62 THE GRANITES OF MAINE. 
been referred to by Professor Wolff. At this place there is a finely 
plicated quartz-feldspar (andesine acid labradorite) hornblende-bio 
tite schist, with accessory pyroxene, titanite, and apatite, striking N. 
15° E., with numerous dikes of pegmatite, up to 2 feet 6 inches 
thick, parallel in places to the strike of the schist. On the southwest 
wall of the lower quarry a tongue of this schist 10 to 15 feet thick 
and 40 feet long lies in the diorite, as shown in PL XT, B. It 
reappears on the northeast wall. 6 The contact of the diabase por- 
phyry of Hermon Hill, near Bangor, is described on page 147. 
TEXT-BOOK REFERENCES ON GRANITE AND BJLACK 
GRANITES. 
A.s the matter contained in the foregoing pages may not fully pro- 
vide answers to all finest ions that may arise in the minds of persons 
interested in tracing the phenomena in granite quarries to their 
causes, the names of a few reliable general works in English on the 
subjects considered are here given. 
Diller, Joseph S. Educational scries of rock specimens collected and dis- 
tributeebfry the United States Geological Survey: Bull. U. S. Geol. Sur- 
vey No. 150. is; is. 
Granites, pp. 51, L70 L80 ; gabbro, pp. 51, 52, 278 288; diorite, pp. 241-244; 
diabase, pp. 264-278; basalt, pp. 51, 52, 254 256. 
Geikie, Archibald. Text-book of geology, fourth edition. London. L903. 
Granite, etc., pp. 89, 90, 203 209, 102 415, 715 809; gabbro, pp. 231, 232, 
L'.Ki : diorite, p. 223; diabase, p. 233; basalt, p. 234. 
Harker, Alfred. Petrography for students: An introduction to the study of 
rocks under the microscope, second edition. 1897. 
Granites, pp. 27-41; gabbros, pp. <'>7 81; diorite, pp. 5 1 66; basalts, pp. 
L88 200. 
Hatch, Frederick II. An introduction to the study of petrology; the igneous 
rocks, second edition. London. 1891. 
Kemp, James F. A handbook of rocks for use without the microscope, third 
edition. New York. 11)04. 
The granites, pp. 33 38; gabbros, pp. 72 71; diorites, pp. 60 62; diabases, pp. 
70-71'. 
Luquer, Lea M. Minerals in rock sections, revised edition. New York. 1005. 
Merrill, Geo. I*. A treatise on rocks, rock weathering, and soils. New York, 
L897. 
Igneous rocks, pp. r.s-64 ; granites, pp. 65-68; diorites. pp. 81, 82; diabases, 
pp. 87, 88; basalts, pp. 90, id : weathering, pp. 170-214. See also the same 
headings in the revised edition of same work, which 1ms just appeared. 
» Wolff, J. E.. Details regarding Maine quarries: Tenth Census, vol. 10, 1888, p. 121. 
h As to the schist and pegmatite, see Basconi, op. cit., p. 61. 
