84 



M.K. HOWARTH 



Fig. 3 Leslie Bairstow, aged 46; taken from a group photograph of the 

 Palaeontology Department, the Natural History Museum, 1954. 



association with the Palaeontographical Society, first as Treasurer 

 for the years 1948 to 1955, then as Vice President from 1966 until 

 1969, and he was a Trustee of that Society for several years during 

 the same period. [Other biographies on Bairstow can be found in the 

 obituary notices published by the Geological Society (Howarth, 

 1996) and King's College. Cambridge (Annual Report, October 

 1996:27-29).] 



Bairstow 's unpublished work 



The originals of the unfinished and unpublished manuscripts left by 

 Bairstow will be deposited in the Earth Sciences Library of The 

 Natural History Museum, London. They can be divided into three 

 main parts, which will now be described in sequence: 



1. The geological map of Robin Hood's Bay. 



2. The stratigraphical description of the Lower Lias. 



3. His collection of ammonites and other fossils, and his list of the 

 determinations of the ammonites. 



GEOLOGICAL MAPS 



Bairstow drew his geological map of Robin Hood's Bay in 1928-30 

 and the top copy formed part of his fellowship submission, now 

 preserved in the archives of King's College, Cambridge. The map 

 was drawn at a scale of 1:2500, and consists of eight sheets, each 

 measuring 320 x 343 mm. Bairstow took (and variously modified) a 



few geographical lines from the 1:2500 sheets of the Ordnance 

 Survey: these were mainly the top and bottom of the cliffs, some 

 paths and field boundaries at the top of the cliffs, a few roads and 

 prominent buildings, and the line of low tide mark. The latter is the 

 low tide mark of ordinary tides on Ordnance Survey maps (ie. 

 approximately half way between low water mark of spring and neap 

 tides), but Bairstow modified the line to be that of low water mark of 

 spring tides, when the maximum amount of rock is exposed on the 

 foreshore. On some low lying areas low water of spring tides exposes 

 much larger areas of rock than ordinary or neap tides, eg. the area 

 occupied by beds 505-530 north of Robin Hood's Bay town. 



Before submission to King's College. Bairstow made machine 

 copies of his map, which he kept throughout his working life and 

 they form the basis of the maps reproduced here. These copies differ 

 from the original maps only in Bairstow's addition of 'datum lines' 

 for locating the ammonites he collected (see the account of his 

 ammonite collection, p. 1 17 below). I considered the possibility of 

 reproducing Bairstow's original maps in the King's College archives, 

 but the small size of the lettering of the bed numbers, the colour, 

 thinness and lack of sufficient boldness of some of the lines, and 

 logistical difficulties of reproducing maps that are larger than A3 (in 

 one direction), were all against direct reproduction of the originals. 

 After consideration of scale and legibility at the final printed size, it 

 was decided to copy the maps at a different scale, and to divide them 

 into the five sheets (see Fig. 4) that give a better division of the 

 outcrops in Robin Hood's Bay than the original eight maps. Tracing 

 was done with great care, so that the geological lines on the resulting 

 maps reproduced here as Figs 5, 6. 8. 11 and 15 are as close as 

 possible to the lines originally drawn by Bairstow. No alterations 

 were made, and in those parts that were checked, such as the seaward 

 edge of outcrops opposite the mouth of Mill Beck, south of Stoupe 

 Beck, and in Wine Haven, the maps appear to be still accurate, 70 

 years after they were drawn. 



Bairstow did not. however, include the lowest and highest beds on 

 his map: the lowest bed he mapped was the seaward edge of bed 422, 

 Low Balk, though he collected ammonites from lower beds down to 

 bed 42 1 . 1 . The outcrops of beds 4 1 8-42 1 , seaward of Low Balk, were 

 added to the map of Fig. 1 1 from observations made at the lowest 

 spring tide of the year on 9 September 1991. when they were easily 

 accessible. Similarly, at the top of the succession, the highest bed 

 mapped by Bairstow was bed 590.3, on the south side of Bulmer Steel 

 Hole, even though this is 250 m south of Castle Chamber, which is 

 usually taken as marking the northern boundary of the bay. The higher 

 beds northwards past Castle Chamber and up to the boundary between 

 the Lower and Upper Pliensbachian ( ie. the Lower/Middle Lias boun- 

 dary ) were also added to the map of Fig. 5 in September 1 99 1 . Thus, the 

 mapping was completed between the lowest bed exposed by the lowest 

 spring tides and the upper boundary of the Lower Pliensbachian. The 

 five large-scale maps are printed here at a scale of 1:5315. 



Map 1 (Fig. 5) is the northernmost map and starts from the highest 

 beds outside the bay to the north-west at the junction with the Upper 

 Pliensbachian. The main geographical feature is the cave of Castle 

 Chamber, where the hard shelly sandstones of beds 599 and 601.1 

 form the floor and roof of the cave. The outcrop is fairly narrow along 

 the whole of this east facing part of the bay, and is subject to 

 aggressive wave action that results in relatively clean rock surfaces 

 and good exposures. 



Map 2 (Fig. 6) covers the whole sweep of the scars north and south 

 of Robin Hood's Bay town, from the ironstone shales at the top of the 

 map, down through the softer, pyritous shales opposite Dungeon 

 Hole and Ground Wyke (Fig. 7), to the hard siliceous shales that form 

 prominent scars opposite Robin Hood's Bay town. These are Landing 



