September 12, 1921 
Canada 
Geological Survey 
Bulletin No. 33 
GEOLOGICAL SERIES No. 40 
FAUNAL AND SEDIMENT VARIATION IN THE 
ANTICOSTI SEQUENCE 
By W. H. Twenhofel 
INTRODUCTION 
Nearly three hundred years ago, the Danish priest, Steno, 
stated that the materials of a deposit may be of diverse char- 
acter because of the different sources from which they come. 
The brilliant Frenchman, Guettard, pointed out that sediments 
are not everywhere deposited in the same thickness. It has been 
shown by many other scientists that sediments vary in character 
consequent upon conditions prevailing at the places of deposition. 
These conclusions would appear to be axiomatic, yet they have 
not been generally applied. 
The history of the past is to be read from a study of the 
processes of the present, but, of course, at any one time the result 
arising from a combination of processes would be controlled by 
the intensity of each process. At present it appears that at 
all places where accessible sediments are being deposited there 
is lateral gradation from one to another type, that at no time 
are the waves and currents depositing the same kinds of material 
everywhere in the same quantity and that on no land and in no 
sea are the animals and plants growing in the same variety and 
abundance over the entire area inhabited. Many things deter- 
mine the type of sediment which may be deposited ; the agents 
of transportation and precipitation, the depth and chemical 
character of the water, distances from sources and differences in 
character of material at the sources are among the most import- 
ant. Many factors likewise enter into the existence of organisms 
19856— 1$ 
