‘Flesh’ atop of the ‘bones’ of bedrock geology

The Surficial geology section is divided into Alluvial landforms & processes, Glacial history & landforms, Glacial rebound & coastal landforms, and Mass wasting. Explore those sub-categories or find general information below. You can also view the entire JuneauNature hierarchy at this site map.

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.

surficial

Surficial versus bedrock geology. For more comprehensive discussion, see Reading Southeast Alaska’s landscape.

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 surficial geology map, I’ve divided landforms into 5 age groups. In the pop-ups, these are listed in the ‘geol_age’ field:

  • triassic: applied only to a couple bare-bedrock roches moutonees near Mendenhall Glacier
  • 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.

In this section

1867-2017: 150 years of change

Background paper for 3 banners commissioned by the Juneau Douglas City Museum, showing changes to iconic landscapes of Áak’w Aaní…

2017 | Richard Carstensen | 41 Pages

Surficial geology, ArcGIS Online

Surficial geology for the Juneau area, hosted by ESRI. I used most of the geologic surface types of R.D. Miller,…

2015 | Richard Carstensen |

Natural history of Juneau trails: A watershed approach

Guide to natural and cultural history of the CBJ, summarizing Discovery’s longterm study on contract with Parks & Recreation that…

2013 | Richard Carstensen | 72 pages

Reading Southeast Alaska’s landscape

How bedrock, foundations, glaciers, rivers and sea shape the land How bedrock influences the shape of mountains and coastal landforms.…

2013 | Cathy Connor|Richard Carstensen | 28 pages