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OCCURRENCE OF BOULDER CLAY 

 AT HUDDERSFIELD. 



T. W. WOODHEAD, M.Sc. Ph.D. 



For more than half a century, geologists in the Huddersfield 

 district have been familiar with deposits containing water-worn 

 material, at ioo feet or more above the present level of the 

 river Colne on which the town stands. These deposits have 

 been frequently exposed in excavations for buildings, drains, 

 railway cuttings and borings. It has been customary to regard 

 them as river gravels, and as indicating the former course of 

 the Colne. 



During the past two years, excavations made in connection 

 with the extensive works of British Dyes, Ltd., in Huddersfield, 

 have furnished an opportunity of examining very numerous 

 sections covering a large area of the alluvial tract of the Colne, 

 especially around the spur known as Briery Bank, which 

 separates the Colne from Lees Beck. This latter stream, which 

 runs almost due north, drains the Kirkburton valley and is 

 suggestively small for so wide a valley ; it bears seven names 

 along its course of seven miles, the last half-mile is known as 

 Lees Beck, and as most of the deposits on its banks, referred 

 to below, occur within this length of the stream, it will be con- 

 venient to use the above name only. 



At the junction of Lees Beck with the Colne, the alluvium 

 covering the valley floor is three-quarters of a mile wide, as 

 shown on the Geological Survey Map (sheet 246), and it varies 

 in altitude from 160 ft. to 200 ft. O.D. 



To account for these deposits, it was presumed that the 

 Colne formerly persued a course from S.W. to N.E., correspond- 

 ing roughly with the track between the present 275 ft. and 

 300 ft. contour lines, and that in course of time it had cut its 

 way along the strike of the Lower Coal Measures in an easterly 

 direction, down to its present level. Hence the gently sloping 

 left bank, covered with a wide stretch of alluvium, and the 

 precipitous right bank, where, as at Dalton Bank Plantation, 

 in a distance of less than 400 yards, it rises from 175 ft. to 

 525 ft., a gradient of 1 in 1-9. 



In the Geological Survey, all these deposits are mapped as 

 alluvium, and in no part of the Colne drainage area is there 

 any indication given of deposits belonging either to the first 

 river terrace, or the high level river gravel ; but to the N.E., 

 beyond the junction of the Colne with the Calder, extensive 

 river terrace deposits are shown on both banks of the Calder, 

 between Colne Bridge and Dewsbury. A smaller area marked 

 ' old river gravel ' is also shown at Kirklees, on the left bank 

 of the Calder. 



Considerable attention has been paid to such deposits in 



1917 July 1. 



