NAPLES FAUNA IN WESTERN NEW YORK, PART 2 20 I 



The sediments of the Black sea are: (i) in the littoral zone and to a 

 depth of about 20 fathoms, accumulations of sandy detritus; (2) to the 100 

 fathom line, gray blue sticky mud, Lorn 35-100 fathoms, rich in M o d i o 1 a 

 phaseolina, etc.; (3) in the great depths the bottom is covered with (a) 

 very fine, sticky, black mud with rich separation of FeS, abundant remains 

 of planktonic diatoms and with fragments of quite young lamellibranchs 

 (early stages of widely scattered plankton forms), (b) dark blue mud ; FeS 

 is here in less measure, but in richer quantity are separations of minutely 

 grained CaCO s making at times thin banks ; skeletons of pelagic diatoms 

 are also abundant. 



From analogy with these observations on the conditions actually exist- 

 ing in a secluded body of sea water, it may be necessary to conceive that 

 the black shale deposits of the Portage with their abundant segregations 

 of iron sulfid, sulfates of lime, barium and strontium and of limestone 

 nodules, are likewise the result of accumulation in water of great depth and 

 imperfect vertical circulation. 



These bituminous muds of Portage time are also permeated with frag- 

 ments of terrestrial drift wood, Lepidodendron, Cyclostigma, Asteropteris, 

 Calamites, etc. But, if we may be guided by the results of recent dredg- 

 ings, these are in themselves no indication of either shallow water or near- 

 ness to land. One might cite in illustration of this the results obtained by 

 the Blake'' in the Caribbean sea, where at a distance of 20 to 30 kilometers 

 from the land and at a depth of over 1200 fathoms, great quantities of 

 terrestrial vegetation, together with the shells of land snails, were brought 

 up. Walther 2 remarks thereupon : 



The contents of many a dredge would have put a paleontologist to 

 confusion, for, as between the deep sea forms of crabs, annelids, fishes, 

 echinoderms, sponges and the mango and orange leaves, bamboo stalks and 

 land snails, it would be difficult to decide whether the deposit was a deep 

 sea or a terrestrial one. In fossil condition this mixture would have been 

 regarded as the deposit of a shallow estuary surrounded by forests, while it 

 actually came from a depth of over 2000 meters. 



The few animal remains that these shales contain are largely necton 



'Agassiz. Three Cruises of the Blake. 1888. 1:291. 

 2 Walther. Einleitung in die Geologic 1894. p. 954. 



