SUMMARIES OF CURRENT NORTH AMERICAN PRE- 
CAMBRIAN LITERATURE.’ 
Hovey,’ in notes on the Isles of Shoals, of Maine and New Hamp- 
shire, states that the general rock constituting these isles is granitic, 
varying in color from white to black, and that this is cut by later 
dikes. 
Hitchcock, C. H.,? gives a general account of the geology of New 
Hampshire, including a sketch of the work and conclusions of the 
first and second New Hampshire state surveys and of subsequent 
workers in the field. Some of the modifications indicated by work 
done since the close of the second state survey are: (1) Archean rocks 
exist as oval areas in the Stamford gneiss and south of Mt. Killington, 
Vt., in the Hinsdale, Mass., area, the Hoosac Mountain, and elsewhere. 
(2) The masses of Bethlehem gneiss are batholites, with inclusions of 
adjacent mica-schists. (3) A study of several areas of hornblende- 
schist proves that they are igneous. 
Daly‘ discusses the porphyritic gneiss of New Hampshire, and 
concludes that it is an eruptive porphyritic granite, at least in its three 
most important areas, of post-Devonian age. 
Cushing® mentions pre-Cambrian rocks in Saranac township and 
Beekmantown, N. Y. These comprise gneisses and gabbro, upon 
which the Cambrian rests unconformably. 
«Continued ffom page 756, Vol. 1V., JouR. GEOL. 
The summaries of current pre-Cambrian literature which have heretofore been 
made by C. R. Van Hise will be continued by C. K. Leith. 
2 Geological notes on the Isles of Shoals, by H.C. Hovey (Abstract): Proc. 
Am. Assoc. Adv. Sci., for 44th meeting, 1895, pp. 136, 137. 
3The geology of New Hampshire, by C. H. Hircucock: Jour. GEoL., Vol. 4, 
1896, pp. 44-62. 
4 Studies on the so-called Porphyritic Gneiss of New Hampshire, by R. A. Day: 
Jour. GEOL., Vol. 5, 1897, pp. 684-722, 776-794. 
5 Geology of Clinton county, N. Y. (preliminary), by H. P. CusHinc: Report of 
the State Geologist of New York for 1893, pp. 475-489. 
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