456 EDSON S. BASTIN 
metamorphism were used. ‘The majority are roofing slates. In the 
second column the averages are recomputed on the water-free basis. 
No. II represents the average of the analyses of 30 pelite schists and 
gneisses, mostly European, though a few from the United States and 
Canada were used. Only those definitely stated to be of sedimentary 
origin, or whose mineral character or geologic occurrence clearly 
showed that such was the case, were included. Schists affected by 
I. SLATES AND PHYLLITES 
AVERAGES CORRECTED FOR 
AVERAGES OF ANALYSES Totat WATER 
No. or DETER- 
MINATIONS 
Percentage Mol. Percentage Mol. 
Weights Prop Weights Prop. 
Si Osage 79 60.49 1.008 62.97 I.049 
INKOAs dane : 79 17715,0 0.172 18.28 0.179 
ICAO 65 abe c 48 2.74 ©.017 2.85 0.018 
We @ianesere es: 48 4.61 0.064 4.79 0.067 
Mic @ inane: 79 2055 0.063 2.61 0.065 
CaOierernisce 79 T3520 0.023 Tar 0.023 
ICAO RE Soman ee 74 2a 0.035 3-44 0.036 
Na,O. 74 Tei2 0.021 aay 0.022 
ABO Racin oininls 46 Onvi3 0.009 0.76 0.010 
COR are 35 Te Ta 0.02 T.1O 0.026 
Ets © aera 28 Bon 0.201 CRs 4 ona g 
5 Oe rtcicieny 28 Ong OMOTOM Malte ites oescme | Neh ieee tee 
Total.. OOo) ll 9 awe 6c Oe 54ers shores 
II.. PELITE SCHISTS AND GNEISSES 
: AVERAGES CORRECTED FOR 
AVERAGES OF ANALYSES TotaL WATER 
No. oF DETER- 
MINATIONS 
Percentage Mol. Percentage Mol. 
Weights Prop. Weights Prop. 
SIOS . wastiace 30 65.46 I.Og1 66.67 He 2003) 
HN Omen oon 20 16.32 0.160 16.64 0.163 
InEAOR ag bac ac 22 4.04 0.025 4.12 0.026 
INCOR sSoiaia a 22 Qe: 0.038 2.76 0.038 
IMUHO) Soa B0 30 2.42 c.o60 2.47 0.062 
Care ecme.: 30 I.50 0.027 1.53 0.027 
ISAO ccesnte co 30 3.40 0.036 Sec) 0.037 
Nia Oe tela 30 1.89 0.031 I.93 0.031 
Mn @ arises 24 0.89 O.OIL 0.QgI O.OI1 
COS ees 2 Noneesy ties See She hee dial ant eee gee 
sO) opances 9 1.87 fovea dole Wat Weenies oe NNN ergls bec 
Le KO a ea ae 9 0.09 OFOO. Se hehe leas Sa PRET ara eN UR 
