CONFINED VS. UNCONFINED

 
 
  

CONFINED FLOW:
  • Channelized flow
  • Flow is parallel to channel 
  • Bounded on both sides
  • Basal/Erosional contacts
  • Accretion:  Lateral, Vertical, Downstream and Upstream
  • Minor change in flow velocity
  • Little change in grain size
  • No gross change in sedimentary structures
  • Geometries:  Ribbons, Lens and Sheets
strat conf
key
conf confined

 
 

CONF-UNCON confin-unconfin
 

                           Sand bar in the Wisconsin River showing confined flow changing to unconfined flow.

 

UNCONFINED FLOW:
  • Flow not in a channel 
  • Flow is in all directions
  • No lateral boundaries, only upper and lower boundaries
  • Erosional/Sharp/Gradational contacts
  • Accreation:  Downstream, Upstream and Vertical 
  • Velocity changes:  from high to low
  • Decrease in grain size:  Finning outward (coarse to fine)
  • Decrease in sedimentary structures
  • Geometries:  Sheets
  • Thinning in direction of flow
 unconfin
key
uncon pic unconfined pic
Web page constructed by Alexis Woods (10/28/03)

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