264 E. A. Walford — A Fault at Tainton Doivn, etc. 



accompanied by rock-specimens from each zone or layer of every 

 formation occurring in Bohemia. 



Finally, we come to a large room, 26 metres long, in which is 

 arranged in 60 cases a general stratigraphical collection. Here are 

 exhibited for comparison, besides Bohemian specimens, those of 

 England, France, Germany, Eussia, America, etc., giving an adequate 

 idea of the character of each formation in other countries. Beneath 

 the windows are placed four table-cases with a general dynamical 

 collection, with lai'ge explanatory labels. Against the wall, upon 

 two large stands, are exhibited casts of remains of great vertebrates, 

 and upon the opposite wall hang geological and palasontological 

 pictures and diagrams. 



The scientific work carried on by the staff of the Geological Depart- 

 ment is as follows : — Gasteropoda of Bohemian Palaeozoic Basin (con- 

 tinuation of Barrande's work), by Dr. J. Pernor ; newer Cretaceous 

 Plants, by Dr. Edvin Bayer; Arachnids from the Coal-measures, 

 by Dr. Ant. Fritsch ; Fishes and Eeptiles of the Bohemian Chalk 

 formation, by Dr. Ant. Fritsch and Dr. Bayer ; Graptolites, their 

 geological distribution in Bohemia, by Dr. J. Pernor ; Tertiary 

 plants and insects from Bohemia, by the Junior Assistants. 



A new guide to the collections is now being prepared. The original 

 specimens are always accessible to all scientific investigators, but 

 cannot be sent away to other Museums. 



VI. — On a Fault at the Foot of Tainton Downs. 

 By Edwin A. "Walford, F.G.S. 



TO the north of Tainton, near Burford, Oxon, the 500 o.d. contour- 

 line passes through the old quarry grounds where the well- 

 known Great Oolite freestone may be seen dipping at a high angle 

 to the north-east. The bank falls 100 feet to the brook, 400 yards 

 distant, where culvert and pipe trenches for new field waterworks 

 have exposed what may be a continuation of a fault marked on the 

 one-inch geological map of the Ordnance Survey as following the 

 course of Coombe Brook, a mile to the north. 



The Great Oolite runs half-way down the bank, and is underlain 

 by a few inches of the pale grey marl of the Fuller's Eartli. The 

 Fuller's Earth is unfossiliferous, and recognizable only by its litho- 

 logical type and horizon. Between the Fuller's Earth and the 

 heavy blue clays of the Upper Lias are two or three feet of sandy 

 limestone, iron-stained, representing the Inferior Oolite. At the 

 bottom of the trench thick blocks of brown and green ferruginous 

 limestone are of the Middle Lias (zone Ammonites spinatus), with 

 the following fossils, Avicula incequivalvis, Pentacrinite segments, and 

 rolled Belemnites, in a nodule bed, a stratum in North Oxfordshire 

 well known as the base of the ' Marlstone ' of the Middle Lias. 

 The stone is of the typical Oxfordshire type, close-grained, oolitic, 

 and of a dark green colour. It gives appearance of a former well- 

 developed extension over the area. It must not be forgotten, 

 however, that the Burford Signett boring for coal in 1874 proved 

 but 3 ft. 6 in. of Middle Lias stone. 



