Glacial striations or glacial grooves are scratches or gouges cut into bedrock by process of glacial abrasion.
The ice contained large amounts of sand, gravel and stone that it had driven up from underlying soil and that provided the abrasive power to cut the grooves. Finer sediments, also in the base of the moving glacier, scoured and polished the bedrock.
You can imagine that, when the ice glided ahead, these sediments functioned as sandpaper. Glacial striations usually occur as multiple straight, parallel grooves.
Most glacial striations were exposed by the retreat of the glacier since the last ice age. As well as indicating the direction of flow of the glacial ice, the depth and extent of weathering of the gouges may be used to estimate the duration of post-glacier exposures of the rock.
These glacial striations are located in the city of Örebro. They are the biggest and most distinctive appearance of glacial striations in the neighborhood. Nearby you see smaller “rocks” on the ground with glacial striations, all with the same direction.
To log this earthcache as found you have to:
- Take the bearing of the direction of the glacial striations and measure the circumference of the rock.
- Where had been the accumulation zone of this glacier, which generated these striations (Internet-research)? Mail us the answers of questions.
- Please upload a photo with you and your GPS in front of the rock with visible glacial striations (A photo is no longer required for the log, but it would be nice).
Logs without correct answer-mails will be deleted. You don´t have to wait for permission. We´ll contact you, if there is a problem.
Don´t post the answers in your log.