Excursion 2014

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NORDQUA

Nordic Union for Quaternary Research

NORDQUA excursion to Sunnmøre, September 22-25, 2014

 

The 2014 NORDQUA excursion was held in the Sunnmøre area of western Norway with its beautiful coastal scenery of the strandflat, and dramatic alpine fjord topography. The excursion was organized jointly between the University of Bergen (Jan Mangerud and John Inge Svendsen) and the Geological Survey of Norway (Eiliv Larsen). Twenty-six participants from five different countries were guided by the three leaders, and they contributed both to scientific discussions and with good spirit to make it all enjoyable. The participants were a good mix of students and professionals with different backgrounds and experiences well suited for generating new ideas and establishing or refreshing contacts. The 2014 excursion field guide is now available on geologi.no.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

We met at the Ålesund airport and went directly to the Skjonghelleren cave were excavations in the mid 1980’s made history both in terms of glacial geology and palaezoology, especially about the Ålesund interstadial 24-38 ka BP. The group was split in two; while one half was in Skjonghelleren the other half visited nearby sites with marine terraces and beach ridges. From Skjonghelleren we drove by our bus in the sub-sea tunnels via the city of Ålesund, and by ferry to our next site at the small island of Dimna. By applying a Russian peat corer, we retrieved a nice core containing the Vedde Ash and surely also the Dimna Ash, although the latter is invisible for the naked eye. Overnight was in the town of Ulsteinvik.

 

 

 

 

 

 

 

 

 

 

 

 

 

On day 2 we went to the outermost coast on the island of Nerlandsøy where we looked at an impressive beach ridge formed at the marine limit which prompted a discussion if deglaciation was followed by marine transgression. After that, we cored two bogs. At Frøystadmyra cores were used to demonstrate sea-level changes, the Vedde Ash, but equally important, deposits of the Storegga tsunami that confused the scientists for many years before the puzzle was solved. The next site, Litlevatnet was isolated from the sea in Late Allerød. Here we had to core several sites in order to find the complete stratigraphy. Thus this became a good learning lesson of the importance of carefully mapping the sediment distribution in basins. The next two nights were spent in Spjelkavik.

 

 

 

 

 

 

 

 

 

 

In Sykkylven where we went on day 3, there is a series of cirque moraines that were formed in the Younger Dryas as glaciers expanded out of the cirques. We drove by some of these moraines and studied the site at Riksheim in more detail. Good sections from abandoned gravel pits reveal both deltaic proglacial sediments and a diamicton from the overriding cirque glacier. After Riksheim we went to an impressive section in a coarse-grained sandur delta at Hundeidvik. Part of the section had very good transitions from top- to fore-sets showing contemporaneous sea level. The last site of the day was the cave Hamnsundhelleren were large-scale excavations we made in the 1990’s disclosed sediments that could be correlated with the sequence in Skjonghelleren, but not the least, opened the possibility that there is an interstadial younger than the Ålesund interstadial.

 

 

 

 

 

 

 

 

 

 

 

 

 

The last day was spent studying the sections and terraces at Skorgenes in Tresfjorden. The site is unique in that ice marginal deltas separated by tills are stacked on top of each other. We had a machine excavating the lower part in order to expose spectacular clastic dikes formed by downward injection. We also discovered a pocket-like feature of fining-upwards sediments that had been in suspension and somehow was associated with the dikes. We didn’t understand this feature, but it reminded the older generation of participants of the so-called seismites demonstrated by Rober Lagerbäck on the NORDQUA excursion in 1987. What a nice way to end the last site of the excursion by tying on to the NORDQUA history.

 

 

 

 

 

 

 

 

 

 

In the afternoon of the last day it started raining, and the next day came with the first heavy autumn storm with docked ships and cancelled planes. Thank you all for some nice days at Sunnmøre, and we are happy you made it home in time.

 

 

Eiliv Larsen, Jan Mangerud, John Inge Svendsen

Map of excursion locations
Coring eagerly for the Vedde and Dimna ash
Frøystadmyra
Hamnsundhelleren
The marine limit terrace at Skorgernes