3ull. nat. Hist. Mus. Lond. (Geol.) 58(2): 81-152 Issued 28 November 2002 



The Lower Lias of Robin Hood's Bay, 



Yorkshire, and the work of Leslie Bairstow 



-Mi.' . ..: . J um 



M.K. HOWARTH 



Department of Palaeontology, The Natural History Museum, Cromwell Road, London SW7 5BD i 



3 1 & 



CONTENTS "t^fci.- ^L . ' ■ 'M ' 



ai^»*,^r>7ii^y^--.*^*^-*''- 1 ^ • -— • . i-- 



Introduction 82 



Leslie Bairstow 82 



Biography 82 



Bairstow's unpublished work 84 



Geological maps 84 



Geological structure of Robin Hood's Bay 93 



Stratigraphical succession 93 



Bed numbers 95 



Detailed succession in Robin Hood s Bay 96 



Lithostratigraphy Ill 



Staithes Sandstone Formation 1 ] 1 



Redcar Mudstone Formation 1 1 1 



Exposures in Robin Hood's Bay now 1 14 



Correlation with previous descriptions 1 14 



Bairstow's ammonite collection 1 15 



Systematic description of the ammonites and nautiloids 1 18 



Family Juraphyllitidae 1 18 



Family Lytoceratidae 1 18 



Family Psiloceratidae 1 19 



Family Schlotheimidae 1 19 



Family Arietitidae 119 



SubfamilyArietitinae 1 19 



SubfamilyAgassiceratinae 123 



Subfamily Asteroceratinae 123 



Family Echioceratidae 125 



Family Oxynoticeratidae 129 



Family Cymbitidae 132 



Family Eoderoceratidae 132 



Family Coeloceratidae 136 



Family Phricodoceratidae 137 



Family Polymorphitidae 137 



Family Liparoceratidae 141 



Family Nautilidae 144 



Biostratigraphy 144 



Acknowledgements 150 



References 150 



SYNOPSIS. Rocks of Lower Liassic (Sinemurian and Lower Pliensbachian) age exposed in Robin Hood's Bay. near Whitby, 

 north Yorkshire, are described from the mapping, stratigraphical descriptions and ammonite collections made by Mr Leslie 

 Bairstow in the years 1927-1970, and preserved in the Palaeontology Department. The Natural History Museum, London. His 

 large-scale map of the geology of the foreshore is published on five sheets at a scale of approximately 1 :5000. The stratigraphical 

 sequence from bed 4 1 8 at the base up to bed 600.5 at the top of the Lower Pliensbachian is 1 63 .74 m thick, and consists of the 

 Redcar Mudstone Formation, for which four members are formally defined - the Calcareous Shale (at the base), Siliceous Shale, 

 Pyritous Shale and Ironstone Shale Members - overlain by the lower part of the Staithes Sandstone Formation. The lowest beds 

 exposed by the lowest spring tides are Sauzeanum Subzone, Semicostatum Zone, in age; ammonites occur in all subzones, and 

 the only uncertain boundary is that between the Masseanum and Valdani Subzones (Ibex Zone), where there are few characteristic 

 ammonites. Bairstow's ammonite collection consists of more than 2360 specimens, all from recorded horizons, and is notably rich 

 in Promicroceras, Asteroceras, Eparietites and Oxynoticeras from the Obtusum and Oxynotum Zones. Echioceratids, Eoderoceras 

 and Apoderoceras from the Oxynotum, Raricostatum and Jamesoni Zones, and Liparoceratids from the Davoei Zone, making it 

 a primary source for Sinemurian and Lower Pliensbachian ammonite biostratigraphy. The recently proposed selection of Wine 



i© The Natural History Museum, 2002 



