AGASSIZ: BERMUDAS. 229 



FOSSILS. 



On a small island to the south of Agers Island I found quite a number 

 of species of marine shells identical with those now living embedded in 

 nearly horizontal aeolian strata a few feet above high-water mark. Also a 

 bank of Chama evidently thrown up or blown up during a hurricane, 

 much as we find Strombus on some parts of the Bahamas thrown up in 

 great banks high above high-water mark. That marine shells should 

 thus be thrown up or blown up to such considerable heights in what 

 may, in proto-Bermudian time, have been a protected sound, as well 

 as is Hamilton Harbor, is not extraordinary. We need only recall 

 the great violence of the hurricanes which sweep past and over the Ber- 

 mudas, during which vessels have dragged their anchors in the sheltered 

 inner harbor of Hamilton, where the wind and sea have a comparatively 

 limited range. 



Below that, but in seolian strata, these fossils extend to low-water 

 mark, apparently embedded in the " base rock." These lower strata 

 have at first sight all the appearance of beach rock ; they consist 

 mainly of particles larger than seolian sand, which probably have not 

 been blown a great distance upward from their base. But these strata, 

 consisting of larger brecciated fragments, have, like other aeolian beds, 

 been changed into the hard ringing limestone so characteristic of 

 nearly all the exposures below high-water mark. 



During the very low tides which prevailed for the last days of my 

 visit at the Bermudas, I was able to trace the existence of aeolian beds 

 underlying the fossiliferous beds with the base rock lying between them. 

 The fossils are embedded in aeolian rock, and in certain spaces, which 

 have become cemented so as to destroy the laminations, they appear 

 to be embedded in the base rock. The existence of these fossiliferous 

 beds above high-water mark in the islands of Hamilton Harbor has led 

 Ptice to assume a period of slight elevation as having occurred in the 

 Bermudas, and further to maintain that much of the interior of the 

 islands is underlain by beach rock, a statement with which Professor 

 Heilprin agrees in the main. The size of the material and the broken 

 shells thrown up at Shelly Beach show how high up material similar 

 to it may, even under ordinary circumstances, have been thrown up and 

 become embodied into aeolian beds without its being any indication of 

 a period of elevation. 



