HILL: GEOLOGY OF JAMAICA. 65 
by the Montpelier beds during the succeeding epoch. As shown in an- 
Other chapter, the age of these beds, although containing a remarkable 
Mixture of Cretaceous and Tertiary fossils, is undoubtedly Eocene, and 
With the Richmond beds they constitute the Eocene system in Jamaica. 
Tum Warre LiwzsrONES. (OckANIO AND CoasT SERIES. ) 
Introductory Statement, — The transitional Cambridge beds grade up 
into rocks of organic oceanic origin. These are the White Limestone 
formation of the official Jamaican Reports, They have no genetic 
relationship with the rocks of the Blue Mountain Series, and differ from 
them in every physical and chemical aspect. 
The interpretation of the white limestones has been one of the 
greatest problems of Jamaican geology. There have been so many di- 
Verse opinions concerning their ago and sequence that it is almost impos- 
Sible to obtain from current literature any approximation of their true 
relations and significance. The difficulties can be readily scen by any 
One who reads the conflicting and apparently involved conclusions in the 
Jamaican Reports. The fragmentary descriptions of their local occur- 
Tence are frequently well written, but through lack of correlation and 
erroneous deduction they fail to clear up the sequence and age of the 
beds, 
All the white limestones have been usually discussed by field ob- 
Servers under one general head, and treated and tabulated as a single 
lormation in thé discussion by European geologists who wrote the Ap- 
Pendix, and one would infer that they are not stratigraphically subdi- 
visible. There are numerous references, however, in the body of the 
Jamaican Reports,’ from which it is obvious that some such distinctions 
Were at least observed, although the geologists failed to differentiate, 
Name, or correlate them, as we shall endeavor to do in the following 
Pages, 
De la Becho? included all the rocks from our Jambridge beds to the 
recent inclusive in his White Limestone, but recognized differences of 
age therein and correctly referred the basal portion to the Eocene. 
Of the field geologists upon the Jamaican Survey, Sawkins held con- 
cerning the White Limestone that “ Uncertainty has prevailed respect- 
ing its precise geological position, but paleontological evidence seems to 
determine a Mid-Tertiary or Miocene period as the epoch of deposi- 
1 See Jamaican Reports, pp. 45, 53, 121, 214, 230, 231, 241, 250, 257. 
2 Mem. Trans, Geol. Soc. London, 1829, pp. 169-171. 
VOL, XXXIV. 5 
