Saginaw Lobe of the Laurentide Ice Sheet, Michigan, USA|doi=10.1016/j.quaint.2011.07.021|volume=260|pages=21–31|journal=Quaternary International|bibcode=2012QuInt.260...21K|year = 2012|last1 = Kehew|first1 = Alan E.|last2 = Esch|first2 = John M.|last3 = Kozlowski|first3 = Andrew L.|last4 = Ewald|first4 = Stephanie K.}}</ref> 
* [[Minnesota]]<ref>[http://www.dnr.state.mn.us/ecs/212Ld/index.html Toimi Uplands Subsection] {{webarchive|url=https://web.archive.org/web/20161021064235/http://www.dnr.state.mn.us/ecs/212Ld/index.html |date=2016-10-21 }} of the Northern Superior Uplands, ''Ecological Classification System''. Minnesota Department of Natural Resources, 2016.</ref><ref name="Clark Hughes Greenwood et al 2009"/> 
* The [[Puget Sound]] region of [[Washington (state)|Washington]] state<ref name=Goldstein1994>{{cite journal |last1=Goldstein |first1=Barry |title=Drumlins of the Puget Lowland, Washington State, USA |journal=Sedimentary Geology |date=June 1994 |volume=91 |issue=1–4 |pages=299–311 |doi=10.1016/0037-0738(94)90136-8 |bibcode=1994SedG...91..299G }}</ref> 
* [[Wisconsin]].

===Asia===
Drumlins are found at [[Tiksi]], [[Sakha Republic]], Russia.<ref name="Clark Hughes Greenwood et al 2009"/>

===South America===
Extensive drumlin fields are found in [[Patagonia]].<ref name="Clark Hughes Greenwood et al 2009"/> A major drumlin field extends on both sides of the [[Strait of Magellan]] covering the surroundings of [[Punta Arenas|Punta Arenas']] [[Presidente Carlos Ibáñez del Campo International Airport|Carlos Ibáñez del Campo Airport]], [[Isabel Island (Chile)|Isabel Island]] and an area south of [[Gente Grande Bay]] in [[Isla Grande de Tierra del Fuego|Tierra del Fuego Island]].<ref>{{cite journal |last1=Prieto V. |first1=Ximena |last2=Winsolow |first2=Margaret |title=El cuaternario del Estrecho de Magallanes I: sector Punta Arenas- Primera Angostura |trans-title=Quaternary in Magallanes Strait: Punta Arenas-Primera Angostura |language=es |journal=Anales del Instituto de la Patagonia |date=1992 |volume=21 |pages=85–95 |hdl=20.500.11893/1410 }}</ref> 

Land areas around [[Beagle Channel]] host also drumlin fields; for example [[Gable Island]] and northern [[Navarino Island]].

===Antarctica===
In 2007, drumlins were observed to be forming beneath the ice of a West Antarctic ice stream.<ref name=smith2007>{{cite journal | last1 = Smith | first1 = A.M. | last2 = Murray | first2 = T. | last3 = Nicholls | first3 = K.W. | last4 = Makinson | first4 = K. | last5 = Aðalgeirsdóttir | first5 = G. | last6 = Behar | first6 = A.E. | last7 = Vaughan | first7 = D.G. | year = 2007 | title = Rapid erosion, drumlin formation, and changing hydrology beneath an Antarctic ice stream | journal = Geology | volume = 35 | issue = 2| pages = 127–130 | doi = 10.1130/G23036A.1 | bibcode = 2007Geo....35..127S }}</ref>

==See also==
* {{annotated link|Crag and tail}}, a similar formation, with a more resilient core (generally composed of [[igneous]] or [[metamorphic rocks|metamorphic]] rock)
* {{annotated link|Glacial landform}}
* {{annotated link|Landform}}
* {{annotated link|Lincoln Hills}}
* [[Mima mounds]]
* {{annotated link|Rogen moraine|Ribbed moraines}}
* {{annotated link|Roche moutonnée}}
* {{annotated link|Sediment}}

==References==
{{Reflist}}

==Further reading==
* {{cite book |last1=Bouton |first1=G.S. |chapter=A theory of drumlin formation by subglacial sediment deformation |pages=25–80 |editor1-last=Menzies |editor1-first=J. |editor2-last=Rose |editor2-first=J. |title=Drumlin Symposium |date=1987 |publisher=Taylor & Francis |isbn=978-90-6191-792-2 }}
* {{cite journal |last1=Charlesworth |first1=J. Kaye |title=Some Observations on the Glaciation of North-East Ireland |journal=Proceedings of the Royal Irish Academy. Section B: Biological, Geological, and Chemical Science |date=1938 |volume=45 |pages=255–295 |jstor=20490769 }}
* {{cite journal |last1=Finch |first1=T. F. |last2=Walsh |first2=M. |title=Drumlins of County Clare |journal=Proceedings of the Royal Irish Academy. Section B: Biological, Geological, and Chemical Science |date=1973 |volume=73 |pages=405–413 |jstor=20518928 }}
* {{cite journal |last1=Linton |first1=D. L. |title=The Forms of Glacial Erosion |journal=Transactions and Papers (Institute of British Geographers) |date=1963 |issue=33 |pages=1–28 |doi=10.2307/620998 |jstor=620998 }}
* {{cite journal |last1=Menzies |first1=J. |title=A review of the literature on the formation and location of drumlins |journal=Earth-Science Reviews |date=April 1979 |volume=14 |issue=4 |pages=315–359 |doi=10.1016/0012-8252(79)90093-X |bibcode=1979ESRv...14..315M }}
* {{cite journal |last1=Millis |first1=John |title=What Caused the Drumlins? |journal=Science |date=1911 |volume=34 |issue=863 |pages=60–62 |doi=10.1126/science.34.863.60 |jstor=1638735 |pmid=17775311 |bibcode=1911Sci....34...60M |url=https://zenodo.org/record/2321046 }}
* {{cite journal |last1=Patterson |first1=Carrie J. |last2=Hooke |first2=Roger LeB |title=Physical environment of drumlin formation |journal=Journal of Glaciology |date=1995 |volume=41 |issue=137 |pages=30–38 |doi=10.3189/S0022143000017731 |s2cid=140583314 |doi-access=free |bibcode=1995JGlac..41...30P }}

==External links==
{{Commons}}
* [http://www.geography-site.co.uk/pages/physical/glaciers/drum.html Diagrams of an idealized drumlin], The Geography Site, United Kingdom. Last accessed January 9, 2023.
* [https://web.archive.org/web/20090801143548/http://gsc.nrcan.gc.ca/landscapes/details_e.php?photoID=445 Drumlin field, northwestern Manitoba], image from Canadian Landscapes Photo Collection, [[Geological Survey of Canada]]. Last accessed January 9, 2023.
* [http://wordsmith.org/words/drumlin.html Word of the day defines ''drumlin''.], [http://wordsmith.org/anu/ Anu Garg], [http://wordsmith.org/awad/about.html A.Word.A.Day]. Last accessed January 9, 2023.
* {{YouTube|7L2rnpWE3jA|French River: Ice Age Outburst}}. Last accessed January 9, 2023.

{{glaciers}}
{{sediment transport}}

[[Category:Glacial landforms]]
[[Category:Glaciology]]