2.4 Volcaniclastic Sediments
69
a
VOLC. ASH (TUFF)
'" . " ) \ , \ MUDSTONE
w
Ü
CI:
::J
o
Cf)
40
b
PROXIMAL
(VOLCANICL.)
DISTAL
(VOlC .+ SILICIClASTiCS)
~ieF<~ ClAST~~~ SUPPORED
CONGlOMERATE
IGNIMBRITE
TAOUGH
CROSSBEDDED
SANDSTONE~
TROUGH
AND PLANAR
CROSSBEDDED
DISTANCE
FROM SOURCE
80
120 km
C
CROSS SECTION OF CHANNEL FILL
AND SHEET -LiKE VOLCANICLASTICS
HYPERCONCENTRATED
FLOOD FLOW DEP.
SHEET FLOOD
DEPOSITS
PALEO-VALLEY FILL (POLYMICTIC
CONGLOM .) :t OVERBANK DEP.
AIR-FALL TUFF
ON PALEOSOL
Fig. 2.26_ a Relative abundance (thicknesses of horizontal bars) of continental volcaniclastic facies in
relation to distance from the source, Miocene, Washington. b Characteristic sections of a in the proximal
and distal range. c Cross seetion perpendicular to
flow direction showing syn-eruption, sheet-like
volcaniclastics and siliciclastic to mixed valley tills
generated in inter-eruption periods. (After Smith
1988)
69
a
VOLC. ASH (TUFF)
'" . " ) \ , \ MUDSTONE
w
Ü
CI:
::J
o
Cf)
40
b
PROXIMAL
(VOLCANICL.)
DISTAL
(VOlC .+ SILICIClASTiCS)
~ieF<~ ClAST~~~ SUPPORED
CONGlOMERATE
IGNIMBRITE
TAOUGH
CROSSBEDDED
SANDSTONE~
TROUGH
AND PLANAR
CROSSBEDDED
DISTANCE
FROM SOURCE
80
120 km
C
CROSS SECTION OF CHANNEL FILL
AND SHEET -LiKE VOLCANICLASTICS
HYPERCONCENTRATED
FLOOD FLOW DEP.
SHEET FLOOD
DEPOSITS
PALEO-VALLEY FILL (POLYMICTIC
CONGLOM .) :t OVERBANK DEP.
AIR-FALL TUFF
ON PALEOSOL
Fig. 2.26_ a Relative abundance (thicknesses of horizontal bars) of continental volcaniclastic facies in
relation to distance from the source, Miocene, Washington. b Characteristic sections of a in the proximal
and distal range. c Cross seetion perpendicular to
flow direction showing syn-eruption, sheet-like
volcaniclastics and siliciclastic to mixed valley tills
generated in inter-eruption periods. (After Smith
1988)