34
FM : FORESET
MACROFORMS
Cbapter 2 Continental Sediments
LA
LATERAL ACCRETION
DEPOSITS
:;~eEiJ- OF : OVERBANK
~
FINES
SG: SEDIMENT GRAVITY
FLOW DEPOSITS
CH : CHANNELS
TO,2-2m
1- 100m
Gms
S9
Fig. 2.10. Basic architectural elements of fluvial deposits. (After MiaU 1985, modified, varying scale.)
Note that there are simple and more complex elements consisting of several simple units. OF
Overbank fines , predominantly vertical aggradation
of lithofacies Fl, mud or silt with thin lenses or
laminae of cross-bedded silt to fine sand. LS Laminated sand sheets, up to several meters thick, produced by flash floods, Sh lithofacies, and other sandy
bedforms. SB Sand bed forms, including Sh, St, Sp,
and Sr lithofacies (see Table 2.1) representing transverse bars, crevasse channel and crevasse splay deposits (cf. Fig. 2.17). GB Gravelly bars and bedforms
CH : CHANNELS
~ ~'
.. .,. --':" :: ';';.~'. ; ...... ~ ..
. . ~_ .. ~ ~
SB : SANDY BEDFORMS
T /1~;;;g'ifl
SB
t GB : GRAVELLY BARS
_ _
AND BEDFORMS
SB
comprising lithofacies Gm and Gp, frequently alternating with SB and MF (in proximal regions). FM
foreset macroforms of the active main channels. LA
Lateral accretion deposits (including point bar deposits), with variable internal geometry and lithofacies,
consisting of different smaUer-scale elements. eH
Channel fills of different size and geometry (cf. Fig.
2.8). The total fill may show several episodes of erosion and refilling (multi-storey fills). MF Mass flow
deposits, rnainly Gms lithofacies, frequently associated with GB. Author's note: the elements FM and
LA are difficult to define clearly. Recent specific
publications distinguish even more elements.
FM : FORESET
MACROFORMS
Cbapter 2 Continental Sediments
LA
LATERAL ACCRETION
DEPOSITS
:;~eEiJ- OF : OVERBANK
~
FINES
SG: SEDIMENT GRAVITY
FLOW DEPOSITS
CH : CHANNELS
TO,2-2m
1- 100m
Gms
S9
Fig. 2.10. Basic architectural elements of fluvial deposits. (After MiaU 1985, modified, varying scale.)
Note that there are simple and more complex elements consisting of several simple units. OF
Overbank fines , predominantly vertical aggradation
of lithofacies Fl, mud or silt with thin lenses or
laminae of cross-bedded silt to fine sand. LS Laminated sand sheets, up to several meters thick, produced by flash floods, Sh lithofacies, and other sandy
bedforms. SB Sand bed forms, including Sh, St, Sp,
and Sr lithofacies (see Table 2.1) representing transverse bars, crevasse channel and crevasse splay deposits (cf. Fig. 2.17). GB Gravelly bars and bedforms
CH : CHANNELS
~ ~'
.. .,. --':" :: ';';.~'. ; ...... ~ ..
. . ~_ .. ~ ~
SB : SANDY BEDFORMS
T /1~;;;g'ifl
SB
t GB : GRAVELLY BARS
_ _
AND BEDFORMS
SB
comprising lithofacies Gm and Gp, frequently alternating with SB and MF (in proximal regions). FM
foreset macroforms of the active main channels. LA
Lateral accretion deposits (including point bar deposits), with variable internal geometry and lithofacies,
consisting of different smaUer-scale elements. eH
Channel fills of different size and geometry (cf. Fig.
2.8). The total fill may show several episodes of erosion and refilling (multi-storey fills). MF Mass flow
deposits, rnainly Gms lithofacies, frequently associated with GB. Author's note: the elements FM and
LA are difficult to define clearly. Recent specific
publications distinguish even more elements.