Table 1 Summary table with the properties and interpretation of all distinguished lithofacies associations (LFA)
From: Multiple Quaternary erosion and infill cycles in overdeepened basins of the northern Alpine foreland
Lithofacies Association | Facies codes | Short description | Bulk composition (in wt%) | Clast shape (%)a | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
CaCO3; TOC; TS | C40 | RA | RWR | n | Striated clastsb | bullet-, or flat-iron- clastsb | ||||
LFA1 Diamicts with sorted interbeds | LFA1.1 | Dms, Dmm | Clast-rich matrix-supported diamictions, ~ 25% with crude stratification | 40–60/w high variability; 0; 0 | 14 ± 6 | 8 ± 2 | 35 ± 6 | 3 | 0 | 0 |
LFA1.2 | Gm | Poorly sorted gravel and clast-supported diamicts with abundant well-rounded clasts | 0 | 0 | ||||||
LFA1.3 | Fl, Sl, Sm, -(d) | Silt and sand with stratification/lamination, few outsized clasts | – | – | – | – | – | – | ||
LFA2 Stratified sands | LFA2.1 | Sm(d), Sl(d), Dm | Stratified sands, with outsized clasts, with diamictic beds | ~ 50; 0; 0 | – | – | – | – | – | – |
LFA2.2 | Sm, Sl (Fl) | Stratified sands, homogeneous, with narrow interbeds of fines | 40–50/w gradual changes; 0; 0 | – | – | – | – | – | – | |
LFA3 Laminated silt and clay | LFA3.1 | Fl(d), Fl, Sl | Laminated fines with variable outsized clast concentrations, sandy interbeds (dm-sized) | 40–55; 0; 0 | – | – | – | – | – | – |
LFA3.2 | Fl | Laminated fines without (or individual, well rounded) outsized clasts | 50–55; 0; 0 | – | – | – | – | – | – | |
LFA4 “Marbled” diamicts | Dmm, Dms | Matrix-supported diamictions, colored according to Molasse bedrock | 25–45; 0; 0 | – | – | – | – | – | – | |
LFA5 Matrix-rich diamicts | Dmm, Dcm | Dark-colored, silt-rich diamicton, densely packed with variable amounts of clasts | 40–55; 0; 0 | 21 ± 7 | 14 ± 7 | 20 ± 10 | 5 | 0 to + | 0 to ++ | |
LFA6 Gravel-rich diamicts | Dcm | Clast-supported diamictons, with sand and silt matrix, densely packed, with glacial striations | 50–60; 0; 0 | 17 ± 2 | 17 ± 7 | 21 ± 1 | 2 | 0 to + | + | |
LFA7 Gravels | LFA7.1 | Gm, Gc, Sm/Sl, Fl | Sorted gravels with fine-grained interbeds | 50-60; 0; 0 | 17 ± 5 | 10 ± 7 | 30 ± 8 | 5 | 0 to + | 0 to + |
LFA7.2 | Dcm, Gm, B | Poorly sorted gravels, boulders layers, and occasional diamictons | 50-60; 0; 0 | 19 ± 5 | 14 ± 5 | 30 ± 11 | 8 | 0 to + | 0 to + | |
LFA8 Gravels w/Interbedded diamicts | Dc/Gm | Interbedded diamictons and gravels | 35–55; 0; 0 | 21 ± 10 | 9 ± 7 | 33 ± 7 | 6 | 0 to ++ | 0 to + | |
Lithofacies Association | Architecture | Micromorphological summary description | Genetic interpretation | |||||||
|---|---|---|---|---|---|---|---|---|---|---|
Typ. thickness (in m) | Occurrence in formations (Fm) and relation to other LFAs | Basal contact | ||||||||
LFA1 Diamicts with sorted interbeds | LFA1.1 | 1–4 | Fm-D (Fm-B?) Overlying bedrock in the deep bedrock troughs Stacking of diamicts (LFA1.1) with thin sorted interbeds (LFA1.2 and 1.3) | Sharp | Abundant polyphase deformation features, abundant in situ grain-crushing | Subglacial till, subglacial cavity fills | ||||
LFA1.2 | 1–1.5 | Sharp | – | |||||||
LFA1.3 | 0.1–0.5 | Sharp | Deformed depositional banding, abundant polyphase deformation featrues, in situ grain-crushing absent | |||||||
LFA2 Stratified sands | LFA2.1 | 5–15 | Fm-B, -D and -E Thick infill in bedrock troughs, underlain by bedrock or LFA1. LFA2.1 and 2.2 typic. in vertical succession and/or interfingering | Gradual or sharp | Minor post-depositional deformation, planar- to cross-bedding | Proximal basin-floor fan with reworking | ||||
LFA2.2 | 10–30 | Gradual or sharp | Distal basin-floor fan | |||||||
LFA3 Laminated silt and clay | LFA3.1 | 10–35 | Fm-B, -D, -E, -G Thick infill in bedrock troughs, underlain by bedrock or LFA2 LFA3.1 and 3.2 typic. in vertical succession and/or interfingering | Gradual | Minor post-depositional deformation, planar- to cross-bedding | Proglacial lake deposits, strong glacier influence | ||||
LFA3.2 | 10–20 | Gradual | Glacier distal lake deposits, weak glacier influence | |||||||
LFA4 “Marbled” diamicts | 2–5 | Fm-E (Fm-B, -D?) Overlying bedrock on trough shoulders Overlain by LFA2 and -3 | Gradual | – | Subglacial till, glacio-tectonized bedrock | |||||
LFA5 Matrix-rich diamicts | 4–8 | Fm-E and -F Diamictons truncating fine-grained valley fill LFA3 (and -2) | Sharp or narrow transition zone | Abundant polyphase deformation features, abundant in situ grain-crushing, narrow deformation zone at contact with LFA2 | Subglacial till strongly influenced by reworking of fine-grained valley fill (mostly in association with LFA2 and 3) | |||||
LFA6 Gravel-rich diamicts | 3–7 m | Fm-I Diamictons in close association with LFA7 and -8 | Gradual (poor recovery) | – | Subglacial till strongly influenced by reworking of gravelly valley fill (mostly in association with LFA7) | |||||
LFA7 Gravels | LFA7.1 | 7–20 | Fm-A, -C, H and -I Limited to non-overdeepened positions, LFA7.2 and 7.1 typic. in vertical succession and/or interfingering In correlated outcrops planar- to cross-bedded | Gradual or sharp | – | Distal fluvioglacial to fluvial outwash | ||||
LFA7.2 | 15–30 | Gradual or sharp | – | Fluvioglacial outwash, more proximal than 7.1 | ||||||
LFA8 Gravels w/Interbedded diamicts | 7–17 | Fm-F and -I Close association with LFA5,6, 7 | Gradual or sharp | – | Alternation between fluvial and mass-wasting processes in ice-marginal and fluvial channel settings | |||||