Introduction

Methods

Surficial G

eolo

gic Map

and

C

ross-Sectio

ns o

f Rich

mo

nd

, Verm

on

tTim

Qu

esnell, Fran

k Piasecki, Sam Kn

app

, Ryan

Van

Ho

rn,

Steph

en W

right

Figure 4: A

rose diagram

depicting

the orientation of glacial striations observed in the m

apping area. The diagram has been

projected to represent the direction of glacial ice

movem

ent from

the

Northw

est to

the Southeast. A second m

ajor trend is oriented closer to W

est-East and represents a time

when

glacial ice

had thinned

and w

as constrained

by the

topography of

the W

inooski River Valley.

This

poster

details research

conducted

on

surficial m

aterials and lan

dforms surroun

ding R

ichmon

d and the

conclusion

s made on

how glacial m

ovemen

t has shaped

the environ

men

t. Richm

ond is located w

ithin C

hittenden

C

ounty,

Verm

ont.

To

the w

est is

Williston

, n

orth is

Jericho, east is Bolton

and to the south is bordered by the

Win

ooski River.

Roughly 1,700 geosp

atial observations w

ere collected over four weeks in

June

of 2018. Our travel routes w

ere constructed usin

g LiDA

R an

d elevation im

agery to estim

ate the most likely p

oints of con

tact between

glacial till and lacustrin

e sedim

ent. Soil p

robes and augurs w

ere used to samp

le surficial layers and

identify glacial till, lacustrin

e sedimen

t and alluvium

. A geologic com

pass w

as used to collect striation

and groove data off of bedrock outcrop

s. Water w

ells foun

d would have their location

and tag n

umber logged to later fin

d the subsurface

stratigraphic

depths

at those

locations,

used to

construct

our cross-section

s. Survey data and the p

resence of less frequen

t landform

s, which

include lan

dslides, terraces, alluvial fans, aban

doned stream

chann

els, eskers, an

d erratics, were recorded usin

g the mobile ap

p Fulcrum

. The survey data an

d observation

s made w

ere used in con

junction

with LiD

AR

and elevation

base m

aps to in

terpolate geologic con

tacts and con

struct a surficial map

in the

software Q

GIS.

Figure 5: (A) Extent of G

lacial Lake Mansfield 2 in the W

inooski River valley. The G

ilette pond outlet allowed drainage of this lake, but is now

at a higher elevation due to isostatic rebound. (B

) Extent of Glacial Lake M

ansfield 2 w

ithin the Winooski River Valley. (C

) With further retreat of the ice sheet the

Winooski River valley becam

e an arm of G

lacial Lake Vermont, eventually

draining to become the m

odern Winooski River.

Geo

logic M

ap Exten

t

Geo

logic M

ap Exten

t

Geo

logic M

ap Exten

t

Figure 2: These cross-sections show the stratigraphy of sedim

ent below w

here glacial lake M

ansfield was. O

f note in this area is the transition from lake sedim

ents to glacial till suggesting that this w

as on the shoreline of glacial lake Mansfield.

Figure 3: These cross-sections show the m

odern deposition of sediment in the W

inooski River valley and H

untington River valley, respectively. The lake sediment layer above

the glacial till layer suggests that the lake formed after the glaciers had already

retreated.

Figure 6: Extent of Glacial Lake M

ansfield 2 within the m

apping area. Identified deltas are labelled. The current elevation of these delta features w

as used to estimate the previous shoreline elevation of the lake (216 m

or 709 feet). The w

ater was blocked by the ice sheet to the N

orthwest, form

ing G

lacial Lake Mansfield 2 at the observed elevation.

Photo (Left):

This photo

displays the diversity of rounded grain

sizes found

along the

esker in the mapping area. The

grains ranged

from

medium

sand to large cobbles. A

soil probe is included for scale.

Figure 1: Our area of study stretched from

the valley of the W

inooski River in the south up to Mill Brook in the

north, covering roughly 60 square kilometers of terrain.

Observations

●T

he abandon

ed stream chan

nel in

the northw

est part of the m

ap in

dicates that a glacier was

presen

t directly to the west. T

he abandon

ed chann

el would have p

rovided the only w

ay for w

ater to go in that area.

●G

lacial striations in

the area of study mostly p

oint n

orthwest to southeast or w

est to east as show

n in

(Figure 4).●

Elevation

s above 216 m did n

ot show sign

s of lake sedimen

ts throughout the entire study area,

indicatin

g that lake levels never rose above that elevation

●D

eltas in w

estern section

have eroded away to reveal eskers, show

ing that the eskers w

ere dep

osited under glacial ice before stream

tributaries formed the deltas

Interpretations

Cross-S

ectionsG

lacial Modeling

ABC

Photo (Right): A

n erratic that w

as dropped in a field as a glacier w

as retreating through the area.

Photo (Right): There are m

any streams

scattered throughout the area of study that are

moving

sediment

towards

the W

inooski River.

Photo (Above): A

sample taken w

ith a soil probe that consists of organic m

aterial on top of lake sedim

ents

Photo (Below): C

ourse sediment depositing

along Huntington R

iver, adding to alluvium

Photo (R

ight): exposed bedrock alongside W

inooski River,

underneath public

bridge. G

rooves from

glacier

carving through

valley floor

can be

measured here.

Photo (Above): B

edrock outcrop in southeast

section. Several

were

measured

to determ

ine direction

of glacial m

ovement