‘Flesh’ atop the ‘bones’ of bedrock geology
Surficial geology is the study of loose, unconsolidated material overlying the bedrock foundation. These layers were deposited, rearranged and eroded by glaciers, fluctuating sea level, streams, landslides, and bulldozers.
While bedrock geologists tend to think in time-frames of millions of years, the surficial story is usually faster paced, taking place over millennia and mere centuries. On the map above, I’ve divided landforms into 5 age groups (geol_age field):
- triassic: applied only to a couple bare-bedrock roches moutonees near Mendenhall Glacier (for map of bedrock types, go here)
- early holocene: marine, glacial and alluvial formations dating back to shortly after the great ice age, ~10,000 years ago
- neoglacial: dating to just the last few millennia
- little ice age: mostly formed since peak of the last glacial advance in the mid-1700s
- anthropocene: built or excavated features mostly since 1950.
Two sub-studies of surficial geology addressed so far on this site are: