Part of NTS Sheets 21A/05, 21B/01, 21B/08 and 21B/09 Nova Scotia Department of Natural Resources - Mineral Resources Branch OFM ME 2010-8
66°30'W 66°20'W 44°30'N 66°10'W 220000mE 21 22 23 24 25 26 27 28 29 230 31 32 33 34 35 36 37 38 39 240 41 42 43 44 45 46 47 48 49 250 51 52 53 54 255000mE N N 000m 000m 19 49 36 Legend
49
MESOZOIC
18
Long 35
Poi nt TRIASSIC
FUNDY GROUP
NORTH MOUNTAIN FORMATION
17
Burns
34
>
Second Point BRIER ISLAND MEMBER (Upper Flow Unit) (^Fnmb) : this unit ( À 150 m) occurs at the
^Fnmb
^Fnmb
Point Cu >
top of the basalt sequence, conformable on unit ^Fnmm and outcrops extensively on the >
northern shorelines except in the central part of the mapped area where it is notably
Mount absent. The basalt is massive, dark grey to grey-green with microcrysts (À 5%) of
Fe
plagioclase and pyroxene with variable (À 30-40%) amounts of mesostasis in a medium-
Shubley
16 ^Fnmm grained, ophitic-textured host. This unit consists of 1 or 2 flow sheets, has colonnade-
> 33 style polygonal jointing (À 1 m) and, at the base, inclined pipe vesicles occur. The lower Sandy
Cove 10-20 m locally (e.g., Morden, Margaretsville) contains felsic material (ca. 65-74 wt. %
66°30'W SiO2 ) in the form of dykes, amoeboid masses and spectacular segregation pipes (3-60
^Fnme 2
cm; 10-15/m ) that are sometimes cored by agate and crystalline silica. Rarely veins of
^Fnmm silica cut the unit and locally areas of intense silica alteration occur.
Whites ^Fnmb ok
15 ro
Point MARGARETSVILLE MEMBER (Middle Flow Unit) (^Fnmm) : this unit occurs between the 32
44°20'N B ^Fnme 44°30'N
s ^Fnmm ^Fnme ^Fnmb
y massive and relatively fresher and flows. Due to alteration the unit is
e ^Fnmm
n recessive and occupies low lying, locally swampy (e.g., Long Island and Brier Island)
id
areas. Significantly, in the eastern part of the mapped area (i.e., Scots Bay) the unit is in G
Fe Eastern contact with the younger Triassic Scots Bay Formation rather than the Brier Island
Mink Head
Western Member. The unit varies in thickness from À 20-40 m in the western part of the mapped
Tommys
^Fnmm ^Fnme
Cove area to À 170 m maximum thickness in the central area; areal exposure varies
14 Head Beach
31 considerably towards the east. Individual flows are fine grained, dark grey to grey-green
> Little and/or red-brown, massive to intensely vesiculated, generally altered and, therefore, very
Cu
K River friable. The unit contains multiple (15-20), thin (À 15-20 m), geometrically complex flow
C
E
>
N >
sheets with abundant, zonally-arranged vesicles (e.g., pipes, vesicle cylinders and
> Y ^Fnme
> B >
IG sheets) which are mostly occluded with different zeolite phases (locally 20-30% by
> D
>
volume) and lesser silica and micaceous material. In thicker flows the cores or lower parts
13 Diatomite Clay
49 can be massive and rarely exhibit columnar jointing. Abundant field evidence (e.g., flow