End Moraine Facies

1
End Moraine Facies
Mud/debris flow
Flowtill
Sheetflow
Debris flow
Bar gravel
Debris flow
Sheetflow
HyperX flow
HyperX flow
Sheetflow
Distal flowtill
HyperX flow
Sheetflow
Stream flow
Stream flow
Overbank
Gelifluction
2
Grounded Ice andGlaciofluvial locations
3
Grounded Ice FaciesUnstratified Diamicts

• Bimodal Particle Size Distribution
• Unsorted pebbles, cobbles, and boulders
• Interstitial matrix of sand, silt, and clay
• Elongate particles show preferred orientation
• Some crude imbrication
• Long axes dipping upstream

4
Stratified Diamicts

• Sediments generated by
• Supraglacial, englacial, subglacial processes
• Better sorting
• Lack the bimodal size distribution associated
  with direct deposition
• Pebbles may be rounded by meltwater transport
• Some stratification from reworking
• Seen in the form of kames, kame terraces, eskers

5
Glaciofluvial Deposits
6
Glaciofluvial Deposits

• Can be deposited in
• Subglacial and englacial conduits
• Supraglacial and proglacial streams
• Lithofacies reflect local sediment supply
• Well stratified and feature sedimentary
  structures at varying scales
• Dependant on stream discharge and sediment supply

7
Facies Distribution

• NOTE
• May be gradation from pure till to type A as well
  as among types!

8
Distinction from Outwash
9
Kames

• Small mound-shaped accumulations of sand or
  gravel
• Form in pockets or crevasses in the ice
• Commonly feature fining upwards sequences
• Large unsorted clasts overlain by sands and silts
• Thermal?

10
Eskers

• Narrow, sinuous ridges of sediment parallel to
  ice flow
• Can include gravels, sands, and silt
• Some facies may be extremely well stratified
• Feature gravels overlain by fine, fluvial
  sediments
• Topped or interbedded with diamictites

11
Glacier Marine Sediment Facies

• By Scott Patterson
• Geol 445 Glacier Geology
• 4/5/03

12
Glacier Marine Sediment Facies Definitions

• Till terrestrial, primary glacier deposited
  diamicton
• Glacimarine drift marine till
• Facies stratigraphic units distinguished by
  lithologic, structural and organic
  characteristics detectable in the field (Boggs
  2001)

13
Proximal vs. Distal
Eyles et al 1991 Boggs 2001
14
Distal Glacier Marine Facies Characteristics

• Settled Sediment
• Extreme variation in clast type (lithology and
  source)
• Dropstones with soft sediment deformation
• Stratification
• Marine fossils (forams and diatoms)

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Sediment plumes off a Glacier
(Cofaigh, 2001)
Soon to be Settled Sediment Norway
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Settled Sediment - Varves

• Sources outer/inter flows
• Stratification
• Fine-grained laminae fine sand/silt silt/clay
• thin from ice
• dark from organics

Eyles et al 1991
17
Dropstones

• Clast lithology gneiss in mudstone
• Boulder
• Subrounded

http//geologyindy.byu.edu/faculty/rah/slides/Rock
20Canyon/Precambrian20Glaciers/dropstones20page
.htm