THE STATE GEOLOGIST. 69 



As to the probable causes which brought about the destruc- 

 tion of the immense quantity of fish-life as is found in the Boon- 

 ton and other localities, these can only be postulated in a general 

 way, and have already been referred to in the preceding pages. 

 It is evident that a vast number of creatures met their death sud- 

 denly, sank to the bottom and became embedded in sediment 

 before their bodies had suffered serious injury, either from decom- 

 position or mechanical disruption. Accidental lengthening or 

 compression of the body, due to wave or current action, and such 

 other deformation as occurred prior to the fossilization process, 

 was no doubt accomplished quickly. It is even possible, in some 

 cases, to determine the direction of current or wave action, since, 

 if two individuals are found lying at right angles to each other 

 on the same slab (as in Plate XIV), and one of them is vertically 

 and the other longitudinally compressed, it is evident that such 

 distortion must have been produced by a force operating - in 

 one and the same direction. Friction of the water on the bot- 

 tom, and the wash of sediment by tidal action, offer convenient 

 and plausible explanations of these appearances. The extent to 

 which the original contour of fish skeletons has become distorted 

 by accidents of fossilization, which seem to have been unusually 

 prevalent at Boonton, cannot be fully appreciated except by those 

 who have had considerable experience in collecting, or in the de- 

 termination of species. 



A variety of accidental phenomena has been suggested to 

 account for the destruction of multitudes of brackish-water or 

 marine organisms simultaneously in such manner as to produce 

 what are known as "bone-beds" or "fish-beds." Amongst the 

 more important of these may be mentioned : ( 1 ) Earthquake 

 shocks; (2) volcanic explosions, with the emission of poisonous 

 vapors; (3) sudden changes in temperature, or in salinity 

 brought about by the shifting of currents, by irruptions from 

 the outer sea into sheltered or brackish-water inlets, or by unusu- 

 ally copious discharges of fresh water into the open sea; (4) 

 the accidental impounding of marine forms within land-locked 

 embayments, including coral island lagoons, coal marshes, inun- 

 dated areas, etc.; and (5) parasitic infections and other physio- 

 logical disturbances. The possibility of some of these agencies 



