Good information about local geology!
This #ThrowbackThursday we are heading back 17,000 years ago (just yesterday in geological terms) to learn about local #glacier remnants.
#Glaciers are powerful forces of change to Earth’s surface; carving valleys, lakes, and sculpting high peaks. However, the glaciers that carved out many of the beautiful alpine areas of the #Caribou-Targhee National Forest are gone today. Nevertheless, we can see the beautiful marks that glaciers left behind.
It is probably more common to think of the glacial valleys of the #Tetons, but did you know the #BearRiver Range on the Caribou NF housed glaciers during the last Ice Age, which ended about 17,000 years ago?
Glaciers are bodies of flowing ice that form from the accumulation of snow year after year. Here in #southeast Idaho, all the snow from the winter melts away by the end of the summer. When the climate was colder, the snow could accumulate high in the peaks of the Bear River Range and flow into the valleys.
Glaciers leave behind distinct shapes on the landscape. If you hike to #BloomingtonLake, you will see the signature of a glacier- a #cirque lake – an overdeepening formed as the glacier flowed and chipped away the rock below. As glaciers flow down valleys, they scrape rocks frozen to the glacier bed against the bedrock below. This creates very fine sediment, called “glacial flour”, which can be found deep in the sediments of #BearLake, another clue that glaciers were here in the past.
Thanks to our local geologist Mariah for sharing this information!
Photos: Bloomington Lake on the Montpelier Ranger District
Photo: The Aletsch Glacier, the largest glacier of the Alps, in Switzerland. This is what the valleys of the Bear River Range likely resembled 17,000 years ago.