224 E. A. WALFOED ON THE ' ; NOETHAMPTON SAND 



16. On the Relation of the so-called " Noethampton Sand" of 

 Noeth Oxon to the Clypetjs-Geit. By Edwin A. Walfoed, 

 Esq., E.G.S. (Read February 21, 1883.) 



The diverse lithological conditions of the deposits in the three 

 great sea- basins of the Bajocian period, the Anglo-Norman, the 

 Cotteswold, and that of the north-eastern counties, have for a long 

 time engaged the attention of geologists in the correlation of their 

 various subdivisions. The Anglo-Norman basin, however, with 

 the rich molluscan fauna of its marly limestones, will not come within 

 the scope of the present paper. It is to that border-land where the 

 estuarine character of the deposits of the northern area becomes 

 merged and lost in the marine strata of the Cotteswold type that 

 I wish more particularly to direct your attention. The greater 

 part of this section of the Midlands, North Oxfordshire, is embraced 

 in sheet 45 N.W. of the Geological Survey. 



It may perhaps be worth while to pause for a few moments to 

 review the present subdivisions of the Inferior Oolite. Resting upon 

 the sands for which Mr. Witchell has appropriately suggested the 

 name of the Cotteswold Sands, and which, throughout the Cottes- 

 wold area, cover the Upper Lias Clay, are the well-known pisolitic 

 beds of the MurcJiisonce-zone. They are exceedingly local in their 

 range, and are soon overlapped by the succeeding Lower Freestone 

 beds. These find their equivalents, according to Prof. Judd and 

 Mr. Sharp, in the lower part of the sandy beds of the Midlands 

 known as the Northampton Sands, and northwards in the equally 

 well-known Dogger of the Yorkshire coast. The succeeding Cottes- 

 wold stage, the Oolite Marl of the Sowerbyi-zone, passes from its 

 marly character in the north to that of a Nermann and coralline 

 limestone southwards, and, much reduced in thickness, courses 

 through Dorsetshire to the coast. A part of this Oolitic sea, as I 

 shall presently show, stretched into North Oxfordshire ; and in the 

 appearance of the Lincolnshire Limestone near Kettering the con- 

 tinuance of the northern deposits of the period has been indicated, 

 whilst in Yorkshire the Millepore beds present a fauna so analogous 

 as to allow of easy correlation. The freestones of the next higher 

 or Bumphresiamis-zone are confined to the south-western area, and 

 though for the most part very barren, are in the Anglo-Norman area 

 of Dorset rich in* a remarkable molluscan fauna. In Yorkshire the 

 Grey Limestones of Scarborough have been referred to this horizon. 

 The zone of Amm. ParJcinsoni which follows, though much better 

 developed in the north-east Cotteswold region, is yet readily to be 

 traced throughout Dorset and the south-west Cotteswolds. It 

 extends into North Oxfordshire under that condition known as 

 the Clypeus-grit with associated strata, which it will be my en- 

 deavour to describe. In Yorkshire Mr. Hudleston finds no evidence 

 of this zone, and is disposed to believe that both it and the Great 



