PREE INSTITUIE OF SCIENCE 
MINERALOGY OF THE NEWARK GROUP IN PENNSYLVANIA 
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REFERENCES 
. Wherry, E. T.—The Newark Copper Deposits of Southeastern Pennsylvania. 
Economic Geology, 3, 1908, 726-738, plate 13. December.) 
. D'Invilliers, E. V.—The Geology of the South Mountain Belt of Berks County. 
Report D 3, Vol. 2, part 1, Second Geological Survey of Pennsylvania, 
Harrisburg, 1883. Pages 217, 218. 
. Spencer, A. C.—Magnetite Deposits of the Cornwall Type in Pennsylvania. 
Bull. 359, U. S. Geol. Survey. Washington, 1908. (December.) 
(Vide p. 42 and pl. V.) 
. Davis, W. M.—On the Relations of the Triassic Traps and Sandstones of the 
Fastern United States. Bull. Mus. Comp. Zool., Harvard College, 
[Geol. Series,] 7, 1883, 249-308. 
. Fenner, С. N.—Features Indicative of Physiographic Conditions, Prevailing at 
the Time of the Trap Extrusions in New Jersey. Jour. Geol., 16, 1908, 
299-327. 
. Hillebrand, W. F.—The Analysis of Silicate and Carbonate Rocks. Bull. 305, 
U. S. Geol. Survey, Washington, 1907. 
Gage, R. B.—Determination of Ferrous Oxide in Magnetite. Jour. Amer. Chem. 
Soc., 31, 1909, 381-385. 
. Beck, L. C.—Views Concerning Igneous Action. Amer. Jour. Sci., [т], 46, 1844, 
333-343. (J Bi 339») 
. Hawes, G. W. — The Trap Rocks of the Connecticut Valley. Amer. Jour. Sci., 
[3] 9, 1875, 185-192. 
. Emerson, B. K.—The Deerfield Dyke and Its Minerals. Amer. Jour. Sci., [3] 
24, 1882, 195-202, 270-278, 349-359; Geology of Old Hampshire 
County, Mass., Mon. 29, U. S. Geol. Survey, 1898. v. pp. 438, 444, 472. 
. Lewis, J. V.—Petrography of the Newark Igneous Rocks of New Jersey. Ann. 
Rept. State Geologist of New Jersey, 1907, 99-167. (v. p. 165.) 
. Dana, J. D.—Origin of the Constituent and Adventitious Minerals of 'Trap and 
Allied Rocks. Amer. Jour. Sci., [1] 49, 1845, 49-64. 
. Fischer—Ueber das Vorkommen von Prehnit, Datolit, und Rutil bei Freiburg i. 
B. Neues. Jahrb. |. Min. u.s.w, 1862, 432-450. (v. p. 442.) 
. Brauns, R.—Albit, analcim, natrolit, prehnit, und kalkspath, verwitterungs- 
produkte eines Diabases von Friedensdorf bei Marburg. Neues Jarhb. 
J. Min. u.s.w., 1892, (2), 1-24. 
. Van Hise, C. R.—A Treatise on Metamorphism, Mon. 47, U. S. Geol. Survey, 
1904, 3327333. 
- Wherry, E. T., and Chapin, W. II. — The Determination of Boric Acid in Insoluble 
Silicates. Jour. Amer. Chem. Soc., 30, 1908, 1687-1701. 
