376 CRETACEOUS. 



conglomerate and sand, with fossils (calci-sponges, etc.), mostly 

 hardened by a ferruginous cement. The surface of this deposit 

 is sometimes curiously weathered and "piped." There has been 

 much dispute as to the age of this gravel, but it is now generally 

 referred to the Lower Greensand. Pebbles of slate, quartz and 

 crystalline rocks, as well as Oolitic rocks, occur, and the beds are 

 evidently the continuation of those exposed at Seend and other 

 parts of Wiltshire. They contain the same species of Nucula, 

 Opis, Emarginula, and Terchratida ; and also some species derived 

 from Oolitic beds (mostly from the Kimeridge Clay and Corallian 

 rocks) ; the Brachiopoda are similar to those met with at Wicken, 

 etc. (See sequel.) The derived fossils are chiefly the remains of 

 Vertebrates ; the Lower Greensand species comprise Sponges, 

 Polyzoa, Echinoderms, Brachiopoda, and bivalve Mollusca, the 

 rarity of univalves being remarkable. The Sponges are most 

 important, both as forming a large part of the gravel and from 

 their good preservation. They have been carefully studied by 

 Dr. G. J. Hinde, and include Tnmacystia {Vtrh'a'IIopora or Verti- 

 ciUites) anastomans, Peronella {Scjphia) raviosa, ElasmococUa {Tragos) 

 Fariiigdonejisis, Corynella (^Scyphia) foraminosa, Synopella [3fafion) 

 puhmiaria, Elasmostoma consobmmm {Mafwn peziza), Raphidoriema 

 {Ma?ion) Faritigdonense, R. inacropora, etc. 



Overlying the Sponge-gravels there is a series of clays and sands with ironstone 

 bands, developed on the Furze Hills and at Cole's Pits, east of Little Coxwell. 

 ' Cole's Pits ' are old excavations, upwards of 270 in number, extending over 

 fourteen acres. They have, by some, been regarded as the remains of early 

 British habitations ; and the largest has been pointed out by tradition as the castle 

 of 'King Cole,' but as Mr. Godwin-Austen has observed, " Geology can counte- 

 nance no fictions except its own, and Cole's Pits are evidently the remains of the 

 open workings for the ironstone overlying the mass of sand." ' 



Some of the hard beds in the Lower Greensand near Faringdon have been made 

 into millstones, and they are used for road-metal, for building walls, etc. 



Shotover Sands. — The Ironsands of Shotover have attracted the 

 attention of many geologists since the time of William Smith, 

 Conybeare, Buckland and Fitton ; but in the early days of geology 

 there was, as before mentioned, much confusion between the Iron- 

 sand of the Wealden and that of the Lower Greensand. 



In ascending Shotover from Oxford we pass over Oxford Clay, 

 Corallian Rocks, Kimeridge Clay, Portland Beds, and then come 

 upon the Ironsand and Ochre series at the top of the hill. This 

 series, 80 feet in thickness, comprises white and yellow, and some- 

 times brown or black sands, sandstones occasionally cherty, blue 

 and white clay, fuller's earth, ironstone, oolitic iron-ore and 

 ochre. Organic remains occur in these beds, especially in the 

 ferruginous layers; they were discovered in 1833 by the Rev. H. 

 Jelly, of Bath, but they have not been noticed in the uppermost 



1 Godwin-Austen, Q. J. vi. 453 ; Archaeologia, v. 7 ; D. Sharpe, Q. J. x. 176; 

 J. Phillips, Geol. Oxford, p. 431 ; E. C. Davey, Trans. Newbury Field Club, 

 1874, vol. ii. ; W. T. Aveline, Explan. Sheet 34 (Geol. Survey), p. 28 ; J. Morris 

 and C. J. A. Meyer, P. Geol. Assoc, iv. 554; Geologist, vii. 5 ; G. Mag. 1866, 

 p. 16; G. J. Hinde, Catalogue of Fossil Sponges, 1S83. 



