Table 1 Lithofacies elements, related abbreviations, and descriptions of their properties
From: Glaciofluvial sequences recording the Birrfeld Glaciation (MIS 5d–2) in the Bern area, Swiss Plateau
Lithofacies | Abbreviation | Description | Interpretation |
|---|---|---|---|
Massive diamict | Dmm | Silt to boulders, unsorted, matrix-supported, 1–5 m thick beds Clasts: Sub-angular to sub-rounded, sometimes broken, some striations visible Matrix: Brown-beige silty fine sand, massive, unstratified | Subglacial tilla |
Dmm-1 | Same structures as Dmm, additionally enriched with quartzite, granite and metamorphic pebbles, gradual basal contacts | ||
Dmm-2 | Same structures as Dmm, additionally enriched with limestones, sharp basal contacts | ||
Massive gravels | Gm | Medium-grained sand to boulders, massive, poorly sorted, mostly grain-supported, few sand lenses, sharp basal contact, 0.5–2 m thick beds Clasts: Sub-angular to well-rounded Matrix: Greyish medium to coarse sand | Longitudinal barsb |
Cross-bedded gravels | Gc | Fine-grained sand to boulders, cross-bedded, moderately sorted, normal and inverse grading, grain and matrix-supported, sharp basal contact, 0.3–1.5 m thick beds Clasts: Sub-angular to well-rounded Matrix: Greyish fine- to coarse-grained sand, sometimes washed out | Longitudinal bars and channel fillsb |
Massive sand | Sm | Fine- and medium-grained sand, massive, medium-sorted, 0.1–1.5 m thick beds | Planar bed flowsb |
Horizontally bedded sand | Sh | Fine- and medium-grained sand, horizontally bedded (mm-scale), well-sorted, normal and inverse grading, sharp basal contact, 0.1–0.5 m thick beds | Planar bed flowsb |
Cross-bedded sand | Sc | Fine- to coarse-grained sand, few gravels, cross-bedded, medium-sorted, normal grading, sharp basal contact, 0.1–0.5 m thick beds | Scour fills, transverse bars, longitudinal bars, sand wavesb |
Laminated and sheared sand and fines | SFl(s) | Clay to medium-grained sand, laminated, sheared, brown-beige colour, sharp basal contact, 1–1.5 m thick bed, underlying Dmm-2 | Deformed pro-/sub-glacial depositsc |
Laminated fines | Fl | Silt and clay, fine lamination interbedded with minor fine-grained sand, well-sorted, sharp basal contact, max. 2 cm thick beds | Overbank depositsb |