26 A. J. Jukes-Browne — Bed Chalk in Suffolk. 



Solaster subglolosus, and at least 100 feet above the base of the Chalk 

 Marl ; and, further, that it has no connection whatever with the red 

 rock which forms the base of the Chalk at Hunstanton and in 

 Lincolnshire. 



It is well known, however, that the Lower Chalk of Lincolnshire 

 contains two other bands of red chalk, and the author's examination 

 of this district for the Geological Survey enables him to compare the 

 Suifolk and Lincolnshire sections in detail. The following account of 

 the Lincolnshire beds is given with the permission of the Director- 

 General, and in anticipation of the Explanation of the Survey Map 

 (Sheet 84), which is now in the press. 



In Lincolnshire, as at Hunstanton, the red (Hunstanton) rock 

 forms the basement bed of the Chalk, and is overlain by four or 

 five feet of hard grey sandy chalk (Inoceramus beds). These are 

 succeeded by about 70 feet of grey chalk with many layers of 

 hard nodular rocky chalk, and including two bands of pink chalk, 

 one (the lower) being in some places of a decided red colour, 

 while the upper band is generally of a yellowish pink tint, 'fhe 

 lower band is of a loose and marly nature inclosing hard lumps, which 

 are generally of a lighter tint inside ; it varies in thickness from 4^ 

 to 7 feet, and sometimes it is only the central part of the band which 

 is of a decided red colour, the upper and lower parts shading into pink 

 and grey ; Holader subglohosus occurs both in and below this band, 

 together with a few other fossils, but Belemnitella plena has not yet 

 been found in Lincolnshire. The upper band consists of much harder 

 and more evenly bedded chalk ; it is generally about seven feet thick, 

 and varies in tint from light-pink to yellowish-white ; it is overlain by 

 a course of hard white chalk surmounted by a band of soft mottled 

 marl, which is usually two feet thick, and exhibits tints of red, grey, 

 and buff. Above this are beds of hard yellowish-white chalk, which 

 seem to represent the Melbourn rock ; these contain Inoceramus 

 mytiloides and Rhynchonella Cuvieri. 



Prom the above description it will be seen that the "West Eow bed 

 closely resembles the lower of the two red bands which are seen in the 

 quarries near Louth, and as this occurs very nearly on the same 

 horizon, I have little hesitation in correlating them with one another 

 as homotaxial beds, though they may not be identical, because they 

 do not appear to be continuous across the intervening space in Norfolk 

 and Lincolnshire. 



Figs. 1 and 2 are comparative vertical sections, showing the position, 

 of these bands of red chalk in Suffolk and Lincolnshire, both being 

 drawn to a scale of 16 feet to the inch ; the exact distance of the West 

 Eow chalk below the Melbourn rock can only be estimated approxi- 

 mately, but the Lincolnshire section is drawn from actual measure- 

 ments taken in quarries at Louth. The upper portions of the two sec- 

 tions are similar, but the lower parts are very different. The base of 

 the Chalk Marl is not seen in Suffolk, but the Marl is known to be 

 between 60 and 70 feet thick, whereas in Lincolnshire there is only 

 some 20 feet of grey and red chalk to represent the combined thickness 

 of the Totternhoe Stone, Chalk Marl and Gault. 



With regard to the horizontal extension of the red chalk in Suffolk 



