5.4 Gravity Mass Flow
217
a
..L.PROXIMAL
DISTAL (BASIN PLAIN, LOWER FAN) ~ -
- - - - - - - - - -
(BASE OF SLOPE, SLOPE )
LOW ·DENSIT Y
HIGH·DENSITY ,
TURBIDITY
~ HIGH·VElOGITY
GURRENT
TURBIDITY GURR.
SLOW COHESIVE
~ FLOW OF PlASTIC MASS
(UPTAKE OF ADDITIONAL WATER)
DEBRIS FLOW DEPOSITS
MIXED
(DEBRITES, OllSTOSTROMES)
SEDIMENT
SANDY TURBIDITES
DF
I
0
SOURCE
TS
0,
• ~ ( SILT. SAND.
MUD TURBIDITES
TM
!
Cl
• • I .. •
SOME CLAY .
. . ...... -'II~~~~~~~~~~~~~~~~~~~·d';b~,~O~Q 1° CARBON~ES •
. .... . :.: ....... " . .:-:.:(' .::.....
~-f' .. °0 C::> I r ~~~~IA6~Y
LlTHIFIED)
see tigs. tor
sand and mud
turbidites
GURRENT
EROSION
AUTOI SCOURING DUE TO
SUSPENSION I LOAD-GENERATED
J FAlL URE PLANES
:!: DEFORMED, FROM
SUBSTRATUM
b
",.... . . . . . J
~
DOWNsLOPE GRADATION
=-===
PE
TM
-_ -
sI
_ _ ~ -
(TRACTION)
WINNOWED MATRIX L--.......... ~_- cm. AMALGA -
TS
ec. EXTRACLASTS '"
MATION
_
_
7'
(pm, POLYMIGT) c:::> ~
gr, NORMAL
C)o~
DF
T
0.1-10
DF gr
m .l-t=::::J::::::,-': DF ig
_ L
A
R_
LUTITE ARENITE RUDITE
T
1-10
m .1 p:... A
R
MATRIX.SUPPORTED ~ ~
GRADING
ClASTS
c>"
01 , OliSTOLITH
<:)10
ie, INTRAClASTS
0
0
(mm, MONOMICT)
D.
bi, BIOTURBATION
L
A R
SLUMP
SL
ig, INVERSE
GRADING
FINE-GRAINED
MATRIX
MUD TURBIDITES
TM
MUD FLOW DEPOSITS
MF
PREDOMI·
I
I
I
see fig. for
I
I lAMINAR FLOW
mud turbidiles
j
I (MUD LOBES)
MF
""
..... /
/",..)
~L r!-r-- ' SLUMP FOlDS
\ <1
INDISTINCT DOWNSLOPE GRADATION ===\ \
- ....
...- LOCALLY :
• -
...... ' \ '
PEBBLY MUD OR
0
MUDDY MATRIX
......
gm, GRADED
MUDSTONE
_
(HIGH CONTENT
:
(MASSIVE) MUD
MF
....
OF SllT AND /OR
Im, (PLANAR) lAMI·
NATED MUD
ee, EXTRACLASTS
(:)
DIATOMS, NANNOS,
ETe,)
0, ~2I 0
BACKGROUND SED.
1Dm:;:=-.., BIOTURBATED (bi)
MF WITH FEW
CLASTS
MF ig
SOFT
INTRACLASTS
(ie)
. L
A
L
A
Fig. 5.13. Conceptual models for proximal and distal
debris flows (a) and mud flows (h), finally evolving
into high- and low-density turbidity currents_ (Based
L
A
R
on different sourees, e.g., Lowe 1982; Stow 1986;
Bourrouilh 1987; Souquet et al. 1987). See text for
further explanation