F. Green schist, sec. 34, T. 48 N., R. 27 W., near center of section. Contains plagioclase, chlorite, and quartz. Analysis by George Stelger, record No. 1447. P. R. C. 986.

G. Sericite-schist associated with the preceding. Mainly sericite and quartz. Analysis by Steiger, No. 1447. P. R. C. 985.

H. Dark-gray, foliated schist, SE. corner of sec. 30, T. 47 N., R. 30 W. Contains quartz, plagioclase, orthoclase, and biotite. Analysis by Steiger, No. 1525. P. R. C. 991.

I. Schistose gneiss, NW. of sec. 35, T. 47 N., R. 26 W. Contains quartz, kaolin, sericite, plagioclase, chlorite, magnetite, and apatite. Analysis by Steiger, No. 1525.

J. Novaculite from Marquette. Described by Williams in Bull. 62. Contains quartz and sericite. Analysis by W. F. Hillebrand, record No. 759.

2. CRYSTAL FALLS DISTRICT, MICHIGAN.

Rocks described by J. Morgan Clements and H. L. Smyth, in Mon. XXXVI. A, B, C, and D by Smyth, p. 274. Analyses by H. N. Stokes, record No. 1721.

A. Granite, sec. 2, T. 41 N., R. 30 W. Contains quartz, orthoclase, microcline, plagioclase, biotite, muscovite, magnetite, hematite, titanite, and occasional apatite.

B. Gneiss, sec. 35, T. 42 N., R. 29 W. C. Mica-schist, sec. 35, T. 42 N., R. 29 W. some microcline, and magnetite.

Same minerals as in A.

Contains biotite, quartz,

Contains hornblende,

D. Amphibolite, sec. 32, T. 42 N., R. 28 W. plagioclase, biotite, and quartz, with a little rutile and magnetite.

The following rocks, with one exception, are described by Clements in his portion of Mon. XXXVI:

E. Mica-diorite, sec. 28, T. 42 N., R. 32 W., southeast of Crystal Falls. Contains plagioclase (andesine), orthoclase, quartz, biotite, hornblende, and titaniferous magnetite. Analysis by Stokes, record

No. 1721.

F. Hornblende-gabbro, sec, 29, T. 42 N., R. 31 W., west bank Michigamme River, east of CrystallFalls. Contains labradorite, hornblende, and iron oxide, with subordinate pyroxene, biotite, and orthoclase. Analysis by George Steiger, record No. 1712.

G. Bronzite-norite, same locality as F. Contains bronzite, hornblende, and labradorite. Analysis by Steiger, record No. 1712.

H. Wehrlite, sec. 29, T. 42 N., R. 31 W., on Michigamme River, east of Crystal Falls. Contains hornblende, pyroxene, olivine, biotite, and iron oxide. Analysis by Stokes, record No. 1721.

I. Picrite-porphyry, sec. 27, T. 44 N., R. 32 W., northwest of Mansfield. Principal minerals serpentine, amphibole, chlorite, ilmenite, all but the last being secondary. Analysis by Stokes, record No. 1721.

J. Pre-Cambrian nonporphyritic metabasalt, from the Hemlock formation. Contains plagioclase, light-green hornblende, epidotezoisite, chlorite, calcite, muscovite, apatite, sphene, quartz, pyrite, and magnetite.

K. Porphyritic metabasalt, Hemlock formation. Same minerals as in J, with feldspar phenocrysts.

L. Porphyritic metabasalt, like K.

M. Metadolerite, large dike in T. 43 N., R. 31 W., east of Mansfield. Hitherto unpublished. Petrographic data furnished by C. R. Van Hise. Contains uralite, labradorite, and ilmenite.

Analyses J, K, and L by H. N. Stokes, record No. 1617.
Analysis M by George Steiger, record No. 1814.

N. Adinole, sec. 8, T. 43 N., R. 31 W., near Mansfield. Contains actinolite, albite, quartz, some chlorite, and epidote. Analysis by George Steiger, record No. 1709.

O. Spilosite. Contains quartz, feldspar, chlorite, epidote, and a little biotite.

P. Spilosite. Contains quartz, feldspar, actinolite, and epidote. Analyses O and P by H. N. Stokes, record No. 1617. These three rocks are contact derivatives of the Mansfield clay slate, q. v.