Question: Is that pyrite crystals in this piece of oil shale? I picked it up on the beach on my last trip. Or is it some strange fossil? Whatever it is, why/how/when do they form like this in the shale?

Yesterday I was on a fieldtrip to the south eastern regions of Scania (which is the most southern Province of Sweden, where I live). It took me among many things to a very small village by the ocean called Simrislund. This place is interesting geological-wise since its one of few places where Cambrian quartzite is very abundat at the surface as bedrock. Most of the bedrock is smooth and grinded flat by the last iceage. Sprinkled all over the landscape and the shoreline is oilshale since this used to cover the cambrian rock but nowdays is eroded away. Further inland the shale is still intact as bedrock. The shale is also full of fossils like brachiopods and trilobites.

One other interesting aspect of the Cambrian quartzite is the human impact on it. At Simrislund there are many rocks with carvings on it from the Scandinavian bronzeage over 3000 years ago. This makes this place both culturally and geologically worth a visit.

Today’s excursion took us to see several types of glacial soil deposits like eskers, sandurs tills, talus, tufa and moraines. I must say that the study of glacial soil formations is much more complicated than I’ve imagined. There are just so many types of formations that I’ve never heard of before studying geology. Not to mention all the types of soils and sediments and the terminology about the different particle sizes and how they behave in terms of erosion and cohesion. I took some pictures of course, however "soil" make poor lousy photo material so I mostly took shots of the landscape today - so no cool macros of minerals today.

Pictures below shows an esker (swe. "rullstensås") covered in Beech forest streching for about half a mile and 40 meters high near the small village of Torna Hällestad. It really knocked the wind out of me when climbing up to the summit since it was such a steep climb. Yes, my physical condition could obviously be much better. Its not like its a mountain…

Picture below shows the stratigraphy of a sandur-deposit. Rounded material often transported with the ice and melting water for hundreds of miles across the landscapes. 

Picture below shows a talus (frost eroded rocks - very uncommon here in the south of Sweden)

The pictures below are from the nice natural reserve in Benestad where we looked at some small deposits of Tufa (Swe "Kalktuff").

Today I was on an excursion around Skåne looking at different bogs and marshes. We drilled soil samples and learned to see the difference between different types of soil, clay, mud and peat. We learned to how to spot the level of humification, acidity and some about the more important fossils of the different stratas. We took samples dating all the way back to just after the last iceage. Around 8000 BC. Here’s a sample of pictures from today.

Picture below. 8000 year old sample of Birch tree. 

Picture below. And then we looked at a fascility that extracted/mined peat.

Got a new camera. Nothing fancy, a "Canon digital Ixus 950 is". But it had a nice macro-function so i took som new photos just for fun.

Picture below is a garnet crystal inside of a amfibolitic rock. Hornblende to be precise. Picked it up on an excursion.

Picture below is of a olivine crystal (or a couple of them of course) inside a basalt rock from a small dead "vulcano" in the middle of Scania. Age about 145 Ma. Picked it up on an excursion.

Picture below is of an ordinary sandstone heavily oxidized with iron found in an Jurassic-Trias-deposit of sand. Its composed of several layers of differently oxidized and dense sediments. Looks more strange than it is. 

The picture below is not totaly geological but still quite nice. A piece of iron slag from Uppåkra (Uppakra) Iron age settlement outside Lund (roughly 700 AD perhaps). Since I started my career with archaeology I also have some archaeological things in my possesions. Some of them I actually found myself on field training exercises like this slag and the piece of pottery below.

The picture below is of a piece of Iron age pottery from the same settlement/village.  

Gotland is the largest island in Sweden. It’s a great place to visit for many reasons, not the least for its history and geology.

The islands largest town Visby belonged to the German Hanseatic-league during the middle ages (it was a community of traders that controlled most of northern Europe at this time). A town of great wealth back then. But after the middle ages the economy fell and that’s basically the reason that the town today is such a great place to visit if you are historically interested, since so much is preserved and not destroyed. Nothing or nobody came after and tore away the medieval town.

For this reason Visby is a haven for people who likes medieval activities. They even have a huge medieval festival and market in early August with everything you would expect to find at such an event. If you are planning a trip to Sweden, then try to fit in a trip to Gotland, you won’t regret it. The picture below shows a medieval knight standing outside the medieval town wall of Visby.

Geology vise the island of Gotland is just one big rock of Silurian limestone, primarily reef built limestone that was deposited at a time when Gotland was a giant reef near the equator. There’s not much other types of bedrock there. But who cares since Gotland is a haven of Silurian fossils.

One basically just has to pick up a rock and it will contain fossils from the Silurian period. I collected some fossils on my week long vacation trip there in August of 2007. I primarily found Anthozoa (corals) of different types. Here are three examples of the several pounds which I dragged with me home after the vacation.

The picture below shows four samples of Rugosa coral.

The picture below shows a sample of Favosites, a tabulate coral.

The picture below shows a sample of Heliosites or “Sun coral”, also a tabulate coral.

The pictures below show the strange formation knows as Rauks. They are the result of erosion that has exposed more harder reef sediments when the more brittle limestone around eroded away. It’s a quite recent event that started after the ice receded from this area after the last ice age (12000 Bp). These rauks are found in great numbers around the coast of Gotland. And yes, they are packed with fossils.

The picture below shows a closeup of the bedrock. As you can se its full of visible macro fossils.

During the excursion yesterday we visited a place called “the priests bathtub” (Swe. “prästens badkar”).  It’s a rocky sandstone beach in the village of of Vik on the east coast of the province of Skåne (Scania) in Sweden. The sandstone is called “Hardeberga sandstone” (or Hardeberga quartzite since most parts of it actually has metamorphosed to some degree). I believe its the oldest forms of sedimentary rocks we have in Sweden.

The sandstone was deposited in the early Cambrian (542-513 Ma). That means that the ocean that slowly erodes the sandstone today isn’t the same ocean as the ocean that the sandstone once was a white beach at. Literally speaking, since the continents have migrated a lot since then. The sandstone was formed on a great depth and pressure and the rocks that were above it have eroded away. Perhaps a mile or two of rocks have eroded for this sandstone to reveal itself. It becomes quite a mental challenge trying to depict this in front of you. First the deposit of the sand, then the rise of new layers of sediments above this, mile after mile, pushing the sand lower and lower and then finally the rise of it all due to tectonic movements, but mostly, actually because of erosion. Quite a journey.  The early Cambrian was another world with another climate, and hardly any breathable air to breathe. No life on land at all, just in the oceans. Hundreds of millions of years before the first dinosaurs even. And now over 500 million years later, half a billion years, it’s a beach, once more.

And inside the rocks, the trace fossils of ancient life that actually survived the journey.

Picture below. Beach overview.

Picture Below. Example of stratigraphy. 

Picture below. Trace fossils. Tracks of "worms". 

Picture below. Sample of Hardeberga Sandstone with trace fossils. You can see small "tubes" that are filled with other sedimentary material. The oldest fossils in my collection. Early Cambrian.

Todays excursion took us, among many things and places to the oil shale deposits (Sv. Alunskiffer) at Andrarum in the south east of Skåne (Scania) in Sweden. These shales dates from the middle and late Cambrian periods (around 500 Ma)

These are my first trilobites ever! They are very small, Agnostus pisiformis, around 0.5 mm - 4 mm in size are seen in the first picture (size slightly increased in this photo). The two larger Olenus attenuatus in the last picture are around 1-3 cm in size when found complete (Ive only got fragmets). One headshot (the "UFO"), one topside back (the "ribs"). The observant viewer can of course see traces of several more Olenus in the image.