hill: geology of JAMAICA. 



11 



limestone by Brown, which we sliall call the Cambridge formation. 

 Woodward, in the text, accidentally no doubt, omits to ni'.'ntion this 

 important formation, and erroneously states ^ that the shales, No. 3 of 

 the figure (our Richmond Beds), are followed by the White limestones 

 of " Miocene age." For verification he refers to a previous article by 

 Barrett," in which we can find no mention of any such sequence. 



Later, T. Rupert Jones also published an illustration of a geological 

 section which he said had been given to him by Barrett, " whose unfor- 

 tunate death had then recently occurred." This section, like that given 

 by Woodward, shows the stratigraphic position of the Orbitoidal lime- 

 stone, 6, (called "Nodular Orbitoidal Limestone,"^ — our Cambridge 



Figure 2. T. Rupert Jones's Interpretation of Barrett's Section of the 



Jamaican Sequence. 



Beds), between the black shales (Richmond) and White limestones. In 

 the legend of the section the age of the Orbitoidal formation is given 

 by a bracket as the ^' Miocene." This is the first section in which the 

 Orbitoidal limestone (our Eocene Cambridge Beds in part) was referred 

 to the Miocene. In the same section the overlying White limestones, a, 

 which we will show embraces formations of the Vicksburg Eocene (old 

 usage, — called Miocene in Woodward's paper previously alluded to) is 

 referred to the Pliocene. Jones states that *^ he understood Mr. Barrett 

 to have referred the great " White limestone " to the Pliocene.* 



In 1864 Duncan and Wall wrongly correlated the Yellow Eocene 

 Orbitoidal limestones at the base of the White limestones with the 

 Bowden beds (Oligocene) which occur above them, and referred the 



1 The Geologist, London, 1862. Vol. V. p. 373. 



2 " On Some Cretaceous Rocks in Southeastern Portion of Jamaica." Quart 

 Jour. GeoL Soc. 1860, Vol. XVI. pp. 824-326. 



8 Quart. Jour. Geol. Soc. London, 1863, Vol. XIX. p. 515. 

 * Ibid., pp. 5U, 515. 



