Revieics — Harrison and JuJies-Broicne's Barbados. 233 



' Barbados is an island some 21 miles long by 11 broad and rising 

 at one point to a height of 1104 feet It is situated at a distance of 

 100 miles from the main chain of the Lesser Antilles, from which ifc 

 is separated by a sea 1500 fathoms deep. It is composed entirely of 

 sedimentary deposits, no volcanic rocks occurring on the island 

 except a little light dust and pumice which was probably ejected 

 from a vent within a radius of 300 miles ; the authors, however, 

 suggest that the elevation may have been due to a laccolite. The 

 absence of volcanic rock is a point of importance, as we have been 

 taught on high authority " that all the Lesser Antilles almost with- 

 out exception are volcanic." 



The rocks are divided into four groups : the Scotland series, the 

 Oceanic series, the Coral limestones and the valley deposits and 

 blown sand. The first consists of an irregular series of sandstones, 

 grits, and shales, with some bituminous clays yielding petroleum, 

 resen-ibling those of Trinidad and Venezuela ; the whole series is 

 much contorted, faulted and even inverted ; they are shown to be 

 more than 600 feet thick, while their base is not seen, and they are 

 unconformably overlain by the succeeding beds. Fossils are very 

 rare in this series, and they are so imperfectly preserved that all the 

 authors can conclude is that they have " general resemblances to the 

 fossils in those deposits of Trinidad which are regarded as Miocene " 

 (p. 15). 



The Oceanic series overlie these unconformably ; the basement 

 bed is a hard blue limestone, a fact of very considerable importance 

 on the question of the deep-sea origin of the succeeding 300 feet of 

 chalky earths, limestones, Eadiolarian marls, and red clays. The 

 evidence of both lithology and palaeontology is conclusive as to 

 the deep-sea nature of the deposits ; thus the Foraminifera indicate 

 a depth of 1000 fathoms, the Echinoid of more than 1000, while 

 the Kadiolaria point to still deeper conditions. The evidence as 

 to age is less satisfactory : the Microzoa are of little value in this 

 connexion ; while of the higher fossils the only one that has been 

 fully worked out is a specimen of Cystechinus crassus, Greg. The 

 authors, therefore, merely quote the opinion of the describer of this 

 fossil, that it was either of Pliocene or Pleistocene age. 



The Coral Bocks form a sheet that covers 144 out of the 166 square 

 miles of the island ; it is rarely more than 200 feet thick, but it is 

 in places as much as 260 feet. The coral rock is merely a rough 

 coarse-grained limestone ; beds of freestone, a very porous building- 

 stone, locally known as dripstone, and some intensely hard compact 

 rock that forms good road-metal, also occur. Much of the coral 

 rock is formed of broken fragments of Corals, Mollusca, and 

 NuUipores. The base of the series is always of loose rubble or half- 

 consolidated coral or marl. In one of the caves opened by the 

 Water Supply Company, the coral rock is seen to rest on a mixture 

 of coral sand and material derived from the siliceous earth : none of 

 the deposits that one might expect to find on Dr. Murray's hypothesis 

 seem to be present, as none such are referred to. The corals and 

 shells examined show that the whole series is of Pleistocene age. 



