382 Tlic American Geologist. Juno, i89» 
indicating that region to be probably the Ophir of the ancients. Rivers 
flowing thence to the sea brought the gold-bearing littoral marine sands 
and gravels, of Paleozoic age (perhaps Devonian or Lower Carbon- 
iferous), which have yielded from $20,000,000 to $38,000,000 of gold 
yearly since 1891. Similar auriferous manne deposits in many other 
parts of the world, including Nova Scotia, North Carolina, the Black 
Hills, the Big Horn range, California, and Alaska, are also noted in 
this paper. Indeed, Dr. Becker shows that nearly all pre-Tertiary 
gold-bearing gravels are of such marine deposition as in the Trans- 
vaal, w. u. 
Reconnaissance of the Gold Fields of Southern Alaska, with some 
Notes on General Geology. By George F. Becker. (From the Eigh- 
teenth Annual Report, U. S. Gaol. Survey, for 1896-97, Part HI, Eco- 
nomic Geology, pp. 1-86, with 31 plates and 6 figures in the text. Wash- 
ington, 1898.) 
This report presents a great amount of detailed geologic informa- 
tion, mainly relating to the gold m.ining and gold-bearing rocks at 
Juneau and other localities on the southern coast of Alaska, based on 
observations by the author in 1895. It will be read with great interest 
on account of the recently discovered and wonderfully rich placer mines 
of the Uppei Yukon district, which are the subject of the next paper. 
The product of gold from the Alaska-Treadwell mine in the fifteen 
years since it was opened, up to the end of the year 1896, was $7,028,649. 
Its ore in 1893 and 1894 yielded only $3.20 per ton, and the cost of its 
working, with daily wages from $2 up to $5, was only $1.35 per ton. 
This mine in 1889 to 1893 produced about two-thirds of all the gold 
mined in Alaska; but since 1893 its proportion has been a half to a 
third, the whole gold production of Alaska in 1896 being estimated, by 
the director of the mint, as $2,055,710. .w. u. 
Iowa Geological Survey. Adiniiiistrativc Reports. (Iowa Geol. 
Survey, vol. 8, pp. 9-49, plates 1-2, 1898.) 
The sixth annual report of the state geologist, Samuel Calvin, gives 
a detailed statement of the work of the survey for 1897. This report 
shows that the activities of the survey have been directed toward a 
number of important lines of research, among which are special work 
on the drift and on the Carboniferous, investigations and aid in de- 
veloping the natural resources of the state, collecting of mineral statis- 
tics and areal county work. During the past year areal county work- 
has been completed in the following six counties: Dallas, by A. G. 
Leonard; Scott, by W. H. Norton; Decatur and Plymouth, by H. F. 
Bain; Delaware and Buchanan, by Samuel Calvin. It is expected 
that the reports on these counties will be published- in the present 
volume (VIII) of the survey. In previous years twenty counties have 
been mapped and reported upon, making a total of twenty-six coun- 
ties in which the work has been completed. 
The report of the assistant state geologist, H. F. Bain, presents 
statements of reconnaissance work conducted in a number of counties, 
