The volcanoes of Scania

(Fig. Modified map from Bergelin thesis showing a handfull of basalt necks. There exist over a 100 in total)

Sweden is hardly famous for its volcanoes and most Swedes doesnt know about them. But we do have them, or at least the remains of ancient ones in the form of basalt necks (swe. “basaltkupp”) in the south of Sweden, in the middle parts of Scania along the Tornqvist zone. This was, as I showed in my last post on the general geology of Scania, an active volcanic province at two major times, with pulses at 191-178 Ma and 110 Ma.

About two weeks ago, me and three other geology students took a road trip to locate some of them. We found three. Knösen, Rallate and Gällabjär. None of them are difficult to locate and can be seen marked on the map above.

But as scenery or kodak moment, the basalt necks are somewhat lacking. Only Gällabjär (seen on first fig below), wich actually stands out from the surrounding landscape is any good in that aspect. The other two are much more difficult to get a descent photo of the entire neck. Covered in forest and shrubs they are pretty, but also camouflaged.

Figs below. Gällabjär (Jällabjär) (roughly pronounced yell-a-bee-aer). Nice nature, but basalt columns are actually scarse here and covered by quaternary sediments.

Fig below. Rallate. The basalt columns are very distinct here. As you can see, tectonic movement have tipped it over.

Fig below. Knösen. A small hill in the forest. A person could easily miss it since it hidden behind all the green beeches (Fagus sylvatica). But I swear, its there. And its a lovely spot to look for olivine rich xenoliths in the basalt.

Figs below. First photo is a basalt specimen from Knösen with some olivine xenoliths. Second photo is sample from Rallate where theres no xenoliths, but instead much cracks filled with plagioclase (not sure on the mineral, please correct me if you think you know). The Gällabjär neck had standard basalt, and I took no photos or sample.

Source of map and general information: Bergelin thesis.

This entry was posted in Excursions & travels, Landscapes & Geomorphology, Mineralogy, Petrology, Scania (Skåne), Tectonics & volcano and tagged , , , , , , , . Bookmark the permalink.

6 Responses to The volcanoes of Scania

  1. olelog says:

    Thank you for some very interesting posts on Skåne. Unfortunately I saw this post and your post on “The Geology of Scania” too late to take it into account in my post on Kullaberg yesterday (just back from holiday!). Thank you also for the link to the Bergelin thesis, which I have just downloaded. At a first glance I am sure I will read it with great pleasure.

    I am looking forward to reading more about the geology of beautiful Skåne on your blog in the future.

    Best wishes

    Ole

  2. Daniel says:

    Ole: Thanks for your comment. Im a frequent reader of your blog.

    I can recommend articles and papers by Ulf Söderlund if you are interested in Kullaberg geology. http://www.lu.se/o.o.i.s?id=12588&postid=1152074

    I can probably get it in full text pdf for you if you are interested.

  3. olelog says:

    Thank you very much. I have seen the abstract, but would certainly be interested in the full text (pdf) if possible.

  4. Daniel says:

    Hi Ole

    I might have spoken to soon about being able to get it. I didnt have access to it from home as I thought I would. However, I will try from the university the next time Im there, and email it to you then.

    /Daniel at Sandbian

  5. Pingback: Allarps Bjär and the stone of manly men | s a n d b i a n

  6. Lenita Bohnmark says:

    This is awsome to read about old Svea. I had no idea that there’d been any vulcanic activities at all in Sweden.
    Having to go at some point when we are visiting.

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