Lake Harrison or Lake Bosworth is the name given to a lake that in parts of the

Ice Age An ice age is a long period of reduction in the temperature of Earth's surface and atmosphere, resulting in the presence or expansion of continental and polar ice sheets and alpine glaciers. Earth's climate alternates between ice ages and gre ...

may have covered much of

the Midlands The Midlands (also referred to as Central England) are a part of England that broadly correspond to the Kingdom of Mercia of the Early Middle Ages, bordered by Wales, Northern England and Southern England. The Midlands were important in the In ...

England England is a country that is part of the United Kingdom. It shares land borders with Wales to its west and Scotland to its north. The Irish Sea lies northwest and the Celtic Sea to the southwest. It is separated from continental Europe b ...

around

Warwick Warwick ( ) is a market town, civil parish and the county town of Warwickshire in the Warwick District in England, adjacent to the River Avon. It is south of Coventry, and south-east of Birmingham. It is adjoined with Leamington Spa and Whi ...

Birmingham Birmingham ( ) is a City status in the United Kingdom, city and metropolitan borough in the metropolitan county of West Midlands (county), West Midlands in England. It is the second-largest city in the United Kingdom with a population of 1. ...

and Leicester. It is suggested that it was formed when ice sheets over

Wales Wales ( cy, Cymru ) is a country that is part of the United Kingdom. It is bordered by England to the east, the Irish Sea to the north and west, the Celtic Sea to the south west and the Bristol Channel to the south. It had a population in ...

and

Northern England Northern England, also known as the North of England, the North Country, or simply the North, is the northern area of England. It broadly corresponds to the former borders of Angle Northumbria, the Anglo-Scandinavian Kingdom of Jorvik, and the ...

blocked drainage north-eastwards, trapping a lake between this and the Cotswolds. Finally the lake made two overflow courses, until drainage by the

Cole Cole may refer to: Plants * Cole crops of the genus ''Brassica'', especially cabbage, kale, or rape (rapeseed). People * Cole (given name), people with the given name Cole * Cole (surname), people with the surname Cole Companies *Cole Motor ...

and Soar could resume due to glacial retreat: *South-east. Across the Fenny Compton Gap into the Cherwell which drains into the

Thames The River Thames ( ), known alternatively in parts as the River Isis, is a river that flows through southern England including London. At , it is the longest river entirely in England and the second-longest in the United Kingdom, after the R ...

. This has become a

wind gap A wind gap (or air gap) is a gap through which a waterway once flowed that is now dry as a result of stream capture. A water gap is a similar feature, but one in which a waterway still flows. Water gaps and wind gaps often provide routes which ...

. *South-west. This course became lasting for the south-west zone of where the lake was, as the

River Avon, Warwickshire The River Avon () in central England flows generally southwestwards and is a major left-bank tributary of the River Severn, of which it is the easternmost. It is also known as the Warwickshire Avon or Shakespeare's Avon, to distinguish it from ...

which flows into the

Severn , name_etymology = , image = SevernFromCastleCB.JPG , image_size = 288 , image_caption = The river seen from Shrewsbury Castle , map = RiverSevernMap.jpg , map_size = 288 , map_c ...

. See also stream capture. The extent of this proposed lake has been disputed, and it is now thought that several smaller

proglacial lake In geology, a proglacial lake is a lake formed either by the damming action of a moraine during the retreat of a melting glacier, a glacial ice dam, or by meltwater trapped against an ice sheet due to isostatic depression of the crust around th ...

s may explain the glacial deposits in the area.

History

The existence of such a lake was originally proposed by W. Jerome Harrison, a pioneer of Midland glaciology, whose 1898 paper recognized the importance of the convergence of great

glacier A glacier (; ) is a persistent body of dense ice that is constantly moving under its own weight. A glacier forms where the accumulation of snow exceeds its ablation over many years, often centuries. It acquires distinguishing features, such as ...

s from the north-west and north-east upon the central counties of England, and postulated that they had ponded up a lake in Leicestershire. Harrison named it Lake Bosworth, since Bosworth Field stands on a part of the glacial lake basin. F. W. Shotton argued in 1953 that a specific place name was inappropriate for such a postulated large area of water, and proposed the name Lake Harrison. He acknowledged that other similar lakes were named after rather better-known geologists such as

Lake Agassiz Lake Agassiz was a large glacial lake in central North America. Fed by glacial meltwater at the end of the last glacial period, its area was larger than all of the modern Great Lakes combined. First postulated in 1823 by William H. Keating, i ...

and

Lake Lapworth Lake Lapworth was a postulated glacial lake in Great Britain, believed to have formed during the last ice age when glaciers ended the northern outlet of the Severn. This ran through the Dee (which passes by Chester). At some point or points it ran ...

. For a time the lake's existence was unquestioned, but more recent studies following the British Geological Survey's mapping of the Warwick area breathed "a refreshing air of controversy into the topic." According to Doug Harwood, "A significantly smaller proportion of the Wolstonian sequence is now regarded as lacustrine or deltaic in origin." Shotton found it impossible to agree with this alternative view and in 1983 fought a "spirited rear guard action" in defence of his original interpretation. Jonathan Radley stated in 2009: "Accordingly, Shotton’s concept of a single widespread lake has been superseded by a new model involving diachronous development of transient lakes and ponds, associated with ice sheets advancing from the north and east." Furthermore, Della and Julian Murton consider that the Bosworth Clays and Silts, also known as the Lower Wolston Clay (part of the Wolstonian which Shotton himself defined) are well defined enough to allow a reversion to its original name, Lake Bosworth.

References

;Citations ;Bibliography * * * * * * * * * * {{DEFAULTSORT:Harrison Former lakes of the United Kingdom Proglacial lakes