RESEARCH· ·1970·

B38
PETROLOGY AND PETROGRAPHY
TABLE 1.-Localities and descriptions of samples referred to in this report
Group
Map
No ..
Field No.
Locality Latitude (N .) Longitude (W .)
General description of sampled rock body
L _ _ _ __ __ 1 67-ASn-264
2 67-ASn-264A
3 67-ASn-503
4 67-ASn-595
2 ________ 5 67-ASn-373
6 67-ASn-438
7 67-ASn-439
3________ 8 67-ASn-137
9 67-ASn-326
10 67-ASn-369
11 67-ASn-434
12 62-ASn-652D
4 ________ 13 61-ASn-477
14 67-ASn-65
15 67-ASn-135E
16 67-ASn-242
17 68-ASn-136
5 ________ 18 67-ASn-41
19 68-ASn-567
20 68-ASn-444
6 ____ ---- 21 68-ASn-566
68-ASn-566B
68-ASn-566C
68-ASn-566D
68-ASn-566E
68-ASn-566F
68-ASn-566 G
68-ASn-566H
(None) ___ 22 Moffit's (1913)
area.
fNone) ___ 23 Smith's (1910)
area.
(None)___ 24 Mendenhall's
(1901)area.
West of Kougarok River_ 65°26'20"
_____ do _________________ 65°26'20"
_____ do _________________ 65°24'20"
164°55'30"
164°55'30"
164°54'30"
West headwaters of 65°42'20" 164°59'50"
Kougarok River.
West of Kougarok River_ 65°30'35" 164°55'50"
Bed of Kougarok River__ 65°28'
_____ do _________________ 65°29'
164°42'30"
164°43'
North of Grantley 65°19' 166°06'30"
Harbor.
East of Kougarok River, 65°37'30" 164°33' 40"
top of Harris Dome.
West headwaters of 65°44' 164°58'
Kougarok River, north
bank of Washington
Creek.
West fork of Kougarok 65°44'20" 164°52'
River, north bank of
Washington Creek.
Northeast shoulder, 65°33' 167°04'
Brooks Mountain.
West bank, Kanauguk 65°32',· 167°31'30"
River.
North shore, Imuruk 65°11'40" 165°46'30"
Basin.
South of Grantley 65°12' 166°12'
Harbor.· .
Southeast of Gantley 65°08'30" 166°22'
Harbor.
East bank, Goodhope 65°53' 164°03'
River.
Headwaters of Nome 64°50'12" 165°12'20"
River.
Southeast of Salmon 64°52' 165°10'
Lake.
Northeast of Salmon 64°57'30" 164°50'20"
Lake.
Southeast of Salmon 64°52'04" 165°10'
Lake.
_____ do ______________________ do __________ do ____ _
_____ do ______________________ do __________ do ____ _
_____ do ______________________ do __________ do ____ _
_____ do ______________________ do __________ do ____ _
_____ do ______________________ do __________ do ____ _
_____ do ______________________ do __________ do ____ _
_____ do ______________________ do __________ do ____ _
Between N orne and _______________________ _
Solomon.
Northeast of Solomon _____________________ ~ _____ _
Tubutulik River, eastern
Seward Peninsula.
Frost-riven massive boulders on surface of
tundra-covered ridge.
Schistose frost-riven boulders surrounding
67-ASn-264.
Frost-riven massive boulders on surfaces
of tundra-covered ridge.
Float boulders in creek bed, surrounded by
tundra-covered hills.
Frost-riven boulders on tundra-covered
ridgeline.
Small outcrop on east bank of river, massive-appearing
blueschist.
Outcrop on west bank of River, relatively
sheared, pyrrhotite noticeable.
Graphitic slate band in chloritic schist,
float on ridgeline.
Thrust "xenolith" in marble.
Outcrop of calcareous, lineated slate.
Outcrop of sheared calcareous slate.
Outcrop, siliceous graphitic bed with
numerous quartz pods.
Outcrop in creek bed, graphitic siltite.
Outcrop at beach level, gray-green mafic
dike, sheared.
Frost-riven rubble of mafic intrusive.
Altered gabbro body intrusive into limestone
and slate.
Altered gabbro dike intrusive into chloritic
schist.
Sheared gabbro intruding limestone schist.
Lenticular body (tuff?) in limestone schist.
Mafic inclusion in limestone schist.
Well-exposed outcrop of chloritic schist,
faint color banding.
Do.
Do.
Do.
Do.
Do.
Do.
Do.
Chloritic schist of the N orne Group, especially
intrusives in marble.
"Greenstones" and chloritic schists of the
Nome Group.
Chloritic schist within or beneath thrust
slices of marble.
The absence of lawsonite and aragonite in the Alaskan
rocks indicates that these rocks are not similar to the
lower grade type III rocks of the Cazadero area, where
the mineral assemblage is glaucophane-lawsonite-chlorite±phengite±aragonite±jadetic
pyroxene-sphene.
Group 2 rocks clearly are retrograde blueschists.
Specimens and mineral assemblages are listed below,
with the unusu'al minerals in italic:
FieZa No.
67-ASn-373 --------
67-ASn-438 ________
67-ASn-439 --------
Description
Chlorite-actinolite-white mica-albitegarnet-epidote-sphene-(aragonite?).
Albite-chlorite-act·inolite-garnetepidote-sphene.
Albite-chlorite-actinolite-epidotegarnet-sphene-glaucophane-calcite.
These rocks clearly show a strong retrogression to
greenschist facies under static conditions; some original
foliation remains but is not inherited by the retrograde
.;