OBJECTID |
MapUnit |
Name |
FullName |
Age |
Description |
HierarchyKey |
ParagraphStyle |
Label |
Symbol |
AreaFillRGB |
AreaFillPatternDescription |
DescriptionSourceID |
GeoMaterial |
GeoMaterialConfidence |
_ID |
AreaFillRGB_MGS |
1 |
--- |
INTRUSIVE ROCKS |
--- |
--- |
--- |
01 |
DMUHeading2 |
--- |
--- |
--- |
--- |
DAS1 |
--- |
--- |
DMU12909 |
--- |
2 |
--- |
Mesozoic(?) [Mz] |
--- |
--- |
--- |
01-01 |
DMUHeading6 |
--- |
--- |
--- |
--- |
DAS1 |
--- |
--- |
DMU12936 |
--- |
3 |
Md |
Diabase |
Diabase |
Mesozoic(?) |
Dark gray, fine-grained diabase. Contacts with surrounding country rocks are not exposed. The only outcrops of this rock type are near the southern quadrangle boundary on the small hill approximately 1.3 kilometers (km) southeast of Ray Corner. |
01-01-01 |
DMUUnit2 |
M#d |
503 |
153,204,255 |
pattern-181 |
DAS1 |
Fine-grained, mafic-composition intrusive igneous rock |
High: GeoMat |
DMU5794 |
142,205,255 |
4 |
--- |
Devonian(?) [D] |
--- |
--- |
--- |
01-02 |
DMUHeading6 |
--- |
--- |
--- |
--- |
DAS1 |
--- |
--- |
DMU12937 |
--- |
5 |
Dgm |
Muscovite granite |
Muscovite granite |
Devonian(?) |
Light gray, fine-grained to medium-grained, foliated, garnet-bearing, muscovite +/- biotite granite. Small outcrops of this unit can be found along the east-west road located just north of Lake Passagassawakeag. |
01-02-01 |
DMUUnit2 |
Dgm |
23 |
255,204,222 |
pattern-014 |
DAS1 |
Coarse-grained, felsic-composition intrusive igneous rock |
High: GeoMat |
DMU5791 |
255,209,225 |
6 |
--- |
DEFORMED INTRUSIVE ROCKS |
--- |
--- |
--- |
02 |
DMUHeading2 |
--- |
--- |
--- |
--- |
DAS1 |
--- |
--- |
DMU12938 |
--- |
7 |
--- |
Devonian-Silurian(?) [DS] |
--- |
--- |
--- |
02-01 |
DMUHeading6 |
--- |
--- |
--- |
--- |
DAS1 |
--- |
--- |
DMU12939 |
--- |
8 |
DSmp |
Mixer Pond Gneiss |
Mixer Pond Gneiss |
Devonian-Silurian(?) |
Medium gray, medium-grained to coarse-grained, strongly foliated, biotite granite. Locally, dikes and sills of light gray, medium-grained, muscovite granite may be present. There are good exposures of this unit on the southeastern side of Pond Hill, west of Lake Passagassawakeag. |
02-01-01 |
DMUUnit2 |
DSmp |
423 |
179,204,222 |
pattern-070 |
DAS1 |
Meta-felsic and intermediate rock |
High: GeoMat |
DMU5793 |
171,199,217 |
9 |
--- |
STRATIFIED ROCKS |
--- |
--- |
--- |
03 |
DMUHeading2 |
--- |
--- |
--- |
--- |
DAS1 |
--- |
--- |
DMU12940 |
--- |
10 |
--- |
Vassalboro Group |
--- |
--- |
--- |
03-01 |
DMUHeading4 |
--- |
--- |
--- |
--- |
DAS1 |
--- |
--- |
DMU12942 |
--- |
11 |
--- |
Silurian-Ordovician(?) [SO] |
--- |
--- |
--- |
03-01-01 |
DMUHeading6 |
--- |
--- |
--- |
--- |
DAS1 |
--- |
--- |
DMU12941 |
--- |
12 |
SOv |
Vassalboro Group, undifferentiated |
Vassalboro Group, undifferentiated |
Silurian-Ordovician(?) |
Gray-weathering, medium gray, fine-grained, plagioclase-quartz-biotite granofels interlayered with greenish gray, fine-grained, calc-silicate granofels and occasional layers of light gray, medium-grained, mica schist. Layers range in thickness from 2 to 10 centimeters (cm). Calc-silicate granofels and mica schist are generally subordinate to the biotite granofels. Locally the granofels contains small amounts of free calcite. There are easily accessible exposures of this unit along Route 7 in small road cuts approximately 500 meters north of, and 1 km south of Jackson Corners. |
03-01-01-01 |
DMUUnit2 |
SOv |
450 |
179,255,153 |
--- |
DAS1 |
Schist and gneiss, of sedimentary-rock origin |
High: GeoMat |
DMU5806 |
179,255,154 |
13 |
--- |
Falmouth-Brunswick Group |
--- |
--- |
--- |
03-02 |
DMUHeading4 |
--- |
--- |
--- |
--- |
DAS1 |
--- |
--- |
DMU12943 |
--- |
14 |
--- |
Ordovician [O] |
--- |
--- |
--- |
03-02-01 |
DMUHeading6 |
--- |
--- |
--- |
--- |
DAS1 |
--- |
--- |
DMU12944 |
--- |
15 |
Obr |
Beaver Ridge Formation |
Beaver Ridge Formation of the Falmouth-Brunswick Group |
Ordovician |
Moderately to deeply rusty-weathering, medium gray, medium-grained, sulfidic and locally graphitic and/or garnet-bearing, quartz-muscovite-plagioclase schist and granofels (Photo 1). Subordinate rock types include light gray, fine-grained, quartz-plagioclase-biotite granofels and gneiss, and rare impure marble. Accessible exposures are found in small road cuts west of Route 7 approximately 300 meters south of Jackson Corners. |
03-02-01-01 |
DMUUnit2 |
Obr |
88 |
255,077,077 |
--- |
DAS1 |
Schist and gneiss, of sedimentary-rock origin |
High: GeoMat |
DMU5796 |
255,089,041 |
16 |
Obrp |
Phyllite |
Phyllite member of the Beaver Ridge Formation |
Ordovician |
Gray-weathering to moderately rusty-weathering, dark gray, fine-grained phyllite. Locally, thin layers (1-3 cm) of lighter colored, fine-grained, quartz-rich +/- carbonate granofels are present. A well-developed crenulation cleavage is prominent in the phyllite. |
03-02-01-01-01 |
DMUUnit3 |
Obrp |
922 |
000,222,222 |
--- |
DAS1 |
Slate and phyllite, of sedimentary-rock origin |
High: GeoMat |
DMU5797 |
000,217,217 |
17 |
Onp |
Nehumkeag Pond Formation |
Nehumkeag Pond Formation of the Falmouth-Brunswick Group |
Ordovician |
Gray-weathering, medium gray, fine-grained to medium-grained, plagioclase-quartz-biotite +/- muscovite +/- garnet gneiss. Subordinate rock types include dark gray amphibolite, and moderately rusty-weathering, quartz-plagioclase-biotite +/- garnet schist and gneiss. The best exposures of this rock unit in the quadrangle are located along the powerline right-of-way, approximately 1.5 km east of Knox Ledge Corner. |
03-02-01-02 |
DMUUnit2 |
Onp |
54 |
255,179,153 |
--- |
DAS1 |
Medium and high-grade regional metamorphic rock, of unspecified origin |
High: GeoMat |
DMU5801 |
255,190,146 |
18 |
--- |
Casco Bay Group |
--- |
--- |
--- |
03-03 |
DMUHeading4 |
--- |
--- |
--- |
--- |
DAS1 |
--- |
--- |
DMU12945 |
--- |
19 |
--- |
Ordovician [O] |
--- |
--- |
--- |
03-03-01 |
DMUHeading6 |
--- |
--- |
--- |
--- |
DAS1 |
--- |
--- |
DMU12946 |
--- |
20 |
Os |
Scarboro Formation |
Scarboro Formation of the Casco Bay Group |
Ordovician |
Slightly to moderately rusty-weathering, medium gray, medium-grained, graphitic, quartz-plagioclase-muscovite-biotite +/- garnet schist. Discontinuous quartz segregations (2-8 cm thick) are common. Compositional layering is generally thin and discontinuous. An easily accessible exposure is a low road cut west of Route 7, approximately 250 meters north of the Sullivan Road intersection, (3 km north of Brooks). |
03-03-01-01 |
DMUUnit2 |
Os |
152 |
235,222,153 |
--- |
DAS1 |
Schist and gneiss, of sedimentary-rock origin |
High: GeoMat |
DMU5802 |
242,215,160 |
21 |
Osg |
Granofels |
Granofels member of the Scarboro Formation |
Ordovician |
Gray-weathering, medium gray, fine-grained, plagioclase-quartz-biotite granofels interlayered with subordinate amounts of greenish gray, fine-grained, calc-silicate granofels and occasional layers of light gray, medium-grained, mica schist. Layering (2-8 cm thick) is prominent and weathered exposures break into slabs. There are good exposures of this unit on Taggett Hill in the southeast portion of the quadrangle. |
03-03-01-01-01 |
DMUUnit3 |
Osg |
254 |
222,179,153 |
--- |
DAS1 |
Schist and gneiss, of sedimentary-rock origin |
Medium: GeoMat |
DMU5803 |
228,185,151 |
22 |
Oce |
Cape Elizabeth Formation |
Cape Elizabeth Formation of the Casco Bay Group |
Ordovician |
Light gray, medium-grained, quartz-plagioclase-muscovite-biotite +/- garnet schist interlayered with light gray, fine-grained, micaceous quartz-plagioclase granofels (Photo 2). Layering of these rock types, generally 2 to 12 cm in thickness, is prominent in most exposures and contacts between schist and granofels are generally sharp. This unit is exposed in low outcrops west of Route 7 approximately 2 km north of the Route 139 intersection at Brooks village. |
03-03-01-02 |
DMUUnit2 |
Oce |
376 |
204,128,102 |
--- |
DAS1 |
Schist and gneiss, of sedimentary-rock origin |
High: GeoMat |
DMU5804 |
201,134,108 |
23 |
Oceq |
Quartzite |
Quartzite member of the Cape Elizabeth Formation |
Ordovician |
Gray-weathering to moderately rusty-weathering, light gray, fine-grained to medium-grained muscovite-biotite quartzite. Locally, layers of moderately rusty-weathering, medium gray, fine-grained phyllite are present. Representative outcrops of this unit are found on Hedgehog Hill in the southeastern part of the quadrangle. |
03-03-01-02-01 |
DMUUnit3 |
Oceq |
487 |
179,102,077 |
--- |
DAS1 |
Quartzite |
High: GeoMat |
DMU5798 |
188,107,087 |
24 |
--- |
Cushing Formation |
Cushing Formation |
Ordovician |
--- |
03-03-01-03 |
DMUUnit2 |
--- |
--- |
--- |
--- |
DAS1 |
--- |
--- |
DMU12947 |
--- |
25 |
Ocwc |
Wilson Cove Member |
Wilson Cove Member of the Cushing Formation |
Ordovician |
Moderately to deeply rusty-weathering, medium to dark gray, fine-grained to medium-grained, sulfidic, quartz-muscovite +/- biotite +/- garnet schist and granofels. Thin layers (< 2 cm) of fine-grained, garnet-amphibole-rich granofels are present locally. The most accessible exposure of this unit in the quadrangle is in a low road cut east of Route 7 in Jackson, approximately 600 meters north of the Brooks town line. |
03-03-01-03-01 |
DMUUnit3 |
Ocwc |
388 |
204,077,077 |
--- |
DAS1 |
Schist and gneiss, of sedimentary-rock origin |
High: GeoMat |
DMU5799 |
199,079,079 |
26 |
--- |
ROCKS OF COMPLEX ORIGIN |
--- |
--- |
--- |
04 |
DMUHeading2 |
--- |
--- |
--- |
--- |
DAS1 |
--- |
--- |
DMU12949 |
--- |
27 |
--- |
Devonian-Ordovician(?) [DO] |
--- |
--- |
--- |
04-01 |
DMUHeading6 |
--- |
--- |
--- |
--- |
DAS1 |
--- |
--- |
DMU12950 |
--- |
28 |
DOpg |
Passagassawakeag Gneiss |
Passagassawakeag Gneiss |
Devonian-Ordovician(?) |
Interlayered light gray, medium-grained, gray-weathering, quartz-plagioclase-biotite +/- muscovite +/- sillimanite schist and gneiss and light gray, medium-grained, strongly foliated muscovite +/- biotite granite to granite gneiss. Boudinage of the granitic rocks within the schist and gneiss is common, along with a strong degree of shearing within both rock types. The best exposures of this unit are in the southeast corner of the quadrangle, along the southeastern shore of Lake Passagassawakeag. |
04-01-01 |
DMUUnit2 |
DOpg |
232 |
222,222,204 |
--- |
DAS1 |
Medium and high-grade regional metamorphic rock, of unspecified origin |
High: GeoMat |
DMU5800 |
216,216,198 |
29 |
--- |
HIGHLY DEFORMED ROCKS |
--- |
--- |
--- |
05 |
DMUHeading2 |
--- |
--- |
--- |
--- |
DAS1 |
--- |
--- |
DMU12951 |
--- |
30 |
--- |
Note on mylonite ages. |
--- |
--- |
The original publication did not assign an age to these deformation-related metamorphic rocks. The age reported here, Permian-Ordovician, represents the range between the age of the original protolith rocks (Cape Elizabeth and Scarboro Formations) and superimposed mylonitic deformation. |
05-01 |
DMUUnit1 |
--- |
--- |
--- |
--- |
DAS1 |
--- |
--- |
DMU12952 |
--- |
31 |
whc |
Whitten Hill Complex |
Whitten Hill Complex |
Permian-Ordovician |
A wide variety of generally fine-grained rock types is present over a relatively short distance across strike in Halfmoon Stream, in the southwest corner of the quadrangle. Rock types include light gray mica-bearing quartzite; light to medium gray calc-silicate granofels interlayered with subordinate amounts of biotite granofels; rusty-weathering, dark gray sulfidic granofels (Photo 5); and rare hornblende gneiss. Outcrop exposure to the northeast of this stream is inadequate to map these various rock types separately along strike. In the central and eastern portion of the quadrangle the unit is thinner and is dominated by deeply rusty-weathering, dark gray, sulfidic, graphitic, quartz-rich granofels and minor schist. The lithologic variability within this unit is displayed in outcrops along Halfmoon Stream. Outcrops of the rusty-weathering granofels in the central portion of the quadrangle are found near the Route 139 crossing of the Belfast and Moosehead Lake Railroad. |
05-01-01 |
DMUUnit2 |
whc |
504 |
153,179,255 |
pattern-335 |
DAS1 |
Deformation-related metamorphic rock |
High: GeoMat |
DMU5792 |
156,177,255 |
32 |
rcm |
Ray Corner Mylonite Suite (Pollock, 2018) |
Ray Corner Mylonite Suite |
Permian-Ordovician |
This bedrock unit is a highly deformed structural complex, characterized by strongly sheared rocks which contain a steeply dipping mylonitic foliation. While there is lithologic variability, the most common rock type is a medium to dark gray, aphanitic to fine-grained, mylonitic gneiss. The very thin layering in the gneiss, defined by alternating shades of gray, typically ranges from 0.2 to 2 cm in thickness. Locally, the mylonite is cut by narrow veins of pseudotachylyte (< 2 cm), some of which are parallel to the mylonitic foliation, and some of which cut across it (Photo 8). In addition, some exposures are cut by complex networks of very thin (usually < 3 mm) white, chalky-weathering veins that cut across all other structural fabrics (Photo 6). Locally, these veins are much thicker (up to 30 cm across) and represent a lithified fault breccia, containing abundant clasts of mylonite with no obvious preferred orientation. Rocks along the northwestern margin of this unit are protomylonitic and contain abundant muscovite fish that show a dextral or right-lateral sense of shear. Rocks along the southeastern margin of the unit are also protomylonitic, but have a different composition, commonly containing thin, fine-grained calc-silicate layers. There are accessible exposures of the unit in a series of low outcrops along the south side of County Road, approximately 500 meters west of Ray Corner. |
05-01-02 |
DMUUnit2 |
rcm |
203 |
222,204,255 |
pattern-334 |
DAS1 |
Deformation-related metamorphic rock |
High: GeoMat |
DMU5808 |
223,201,255 |
33 |
bpm |
Basin Pond Mylonite |
Basin Pond Mylonite of the Ray Corner Mylonite Suite |
Permian-Ordovician |
Medium gray to dark gray, fine-grained mylonitic to ultramylonitic gneiss that commonly is interlayered with medium gray, fine-grained biotite granofels with subordinate amounts of calc-silicate granofels and rusty-weathering phyllite. Thin (< 2 cm) discordant pseudotachylyte veins and/or zones of light gray lithified fault breccia and cataclasite are present locally. This unit is exposed in large road cuts on Route 7, approximately 800 meters north of Brooks village (Route 139 intersection). |
05-01-02-01 |
DMUUnit3 |
bpm |
405 |
179,153,255 |
pattern-333 |
DAS1 |
Deformation-related metamorphic rock |
High: GeoMat |
DMU5805 |
191,145,255 |
34 |
ssm |
Sunny Side mylonite |
Sunny Side mylonite |
Permian-Ordovician |
Thin zone of mylonite and ultramylonite mapped at the south edge of the quadrangle, inferred from mapping in the Morrill quadrangle (Pollock, 2010). |
05-01-03 |
DMUUnit2 |
ssm |
203 |
222,204,255 |
pattern-335 |
DAS1 |
Deformation-related metamorphic rock |
High: GeoMat |
DMU5807 |
214,204,255 |
35 |
my |
Mylonite |
Mylonite |
Permian-Ordovician |
Light to medium gray, fine-grained to medium-grained, porphyroclastic mylonite (Photo 7). Porphyroclasts are most commonly feldspar, but carbonate-rich clasts are abundant locally. Layering in the mylonites, where present, is generally on the order of 0.2 to 2 cm in thickness. The mylonitic foliation is steeply dipping. Kinematic indicators consistently show a dextral or right-lateral sense of shear. These mylonites are coincident with the Hill 806 fault originally mapped by Pankiwskyj (1996). There are good exposures of this unit approximately 300 meters north-northwest of Styles Cemetery near the east edge of the map. |
05-01-04 |
DMUUnit2 |
my |
6 |
255,128,255 |
pattern-335 |
DAS1 |
Deformation-related metamorphic rock |
High: GeoMat |
DMU5795 |
255,135,255 |