Ackmore to Zwingle Home Series Names cf. Roberts Creek Member Dark Colored (Organic-Enriched) Sediments: (Usually Late Holocene in Age)
- Very dark gray to grayish brown loamy sediments grading to sand and gravel at depth
- Unit lacks stratification except in the lower, coarser part.
- Plant material (leaves, wood, stems, charcoal) is common in lower part
- Well-expressed soils with overthickened A horizons (topsoil layers) are developed into the upper part of the unit.
- Unit is found on modern floodplains, generally in a narrow belt paralleling the modern channel.
- Sediments were deposited between 4000 and 500 years before present.
- NRCS Map Units with these series are on floodplains, upland drainageways, footslopes,
alluvial fans, stream terraces.