Glacial Tills and Moraines

recessional moraines

Commonly found with kettle lakes: sands and gravels; __________ __________

Outwash

Deposited beyond terminus of ice (in periglacial or proglacial). Well sorted, well rounded. Melt water

Lateral moraine

Deposited lateral to the glacier

subglacial, supraglacial, flow

Deposition types of till (3)

base

Drumlins are formed with processes at the ________ of the glacier

continental

Eskers are associated with __________ glaciers

stagnant

Eskers are formed near the _______ end of ice sheets

fan shape

Eskers sometimes terminate in a

end moraine

Forms at the end of the glacier

striations

How are debris flows different from diamicton? (both are poorly sorted)

Surpraglacial

In this kind of till, sediment is deposited by melting in the Zone of Ablation. Material on top of glacier accelerates melting

water

Kames are _____ deposited

Supraglacial

Melt-out till and ablation till are subcategories of this till deposition type

unstratified

Moraines are _______

Till

Most unstratified glacial drift is _____. Not deposited directly by ice

drumlins

Mostly depositional features elongated in direction of ice flow w/ various proportions of bedrock

Unstratified Glacial Drift

Poorly sorted. Class may be angular or rounded.

30

Push moraines often develop shear zones at _____ degrees. Called "thrusts"

Deformation till

Sediment is deposited and under influence of SHEAR. Ice moves while it deposits

subglacial melt out till

Sediment is released as blocks of non-moving ice melts

Stratified Glacial Drift

Sediment transported by moving water. Commonly sorted. Clasts commonly rounded

oceans, lakes, rivers, land

Stratified glacial drift deposition can take place in

shallow; steep

The glacier moved in direction of the ________ side of the drumlins, over the _____ side

Moraine

These are deposited along the margins of ice and made up of drift. It is a depositional feature whose form is independent of topography and constructed by a drift- most ice-deposited

drumlins

These are wider than they are high

Interior ice contact

These features are within or underneath the glacier

Flow Till

This is not a "true" till. Glacially derived sed.s, later deposited by gravity. This is highly stratified gravity flow

Lodgement till

Till when particles get lodged against bedrock

Push Moraine

aka Thrust-block. Where older till deposits and then is deformed by advancing ice. Internal deformation in older dep. shows evidence of shear or thrust. The max compression stress in this moraine is horizontal

Kames

are formed where a cavity or hole in ice begins to melt. Filled up with stratified sediment.

Kames

common dep. feats associated with ice. Mountain like hills of layered sand and gravel

Medial moraines

debris along lateral edges of glacier merge where glaciers come together and appear as linear belts on the glaciers. Thin

Kettle Lakes

depression formed by isolated blocks of ice buried in stratified drift.

Eskers

elongate deposits that are typically stratified sands and gravels that can curve or be straight or branch or intertwine

Kame Terraces

form from drift that accumulated between melting ice and valley walls

ground moraines

form undulating planes that occur over vast areas and do not have a lot of relief (<10m thick)

8; 25

glacial drift covers approx. ___% of all land and ____% of N.A.

Incipient Kame

sediment moves into lake--> full of sed and gravel

subglacial diamicton

sediment typically with wide range of sizes of material that is often angular. Mud matrix. Used to reference glacial mov. in geologic record

recessional (disintegration)

superglacial debris in ice blocks. As ice melts, the glacier recedes, creating _____ moraine

sandur

this is dep. as glacier recedes and is produced by continuous lateral shifting of channels. Usually associated with large continental glaciers. aka outwash plane

Terminal moraine

type of end moraine that represents the greatest extent of the moraine. Furthest end moraine in a series of melt and cool

Interlobate moraine

"between the lobes" when 2 come together

stratified and unstratified

2 types of glacial drift

lodgement, subglacial melt out, deformation

3 types of subglacial till