32 WILLIAM J. MILLER 
exhibited over the weathered surface. No. 57 of the table repre- 
sents a thin section. The large euhedral crystals of plagioclase 
(chiefly labradorite) are generally fringed with rather clear granu- 
lar scapolite, while their interiors are considerably decomposed. 
On one side this rock is moderately foliated, the feldspars being 
drawn out into crude parallelism. This foliated portion is not 
sharply separated from the rest of the rock. Within the foliated 
portion, and not sharply separated from it, there is a tongue or 
dikelike mass of gabbro very rich in dark minerals, chiefly horn- 
blende. 
TABLE I 
MINERALS BY VOLUME PERCENTAGES IN THIN SECTIONS OF THE ANORTHOSITE- 
GABBRO AND CLOSELY ASSOCIATED Rocks 
g & 
Es = 
ny fie) 3! 3 3 
rey @5=\|| 5] a 
2 pis) PH) on (a) o 
S| ne] ze OS) 9 vv o 
5 So) 6 | 2) 2sileal S 6 5 o 3 s 2 | » 
Z |Sa| 3) BISEISE BS] o | 2] ely] & ae ei esol Ot eae 
o aq g & om os g = q = =] 5 & a= cs fo) ea) Ss = 
ESE PCIE esl CuCcSIMEOrcNEL a) & | 8 | 2) 3 
wa fe | elit | et ll ea | | Pt] 3 S| See Sel <a |] Sie 
staat ileal (Vr lio Sollee alles Ballinn Os: 6 8 Ib Little opel are, Lita Ciiieelinasull 3 
ose OFM 7A | eccnetee || Sheyavel ep eueastl eeeevel lime LO 5 2 Belper sec ds 2 Pel A AIR ccc ldiic y isichc 5 
saree @ Ilse picrotes| Witter eievorn 7 7 A lo Sea ene ter aoe ceoncllaccacollacualiocas 
siatege 6 eye a7 Ng eerya |b Bee ye (eel ieee Ie ooroe Pe IN Gis atoy orto ons eo liscsperelireere 
Sajents 7 5) lanocilososl) Qe Io @ |, i eiase8 8 ae ee ee obey Gio ties) cic. d| ico. 
ante I 64 aol laos BN) Nee sally Pen ete I a. va:llecore atlra evento: ticle ieee tetera 
cand I Aad ohn SA hetyicy pe o)ue Pata ede 2h Keer sal re ea oer ee caved epee E + |aeeleteediss le: otoveletaveta 
eset I 50 I4 Day Sea home| eT CELE nee ey | a ‘4, MWe cuakarseelltaratedl Oeetete 
Sear I | 46 eS anern| le eRe) PXOs'| aes 8 erclre|lonachara vege feee Fe eee Aor |e 
Hanes 7 BO listers) eA Seale Tea leprarses ally eA PE Ged eeonicacsoollogaclincod 
eT 5 64 Bigs nee ae Hy] case o|[Nlavocil lave e onelllt «cele eeeteiell lg suet Pe ebled Male T Eel el ie 
In the coarse-grained gabbro at locality 1, less than a rod from 
the rocks above described, there is a highly foliated zone or belt 
of very variable rocks about a yard wide. Much of this rock is 
fine grained, dark gray, highly foliated, and uniform in appearance, 
a thin section being represented by No. 51 of the table. There 
appears: to be no true granulation. Another facies of this zone 
is a highly foliated, medium-grained, light-gray gabbro which in 
thin section is represented by No. 56 of the table. Still another 
facies consists of fine-grained, highly foliated, alternating bands 
of practically pure white plagioclase and gray gabbro, these bands 
varying in width from one-tenth of an inch to an inch or two. 
No. 58 of the table gives the minerals contained in a thin section 
of this third facies. 
