680 The Great Salt Lake in Former Times. [ November, 
and there is an absence of any fresh-water mussels (Unio, etc.). 
“ The salt,” however, which is so prominent a characteristic of 
the present Sevier and Great Salt lakes, and abounds in all the 
later sediments. of the shrunken ancient lake, is nearly absent 
from the beds most clearly associated with the upper beach; and 
its distribution indicates that Lake Bonneville, if not perfectly 
fresh, was at least far less saline than either Great Salt or Sevier. 
La 
ke.” Again, farther on, Mr. Gilbert inquires whether “ the 
basin contains the amount of salt which would have sufficed to 
render the great lake briny. The ancient volume was no less 
than three hundred times greater than that of Great Salt Lake 
(when surveyed by Captain Stansbury), and the brine of the 
latter, so greatly diluted, would give only one thirteenth of one 
per cent. of salt. But if weʻadd to the salt of Great Salt Lake 
that of Sevier Lake, and the far greater but indeterminate quan- 
tity accumulated in the sediments. of the lower parts of the two 
deserts, we shall probably have enough to give Lake Bonneville, 
if it were undrained, the salinity of the ocean. In fine, we are 
led to. believe that, while Lake Bonneville certainly held less salt 
than do its modern representatives, its recorded phenomena com- 
prise no fact that places it definitely among either fresh or salt 
lakes.” As bearing on the question whether the ancient Bonne- 
ville Lake was. salt, brackish, or fresh, and whether the shells in 
the Bonneville beds. lived in the waters of the lake itself and not 
alone in the tributary streams, we may cite the case of Lake 
Tanganyika, whose outlet has been discovered by Lieutenant 
Cameron. This explorer in his diary ! in one place says, “ Such 
an amount of water comes into the lake, and there are no signs 
of change of level, so that it seems impossible to dispose of all 
the surplus water by evaporation; besides which, so many 
streams run through salt soil that, if it were disposed of in that 
way, the lake would be as salt as brine.” Again he says, af The 
whole country was at one time an enormous lake; . - + - of this 
sea, most probably a fresh-water one, Tanganyika, the Nyanzas, 
and the Livingstone lakes are probably the remains. It may 
have been salt, witness salt soil of Uvinza and Ugaga, and fresh- 
Farther 
ened by the continual rain-fall of thousands of years.” 
on he says, “The Lukuga is the outlet if any ; it tastes the 
same as the Tanganyika, slightly salt (not salt, but peculiar), 
and not fresh, like the other rivers.” . 
Have we not here a parallel between the present Lake 
1 Journal of the Royal Geographical Society, 1875, pp. 202, 210, 227. 
Tan- 
EEUE IEEE RAEN a A IEE E ee 
ae 
Se A ee ae TET eee E E a Ne EE T 
