JOSEPH PRESTWICH. 659 



cil in 1846, when Murchison was president and Sedgwick, Buckland, 

 Fitton, Lyell, De la Beche, and others were his associates. 



He had now for some years been particularly occupied in what may 

 be considered his chief work — the elucidation of the Eocene strata of 

 the London and Hampshire basins. 



Commencing in the London area he zealously traversed the country 

 wherever the Lower Tertiary strata were to be found, and hardly an 

 outlier of any importance escaped his observation. Mr. Whitaker, 

 who, more than any other man, has followed in the footsteps of Prestwich 

 over this large region, referred in 1872 to the literature of the subject, 

 and remarked that the period 1811 to 1860 " might well be called the 

 'Prestwichian period,' from the author who first clearly made out the 

 detailed structure of the London Basin." 1 



After certain preliminary studies the interest and difficulties of the 

 subject, as Prestwich himself relates, speedily induced him to take it 

 up with more earnestness and determination, and eventually led him 

 to extend his inquiries over an area which at first he never contem- 

 plated. With true enthusiasm he remarked, "The Tertiary geology of 

 the neighborhood of London may be wanting in beauty of stratigraphical 

 exhibition and in perfect preservation of orgauic types, but in many of 

 the higher questions of pure geology — in clear evidence of remarkable 

 physical changes — in curious and diversified palseontological data, 

 however defaced the inscriptions, which is, after all, but a secondary 

 point, few departments of geology offer, I think, greater attractions." 

 These statements were made in 1849 when De la Beche handed to him 

 the Wollaston medal, which had been awarded by the council of the 

 Geological Society. He had then completed but a portion of those 

 labors which established his reputation as the leading authority on our 

 Tertiary strata. Having already extended his researches from the 

 London to the Hampshire Basin, he subsequently followed the strata into 

 Belgium and France, correlating the divisions he had made in this 

 country with those established abroad by D union t and D Archiac. 



His great aim was, by studying in detail the lithological characters 

 of the strata and their fossils, to mark out the main subdivisions in 

 the Eocene system, and to picture the ancient physical conditions 

 which attended their formation. By following the strata from point to 

 point he was enabled to record the mineral changes which many of the 

 subdivisions undergo, and to note the changes in fauna that accompany 

 these variations in sedimentary condition. He also showed how differ- 

 ences in the flora in certain formations pointed to distinct land areas. 

 Thus were fossils employed, as they should be in geological inves- 

 tigations, in interpreting the physical conditions of the strata after 

 the stratigraphical features had been determined, and in aiding the 

 subsequent correlation with distant deposits. 



1 Mein. Geol. Purvey, A^ol. IV., page 395. 



