‘986 THE JOURNAL OF GEOLOGY. 
upturned edges rests a series of late Cretaceous, Tertiary and Pleisto- 
‘cene sediments and lavas. 
The igneous rocks are divided into an older series of Jura-Trias 
and Paleozoic age comprising diabase and porphyrite, gabbro, norite, 
peridotite and pyroxenite, granite, quartz-porphyrite, quartz-porphyry 
and diorite, and a later series comprising rhyolite, andesite and vari- 
‘ous basalts. 
Results of Stream Measurements. By F.H.NEweE.LL. Fourteenth Ann. 
Report of the U. S. Geol. Survey, 60 pp. and 2 maps, 1895. 
This paper gives the results of operations of the Division of Hydro- 
graphy up to 1893, showing in concise form the mean monthly, mini- 
mum and maximum discharge of rivers in various parts of the United 
‘States. Most of the streams measured are in the West, where data 
of this character have especial value in considering the question of 
irrigation, and to a less extent that of water power. There are also 
given facts concerning some of the eastern streams. The most impor- 
tant feature of the paper, however, is to be found in the last part, in a 
discussion of the depth of run-off for the United States and the rela- 
tion between mean annual rainfall and mean annual run-off. To illus- 
trate, this small diagrammatic maps of average annual precipitation and 
run-off are given, and a diagram showing the general relationship 
between these. This discussion is necessarily general and preliminary 
to the preparation of more detailed maps which can be made only 
after observations have been carried on through many years. 
Report on the Coosa Coal Field with Sections. By A. M. Gipson, Assist- 
ant Geologist, Pp. 143, 1 plate. Geological Survey of Alabama. 
Montgomery, 1895. 
This report deals with a coal field which, though long known, has 
not heretofore been adequately brought to public notice. ‘This field is 
about sixty miles long by five to eight wide containing 345 square miles 
of productive area. It lies mainly in St. Clair and Shelby counties, 
the most southeastern division of the Alabama coal field. It lies ina 
synclinal fold of coal measures between the Cahaba and Coosa (Silu- 
rian) valleys. The reports shows that this field contains much undevel- 
‘oped coal, embracing a large number of minable seams, some of which 
are of unusual thickness. The coal is generally very good, low in ash 
