12

i i i i i i i 3 i
s.000N PIERCE paseuine _
/s.800N
600M
201
4.300N EXPLANATION
7 PON OUTLINE OF MAGNETIC ANOMALIES IN GAMMAS.
4.200% AAA O00 AREA
*
scace ¢

ago 20300 reer

Figure 6. - Sheet 4 of 4, plan of Pierce anomalies, Hammond Plantation,
showing relation to Matthew Carpenter-Farm anomalies.



33

TABLE 15 - Diamond-drill-hole logs!/ (con.)

Pierce DDH-3

Interval, feet

Description

0-28 ..
28-71 ..

71-109 ..
109-122.5

122.5-126.5 .
126.5-127.5
127,5-136.5 .

136.5-137 ..
137-144.5
144.5-145 ..

145-172.5 ...0.

Overburden.

Dark-green, laminated slate containing sulfide at various places,
for example, 32 feet.

Fault breccia or microboudinage at 32 feet.

Abundant limonite staining in badly broken core at 65-65.5,
67.5-68.5, and 69-70 feet; possible shear zones.

Slaty, gray-blue siltstone, with a few thin, calcareous laminae.

Finely laminated to massive gray-blue slate. Gray-white laminae
are calcareous. Small fault at 116 feet.

Gray, fine-grained quartzite.

Dark-green, laminated slate,

Manganiferous banded magnetite-chlorite rock and banded hematite
rock. This interval is cut by abundant microfaults and gash
veinlets. Limonitic layer at 128.5-129 feet probably represents
altered carbonate-type ore.

Light-green slate.

Dark-green slate.

Laminated green chloritic slate, with reddish-purple layers con-
taining magnetite and hematite.

Large bleb of sulfide, 1 inch across, at 145 feet, surrounded by
small leach cavities.

Dark-green slate, with thin, gray, calcareous laminae.

Bottom of hole at 172.5 feet.

Bedding at- | Makes angle with core axis-|| Bedding at- [Makes angle with core axis-
35 feet 60° 105 feet 65°
43 feet 70° 110 feet 80°
50 feet 68° 115 feet 77°
65 feet 87° 126 feet 76°
71 feet 88° 130 feet 74°
75 feet 82° 145 feet 65°
81 feet 77° 150 feet 68°
85 feet 76° 155 feet 63°
90 feet 78° 160 feet 58°
95 feet 76° 165 feet 62°
100 feet 75° 170 feet 60°

Pierce DDH-4

Interval, feet

Description

0-21. .
21-34
34-35
35-43

43-4365 wesoee

43.5-44.6 weseee

Overburden.

Dark-green slate, with light-gray, calcareous laminae.

Interbed of manganiferous laminated banded hematite (magnetic).
Dark-gray, feldspathic, fine-grained rock; resembles a graywacke.
Pyrite coating along joints is common.

Manganiferous laminated rock, containing light-gray and red hema-
titic laminae. Rock is nonmagnetic.

Brecciation in rock similar to core interval between 43 and 43.5
feet.

1/ See footnote at end of table.


29

with manganese in a higher state of oxidation. This sample yielded manganese read-
ily, however, when a small amount of reducing agent, such as ferrous iron or sulfur
dioxide was added to the slurry. Although higher percentages of manganese than iron
were extracted, sulfuric acid leaching was not particularly selective. Results of
the tests are shown in table 12.

Both hydrochloric and nitric acids were slightly more effective than sulfuric
in extracting manganese from the samples. A reducing agent was required with sample
A-31. One test with 1 part 20-percent HC1 solution for each part of ore by weight
produced a clarified liquor with a concentration of manganese high enough to deposit
hydrated (MnC12) manganese chloride crystals on cooling. The results are shown in
tables 13 and 14,

TABLE 12. - Results of dilute H2S04 leaching tests! on samples of ore~ 2!
from Pierce and Nickerson-Farm-prospect deposits

Recovery in leach solution
Ore Time, Temperature, Mn Fe
Designation Grams hours °C. Grams Percent Grams Percent
4-30. vases] 9-25] 0.5 0.376 | 44.80 | 0.123 7.47
A-30 9.26 | 1.0 465 | 55.48 162 9.86
A-30 9.25 | 3.0 572 | 68,22 +240 | 14,64
A-30 9.26 | 7.0 .663 | 79.01 333 | 20.29
A-31 10.87 3 25 027 2.74 038 1.98
A-31 10.87 | 1.0 032 3.25 047 2.46
A-31 .. 10.88 | 3.3 040 4.01 .073 3.78
A-31 10.88 | 7.0 +054 5.40 .113 5.91
4-313). 10.88 | 3.0 -901 | 90.68 - -
a3! , 10.88 | 7.0 927 | 93.33 - -
A-28 8.39 5 751 | 75.58 422 | 21.11
A-28 8.38 | 1.0 830 | 83.60 -506 | 25.31
A-28 8.38 | 3.0 -905 | 91.17 -596 | 29.83
A-28 8.39 | 7.0 .915 | 92.13 -639 | 31.96
A-29 8.05] 1.0 .871 | 87.73 650 | 38.80
A-29 8.05] 3.0 894 | 90.07 «717 | 42.83
A-29 .. 8.05 | 7.0 +903 | 90.94 «721 | 43.05
A-30 .. 10.95 25 60 733 | 73.90 350 | 18.01
A-30 .. 10.96 | 1.0 .790 | 79.57 +417 | 21.49
A-30 . 10.95 | 3.1 -860 | 86.65 518 | 26.69
A-30, 10.95 | 7.1 -903 | 91.03 =573 | 29.49
A313) 10.87 | 7.0 1946 | 95.32 | - :
a-314/ oo, 10.88 | 3.0 665 | 66.94 - -
A-314/ , 10.88 | 7.0 .687 | 69.21 - -
A-3 12) 10.88 | 3.0 491] 49.48 - -
A-315/ .........4.| 10.88 | 7.0 491 | 49.48 - -

1/ Leaching solution consisted of 60 ml. of 1.506 N H2SO,3 mole ratio acid/Mn = 2.5.
2/ Ore ground to minus-65-mesh.

3/ Approximately 10 grams 118 7H20 added to slurry - amount theoretically required
to reduce MnIV to MnIl

4/ Same as footnote 3, except amount of FeSQ4.7H20 reduced by half.
5/ 24 ml. H2S03 (6 percent) added to slurry. Amount of HyS0, available reduced so
that mole ratio of total S/Mn = 2.5.


38

TABLE 15. - Diamond-drill-hole logs’ (con.)

Burnham DDH-1

Interval, feet

Description

0-17 ....
17-47 we eeeeee

261-261.6 .....

261.6-294.6 .....

294.6-311.5 wo...

Overburden,.

Gray, fine-grained, massive quartzite.

At 27.4 feet: Lenslike, small (1 inch) pods containing coarse-
grained quartz, feldspar, and other material. These may be
local conglomeratic layers. At 28.5 feet: Quartz vein. At
42,.5-47 feet: Brown, limonite-stained, sheared, fine-grained
quartzite.

NOTE: The term "quartzite" is used only as a field name. The
rocks are probably low-rank graywacke.

Dominantly, gray-green slate, with a few quartzite interbeds.
Gray and brown, fine-grained quartzite.

Gray-blue slate interbeds at 111-114, 167.5-169, 184-186,
229-229.5, 231-231.5, 237-237.5, and 259-259.5 feet.

Quartz veinlets at 127.6-128, 130, 131-132.5, 182, 194-195,
197-199, 215-217, 221.5, 223-226, 227-228.5, 231.5, 236-237,
250-250.5, and 253.5-254 feet.

Coarse-grained quartzite between 167-196 feet. Graywacke, with
black-slate fragments between 193-195, and 201-205 feet.

Hit water between 200 and 207 feet.

Breccia zone between 207-210 and 213-215 feet.

Dark-green vesicular igneous rock (metaandesite?). Upper contact
not apparent owing to broken nature of core. Lower contact sug-
gests conformable contact with sedimentary rocks. Igneous rock
highly chloritized and characterized by calcite-filled vesicles.
Not clear if this is a sill or an interbedded extrusive; baking
effects not noted on either side.

Gray-green, fine-grained quartzite, with green and gray slate
interbeds.

Dark-green, chloritized, igneous rock similar to that between
261-261.6 feet. Contact relationships with the preceding
sedimentary rocks not clear owing to broken nature of core. No
baking effect discernible. Calcite-filled vesicles noted be-
tween 304,5-306 feet. This rock is variably magnetic.

Bottom of hole at 311.5 feet.

Bedding at- | Makes angle with core axis- Bedding at-| Makes angle with core axis-
49 feet 45° 120 feet 42°
55 feet 40° 126 feet 40°
65 feet 42° 146 feet 40°
70 feet 38° 180 feet 50°
80 feet 34° 185 feet 65°
84 feet 30° 222 feet 40°
91 feet 28° 231 feet 50°
100 feet 45° 237 feet 48°
110 feet 31° 277 feet 50°
114 feet 40°

1/ Table furnished by Louis Pavlides and L. A. Brubaker, Federal Geological Survey.

INT. = 8U,OFMINES.PGH..PAL 9021


Bose ine fr mogratomete sive

——

ron-pipe morker

10 containing outrop

Mongonitarous shale outerop
Toor Site ond dip of beds

Contours rem Houten qouctorg, US.6S.
SCALE

100,

saaanaaaanaatt

ls.200%
|.00on
|sa00n

Figure 2. - Plan showing outcrops of manganiferous rock on Nickerson-Farm prospect, Hodgdon Township.


16

Pierce Deposit No. 2, Diamond Drilling

Three inclined holes, totaling 499 linear feet, were drilled in Pierce deposit
No, 2 at intervals of 400 and 800 feet along the strike (see fig. 3). They are also
plotted in vertical section (see figs. 7 and 8). Diamond-drill hole 2 (DDH-2),
drilled in a wider area in the anomaly, made two intersections of manganiferous ma-
terial, The upper bed or lens, measuring 6 feet true thickness and liberally
sprinkled with fine pyrrhotite, assayed 10.3 percent Mn, 19.3 percent Fe, and 2.1
percent S, The lower bed, 49 feet true thickness, assayed an average 12.9 percent
Mn and 19,7 percent total Fe. DDH-5, drilled under a weaker magnetic area along
the strike of the anomaly, intersected the deposit, cut 29.0 feet true thickness,
and averaged 10.6 percent Mn and 20.8 percent Fe. DDH-6, in a gap of the anomaly,
was drilled to determine if the deposit was continuous between local areas of high
magnetic intensity. This drill hole intersected 11 feet true thickness of laminated,
manganiferous, hematitic rock, containing relatively less magnetite than the quan-
tity found in the other drill-core intersections. The core assayed 12.5 percent Mn
and 20.6 percent Fe.

Excluding the upper intersection in hole 2, the 3 drill-hole intersections in
the deposit averaged 29.7 feet true thickness and assayed an average of 12.1 percent
Mn and 20.1 percent Fe. The average dip of the deposit, determined by drilling, is
57° SW.

Pierce Deposit No. 3, Diamond Drilling

It was necessary to open 1,350 feet of access road by a circuitous route through
a swampy wooded area to reach Pierce deposit No. 3. Only one inclined hole (No. 4)
was drilled in the anomaly; it intersected 12.5 feet true width of deposit and aver-
aged 12.4 percent Mn and 21.2 percent Fe (see table 1). As intersected in the drill
hole, the deposit dips 57° SW. An unusual, variegated section of core at 50.3 feet
of hole depth, shown in photograph (fig. 9), is composed of thin laminations, in
bands up to 1/4 inch in thickness, of siliceous hematite and slate, and includes
bands or pods of impure manganese carbonate, as much as 3/16 inch in thickness.
Four core samples, which assayed 10.6 to 30.4 percent Fe, were also analyzed for
phosphorus and ranged from 0.279 percent in the sample containing the lowest assay
of iron to 1.194 percent in the sample containing the highest assay of iron.

Diamond Drilling, Burnham Anomaly, Hammond Plantation Township

Burnham drill hole 1, shown in plan (fig. 10) was diamond-drilled, AX size
(1-1/8-inch-diameter core), at 45° to test the unexposed rock in the vicinity of the
north side of the anomaly. No manganiferous rock was found in the core. The drill
hole passed through quartzite and slate interbeds and intersected chloritic igneous
rock, variably magnetic at 294.5 feet. Drilling was stopped at 311.5 feet. Water
under pressure was encountered between 200 and 207 feet. The vesicular andesite,
thought to be an igneous flow or a sill, is indicated by drilling and trenching to
be about 75 feet in width.

Nickerson-Farm Prospect, Hodgdon Township

Field work on the Nickerson-Farm prospect was started April 21 and completed
May 26, 1953. A north-south base line was transit surveyed for a linear distance of
3,200 feet. Stakes were set at 200-foot intervals, and east-west traverse lines
were turned and picketed from each stake. The magnetometer-survey party extended
the traverse lines for an aggregate distance of 24,000 feet, and magnetometer


34

TABLE 15. - Diamond-drill-hole logs£/ (con.)
Pierce DDH-4 (Con. )

Interval, feet

Description

44.6-55.5 ceeeee

55.5-88.6 1.2.26.

Manganiferous banded and laminated hematite rock varying from
slightly magnetic to nonmagnetic in character, and banded mag-
netite-chlorite rock of a highly magnetic character; latter
rock type is dominant between 53,.5-54.5 feet.

Dark-gray, massive graywacke similar to that between 35-43 feet.

Bottom of hole at 88.6 feet.

Bedding at- | Makes angle with core axis- || Bedding at- | Makes angle with core axis-
23 feet 80° 45 feet 45°
30 feet 75° 50 feet 90°
34 feet 60° 55 feet 85°
Pierce DDH-5
Interval, feet Description
0-9 40. Overburden.
9-75.2. Gray-green silty slate, slightly calcareous. Between 36-66 feet

7542-90.2 .eeeee

90.2-104.7 ..

104.7-120 .......
120-160 .......

the slate is well laminated; light-color laminae is calcareous.

Thin lenses of pyrite at 67, 68, and 70 feet.

Manganiferous, finely banded and laminated, variably magnetic
rock consisting of hematitic laminae, shale laminae, light-color
(presumably carbonate-bearing) laminae, and some green, chloritic
laminae,

Rock is cut by abundant gash veinlets of feldspar and quartz con-
taining a fibrous yellowish-green mineral, which may be of be-
mentite-ganophyllite type. Pyrite is associated with or near
these veinlets, as well as in laminae; also is finely dissemi-
nated without any apparent connection with veinlets.

At 86 feet some banded hematite rock display an intricate system
of small normal faults, suggesting a preconsolidation feature
generally developed in muds.

Manganiferous, banded and laminated, dark-green, chloritic rock,
resembling manganiferous siliceous, carbonate-type rocks con-
tained in Littleton Ridge deposit. Lighter color laminae are
presumably mostly impure carbonate (no effervescence with cold
HC1), and some contain very finely divided hematite. This
chloritic rock is more highly contorted and contains areas sug-
gestive of microboudinage. Gash veining, also present in this
sequence, is similar to that described in above unit, Sulfide
also is present. Both are associated with quartz-feldspar vein-
ing and as thin veinlets of sulfide within manganiferous rocks.
Quartz-feldspar veining at 102-102.5 , 103.5, and 104.7 feet.
Laminated gray and green slate. Pyrite at 119.7 feet.

Dark-gray to black slate, with some calcareous laminae, as well
as a few green-slate interbeds. Pyrite occurs as massive laminae
or is finely disseminated throughout rock or concentrated in
small blebs. Calcite veins are also present throughout this
lithology.

Bottom of hole at 160 feet.

I7 See footnote at end of table.


INVESTIGATION OF MANGANESE AREAS, HAMMOND PLANTATION
AND HODGDON TOWNSHIPS, SOUTHERN DISTRICT,
AROOSTOOK COUNTY, MAINE

by
N. A. Eilertsen1/

CONTENTS

SUMMMATY .cecsecccccecccocens
Introduction ...
Acknowledgments .......00
Location and accessibility .
Physical features and climate
History and ownership ........
Description of deposits .
Pierce deposits ....
Burnham anomaly ......
Nickerson-Farm prospect ....
Character of ore .. oe
Pierce deposits ......
Nickerson-Farm prospect .
Work by the Bureau of Mines
Pierce deposits ...cccccecccceccccccvcves
Pierce deposit No. 1, diamond drilling and trenching
Pierce deposit No. 2, diamond drilling ...........
Pierce deposit No. 3, diamond drilling ..

Diamond drilling, Burnham anomaly, Hammond Plantation
TOWNSHIP .eccececccccccccccccceceececereessssssesscsccece
Nickerson-Farm prospect, Hodgdon Township .....ccsecceeeee

Diamond drilling, trenching, and sampling the

Nickerson-Farm prospect .c.cccsccccceccee
Chemical and metallurgical investigations .....

Determination of magnetic fractions in drill-core and
trench samples ......cccecccccccccccvccevccccccscccscsces

ro
DARWOUVYUUUUER PENNE E

pe

i/ Mining engineer, Bureau of Mines, Region V, College Park, Md.

Report of Investigations 5392


27

TABLE 8. - Screen tests on fractions resulting from Dings-Davis-tube
magnetic separation of samples E-1072 and E-1073

Fractions
Magnetic, A Middling, B Nonmagnetic, C
Mesh Grams | Percent | Grams | Percent | Grams [| Percent
Sample E-1072
+100 ..... on - - - - 2.50 5.5
-100+150 . seeee - - - - 3.10 6.8
~150+200 . - - - - 2.05 4.5
-200+270 . 1.75 13.9 0.15 9.3 3.75 8.3
-270+325 . 2.10 16.7 50 21.1 6.60 14.5
7325 wees 8.75 69.4 +96 59.6 27.40 60.4
Total : 100.0 : 100.0 =. 100.0
Sample E-107.
+100 ..... - - - - 4.30 8.3
-100+150 . - - - - 4.40 8.5
-150+200 . - - - - 3.80 7.3
-200+270 . - - 0.10 3.6 5.15 9.9
-270+325 . 0.45 8.6 +09 32.1 4.70 9.1
7325 caeee 4.75 91.4 -18 64.3 29.45 56.9
Total - 100.0 - 100.0 - 100.0
TABLE 9. - Removal of synthetic magnetite after roasting
Description of Mn | Fe | P | Sid, | Percent of
sample Percent total weight
Sample E-1072-C
Magnetic portion .... 21.0 1.11 | 25.6 57
Nonmagnetic portion . 13.9 85 | 35.1 43
Sample E-1073-C .
Magnetic portion ......seceeeeee | 16.2] 21.0 77 | 26.5 65
Nonmagnetic portion ............| 16.7] 15.9 76 | 32.9 35

Flotation Tests, Nickerson-Farm Prospect

The diamond-drill core of hole 2, Nickerson-Farm prospect, contains white to
buff laminae and layers up to half an inch in thickness in the hanging- and foot-
wall slates of the deposit. Particles of this material, when subjected to petro-
graphic examination, indicated the presence of manganese carbonate - assumed to be
rhodochrosite, A specimen, consisting of a layer half an inch in thickness, in the
foot-wall slate was gouged from drill core at a depth of 231.5 feet. Its complex
composition yielded assays as follows:

Percent

Mn ceeeeeeeee 20.30
5.27
12
26.44
5.13
2.88
221
2,01
251



—-s

INGLINATION -50°

D.DH. | ELEV.COLLAR 562.4'

Pe COORDINATES:
+ 'N4,730
£4400

BEARING:
H DUE NORTH

FOOTAGE

NTERVAL| ASSAY, PERCENT

\-ROm-| TO-

FT. MN. FE

1351.0\148.0,

17.0 9.60| 19.95

PIERCE NO.! DEPO

SIT

580

—-s

INCLINATION-“5O°
D.0H.3 ELEV.COLLAR 563.6°

N=—

jURDEN

COORDINATES

ea 390

BEARING:
QUE NORTH

FOOTAGE _|INTERVAL| ASSAY, PERCENT

|FROM-| TO- FT MN FE

127. 5}136.5. 9.0 ILS 4 19.02

PIERCE NO.I DEPOSIT

NE ~—

TRENCH 3
eNcn

PIERCE NO.2 DEP

osit 2% 10 0

—> SW
INCLINATION-45° 550
ODH.2 ELEV. COLLAR 545.7'
VERB UR ORCI 540
COORDINATES:
N 4,865 520
E 6,400
BEARING: 500
N3°30'E
480
460
FOOTAGE [INTERVAL] ASSAY, PERCENT || ,
FROM TO- aa MN FE
8.0] 645| 65 | 7031 | 19.03 ||,
\ 107.5|158.2| 50.7 | 12.93 | 19.69
scaue
er

INGLINATION~48*
O.0H.5 ELEV. COLLAR 554.0

COORDINATES:
N5,022
£5,595

BEARING:
DUE NORTH

FOOTAGE |INTERVAL| ASSAY, PERCENT.

FROM-| TO- FT MN FE

75.6\1048\ 29.2 10.59. 20.77

100 PIERCE NO.2 DEPOSIT

Figure 7. - Vertical sections through diamond-drill holes 1, 2, 3, and 5, Pierce deposits.

€1


[7,200 N_

6,800 N

rn T re T rm T J T o T wu
8 3 ° 3 ° 8
8 3 8 8
3! 3) & 2 3 3
* a 3 3| | ©
7,800N

INCLINATION -45°
ELEV. COLLAR 672.0"

D.D.H.1

COORDINATES:
N 7,365
E 5,300

BEARING:
DUE SOUTH

100

— 300. 7 EXPLANATION

— 200. GZ SURVEY COORDINATES ARE ASSUMED.
ANOMALY IS PLOTTED IN GAMMAS.

>) INDICATES NEGATIVE ANOMALY.

VESICULAR ANDESITE DIKE.
CONTAINS DISSEMINATED MAGNETITE.

GREEN SLATE

100

SCALE
° 50100 200 300 FEET

Figure 10. - Part of Burnham anomaly, showing location of trench 1 and diamond-drill hole 1.

61


15

TABLE 1. - Analyses of diamond-drill cores, Pierce deposits (Con.)

(Minus-65-mesh screen, David-tube magnetic separation)

Diamond-drill hole 6, Pierce deposit No. 2

Sample
Footage interval, Core assay, percent Magnetic fraction

From- __To- feet Mn Fe s P Weight, percent
71.4 74.6 3.2 0.41 { 5.52] 2.38 : =
74.6 78.0 3.4 9.18 | 25.73] 1.17 - 19.3
78.0 86.0 8.0 13,98 | 18.42] .47 : 11.6

Total .. 11.4 12.55 [20.60] .68 = 13.9
86.0 90.0 4.0 4.31] 8.15] .49 =

Total .. 18.6 - - = - Core recovery, 91.3 percent

Diamond-drill hole 4, Pierce deposit No. 3

30.0 34.0 4.0 3.73 | 11.23} 0.53 - -
34.0 35.5 1.5 6.48 | 16.43 +36 - -
35.5 43.0 7.5 1.52] 9.59{ 11 - -

Total .. 13.0 : = - - -
43.0 44.6 1.6 11.60 | 17.49] .23 | 0.547 11.8
44.6 53.2 8.6 12.20] 21.56] .57] .732 36.8
53.2 54.6 1.4 9.23 | 30.38] .14] 1.194 51.7
54.6 55.5 oe) 20.32 | 10.62 234 2279 20.4

Total .. 12.5 12.38 | 21.24 +46 727 34.1

Total .. 25.5 - - - - Core recovery, 94.5 percent

TABLE 2. - Analyses of trench samples, Pierce deposit No. 1

(Minus-65-mesh screen, Davis-tube magnetic separation)

Trench 1
(Measured north to south)
Sample
Footage interval, Core assay, percent Magnetic fraction
From- To- feet Mn Fe s Weight, percent
) 3.1 3.1 11.48 | 19.75 | 0.58 21.2
3.1 5.3 2.2 10.58 | 30.59 18 49.0
5.3 13.3 8.0 12.84 | 22.61 62 29.1
13.3 1.3 8.0 12.04 | 21.36 229 20.9
Total ...... 21.3 12,11 | 22.55 44 26.9
Trench 2
(Measured north to south)
0 4.0 4.0 9.64 | 34.76 | 0.087 51.3
4.0 8.0 4.0 9.04 | 38.59 15 56.2
Total ...... 8.0 9.34 | 36.68 12 53.8
Trench 4
(Measured north to south)
0 3.9 3.9 11.15 | 22.06 | 0.45 10.9
3.9 10.5 6.6 16.40 | 21.00 344 26.1
10.5 16.9 6.4 12.38 | 28.59 +22 26.3
Total ....... 16.9 13.67 | 24.12 36 22.7



28

The material was not tested for other elements.

Flotation tests were tried on a composite section of slate core, averaging
about 5 percent Mn from 27.0 feet in hole 2 (see table 10). The first test was made
on a sample ground to pass 65-mesh, but loss of slime was high. To overcome this,
subsequent samples were ground to minus-48-mesh. A total of 10 tests was tried,
using various combinations of collectors and other flotation reagents. Assays of
the rougher concentrates in the tests ranged from 13.3 to 17.6 percent Mn. Test 8
is typical of the results obtained. In this test the equivalent of 0.5 pound sul-
phuric acid per ton was used to adjust the pH of the pulp, and 0.6 pound oleic acid
per ton as a collector,

TABLE 10. - Flotation test 8

Weight, Analyses, percent Distribution
Product percent Mn Fe P |} siog Mn Fe Pp
Rougher concentrates 12.8 13.8 14.8 | 0.42] 21.5] 31.6 18.0 | 27.8
Rougher tailing . . 87.2 4.39 | 9.89] .16 - 68.4 | 82.0 | 72.2
Composite .. . 100.0 5.6 10.5 19 = 100.0 | 100.0 [100.0

Although it was found possible to concentrate some of the material composing
the laminae and thin layers in the slate, no indication was given that a pure manga-
nese mineral could be recovered by ore-dressing methods alone.

Leaching Tes ts8/

Representative samples of ore were cut from the crushed and blended drill cores
obtained from the Pierce deposits and the Nickerson Farm in southern Aroostook County.
Samples were also cut from consolidated trench samples on the Nickerson Farm.

After the samples were ground to minus-65-mesh and thoroughly blended, they were
analyzed for manganese and iron content. The manganese content ranged between 9 and
13 percent, and the iron content between 17 and 24 percent. These data are summa-
rized in table 11.

TABLE 11. - Partial analysis of southern Aroostook County
manganese-ore samples

Designation Ore body Analyses, percent
Mn Fe
A-28 ... Pierce hole 1 ....sseeeeesevveeee 11.84 | 23.85
A-29 . « | Plerce hole 2 .sscscececseceeeees 12.33 | 20.80
A-30. aoe «+e. | Composite of Nickerson hole 2
and trench 1 ......eeseeeeeeeeee 9.06 | 17.73
A-31 ...ceeeeeeeeee | Composite of samples from
Nickerson trench 1 .......- 9.13 | 17.64

A number of sulfuric acid leaching tests were performed on the various samples
to determine: (1) Whether differences existed in leachability, (2) the optimum time
and temperature required for the best extraction of manganese, and (3) whether man-
ganese could be extracted selectively. Results indicated that most of the manganese
was extracted from all samples at 60° C., except A-31, which was a surface sample

87 Section written by R. T. MacMillan, former chemist, Minerals Processing Branch,
Bureau of Mines, Region VIII.


10

g 3 3 3 3 3 3 3 3 3 4 3 3 3 8 3
a a 4 a = E 3 a 3 a a 3 a a g
lezoon a se os 8 we es 1
s
coon 38 2 2 _ 26 0 A A . us “4 x F s
33 3
sea 0 23 20 ae aa
}5.800N 24 263 322 198 184 294 cr
.
s.600n
»
s.200n 29
2
”
S200. so

EXPLANATION

(BON OUTLINE, OF MAGNETIC ANOMALIES IN GAMMAS.
CONTOUR INTERVAL, 1000 GaMMas.

4,200N
(QO OUTLINE OF NEGATIVE ANOMALIES.
AAA WOODED AREA SCALE
eg 109 00 309400
|4,000N

Figure 4, - Sheet 2 of 4, plan of Pierce anomalies, Hammond Plantation.


Southern-district deposits have been surficially examined by various interests
during the past 20 years and have been described in published reports of the Federal
and State Geological Surveys. Bureau of Mines metallurgical studies of material
from deposits of the Southern district covered by this report indicate that manga-
nese is largely present as a carbonate and that much of the iron content is magnet-
ite. Manganese can be recovered from carbonate-type ores, after heat treatment, by
leaching with certain ammoniacal solutions. Ores of the Southern district would
thus appear to be more amenable to this type of beneficiation than those of the
Central and Northern districts, Detailed magnetic surveys are required to determine
if the limited surface exposures indicate large deposits and whether subsurface ex-
ploration is necessary to sample the material.

ACKNOWLEDGMENTS

Acknowledgment is made to A. P. Burnham, a State game warden, for assistance
rendered the Bureau of Mines when the manganiferous float at "B" stream, Hammond
Plantation, was discovered during the summer of 1952.

Louis Pavlides and L. A. Brubaker of the Federal Geological Survey logged the
diamond-drill cores and furnished the diamond-drill-hole logs (table 15) in this
report.

LOCATION AND ACCESSIBILITY

The Pierce deposits in Hammond Plantation Township are on the northwestern
boundary of the Southern manganese district in Aroostook County, Maine, about 8
miles northwest of Houlton, the county seat.

The Burnham anomaly is also in Hammond Plantation Township on "B" road, three-
quarters of a mile south of the Pierce deposits.

Hammond Plantation is accessible by traveling 1 mile north of Houlton on U. S.
Route 1 (see fig. 1), then northwest on improved "B" road, 5 miles to "B" school.
The Pierce deposits are then accessible by traveling 2-1/2 miles westerly from "B"
school on "B" road, thence, on a graveled woods road leading north, 1-1/4 miles to
a bridge across "B" stream.

The Nickerson-Farm deposit is in Hodgdon Township on the southern boundary of
the Southern manganese district. It is accessible from Houlton by traveling south
over U. S. Route 1 for 8 miles to the Nickerson home, The anomalies are south of
the dwelling.

The Bangor-Aroostook Railroad serves the area and carries freight and passenger
traffic through Houlton, The Canadian Pacific Railway has a freight terminus at
Houlton over a track that crosses the international boundary east of Houlton.

The New England Telephone & Telegraph Co., part of the Bell System, serves the
area, and electric power is distributed by the Maine Public Service Co.

Northeast Airlines, Inc., provides daily scheduled service through Houlton,

The nearest ocean-shipping point is Searsport, by rail 30 miles south of Bangor
and 166 miles from Houlton,


TABLE 5. - Analyses of composite samples from diamond-drill cores

Calculated
assays from

(Assays, percent) tables 1 and 3
Drill Inter- Loss

hole Footage val, |Fus 2/| total] total |Fus.-H£.2/] Fus.2/ on Fus.4/] Total

No. Deposit From- To- feet Mn Fe P Sidg A103 Ss CaO| MgO}ignition Mn Fe

1 | Pierce No. 1/131.0 148.0] 17.0 | 9.52 | 19.84}0.666] 20.86 7.32 |0.29 |] 4.00)0.40) 15.41 9.60 | 19.95

3 |Pierce No. 1/127.5 136.5} 9.0 {11.26 | 18.98} .590} 23.42 8.90 | .51] 2.02} .33} 12.24 | 11.34 | 19.02

2 |Pierce No. 2/107.5 158.2} 50.7 {13.04 | 19.76] .582} 20.14 6.66 | 31] 2.55} .49} 14.77 | 12.93 | 19.69

5 |Pierce No. 2} 75.6 104.8] 29.2 |10.44 | 20.76] .633| 19.90 7.18 | .92] 1.95) .13} 15.44 | 10.59 | 20.77

6 |Pierce No. 2] 74.6 86.0] 11.4 |12.41 | 20.69} .696} 15.92 5.54 | .68 | 2.64) .28| 19.46 | 12.55 | 20.60

4 |Pierce No. 3} 43.0 55.5] 12.5 |12,27 | 21.11) .696; 17.93 6.92 | .50] 3.31) .53} 15,15 | 12.38 | 21.24

2__|Nickerson 75,0 144.5] 69.5 | 9.19 |17.74] .621] 27.98 9.81 | .42 13.27] .58] 11.30 9.27 | 17.63
1/ Fusion method, 2/ Fusion and hydrofluoric method,

TABLE 6. - Analyses of composite samples from trenches
Calculated
assays from
(Assays, percent) tables 2 and 4
Inter- 1/ Loss

Trench, Footage val, |Fus.—'| Total] Total Fus.-Hé.2/ Fus.2/ on Fus.2/ Total

No. Deposit From- To- | feet Ma Fe P si02 A1203 s CaO] MgOlignition Mn Fe

1 |Pierce No. 1] 0 21.3] 21.3 [12.16 | 22.68/0.678] 20.48 6.90 [0.48 | 1.74/0.28) 11.65 | 12,11 | 22.55

2 |Pierce No. 1] 0 8.0) 8.0 | 9.44 | 36.52)1.273 9.87 1.98 | .13 | 3.23] .77] 10.64 9.34 | 36.68

4 |Pierce No. 1] 0 16.9) 16.9 |13.71 | 24,29] .798} 19.43 6.62 | .22]1.28) .22 9.85 | 13.67 | 24,12

1 | Nickerson 0 30.0] 30.0 | 9.06 | 17.82] .462| 33.80 11.57 | 04] 1.23} .21 7.33 9.27 | 17.60
1/7 Fusion method. 2/ Fusion and hydrofluoric method.

SZ


—__ne

sw

é é é
E E €
INGLINATION -50* & 8 3
ELEV COLLAR 522 0
DK a 4 3
INCLINATION ~45*
coorowat v ELEV. COLLAR 5002
N6,048, oone
£6,125
BEARING: -
s3ztw cooroinares:
| NS .e79
| e5ies4
BEARING.
N32
eo :
WOLE [__FoOTAGE | INTERVAL, | AVERAGE, &
no. [FROM | To FT. Me] _fe
300] ase] see 125) Tie
[ese Case 22 woo} 1627|
EXPLANATION rasa [90 36 | sor] 926
ioe] ero] we | em] oie
ero] 70] 480 | $9 | 1088
VEROUROEN
ovenaunoe 2 [psepmes[ sss [927] 6
Tees [ese S00] 12.42
esa | 20 Tro] 6-08
01 OF BEDDING . zo aso 309] 10.34

REFER TO ANOMALY FIGURE 10.

scace
ee ee ee
reer

Figure 12. - Vertical sections through diamond-drill holes 1 and 2, Nickerson-Farm prospects.

<4


8.
9.
11.
12,

13.

14,

15.

TABLES (Con.)

Screen tests on fractions resulting from Dings-Davis-
tube magnetic separation of samples E-1072 and E-1073 ...
Removal of synthetic magnetite after roasting ........ .
Flotation test 8 .cccccccciccccccccccccccscccceecssseecees
Partial analysis of southern Aroostook County manganese-
OTe SAMPLES .esceeeccccccccccccccvnceccocccassscesssccees
Results of dilute H2S0, leaching tests on samples of ore
from Pierce and Nickerson-Farm prospect deposits . .
Results of dilute HNO3 leaching tests on samples of ore
from Pierce deposit DDH-2 and Nickerson-Farm prospect
trench 1 .. see e cece eee c cere rererccerccce
Results of dilute HCl leaching tests on samples of ore
from Pierce deposit DDH-1 and Nickerson-Farm prospect
trench 1 .. sec ecececccceeces
Diamond-drill-hole logs ...ccecccccccccccccscccscceccecces

iii

27

30

30
31


di

PONE

NOU

CONTENTS (Con.)

Composite samples from drill cores and trenches ........6
Upgrading manganese by magnetic separation .....
Flotation tests, Nickerson-Farm prospect ......
Leaching testS ...ssceseeoeee

ILLUSTRATIONS

Location map, manganiferous deposits, Southern district,
Aroostook County, Maine ...ccccccccccccccccccccsccaccces
Plan showing outcrops of manganiferous rock on Nickerson-
Farm prospect, Hodgdon Township .esccccsececccececvees
Sheet 1 of 4, plan of Pierce anomalies, Hammond
Plantation .esscccccsccccecccccnccsccnscsccessscessseere
Sheet 2 of 4, plan of Pierce anomalies, Hammond
Plantation .ecsecsecsccccecscecvccccesssscvessssesscseces
Sheet 3 of 4, plan of Pierce anomalies, Hammond
Plantation ..sccccececcrccccccccesceccescosccscesssorees
Sheet 4 of 4, plan of Pierce anomalies, Hammond
Plantation, showing relation to Matthew Carpenter-Farm
ANOMALLCS .esssecceccccccrsccecncccesnceseeesescensecees
Vertical sections through diamond-drill holes 1, 2, 3,

5, Pierce depOSitsS .oscecccccccccccccccccccccccvcccscece
Vertical sections through diamond-drill holes 4 and 6,
Pierce deposits .. eee eee e er cccceseeeceeeees
Core specimens from Pierce deposits and Nickerson-Farm
PLOSPECE ceveevccccccscccverccecsccesrevsseecsessssseese
Part of Burnham anomaly, showing location of trench 1
and diamond-drill hole 1... cece cece cer crc cccccccccee
Plan of Nickerson-Farm anomalies, including holes 1 and
2 and trench 1...
Vertical section through diamond-drill holes 1 and 2,
Nickerson-Farm prospect .esccccecccccsccccccccccevcceses

TABLES

Analyses of diamond-drill cores, Pierce deposits .
Analyses of trench samples, Pierce deposit No. 1 ....
Analyses of diamond-drill cores, Nickerson-Farm prospect.
Analyses of trench samples, Nickerson north-south

deposit ..
Analyses of composite samples from diamond-drill cores ..
Analyses of composite samples from trenches ......essseee
Results of Dings-Davis tube tests for removing natural

magnetite, PeETCeNt ceserececccsceccccceccccceccscesesece

Page

24
24
27
28

10
1

12
13
17
18
19
21

22


11

3 rm od a a a a] Tq a a
3 g 3 8 3 3 i : i i E i i
|< coon 3 3 i 8 8 g g Fe E § E
} 5.8C0N
354 ‘ 635
}5.600N 27 “488
we v0 vol
os =
-
‘e
« ‘ss
we ”
200" - ‘8
ie ‘a
a wae
va ‘

5,000 N ss 6

ae TIMBERED DAM STRUCTURE

EXPLANATION

00 > 80 ‘poo “ as
Oo, ouTuine OF MAGNETIC. ANOMALIES IN GAMMAS.
we Sees Mate GN AS ose
——
; ~ ms me 2m » -
= a wooDED AREA
i wr
wooos
008 ws scave x 20
eso ope ego 500 reer wo:
vee > zs >
$
vm a 5
| 3.600N_ 170 cc eae
= za
- a 22

Figure 5. - Sheet 3 of 4, plan of Pierce

anomalies, Hammond Plantation,


SUMMARY

This report describes field investigations conducted in 1953 of two occurrences
of manganese and a separate magnetic anomaly in the Southern manganese district of
Aroostook County, vicinity of Houlton, Maine - the Pierce deposits, in Hammond Plan-
tation Township; the Burnham anomaly, also in Hammond Plantation; and the Nickerson-
Farm prospect in Hodgdon Township. The manganese occurs in a thinly laminated sedi-
mentary rock containing manganiferous carbonate interlayered with fine-grained meta-
morphosed sediment, rich in chlorite or hematite. The surrounding rocks are mostly
dark gray-green slates.

Samples composited for metallurgical testing from the Pierce deposits and the
Nickerson-Farm prospect assayed 9.0 to 12.3 percent of manganese. More than 90 per-
cent of the manganese could be extracted with sulfuric acid, but in most instances
30 to 40 percent of the iron was also extracted. Leaching tests indicated that,
after being reduced in a hydrogen stmosphere at 600° C., about 85 percent of the
manganese could be selectively extracted by a solution of ammonia-ammonium carbonate
with iron extraction of only 14 percent.

The Pierce deposits were explored by 6 short diamond-drill holes, which indi-
cated that the manganiferous beds varied from 6.5 to 50.7 feet in thickness. The
manganese content varied from 9.6 to 12.9 percent. The extent of the deposits is
indicated by 3 parallel magnetic anomalies, which range in length from 4,600 to
8,400 feet.

The Burnham anomaly, partly explored by the Bureau in 1951, was investigated
further. No manganiferous material was intersected by the one diamond-drill hole
drilled to test the unexplored north contact of the igneous rock which may be either
a flow or a sill. It was concluded that this rock is entirely responsible for the
anomaly,

The Nickerson-Farm prospect was explored by 2 short diamond-drill holes and 1
trench after 2 magnetic anomalies had been outlined by a ground-magnetometer survey.
The anomalies, which are nearly at right angles to each other, are 1,000 and 1,800
feet in length. One of the two diamond-drill holes in the east-west deposit indi-
cated a thickness of 64 feet and an average 9.3 percent of manganese. Channel sam-
ples cut in 30 linear feet of trench, exposing weakly magnetic shale near the center
of the north-south deposit, also yielded an average assay of 9.3 percent of manganese.

INTRODUCTION

This project is part of a program begun by the Bureau of Mines in 1949 to in-
vestigate low-grade manganese deposits in the three districts of eastern Aroostook
County, Maine. Manganese minerals in the Aroostook deposits are microscopic in par-
ticle size and refractory to concentration by ore-dressing methods. However, some
upgrading can be accomplished by removing the magnetic iron.


540

520

500

480

460

NE~<=— —~ SW

INCLINATION ~45°30"
ELEV. COLLAR 555.9'
RBURDEN
COORDINATES:
1 N5045
E5170

0.0.H. 6

BEARING:
N6°30'E

FOOTAGE _|INTERVAL| ASSAY, PERCENT.

FROM-| TO- FT MN FE

74.6 | 86.0 4 12.55 | 20.60

440
PIERCE NO.2 DEPOSIT
v= —s
v INCLINATION-SO®
See 0.0.4.4 EL ev, COLLAR 559.!"
BURDEN
a COORDINATES: BEARING:
N5,975 DUE NORTH
£5,800
|s20_
FOOTAGE [INTERVAL ASSAY, PERCENT
| 500 \ FROM-| TO- | FT. MN | FE
43.0| 555| 12.5 | 12.38 | 2124
480

SCALE
——— ee
20 10 0 20 40 60
FEET

PIERCE NO.3 DEPOSIT

Figure 8. - Vertical sections through diamond-drill holes 4 and 6, Pierce deposits.

17


Bureau of Mines
Report of Investigations 5392

| GEOLOGy {
el Ym “2

INVESTIGATION OF MANGANESE AREAS, HAMMOND
PLANTATION AND HODGDON TOWNSHIPS
SOUTHERN DISTRICT, AROOSTOOK COUNTY, MAINE

By N. A. EILERTSEN

United States Department of the Interior — April 1958

metadc38667




PHYSICAL FEATURES AND CLIMATE

Hammond Plantation is a rugged wooded area of second-growth pine and spruce
forest, inaccessible by road, except in the partly cultivated strip inside its
southern border. "B' stream meanders easterly across the southern part of township
"B," and a series of tributary brooks drains low areas between several ridges, which
rise in a northwesterly direction. In 7-3/4 miles across the township the stream
drops 282 feet from "B'" lake (altitude, 722 feet in southwestern Hammond Plantation
to the eastern boundary of the township (altitude, 440 feet).

The Nickerson-Farm prospect in Hodgdon Township is on the southwestern slope of
Daggett Hill, fronting the Meduxnekeag River at an elevation of 470 feet.

The climate of Aroostook County is pleasant and mild in summer but severe in
winter. The average annual temperature is about 40°,4/ and annual precipitation
about 30 inches.

HISTORY AND OWNERSHIP

The three parallel Pierce deposits (Nos. 1, 2, and 3) in Hammond Plantation
were discovered during the Bureau of Mines investigation of the area in 1953, fol-
lowing reconnaissance by the Bureau in 1952. They are in the southern portion of
lots 28 and 29 - woodlands owned by the Great Northern Paper Co., Madigan & Pierce,
agents, Houlton, Maine.

The Burnham anomaly is on the farm of Henry and Arthur Carpenter in Hammond
Plantation. This anomaly was partly explored by the Bureau of Mines in 1951, when a
search was being made for the source of the Burnham float.3/ The float consists of
manganiferous magnetite-rich boulders, containing up to 13 percent Mn.

The Nickerson-Farm prospect contains the southernmost outcrops of manganiferous
sedimentary rock in the Southern district. The deposits are on the 163-acre farm of
Chester H. Nickerson. Paul F, Eckstorm examined and sampled the outcrops on the
Nickerson Farm and other manganese deposits in Aroostook County during 1941 for the
State of Maine, and his work is referred to in the published reports of Trefethen4/
and Miller.>

DESCRIPTION OF DEPOSITS

Pierce Deposits

The Pierce deposits are three beds of manganiferous sedimentary rock, The ma-
terial composing the deposits is lithologically complex, as the manganiferous rock
ranges from a chloritic carbonate stratum to impure siliceous hematite beds. The
deposits are enclosed and separated by a series of interbedded shales, slates, and
graywacke.

27 U. S. Weather Bureau, Climatological Data, New England. Annual Summary, 1950;
vol, 62, No. 13, pp. 394 and 397.

3/ Eilertsen, N. A., Investigation of the Littleton Ridge Manganese Deposit and
Vicinity, Southern District, Aroostook County, Maine: Bureau of Mines Rept.
of Investigation 5104, 1955, pp. 32-39.

4/ Trefethen, Joseph M., Report of the State Geologist; State of Maine, 1942-43,

- 30.

S5/ wilier, Ralph L., Manganese Deposits of Aroostook County, Maine: Maine Geol.

Survey Bull. 4, 1947, pp. 38, 73, and 74,


EXPLANATION

LLittleton Ridge deposit.

2.Prospects north ot
Henderson Hill.

3.Henderson Hill prospect,|
4.Prospects between
Henderson Hill ond
Westford Hill.
S.Westford Hill prospects
G.Haskell prospects

7.Daggelt Hill prospect

B.Nickerson Farm
prospect,

9.Gardner prospect
10.8enn prospect.

I.Stewart prospect

(2.Adams mountain
prospect.

13.0ther manganese
prospects.

14.Motthew Carpenter
Form deposits.

\S.Pierce deposits and
anomalies.

“y Area containing

“ manganiferous

outcrops.

Linneus
LOCATIONS OF DEPOSITS, EXCEPTING THOSE IN HAMMOND TOWNSHIP,
ARE TAKEN FROM PLATES, BULLETIN, MAINE GEOLOGICAL SURVEY, 1947,

BASE MAP FROM HOULTON AND SMYRNA MILLS QUADRANGLE SHEETS,
U.S. GEOLOGICAL SURVEY.

ScaLe

mILes

Lone

LAKE

Littleton

|

Cort

—

iL...

i"

MAINE
‘BRUNSWICK

NeW

Figure 1. - Location map, manganiferous deposits, Southem District, Aroostook County, Maine.



36

TABLE 15, - Diamond-drill-hole logs2/ (con.)

Nickerson DDH-1

Interval, feet

Description

0-9.6 .
9.6-129 .

Overburden.

Gray-green slate, with a few thin quartzite and calcareous lam-
inae, Sparse manganese stains along fractures and cleavage be-
tween 9,6-15.5, 18-18.5, 20-21, and at 23.5, 26.5, 31.5, 34,
36.5, and 37.5 feet.

At 96 feet, thin, dark-green to black laminae; may be carbon-
aceous,

Pyrite (generally distorted cubes) at 60, 61, 75.5, 79.5, 85.5,
100, 101-104, 105, 108.5, and 120.5 feet.

Pyrite, associated with thin white laminae at 35, 40.5, 71.5,
77.7, 80, and 87-89.5 feet.

Finely laminated and banded manganiferous hematitic quartzite at
123.2-125.4 feet. Chlorite-carbonate rock and green slate be-
tween 125,.4~129.0 feet.

Bottom of hole at 129 feet.

Bedding at-| Makes angle with core axis- Bedding at- | Makes angle with core axis-
16 feet 38° 96 feet 20°

35 feet 27° 100 feet 24°

46 feet 32° 105 feet 39°

60 feet 12° 110 feet 34°

65 feet 16° 115 feet 40°

70 feet 13° 120 feet 16°

75 feet 35° 125 feet 9°

80 feet 34° 129 feet 27°

85 feet 40°

Nickerson DDH-2

Interval, feet

Description

0-10.8 ......
10.8-37.0 ...006

37-75 seeeeeee

75-144.5 weeee

Overburden.

Gray-blue slate, with thin quartzite laminae. Bedding microcon-
torted in many places, Pyrite present along 1/4-inch laminae at
25 feet.

Gray-blue slate, with thin quartzite laminae and manganiferous
zones composed of chlorite-carbonate layers and reddish, hema-
titic laminae, with associated pyrite. Pyrite zones occur at
35, 36.5-37.5, 42.5-43, 44-44.5, 45.5-46, 52.5, 54-57, 60-61.5,
71.5-72, and 72,.5-73.5 feet.

Possible shear zone at 50 feet, characterized by green,
chloritic veinlets, with abundant sulfide.

Between 52-60 feet, abundant contortion and microfaults, quartz,
and chlorite veins.

Magnetic, finely laminated and banded, manganiferous, hematitic,
magnetitie-chlorite rock; possibly contains carbonate. Pyrite
present throughout this interval, in places forming 1/4- to
1/2-inch metacrysts. Bedding laminations pass through meta-
crysts and retain orientation of wall-rock layering at 175 feet.
Sulfide also present as thin laminae as well as veinlets.

Quartz-chlorite-carbonate veinlets at 93-93.5, 96, 97, 121.5,
123-124, 125, 127, 129, 131.8, and 132.5 feet.

7 See footnote at end of table.


24

TABLE 4. - Analyses of trench samples, Nickerson north-south deposit

(Minus-65-mesh screen, Davis-tube magnetic separation)

Trench 1
(Measured west to east)

Sample Core assay,
Footage interval, percent Magnetic fraction
From- To- feet Mn Fe Weight, percent
0 10.0 10.0 11.04 | 18.73 0.05
10.0 20.0 10.0 8.65 | 17.54 None
20.0 30.0 10.0 8.12 | 16.53 None
Total ...... 30.0 9.27 | 17.60 =

Composite Samples From Drill Cores and Trenches

After being assayed, some of the excess material from core samples and trench
samples, listed in tables 1 to 4, was combined by adopting a uniform weight in grams
per linear foot of core or trench involved. This was done to check the average cal-
culated assays in the above tables and to permit assaying for other elements in the
deposits. Assays of all composite samples of diamond-drill intersections and manga-
niferous material in trenches are listed in tables 5 and 6, respectively. The aver~
age calculated assays from tables 1 to 4 are shown also for comparison.

Upgrading Manganese by Magnetic Separation

Following Bureau of Mines instructions, a contract laboratory made two overall
samples of Pierce deposits Nos. 1 and 2 by blending representative fractions from
the composite-sample rejects listed in tables 5 and 6. The material had already
been ground through 100-mesh for assaying.

Sample E-1072, Pierce deposit No. 1, was weighed at 3 grams per foot true width
of ore zone intersected in the following diamond-drill holes and trenches:

Grams
Diamond~drill hole:
No. 1. 45.0
No.3. 25.5
Trench:
No. 1 wae. wee 58.5
No. 2. eee 24.0
No. 4 .... oon
Total weight ......... 202.

Sample E-1073, Pierce deposit No. 2, was weighed at 4 grams per foot true width
of ore zone intersected in the following diamond-drill holes:

Grams

Diamond-drill hole:
NO. 2 ceeceecccsscccceeee 192
No. 5. eee 108
No. 6 .... wee 44
Total weight ......... 344



TABLE 3. - Analyses of diamond-drill cores, Nickerson-Farm prospect

(Minus-65-mesh screen Davis-tube magnetic separation)

Diamond-drill hole 1, east-west anomaly

Sample Core assay,
Footage interval, percent Magnetic fraction
From- To- feet Mn Fe Weight, percent
90.0 100.0 10.0 1.34 7.10 -
100.0 110.0 10.0 -90 7.02 -
110.0 120.0 10.0 1.02 7.66 -
120.0 123.2 3.2 2.75 6.39 -
Total ...... 33.2 1.25 7.18 =
123.2 125.4 2.2 11.00 *| 16.27 =
125.4 129.0 3.6 5.07 9.26 -
Total ...... 39.0 - - Core recovery, 93.1 percent
Diamond-drill hole 2, east-west anomaly
10.8 13.0 2.2 6.17 9.58 -
13.0 20.5 7.5 1.96 9.10 -
20.5 25.0 4.5 1.97 8.38 -
25.0 27.0 2.0 5.07 | 10.86 -
Total ...... 16.2 2.92 9.18 :
27.0 33.0 6.0 4.36 | 10.84 -
33.0 43.0 10.0 5.44 9.87 -
43.0 53.0 10.0 5.36 9.71 -
53.0 63.0 10.0 7.36 | 11.49 -
63.0 70.0 7.0 2,52 9.87 -
70.0 75.0 5.0 4,79 | 12,13 =
Total ...... 48.0 5.19 | 10.53 -
75.0 80.0 5.0 7.06 | 21.98 10.42
80.0 90.0 10.0 10.60 | 16.48 15.03
90.0 100.0 10.0 10.39 | 17.87 23.72
100.0 110.0 10.0 6.25 | 16.00 14.63
110.0 120.0 10.0 9.26 | 16.85 23.67
120.0 130.0 10.0 9.14 | 18.22 7.67
130.0 140.0 10.0 10.43 | 17.09 22.17
140.0 144.5 4.5 10.68 | 20,11 33.17
Total ...... 69.5 9.27 | 17.63 18.27
144.5 150.0 5.5 4.87 | 10.76 9.55
150.0 160.0 10.0 3.57 7.67 +33
160.0 170.0 10.0 6.66 18.42 -
170.0 180.0 10.0 8.28 | 11.87 -
180.0 183.2 3.2 4.02 | 13.08 -
Total ...... 38.7 5.80 | 12.42 -
183.2 190.0 6.8 2.83 7.02 -
190.0 200.0 10.0 1.77 7.18 -
200.0 210.0 10.0 294 6.39 -
210.0 213.5 3.5 1.22 7.26 -
213.5 215.0 1.5 2.40 6.71 -
Total ...... 31.8 1.70 6.88 :
215.0 220.0 5.0 6.25 12.29 -
220.0 225.0 5.0 4.17 9.10 -
225.0 233.0 8.0 4.95 9.90 -
Total ...... 18.0 5.09 | 10.34 -
Grand total. 222,2 = TT Core recovery, 94.1 percent





14

TABLE 1. - Analyses of diamond-drill cores, Pierce deposits

(Minus-65-mesh screen, Davis-tube magnetic separation)

Diamond-drill hole 1, Pierce deposit No. 1

Sample
Footage interval, Core assay, percent Magnetic fraction
From- To-~ feet Mn Fe Ss Weight, percent
125.0 131.0 6.0 3.33 [10.83 | 5.71 :
131.0 140.0 9.0 11.81 | 28.11 225 45.0
140.0 148.0 8.0 7.11 10.78 234 20.7
Total ....... 17.0 9.60 | 19.95 229 33.6
148.0 153.0 5.0 257 3.88 79 =
Total .. 28.0 - - - Core recovery, 70.7 percent

Diamond-drill hole 3, Pierce deposit No. 1

127.5 128.5 1.0 9.68 | 31.98 | 0.58 50.9
128.5 133.5 5.0 15.38 | 22.38 39 33.4
133.5 136.5 3.0 5.17 9.11 | 1.26 wl
Total . see 9.0 11.34 19.02 70 24,2
136.5 144.5 8.0 Al 6.49 231 -
144.5 145.0 Pe) -37 8.55 | 3.25 -
145.0 150.0 5.0 40 3.62 272 -
150.0 160.0 10.0 238 4.07 87 =
Total ....... 32.5 - - - Core recovery, 86.5 percent
Diamond-drill hole 2, Pierce deposit No. 2
50.0 58.0 8.0 2.11 7.30 | 2.50 -
58.0 64.5 6.5 10.31 | 19.30 | 2.10 -
64.5 70.0 5.5 1.05 4.08 86 -
Gray slate
106.5 107.5 1.0 1.71 4.24 252 -
107.5 110.0 2.5 11.96 | 19,92 +50 7.9
110.0 120.0 10.0 13.40 | 21.74 ell 27.4
120.0 130.0 10.0 12,64 | 22.90 +29 22.6
130.0 140.0 10.0 15.28 | 19.60 12 26.1
140.0 150.0 10.0 12.80 | 20.16 | 0.39 27.0
150.0 158.2 8.2 10.32 | 12.77 80 al
Total ....... 50.7 12,93 | 19.69 33 20.7
158.2 163.0 4.8 2.23 7.88 47 =
Total ....... 76.5 - = - Core recovery, 91 percent

Diamond-drill hole 5, Pierce deposit No. 2

75.6 78.0 2.4 10.17 | 33.55 | 0.19 46.3
78.0 86.0 8.0 11.64 | 24,15 49 17.9
86.0 89.8 3.8 13.94 | 18.71 31 27.5
89.8 96.0 6.2 11.32 | 20.52 256 14.1
96.0 100.0 4.0 9.47 16.89 1,12 4.9
100.0 104.8 4.8 6.40 | 13.91 | 2.77 3
Total . 29,2 10.59 | 20.77 92 16.0
Total . 29.2 - - - Core recovery, 100 percent



31

Ammonia-ammonium carbonate extraction has an advantage over other solvents in
that the manganese is readily precipitated from solution as an easily filtered man-
ganese carbonate product, This is accomplished by driving off some of the ammonia
under the influence of heat; the ammonia, of course, is collected and returned to
the process. Extracting manganiferous slag clinker by ammonia-ammonium carbonate
solution has been successfully tested on pilot-plant scale.2/

A 10-percent solution of (NH4,C1) ammonium chloride was also found to be an ex-
cellent solvent for the manganese in these samples after the manganese was reduced
to the divalent state. For the leaching reaction to proceed, the ammonia produced
by the reaction must be removed by a jet of steam, After cooling and condensing,
the resulting ammonia solution is available for selective precipitation of the man-
ganese and iron hydroxides from the clarified extract liquor. Thus, reagent costs
in such a process would be whatever is necessary to replenish losses. High-purity
iron and manganese products would result by controlling the pH during the precipi-
tation step. Eighty- to eighty-six-percent recoveries of manganese were obtained.

TABLE 15. = Diamond-drill-hole logs“!

Pierce DDH-1

Interval, feet Description
0-13 seeee| Overburden,

13-96 ..........| Dark-green, chloritic slate with laminae of very dark green chlo-
ritic slate. Quartz veins at 24,7, 28-28.5, and 30.5 feet.

Dark gray-green slate, with calcareous laminae.

Dark-gray, laminated slate. Massive sulfide zone, 1-1/2 inches
in thickness, at 130 feet.

131-148 .........] Finely laminated and banded rock containing lightly colored red,
hematitic laminae, as well as pods or beads, possibly of carbon-
ate composition.

At 133 and 134.5 feet: Quartz-feldspar veinlets containing a
yellow-green mineral that suggests one of ganophyllite or be-
mentite series, Pyrite also present,

148-185 .........| Dark-gray-green slate, with some calcaerous laminae, Pyrite
abundant throughout this interval.

Bottom of hole at 185 feet.

96-128 ..
128-131 ..

Bedding at- | Makes angle with core axis- Bedding at- | Makes angle with core axis-
22.5 feet 47° 105 feet 62°
39 feet 69° 110 feet 74°
45 feet 69° 115 feet 74°
50 feet 59° 120 feet 67°
55 feet 54° 131 feet 76°
60 feet 66° 135 feet 80°
65 feet 65° 140 feet 72°
70 = feet 63° 150 feet 73°
76 feet 60° 160 feet 65°
80 feet 62° 170 feet 65°
85 feet 53° 180 feet 62°
90 «feet 57° 185 feet 65°
100__ feet 71°

1/ See footnote at end of table.

9/ Heindl, R. August, Ruppert, J. A., Skow, M. L., and Conley, J. E., Manganese
From Steel-Plant Slags by Lime-Clinkering and Carbonate-Leaching Process.
Part I. Laboratory Development; Bureau of Mines Rept. of Investigations
5124, 1955, 98 pp.


32

TABLE 15. - Diamond-drill-hole logs2/ (con.)

Pierce DDH-2

Interval, feet

Description

0-8 .eceeeeee
8-58

64.5-107.5 ..00.

107

158

25-158.2 ..00

22-184 ceeeeee

Overburden.

Gray-blue slate, with light-gray calcareous slate.

Green, laminated and banded, manganiferous chlorite-carbonate
rock,

Pyrrhotite abundant; appears to be disseminated along bedding as
well as replacing beds, Rocks containing this sulfide are ex-
tremely magnetic at 63.5-64.5 feet.

The chlorite-carbonate rock is cut by quart-feldspar-chlorite
veinlets at 59, 62.5 and 63 feet.

Red hematite pods and blebs (1/4 inch) at 58 feet.

Gray slate with calcareous laminae; in places contains zones re-
sembling stretched limestone pebbles at 68-70, 89-92, and 97-99
feet.

Highly calcareous (possibly microfossiliferous) zone between
71-73.5 feet.

Dark-green to black to red, laminated and banded, manganiferous
chlorite-carbonate rock, as previously described, Finely crys-
talline magnetite below 118 feet imparts strong magnetic prop-
erty to this rock.

Small blebs and pods (1/8 to 1/4 inch) of light-color material
occur elongate in plane of bedding.

Hematitic laminae, imparting a reddish color to rock, are present
in many places at 137-140.5 feet.

Sulfide abundant, occurring both as distinct, distorted cubes
(metacrysts) and along thin laminae at 137-140.5 and 157 feet.

Laminated green-slate interbed at 155-156 feet.

Quartz-feldspar veins at 109, 135.5, and 137-140.5 feet.

Finely laminated and banded, dark-green and light-green slate.
Very fine grained pyrite abundant, especially in dark-green
slate.

Chlorite-carbonate rock interbed between 167,5-168 feet.

Bottom of hole at 184 feet.

Bedding at- | Makes angle with core axis- || Bedding at- | Makes angle with core axis-
10 feet 52° 120 feet 82°
15 feet 60° 125 feet 65°
36 feet 45° 130 feet 77°
40 feet 62° 135 feet 90°
55 feet 43° 140 feet 75°
60 feet 51° 145 feet 90°
65 feet 65° 150 feet 85°
74 feet 62° 155 feet 85°
83 feet 50° 160 feet go°
95 feet 58° 165 feet 85°
103 feet 37° 170 feet 80°
110 feet 48° 183 feet 80°
115 feet 60°

7

See footnote at end of table,


20

readings were taken at 500 stations, measured at intervals ranging from 25 to 200
feet on the grid within the boundaries of the farm. Two anomalies were mapped (see
fig. 11). The east-west anomaly is 1,000 feet in length, and the north-south de-
posit has been mapped by an anomaly for 1,800 feet. The necessity for a magnetom-
eter survey to outline the trend of deposits under overburden is illustrated by com-
paring the map showing the relatively few manganiferous-rock outcrops (fig. 2) with
the anomalies shown in figure 11.

Diamond Drilling, Trenching, and Sampling the Nickerson-Farm Prospect

The east-west anomaly, the first to be mapped, was sampled by two diamond-drill
holes, Nickerson drill hole 1, inclined 45° from the northeast side of the anomaly,
was discontinued at 129 feet when it was found that the hole was being drilled from
the footwall side of the deposit. The drill was then moved to the site of Nickerson
hole 2 (see fig. 11), inclined 45° in the opposite direction (NE.). After passing
through 10.8 feet of overburden, hole 2 entered gray-blue slate, which contains
scattered thin laminae of impure (siliceous) manganese carbonate from 27 to 75 feet
(See fig. 12). The main body of the deposit, intersected at 75 to 144.5 feet, averaged
9,27 percent Mn and 17,63 percent Fe. The footwall of the deposit is interbedded
green and gray slate, with interbeds of manganiferous rock and scattered thin lam-
inae of impure siliceous material containing manganiferous carbonate. Drilling was
stopped at a depth of 233 feet in gray slate. The ore zone in hole 2, strongly con-
torted by folding, is 65 feet true width and dips about 65° SW.

A total of 261.2 feet of core in holes 1 and 2 was split and divided into 37
samples for assaying, as listed in table 3.

A small outcrop of gray-black shaly, laminated, manganiferous chloritic rock,
discovered while transit surveying the north traverse line from base-line station
4,000 N., 1,900 feet south of drill hole 2, was later found to be near the center of
the north-south anomaly. A trench was cut 30 feet in length, and 3 channel samples,
each 10 feet in length, were chipped across the bedding. The average assay of these
samples, as shown in table 6, is 9.27 percent Mn and 17.60 percent Fe. The local
strike of foliation in the shale is northeast, and the dip 85° NW.

The coincidence of average assays obtained in the relatively high magnetite-
bearing ore zone of drill hole 2 and the nonmagnetic material of the north-south
deposit indicates that the two deposits are segments of the same manganiferous bed.
Diamond drilling is necessary in both segments of the deposit to permit further sam-
pling for metallurgical research,

CHEMICAL AND METALLURGICAL INVESTIGATIONS

Determination of Magnetic Fractions in Drill Core and Trench Samples

Core and trench samples, ground to pass 65 mesh were subjected to Davis-tube
magnetic separation. The quantity percentage of magnetite recovered, as shown in
tables 1 to 4, is only relative to the particle size of the grind. Fine grains of
magnetite are not completely unlocked from other mineral constituents.






37

TABLE 15. - Diamond-drili-hole logs4/ (con.)

Nickerson DDH-2 (Con.)

Interval, feet Description
75-144.5 (Con.) | Zone of white to pinkish pods 1 inch thick at 96.5 feet. Pods
also at 90.5, 96, and 135.8 feet.

Green slate interbed at 107,5-110.5 feet.

Quartz veining at 99.5 and 102.5 feet.

Brecciation between 100,5-101 feet.

144,5-183.2 ...... | Gray slate, with a few quartzite laminae interbedded with finely
laminated and banded manganiferous rocks as described between
75-144.5 feet. Manganiferous zones at 147-147.9, 149.5-150,
154.7-156, 160-162, 163-173, 174,5-175, 176.5-177, 178.5-179.5,
and 182.2-183.2 feet.

Quartz-feldspar-chlorite veinlets at 146, and 154.5-154.7 feet.

183.2-233 ........ | Gray slate, with a few quartzitic- and sulfide-bearing laminae,
which in a few places are highly contorted.

Chlorite-carbonate-rock interbeds at 215-219, 222.5-223.5, and
228.5-229.5 feet.

Contorted, pale carbonate (rhodochrosite) layer, 1/4 to 1/2
inch thick, at 231 to 232 feet emerges at 2 places along core;
near bottom of hole a disrupted layer (1/4 inch thick) of
similar material.

Bottom of hole at 233 feet.

Bedding at- [Makes angle with core axis- Bedding at- |Makes angle with core axis-
11 feet 60° 110 feet 76°

15 feet 45° 120 feet 16°

20 feet 58° 130 feet 20°

25 feet 82° 135 feet 15°

30 feet 80° 140 feet 55°

35 feet 32° 145 feet Parallel
40 feet 56° 150 feet 10°

45 feet 40° 155 feet 10°

50 feet 58° 160 feet 35°

57 feet 54° 165 feet 50°

65 feet 51° 170 feet 28°

73 feet 60° 175 feet 33°

80 feet 55° 180 feet 25°

85 feet 35° 187 feet Parallel
90 feet 63° 206 feet 25°

95 feet 15° 216 feet lo°

100 feet 26° 228 feet 26°

105 feet 67°

1/7 See footnote at end of table.


Nickerson-Farm Prospect

The manganese-bearing rock of the Nickerson-Farm-prospect deposits is fine
grained and thinly laminated. The parts of the deposits that have been intensely
folded contain both magnetite and hematite. The weathered surface is stained by
black manganese oxide. Primary manganese minerals are obscure, Chemical tests in-
dicate that manganese occurs as an impure carbonate associated with iron and silica.
The colors of the rock range from gray-green through shades of red to black. Pyrite
occurs in minor quantities as scattered metacrysts and as fine-grained, thin laminae
and veinlets.

Dark-gray shale, which may be weathered siliceous chlorite-carbonate rock, is
exposed in a trench in the southern part of the south Nickerson anomaly. This part
of the deposit does not appear to be greatly disturbed by folding. The material is
not attracted by a hand magnet. Assays of manganese and iron in the nonmagnetic
shale are identical with assays of the highly metamorphosed material of the north
anomaly, which is rich in magnetite.

Fine-grained, impure manganese carbonate occurs as thin, light-gray laminations
and also as layers, 1/4 to 1/2 inch in thickness, scattered or bunched in the hang-
ing-wall and foot-wall shales of the east-west trending deposit outlined by the north
Nickerson anomaly. The laminations and layers, which are highly siliceous, turn
buff to black after exposure to weathering.

The specific gravity of material from the Nickerson-Farm prospect was found to
range downward from 3.60 to 3.00, depending upon the manganese and iron content in
the specimens weighed. Tonnage factors would thus range from 10 to 11 cu. ft. per
long ton of ore in place,

WORK BY THE BUREAU OF MINES

Following reconnaissance in the "B" stream area in Hammond Plantation during
the summer of 1952, the Bureau of Mines conducted further investigations in the
Southern district of eastern Aroostook County during the spring of 1953. The work
completed during the 2-1/2-month period from April 15 through June 26, 1953, was
confined to discovery and exploration of the Pierce deposits in Hammond Plantation,
further investigation of the Burnham anomaly (also in Hammond Plantation), and ex-
ploration of the Nickerson-Farm prospect in Hodgdon Township. Magnetometer surveys
were employed to outline the deposits, and spot sampling was accomplished by core
drilling and trenching.

The site of the Nickerson-Farm prospect in Hodgdon Township, far removed from
Hammond Plantation, was chosen for investigation because it is the southernmost of
the manganese areas in the southern district, is readily accessible, and reports of
the Federal and State Geological Surveys record material that assayed about 9 per-
cent Mn.

The Bureau of Mines contracted with the Federal Geological Survey to furnish a
magnetometer-survey party. The magnetic contours, which appear on maps of this re-
port, were traced from work maps prepared in the field for the Bureau of Mines by
Bromery/ and Shuler.//

6/  Bromery, R. W., geophysicist, Geophysical Branch, Federal Geological Survey.
7/ Shuler, R. M., scientific aide, Geophysical Branch, Federal Geological Survey.


aI a] ry ry = re ry rr a a] re a] ay a gy J]
E q 3 3 3 3 2 E El 3 2 i g 3 B g 3
3 5 5 4 $ a 3 ? a 2 a 3 a 3 3 3 3
.
3
16.200N_ 5 ay 56 -29
4 PIERCE NO.3
° 683 63 232 »
Se weer La
s 40
Fe
is
tae
s 3
3
a
2
eo o
}2.800 N 2
“° g
3}
34 =
5.600% Ler gi
3!
gi
a ii
s400n
3
H
o
me
5.2001
5,000
4,800n 4a PIERCE
TRENCH 4:16 9:AVERAGE ASSAY, 13.67% Mn.
}4.600N_
4.400% scale
THIS MAP 1S ALL-FORESTED AREA
g0__s00 reer Wap “COORDINATES ARE ASSUMED FROM STAKE AT
—_—_— Satine POINT, 5,000N AND 5,000
EXPLANATION
|4,200N PO QUTLINE OF MAGNETIC ANOMALIES IN GAMMAS.
CONTOUR INTERVAL, |900 GaMMas
OUTLINE OF NEGATIVE ANOMALIES.
—— — aasetine, Transit surveys
4,000m

Figure 3. - Sheet 1 of 4, plan of Pierce anomalies, Hammond Plantation.


INVESTIGATION OF MANGANESE AREAS, HAMMOND
PLANTATION AND HODGDON TOWNSHIPS
SOUTHERN DISTRICT, AROOSTOOK COUNTY, MAINE

By N. A. EILERTSEN

* «© « «© « « « « « Report of Investigations 5392

Lee

UNITED STATES DEPARTMENT OF THE INTERIOR
Fred A. Seaton, Secretary
BUREAU OF MINES
Marling J. Ankeny, Director

Work on manuscript completed February 1957. The Bureau of Mines will welcome reprinting of this paper, provided
the following footnote acknowledgment is made; ‘‘Reprinted from Bureau of Mines Report of Investigations 5392."”

April 1958


30

TABLE 13. - Results of dilute HNO3 leaching tests on samples of ore from
Pierce deposit DDH-2 and Nickerson-Farm prospect trench 1

/ Recovery in leach solution
Ore~ Time, Temperature, Mn Fe

designation Grams hours °c. Grams Percent Grams Percent
A-292/ seeceeee | 8.054 0.5 0.8725 87.86 0.5907 35.27
A-292/ on we | 8.054 1.0 -9108 91.71 +6603 39.42
A-292/ 8.054 2.0 ~9273 93.37 6913 41.27
A-292/ 8.054 3.0 -9389 94.54 7214 43.07
A-312/ 10.867 5 60 0613 6.18 - 1026 5.35
A-312/ ., 10.867 | 1.0 0745 7.51 1370 7.15
A-312/ 10.867 2.0 0867 8.74 - 1648 8.60
A-312/ 10.867 3.0 0927 9.34 . 1880 9.81
A-313/ «+ | 10.867 3.0 29755 98.32 1.705 88.94
A-314/ ........ | 10.867 | 3.0 +9519 | 95.94 | 1.380 71.99

1/ Ore ground to minus-65-mesh.

2/ 1.5 N HNO, used in Mn/acid mole ratio = 5.

3/ Sample reduced in Hz, 3 hours at 675° C.; 1.5 N H2S04 used in mole ratio
Mn/acid = 2.5.

4/ | Sample reduced in H2, 3 hours at 675° C.; 1.5 N HNO3 used in mole ratio

Mn/acid = 5.

TABLE 14. - Results of dilute HCl leaching tests on samples of ore from
Pierce deposit DDH-1 and Nickerson-Farm prospect trench 1

Recovery in leach solution
orel/ Time, Temperature, Mn Fe

designation Grams | hours °C. Grams Percent Grams Percent
a-312/ ........ | 10.87 | 0.5 0.0388 | 3.91 | 0.0504 | 2.63
A-312/ ., 10.87 | 1.0 2742 10464 | 4.67 0695 | 3.63
A-312/ . 10.87 2.0 +0579 5.83 -0983 5.13
A-312/ 10.87 3.0 20731 7.37 «1164 6.07
A-313/ 10.87 3.1 ~9398 94.69 22521 13.14
A-313/ 10.87 3.2 9175 92.44 2529 13.19
A-284/ 8.39 253 60 +8629 | 86.92 +5047 | 25.24
A-284/ 8.39 1.05 9127 91.93 +5540 27.70
A-284/ 4... . 8.39 2.0 +9318 93.86 5932 29.66
A-284/ see 8.39 3.0 +9356 94.24 5999 30.00

1/. Ore ground to minus-65-mesh.

2/ Acid used, 60 ml. of 1.5 N HCl; mole ratio HC1/Mn = 5.

3/ Acid used, 60 ml, of 1.5 N HCl, with 7.18 grams FeC12.4H20 (27.6 percent Fe)
added. Mole ratio. HC1/Mn = 5.

4/ Acid used, 1.5 N HNO3; mole ratio Mn = 5.

The ease with which manganese was extracted from these ores encouraged the
belief that it might be present largely as an oxide instead of in the more complex
silicate forms, which are found in other parts of Aroostook County. If this were
so, the manganese could be extracted by ammonia-ammonium carbonate solution, provided
the manganese was first reduced to its divalent form.

A test was made using ammonia-ammonium carbonate solution on ore reduced at
600° C. in a hydrogen atmosphere. Approximately 85 percent of the manganese and 14
percent of the iron were extracted.


Split-core specimen of dark-gray
siliceous manganiferous chlorite-
carbonate rock containing laminae
and bands of fine magnetite, From

Pierce deposit No.2, hole 2 at
131.5 fe.

Core specimen from Nickerson-Farm
prospect, hole 2 at 94.6 feet. Magnetite-
chlorite rock containing numerous thin
laminae of fine magnetite and hematite.
The rock is nearly black when polished.

Polished surface of split core from
Pierce deposit No. 3, hole 4 at 50.3
feet. Fine laminae and bandsof hem-
atite, magnetite and white siliceous
manganiferous carbonate occur in
magnetite-chlorite rock. Bands range

in color: red, gray, black, and white,

8T

Polished-core specimen from Nickerson-
Farm prospect, hole 2 at 37.5 feet. Bands
and pods of white siliceous manganiferous
carbonate follow folds in dark-gray slate.
Bands darken after exposure to atmosphere.

Scale
———————

inches

Core specimen of dark-gray slate containing white
to buff layer of siliceous manganiferous carbonate,
assaying about 20 percent manganese, 5 percent iron,
and 26 percent silica, From Nickerson-Farm pros
pect, hole 2 at 231.5 feet.

Figure 9. - Core specimens from Pierce deposits and Nickerson-Farm prospect.





26

The two composite samples were subjected to selective magnetic separation in
the Dings-Davis tube. Selectivity was accomplished by varying the magnetic intensity
with a bank of lamps and a rheostat in the direct-current circuit. With this ar-
rangement, the first magnetic concentrate was removed with a low magnetic flux, and
a high-grade, clean separation was obtained. The tailing from the first separation
was then passed through the tube and treated with the highest magnetic flux, which
concentrated the weaker magnetic particles into a middling. The tailing from the
second separation composed the nonmagnetic fraction.

By controlling the pull of the electromagnet, the weak magnetic material can be
drawn off separately. After being assayed, the middling can be added to the concen-
trate if rich enough or, if too lean, can be rejected with the tailing.

The head samples and the corresponding three fractions resulting from magnetic
separation were assayed; the results are shown in table 7. Before being assayed the
nonmagnetic fraction containing most of the manganese was reduced by roasting to
drive off all volatile matter.

TABLE 7. - Results of Dings-Davis tube tests for removing
natural magnetite, percent

Sample Material Mn Fe Pp Si0) | Al,03
E-1072 .. Composite head sample .. 11.36 | 28.39 | 0.768 | 19.23 6.43
A seen Magnetic portion . 5.32 51,17 501 6.54 1.73
B Middling ......... 3.48 | 45.41 «390 8.40 1.88
cl/ .. Nonmagnetic portion . 15.64 | 17.88 | .972 | 26.06 | 9.45
E-1073 Composite head sample . 11.92 | 20.17 609 | 19.39 6.56
A... Magnetic portion ... 4.92 | 49.79 429 8.43 1.86
B r Middling ......... 4.60 | 32.60 -420 | 14.54 2.72
ch Nonmagnetic portion ...... 15.92 | 19.46 | .788 | 26.30 | 8.62

Loss on

Sample Material s cao MgO | ignition |Weight
E-1072 .. Composite head sample . 0.346 [2.38 23 12.35 -
A seeee Magnetic portion .... 2085 | 1.61 67 - 19.7
Baeeeese Middling ... ~130 | 1.77 80 - 5.2
cl/ ., Nonmagnetic portion .... 2350 | 2.97 | .15] 14.22 | 75.1
E-1073 Composite head sample . 555 | 2.47 234 15.89 -
Aes Magnetic portion .....e... 210 1.37 96 - 11.9
Bias Middling ... on +280 | 2.21 | 1.08 - 3.8
cl? Nonmagnetic portion ... -190 | 2.70 | .25| 18.28 | 84.3

1/7 Assayed after reduction roast.

Results of screen tests to determine the fineness of grinding three products
from each of the samples listed in table 7 are shown in table 8.

Further tests were made in the laboratory of the Eastern Experiment Station of
rejects (excess material after assaying, forwarded to the Bureau by contract labora-
tory) of samples E-1072-C and E~1073-C, listed in table 7, It was of interest to
learn if manganese could be upgraded further by separating the synthetic magnetite
produced by the reduction roast. As the rejects had been disturbed in making screen
tests and some of the fine material had probably been lost in handling, each sample
of manganese was check-assayed; the rejects were found to have been slightly up-
graded in manganese to 16.0 and 16.2 percent, respectively. Subjected to Davis~-
tube magnetic separation, the two fractions produced from these samples (see table
9) showed no appreciable difference in concentration of manganese.


35

TABLE 15. - Diamond-drill-hole togs*! (Con.)

Pierce DDH-5 (Con.)

Bedding at- |Makes angle with core axis- Bedding at- | Makes angle with core axis-
15 feet 69° 100 feet 90°
20 feet 75° 105 feet 75°
37 feet 70° 110 feet 70°
45 feet 75° 115 feet 75°
50 feet 81° 120 feet 82°
55 feet 83° 125 feet 85°
60 feet 82° 130 feet 83°
65 feet 80° 135 feet 82°
73 feet 85° 140 feet 77°
76 feet 71° 145 feet 79°
82 feet 65° 150 feet 82°
86 feet 75° 155 feet 68°
90 feet 70° 160 feet 74°
95 feet 73°

Pierce DDH-6

Interval, feet Description

0-16 ........ | Overburden.

16-74.8 . Gray silty slate, with a few light-gray laminae,
74.8-78.0 .. Manganiferous banded chlorite-carbonate rock, consisting of
siliceous carbonate laminae separated by black-shale partings.
Dark-green slate,
Manganiferous laminated and banded hematite rock; in places con-
tains magnetite. Quartz-feldspar veins in a few places.

78-78.5 .
78.5-86 ...

86-104 ....... | Manganiferous laminated and banded gray-green, chlorite-carbonate

layers and black slate.

104-115 ....... | Dark-green chloritic slate, cut by a few gas veinlets of quartz-
calcite, Pyrite abundant throughout this rock, both as irregular
blebs and disseminated along bedding.

Dark-green slate, with light-color, calcareous interbeds. Cal-
cite veinlets at various places throughout this interval.

Bottom of hole at 155 feet.

115-155 ..

Bedding at- | Makes angle with core axis- T Bedding at- | Makes angle with core axis-
25 feet 70° 115 feet 64°
30 feet 83° 120 feet 72°
35 feet 78° 125 feet 75°
40 feet 75° 130 feet 72°
53 feet 79° 135 feet 74°
63 feet 80° 140 feet 72°
75 feet 68° 145 feet 68°
85 feet 77° 150 feet 80°
105 feet 71° 155 feet 76°
110 feet 71°

L/ See footnote at end of table.


21

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ver “ats “628 (P29 OUTLINE OF MAGNETIC ANOMALIES IN GAMMAS,
SCALE —— ——— BASELINE, TRANSIT SURVEY.

° 200 300,400 ©) PLAN OF CIAMOND-DRILL HOLES. “8008
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Figure 11. - Plan of Nickerson-Farm anomalies, including holes 1 and 2 and trench 1.


Deposits 1, 2, and 3, numbered consecutively from south to north, are about 300
and 1,000 feet apart, respectively. They are concealed by overburden, except where
Pierce deposit No. 1 is exposed in three Bureau of Mines trenches near a bridge that
crosses "B" stream. The deposits are indicated by 3 narrow anomalies, which strike
about N. 83°W.; the longest, outlining Pierce deposit No. 1, measures 8,400 linear
feet, Spot drilling on the deposits by the Bureau of Mines indicated a dip of 57°
to 60° SW. and a thickness of 6.5 to 50.7 feet.

Burnham Anomaly

The Burnham anomaly is 4,500 feet long. Trending east-west, it is 1,800 feet
north of the Burnham-float area on the Henry and Arthur Carpenter Farm in south-
eastern Hammond Plantation. The anomaly is caused by a dark-green vesicular igneous
rock, which may be either a flow or sill of andesite. It contains disseminated mag-
netite, which is responsible for the magnetic attraction. A flat slab of manganif-
erous rock float, composed of fine red and gray laminations, was found in 1951 ina
trench that exposed the south side of the andesite. This lent encouragement to ex-
ploring the north side of the anomaly.

The south side of the flow or sill is in contact with gray-green slate, and the
north side was found by diamond drilling to be in contact with gray-green, fine-
grained quartzite, with green and gray slate interbeds.

Nickerson-Farm Prospect

Several manganiferous rock outcrops are found on the Nickerson Farm in Hodgdon
Township on U. S. Highway No. 1 (see fig. 2). The surface indicates beds of manga-
nese-stained, magnetite-rich shale or slate - material similar in composition and
texture to the chlorite rock of the Pierce deposits in Hammond Plantation. An ex-
posure in a rock cut on the east side of U. S. Highway No. 1, fronting the Nickerson-
Farm buildings, contains manganiferous rock similar to that found on the south side
of a knoll, 500 feet east of the road, and in several small outcrops 1,000 feet
southeast of the knoll.

Two deposits are outlined by magnetic surveys, and the patterns produced indi-
cate that the area has been intensely folded and faulted. Because of irregularities
in strike and dip, exploration would be difficult without the aid of magnetic surveys.

CHARACTER OF ORE

Pierce Deposits

The manganiferous rock of the Pierce deposits is characterized by fine-grained,
thin laminations, blocky fracture, high specific gravity, and nonuniformity of hema-
tite and magnetite content. It has a wide range of color, from hematitic red through
gray, gray-green and black, Light-color siliceous laminae and thin, nearly white
bands in unweathered rock contain impure manganese carbonate. The rock is cut by
fine microfaults and gash veinlets containing minor feldspar, quartz, and calcite.

Magnetite, which probably results partly from local recyrstallization of hema-
tite, is not uniformly distributed. Heavy concentrations of magnetite occur as thin
laminae in dark bands, as much as 1 foot in thickness. A scattering of fine pyrite
and pyrrhotite is noted in some drill cores. Chemical tests indicate that most of
the manganese is combined with iron as impure carbonate. Several specimens taken
from these deposits were found to average 3.55 specific gravity, equivalent to about
10 cu. ft. per long ton of ore in place.


Details of field work completed and results of sampling and laboratory tests
are described in the following chapters.

Pierce Deposits

The manganiferous deposits in the vicinity of "B" stream, Hammond Plantation
Township, were completely covered by overburden, and it was apparent that ground
magnetometer surveys were needed to locate, outline, and trace the deposits before
other exploration could be undertaken.

A winter road, 1-1/4 miles in length, used for hauling timber and pulpwood from
"B" stream to "B" road, was repaired and conditioned for an access road,

While the 2 diamond drills were in operation - 1 each at the Burnham anomaly in
Hammond Plantation and the Nickerson-Farm prospect in Hodgdon Township - transit
surveys of base lines for mapping the Pierce anomalies were started May 1. The base
lines originate from a point on the north side of "B" stream, arbitrarily designated
as map coordinates 5,000 N. and 5,000 E. A total of 43,600 feet of transit-surveyed
base lines and traverse lines were brushed in the vicinity of "B" stream, and stakes
were set at 200-foot intervals. The magnetometer-survey party brushed and extended
traverse lines north-south for an additional 20,000 linear feet. Readings were taken
on more than 1,350 stations at measured intervals ranging from 25 to 50 feet over
50,000 feet of traverse lines. As a result of this work, three east-west-trending
anomalies (see figs. 3, 4, 5, 6), were mapped. The first and southernmost anomaly,
outlining Pierce deposit No. 1 was traced for a distance of 8,400 feet; the second,
Pierce deposit No. 2, 300 feet north of Pierce deposit No. 1, was traced 4,600 feet;
and the third anomaly, Pierce deposit No. 3, 1,000 feet north of Pierce No. 2, was
traced intermittently for a length of 5,200 feet.

Diamond drilling of the Pierce deposits was only of a preliminary nature to in-
vestigate the character of the ore and obtain samples for metallurgical tests. Six
short, inclined holes were drilled, totaling 945 feet. A total of 210.3 feet of core
was split and divided into 39 samples for assaying. Determinations for manganese and
iron are shown in table 1. Details of sampling the deposits are described separately.

Pierce Deposit No. 1, Diamond Drilling and Trenching

The deposit was tested by 2 short, inclined, diamond-drill holes and 3 surface
trenches. Drill holes 1 and 3 are plotted in plan (see fig. 3). The average true
thickness of the intersections of ore in the 2 holes (see fig. 7) is 12.5 feet; the
ore contains 10.2 percent Mn and 19.6 percent Fe. The average dip of the deposit,
as indicated by drilling, is 60°SW. The dip of the bed is indicated by the fine
lines on the vertical sections (see fig. 7).

Three trenches, opened to bedrock across Pierce deposit No. 1, total 195 linear
feet. The average true thickness of the ore exposed by trenching is 13.8 feet; it
averages 12.2 percent Mn and 25.5 percent Fe. A total of 9 channel samples was cut,
and the corresponding assays are shown in table 2.