Surface Geology types

• Qa1
• Oldest alluvium – Bedded silt, sand, and gravel, mostly underlying higher terraces.
• Qpf
• Non-glacial and glacial sedimentary deposits of pre-Fraser glaciation-age (sand/gravel/silt/clay/peat).
• Qva
• Advance outwash – Well-stratified fluvial sand and gravel. Almost devoid of silt or clay (Esperance Sand). Good water infiltration rates.
• Qvlc
• Lahar deposits – Unconsolidated volcanic-clast-rich (silt/clay, Lawton Clay).
• Qvr
• Recessional outwash – bedded sand and gravel, moderately to well sorted.
• Qvrl
• Recessional outwash – silt/clay.
• Qvt
• Till – Lodgement till with some stratified fluvial sand and gravel. Generally underlies an undulating surface, with deposits a few meters to a few tens of meters thick. Very poor water infiltration rates.
• Qw
• Wetland deposits – Wetland and bog deposits. Peat and alluvium, organic silt, commonly poorly drained.