HILL: GEOLOGY OF JAMAICA. 9 



pages is by Sir Roderick I. Murchison. The first general summary of 

 the island is by James Gay Sawkins. Individual reports of the difierent 

 parishes are by Barrett, Wall, Sawkins, Lennox, and Brown. The Ap- 

 pendix contains a discussion and resume of the paleontology and age of 

 the rocks of the Caribbean Sea by Robert Etheridge, with paleonto- 

 logic determinations by Duncan, Carrick Moore, T. Rupert Jones, and 

 others. 



In the reports upon the individual parishes each field worker used an 

 independent and often conflicting nomenclature for the various forma- 

 tions described, and frequently expressed contradictory opinions con- 

 cerning the age of the same formations. For instance, as has been 

 pointed out by other writers ^ with respect to the age of the White lime- 

 stone, " the reports of the surveyors are inconsistent with one another^ 

 In some places (as on pp. 23 and 149) it is called Miocene; in others 

 (pp. 29 .and 30), Pliocene, and in the tabular view at the end of the 

 volume it is labelled Post-Pliocene." This confusion is equally apparent 

 concerning all other formations discussed. 



The report is deficient in local stratigraphic sections by which the 

 discrepancies might be corrected. On the other hand, the parties who 

 attempted to correlate and generalize the individual reports in the 

 Appendix went to the other extreme, and reduced the nomenclature to 

 a compact but an illogical arrangement. In general, the descriptive 

 portions of the report are fair, but its conclusions concerning the classi- 

 fication, sequence, and age of the rocks leave the reader in a state of 

 confusion. * 



We cannot point out all of these discrepancies ; a comparison of the 

 three summaries given in different parts of the volume will sufficiently 

 exhibit them.^ The cliief confusion resulted from the attempt of those 

 who wrote the summaries to include the various formations of the local 

 observers under certain broad generic terms, such as the " White " 

 or "Yellow" limestones, whereby the whole succession and age of 

 these rocks, whose correct interpretation is most essential to an under- 

 standing of the geological history of the island and the Antilles, was 

 confused. 



These errors resulted from erroneously correlating the Eocene Yellow 

 limestones with the Miocene (old usage) Bowden beds. The former 

 occur at the base of the entire series of White limestones, and the latter 



^ Jukes-Browne and Harrison, Jour. Geol. Soc. London, No. 190, Vol. XLVIII. 

 p. 219. 



2 Jamaican Keport, pp. 128, 186-189, and table at end of volume. 



