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MEMOIRS OF THE GEOLOGICAL SURVEY.

ENGLAND AND WALES.

THE GEOLOGY OF

THE CARBONIFEROUS LIMESTONE, YOREDALE ROCKS,
AND MILLSTONE GRIT OF

NORTH DERBYSHIRE.

(PARTS OF SHEETS 88 S.E., 81 N.E., 81 S.E., 72 N.E., 82 N.W.,
82 S.W., AND 71 N.W.)

BY

PROFESSOR A. H. GREEN, M.A., F.R.S.,
C. LE NEVE FOSTER, B.A., D.Sc., F.G.S.,
AND J. R. DAKYNS, M.A.

2ND EDITION, WITH ADDITIONS, BY

PROFESSOR A. GREEN, M.A., F.R.S.,

AND A. STRAHAN, M.A., F.G.S.

PUBLISHED BY ORDER OF THE LORDS COMMISSIONERS OF HER MAJESTY'S TREASURY.

LONDON:

PRINTED FOR HER MAJESTY'S STATIONERY OFFICE,

BY EYRE AND SPOTTISWOODE,

PRINTERS TO THE QUEEN'S MOST EXCELLENT MAJESTY.

And to be purchased, either directly or through any Bookseller, from

EYRE AND SPOTTISWOODE, EAST HARDING STREET, FLEET STREET, E.C.; or

ADAM AND CHARLES BLACK, 6, NORTH BRIDGE, EDINBURGH; or
HODGES, FIGGIS, & Co., 104, GRAFTON STREET, DUBLIN.

1887.

Price Five Shillings and Sixpence.

Pierce fund

64019

NOTICE.

THE area described in this Memoir was originally surveyed by Professor John Phillips and Sir Warington W. Smyth; some of the southern part by Sir A. C. Ramsay (then Director of the Survey), Professor Hull, and Mr. H. H. Howell; the maps being published between the years 1852 and 1856.

Some years later the sub-divisions of the Millstone Grit and Yoredale Rocks were inserted by Messrs. Hull, Green, Foster, Dakyns, and the late J. C. Ward; new editions of the maps containing the additions made by these surveyors were published during the years 1866-68.

The information collected during this re-survey was given in the first edition of this Memoir, which was published in 1869. It included a description of parts of the western margin of the Yorkshire Coal-field, now more appropriately placed in the Memoir on that Coal-field which was published in 1878.

The rocks lying between the supposed base of the Millstone Grit and the top of the Thick or Scar Limestone beds of the Carboniferous Limestone were described as " Yoredale Beds " by Professor John Phillips, from their supposed typical development in Yoredale (Wensleydale); and in applying this classification to Derbyshire, a thick bed of sandstone was included in the Yoredale Series, and the name "Yoredale Grit " was given to it.

During the progress of the survey over South Yorkshire and Lancashire it became impossible to separate this Yoredale Grit from the rocks hitherto looked upon as the base of the Millstone Grit, and it was found necessary to include the entire series of grits and shales down to the base of the Yoredale Grit in the Millstone Grit. The reasons for this were given in the Memoir on the Yorkshire Coal-field (p. 33), and are repeated here (p. 6). It became, therefore, necessary to discontinue the use of the term "Yoredale Grit"; Farey's original term of "Shale Grit" seemed in every way the best, and this is the name now adopted. Other and minor changes in the nomenclature and classification are described in the pages referred to.

U 18863. Wt. 10025.

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