EXCERPTS
FROM THE
U.S. GEOLOGICAL SURVEY
SURFICIAL MATERIALS MAP OF CT

Sandwiched
between the Region’s soil layer (see
local soil constraint maps) and its bedrock (see
local bedrock maps) is an important middle layer
of glacially deposited material.
Mapping of these glacial "surficial materials" by
municipality is available from the U.S. Geological Survey’s
1992 Surficial Materials Map of Connecticut. The
legend for the 1992 map
is available as a pdf file and map excerpts
are available below:
USGS
SURFICIAL MATERIALS MAP OF BETHEL CT
USGS
SURFICIAL MATERIALS MAP OF BRIDGEWATER CT
USGS
SURFICIAL MATERIALS MAP OF BROOKFIELD CT
USGS
SURFICIAL MATERIALS MAP OF DANBURY CT
USGS
SURFICIAL MATERIALS MAP OF NEW FAIRFIELD CT
USGS
SURFICIAL MATERIALS MAP OF NEW MILFORD CT
USGS
SURFICIAL MATERIALS MAP OF NEWTOWN CT
USGS
SURFICIAL MATERIALS MAP OF REDDING CT
USGS
SURFICIAL MATERIALS MAP OF RIDGEFIELD CT
USGS
SURFICIAL MATERIALS MAP OF SHERMAN CT
These
glacial deposits under the soil are divided into two broad
categories, glacial till and glacial stratified meltwater
deposits.

Glacial
till deposit - an unsorted mix
Till is the most widespread glacial deposit. It was laid down
directly by glacial ice and is characterized by unsorted sand,
silt and clay with variable amounts of stones and large boulders
mixed in.
The
second category, glacially stratified meltwater deposits,
were concentrated in valleys by streams and lakes in front
of the retreating ice.
Glacial
meltwater deposit - sorted and usable
These
water related deposits are in layers of sorted gravel, sand,
silt and clay. The well sorted gravel areas are the major
groundwater aquifer well sites, sometimes in competition with
sand and gravel mining activity found in these same deposits.
A
few small post glacial sediments are also included on the
map. These are primarily floodplain alluvium and swamp deposits.
Alluvium is largely reworked from glacial materials and has
similar physical characteristics.
Aside
from their value to siting high capacity water supply wells,
these maps have the following uses in local planning and development
(Dr. Jack to fill in):
1.
XXXXX XXXXXXX XX XXXX XX XXXXXXXXXXXX XX X XXXXX X X XXXX
XX XXXXXXXXXX X XXXXX XXX XXXXXXXXX X XXXXXXXX X X XX XXXX
XX XXXXXXX XX XXXXXXXXX X XXXX XXXXXXXXXXXXX X X XX XXXXXXXX
XXXX
2.
XXXXX XXXXXXX XX XXXX XX XXXXXXXXXXXX XX X XXXXX X X XXXX
XX XXXXXXXXXX X XXXXX XXX XXXXXXXXX X XXXXXXXX X X XX XXXX
XX XXXXXXX XX XXXXXXXXX X XXXX XXXXXXXXXXXXX X X XX XXXXXXXX
XXXX
3.
XXXXX XXXXXXX XX XXXX XX XXXXXXXXXXXX XX X XXXXX X X XXXX
XX XXXXXXXXXX X XXXXX XXX XXXXXXXXX X XXXXXXXX X X XX XXXX
XX XXXXXXX XX XXXXXXXXX X XXXX XXXXXXXXXXXXX X X XX
4.
XXXXXXXX XXXX1. XXXXX XXXXXXX XX XXXX XX XXXXXXXXXXXX XX X
XXXXX X X XXXX XX XXXXXXXXXX X XXXXX XXX XXXXXXXXX X XXXXXXXX
X X XX XXXX XX XXXXXXX XX XXXXXXXXX X XXXX XXXXXXXXXXXXX X
X XX XXXXXXXX XXXX
|