Roman and Mediaeval History, Illlustrated Travel Journals, Mediaeval Literature, Geology

  The Volcano that Burped - The Blue Dome near Eschwege

The Blue Dome (Blaue Kuppe) near Eschwege in northern Hessia is an interesting geological feature. It is a 10-12 million year old volcano that never really erupted but got stuck in the surrounding sandstone instead. The area was used as quarry from the 17th to th 20th century which shaped most of the bizarre rock formations. Today it is a Nature Reserve.

Blue Dome, view into the south bassin

We have to go back in time a bit. The uppermost rock layer in the area is sandstone which got deposed there during the Triassic period (250-200 million years ago). It's the same strata that can be found in other places along the Werra / Weser river - the Blue Dome is only a few miles from the Werra (1).

The north bassin (with sheep)

Some 12 million years ago, a volcano started its way up through the sandstone. This happened frequently in the area - the Meissner mountains include layers of basalt from volcanic activity during that time. But in case of the Blue Dome, the volcano never truly erupted.

Detail shot of the south bassin

Instead, the volcano just burped, so to speak, leaving behind three conduits of basalt among the sandstone. The magma got stuck in the sandstone strata where it cooled into the usual longish hexagonal pieces. Only a bit of tuff reached the surface.

Basalt and buchite (right), tilted by shifting of the ground

The surrounding sandstone was changed by the heat and pressure; the quartz molecules in the stone turned to a molten glass stone called buchite, also known as 'fried sandstone'. The basalt is rich in olivine (a magnesium iron silicate), which gives a ochre tinge to the usually blueish basalt (2).

Closeup of the olivine basalt

What once was a perfect dome eroded over time. Further changes were made by quarrying the sandstone and basalt, so that we now have two bassins with remaining rock formations.

Basalt, buchite, sandstone, and a tuff layer on top

The rock formations and their interesting genesis already attracted the naturalist and explorer Alexander von Humboldt (1769-1859). I couldn't find the exact date of his visit, but since he studied in Göttingen, it could have been some time around 1789. He also visted geological formations at the Rhine during that time.

Remaining wall of the north bassin against the light

The Blue Dome is today a Nature Reserve because of its interesting geology. There is a way along the ridge of the bassins, but the bassins themselves are officially off-limit. *Looks if someone watches her going a bit closer to the rocks. Sneaks around and takes some photos.*

South bassin, another detail shot from the other side

1) I wonder if I should write a post detailing the development from the Variscan orogeny and the Zechstein sea to the Mesozoicum since I've refered to these things in several posts.
2) Olivine usually is greenish in colour, but when the iron comes in contact with air, it will rust.


  Castles, Celts, and some Churches - Summer Tours 2016

I undertook no larger journey this year, but my father and I - sometimes together with some friends - did a number of day tours and hiking trips which accumulated a fair amount of photos. So there will be a Back With Booty post.

Of, course, we can haz castles and castle ruins. *grin*

Castle Scharfenstein

Castle Scharfenstein near Leinefelde in Thuringia dates to the early 13th century, though it suffered from a severe fire in the 1430ies and was rebuilt in a more moderate scale. Like so many historical buildings in the former GDR it was neglected, but restoration is going on since 2006 and by now the castle is in pretty good repair.

Castle Altenstein near Bad Sooden-Allendorf

The castle is known as Altenstein (Old Rock) or Altenburg (Old Castle). It's a pretty obscure 14th century castle, and I couldn't find much information about its history. Its lords were vassals of the landgraves of Thuringia in the 15th century, but the castle eventually fell to Hessia. It was returned to the county of Thuringia after WW2. Today, only some ruins are hidden in the woods.

The great hall of Castle Grebenstein

The walls of the impressive great hall (palas) of Castle Grebenstein near Kassel still survive. The 13th century castle played an important role in the ongoing quarrels between the landgraves of Hessia, the archbishops of Mainz and the landgraves of Thuringia. It was in possession of the Counts of Everstein in the late 13th century who also held Castle Polle at the Weser. Thus Castle Grebenstein is another knot in the net of the connections of local noble families.

Remains of Castle Greene

The keep of Castle Greene has been restored like in many other castles, but only some ruins are left of the curtain walls and other buildings. The castle controlled the river Leine and has seen a fair amount of interesting history which I'll have to hunt down.

Castle Tannenburg on a hazy summer day

This one, situated near the village of Nentershausen in Hessia, has been restored and offers a nice place for weddings and other celebrations. They also serve Mediaeval food, though adapted to modern tastes - you can get coffee. *grin* When I asked for a guidebook, the reply was that some historians are working on it but it'll take time because there are so many contradictory sources. I know that problem only too well.

Castle Sachsenburg in the Harz mountains

Of the famous Castle Sachsenburg near Walkenried, one of the main Harz fortresses of the emperor Heinrich IV, only a few ruins remain. He was forced to dismantle the castle after the peace with the rebellious Saxon nobles, and it was never restored. Though I'm sure there is more hiding under the earth than one can see - a bit of archaeogical digging should prove interesting. Anyone got the funds? ;-)

We also revisited two castles.

Castle Weidelsburg, the western hall which had been scaffolded in during our first visit

When I visited the Weidelsburg in 2008, repair work had been going on and the western keep had been scaffolded in. I wanted to return once the whole sandblasting, mortar replacing and cleaning of brambles in the zwinger would be done with. The castle looks really nice now - and it was impressive already before.

Hanstein Castle

The Hanstein is not so far from where I live, so it was not a big deal to go there again with my new camera. The posts about that castle need to be rewritten, and I could do with some additional photos.

Remains of the palatine seat in Gelnhausen

Another visit brought us to the palatine seat in Gelnhausen. It played an important role in the history of the Staufen family (esp. in the feud of the emperor Friedrich Barbarossa with Heinrich the Lion), which is why I wanted some photos of that one for a long time. I had been there as child, so it was a trip down the memory lane as well. It seemed larger to me back then.

There was more than castles, of course.

Glauberg, the tumulus

On the way back from Gelnhausen we stopped at the famous Celtic Museum on the Glauberg. That's another place that had been on my wish list for quite some time. Those Celts are just fascinating.

Glauberg, head shot of the famous statue

And here's the guy which graces the cover of at least two thirds of all books about the Celts, the 'Celtic prince with the leaf crown'. The statue probably stood on top of the tumulus once; now it is inside the museum. I was surprised that the guy isn't much taller than I am - somehow I got a mental image of a 8-10 feet tall statue.

The Romanesque church of Wahlshausen monastery

St. Mary's Church in Wilhelmshausen near Kassel is all that remains of the monastery of Wahlshausen. It is another of those pretty Romanesque churches you can find in German villages. It is also the burial site of the last Lord of Sichelnstein, Bardo, who died in 1239 (though the tomb doesn't remain).

Salzwedel, the castle keep, with the Monk's Church in the background left

Salzwedel had been an important town involved in the salt trade in Mediaeval times, and member of the Hanseatic League. Unfortunately, it was situated in the GDR and thus neglected. Much has been done after the reunion, but it can't rival its big sister Lüneburg.

Salzwedel, interior of St.Laurent Church

The architecture is mostly brick, typical for the nothern German Hanseatic towns. The keep of the castle remains as well as several churches of Romanesque and Gothic style. But else the place is rather quiet, and some houses still in bad need of repair.

Arendsee monastery, the church

The Benedictine monastery (or rather, nunnery) in Arendsee was founded in 1183. It is a beautiful example of Romanesque brick architecture. The church survives intact, but of the other buildings only ruins remain. Pretty, picturesque ruins on a hill at a lake that shone with a clear blue on that sunny afternoon.

Arendsee, remains of the monastery buildings

Lovely and peaceful.

Don't miss the second post about our summer tours below. That one gives glimpses into our hiking tours.

  Rocks, Romans, and a Ringwall - Hiking Tours in Summer 2016

I've already presented the hiking tours in the juniper heath near Rossbach and the 'Hessian Switzerland'. Here are some more we did this year.

Karst landscape in the Meissner

The tours included a second - and more extended - visit to some of the most interesting karst formations in the Meissner, with its pretty white limestone rocks and hidden sinkholes. One better remains on the official paths. *grin*

Basalt and red sandstone on the Blue Dome (Blaue Kuppe)

Another interesting geological formation is the Blue Dome (Blaue Kuppe) near Eschwege. That one consists of volcanic basalt high in olivine from 12 million years ago, which rose through a layer of coloured sandstone. It had been quarried until 1920, but today the area is a nature reserve.

Devil's chancel, Werra valley

Of course it wasn't the devil - who gets blamed for all sort of odd rocks that stick out in a landscape, but geological processes that shaped the protruding rock of coloured sandstone which offers a nice view into the Werra valley. But the name Teufelskanzel (Devil's Chancel) sounds more fun than something like 'Red Sandstone Cliff'.

Nature reserve with very old trees near Sababurg Castle

It is no genuine jungle, but the forest near the Sababurg has been left to grow since 1907 and it looks fairly primeval by now. The land had formerly been a forest where the pigs and cows would be driven to feed, so the vegetation was kept short except for some large trees. The sunlight reached the ground, and after the place became a nature reserve, younger trees could grow up between the old veterans. Some of the old ones look really twisted now.

Carolingian ringwall near Bad Sooden-Allendorf

On a mountain looming behind the town of Bad Sooden-Allendorf at the Werra, remains of a Carolingian earthen ringwall can be found. It is so overgrown that it really takes some imagination, though. Even less - that is, nothing - remains of the timber and wattle-and-daub houses inside the fortification. It was likely erected to protect the salt mines at the Werra, but little is known of the history of the site.

The Bruchteiche lakes near Bad Sooden-Allendorf

On the way up to the ringwall one passes some artificial lakes, the Bruchteiche, which were dug out in 1910 to cover the increasing need of drinking water in the spa town of Bad Sooden. The salt has been used for medical purposes since that time. The twin town of Bad Sooden-Allendorf is still a spa town today.

The Roman battlefield at Kalefeld / Harzhorn

The 3rd century battlefield at Kalefeld / Harzhorn, where Romans fought against Germans and which had been discovered in 2008, now includes a hiking way with information tablets and marked spots in the landscape that explain the battle. It is indeed very informative and interesting. And a nice walk, too.

The Oder in Bad Lauterberg / Harz

I'll leave you with some cold water: the Oder river in the spa park in Bad Lauterberg in the Harz. After the route diversions between Göttingen and the Harz which had annoyed us for several years, have finally been cleared up, we'll plan to go there more often again.

  From Paleolithic Cave to Mediaeval Church - The Steinkirche near Scharzfeld / Harz

The karst landscape in the southern Harz not only has some interesting rock formations and a castle that makes use of the limestone cliffs as curtain walls, but some caves as well. One of these can be found near the village of Scharzfeld. Excavations have shown that is was used as shelter since the Paleolithic time, but more unusual is its use as church in the Middle Ages.

Entrance of the cave

The cave is a fracture cave, formed by erosion of soluble material (gypsum) which left a cleft in the harder rock (dolomite) along natural fissures in the rock. The entrance had been much narrower; it was extended in the Middle Ages.

The way up to the cave (260 metres above NN) is rather steep and the 9 metres high cliff wall almost vertical. The dolomite rock continues above the cave for several more metres in the shape of a sort of ridge; it also forms a second wall on the side of the plateau. This defensible position may later have attracted an early Christian community.

The cliff seen from the way to the cave

Excavations on the plateau took place as early as 1925-28 under the supervision of Professor K.H. Jacob-Friesen, director of the Provincial Museum (today Lower Saxony State Museum, Hannover). He discovered a Mediaeval graveyard on the plateau which had been in use from the 8th until the 15th century, as well as some pieces of Gothic tracery and roof shingles near the cave entrance which point at some sort of man-made entrance hall to the cave church during that time. A number of pottery shards date to the 13th to 15th centuries. An excavation in 1937 was supposed prove that the cave had been a Germanic cultic site, but no finds could confirm that.

The way to the cave

Below the graveyeard, in a depth of 1.20 metres, is a layer of yellow dolomite sand, the weathering product of the dolomite rocks. It contains remains of the bones of Ice Age wildlife and flint tools dating to the late Paleolithic Magdalenian (BC 17,000 - 12,000), also known as the age of reindeer hunters. Interesting is layer of charcoal ash 2 cm thick and 80 cm in diamters within the dolomite sand in the middle of the plateau, surrounding a flat dolomite plate which is supposed to have served as some sort of Ice Age barbecue. The finds of flint tools and shards were most dense around this fireplace; even a bone needle survived - the people of the Magdalenian were known not only for their advanced flint technology (for example microlith arrow and harpoon points) but also for working bone, antler and ivory.

View into the valley

It would have been a good spot for the Paleolithic hunter-gatherers some 12,000 years ago: a nice cave with a plateau on a cliff that offers a good view over the Oder valley (1) and the Harz foothills. The valley would have been a steppe landscape at the time, populated by reindeer, bison, steppe horses, but also smaller animals like mountain hares and ptarmigan.

The cave, then much smaller in width, was likely not used as a permanent living place. The assumed scenario is that the Magdalenian hunter-gatherers followed the wandering of large herbivores, esp. reindeer and used the place during the hunting season as seasonal lodge.

Church and Hermit's Cave (to the left)

There are several legends about the beginnings of the use of the cave as church, involving a hermit and a miracle - in some versions ascribed to St. Boniface (about AD 732) - by which the cave was shaped. But there are no written sources about the early Middle Ages; the first mention of a church, the 'Chapel at the Knight's Stone', dates to the 15th century. The Gothic traceries and the pottery shards, as well as a dated coin, point at a use of the cave as church since the 13th century, and in case the door arch is indeed Romanesque, it would date the church back to the 12th century.

Closeup of the entrance

Though it is likely that a church existed there much earlier, esp. considering the fact that the site was used for burials since the 8th century. Else there would have been no reason why the surrounding villages would not simply have quarried the dolomite and gypsum kalk to build a stone church down in the valley which would have been easier to access, instead of expanding a natural cave. The cave was probably sacred already (2). It was also easier to defend and may have served as fortified church - in that function it may have played a role again in the 15th century when it appears in the chartes.

The cave church seen from the side

The importance of the church, or chapel, as family inheritance did not last long; after 1586 the cave church disappears from written documents. One can assume that it was no longer used as church after that time. We don't know if it was used for something else like storage - if that was the case it left no archaeological traces. It is also unknown since when the name Steinkirche (Stone Church) was used for the cave.

Interior of the cave

The interior of the cave is a hall of 28 metres length, and a bredth of 7 to 9 metres. The fracture cave had been to small for a church and was expanded sideways - one can see the difference of the new rock floor and the old floor which is a mix of clay and dolomite sand. The wall in the back of the cave is 6.60 metres high. There is a small cleft leading further into the bedrock. A vertical shaft in the ceiling gives some light. It once held a bell which has been transfered to the village church.

The chancel at the gate

The 6 metres wide entrance to the church had once been closed by a timber gate; one can still see the tongues and the wall plugs for the hinges. The rounded arch may have been a Romanesque feature but it can as well have been built that way because it fits the shape of the cave. At some time there must have been a Gothic entrance hall made of quarried and worked stones as the finds of tracework show. That way the chancel which has been hewn into a natural crack in the dolomite rock was inside the building. Today it is outside the gate. One female burial has been discovered directly below the chancel.

The Hermit's 'Cave

The side wall holds another small natural cave which has been extended. It forms a 3.50 metres wide chamber with a 'backdoor' leading up to the ridge. It is called the Hermit's Cave, though there is no proof that a hermit actually lived there. Maybe it had been a side altar like the ones you can find in the side chapels in Gothic churches.

The altar niche

Interest in the cave was renewed when Romantic painters like Ludwig Richter (1803-1884) traveled around in search for romantic and picturesque nature and ruins. Richter painted the cave in 1828 (complete with a shepherdess and some goats). The Steinkirche is one of the most important prehistoric monuments in Lower Saxony. Today the place is quite popular with neo-pagans.

View out of the cave (without goats and a shepherdess)

1) Not the more famous Oder at the border to Poland but a smaller river which springs in the Harz and confluences into the Rhume. Some of its seepage also feeds the Rhume springs.
2) Despite the lack of Germanic archaeological finds it is not impossible that the cave was used as sacred site by the local Germanic tribe; it's the sort of place that would have attracted a Christian missionary to turn into a church. But there is no proof that such a continuation in the use of the cave did indeed take place.


  Hiking in Hessian Switzerland (Hessische Schweiz)

We've been doing some more hiking tours south of Göttingen. One of the areas - situated near Eschwege - is called the Hessian Switzerland (Hessische Schweiz) due to its mountains and pretty vistas. Here are some photos of a walk we did back in May.

View from the 'Salt Woman' viewpoint towards Eschwege

The dominating feature of the area is the Gobert, a musselkalk ridge which runs from the Hainich in Thuringia to the Werra valley in Hessia. It is one of the largest sturzstrom areas in Germany - errant rocks and boulders of the prehistoric slides can still be seen all over the place. A sturzstrom is basically an XXL landslide with a much larger horizontal impact and distribution of material.

Another pretty view

The plateau of the Gobert proper near the village of Hitzelrode is about 570 metres high and covered with calcareous beech forest and some rare orchids which I can never find. Several hiking tours explore the ridges and valleys that have been cut into the mussekalk by brooks and rivers. The tour we did is not so difficult, but there is another tour that comes so close to some cliffs that you need a good head for heights (which I don''t have).

The way on top of the Gobert

The particular geology of the area goes back to the border between the Upper Bunter sandstone (some 245 million years ago) which consists of 'waterproof' layers of clay and silt, and the strata of water permeable musselkalk above it. Due to the water that permeates through the musselkalk and collects on the clay of the upper Bunter, the rocks formations in the area have been rather unstable, leading to landslides, sturzstroms and rockfalls, the formation of cliffs, crevices and caves.

Cliffs at the Horse Cave

Both rock strata - together with the third and youngest, Keuper - belong to the Germanic Trias which followed the period of the Zechstein Sea. The Zechstein Sea and the following age of alternating arid times and ingressions by the sea stretched from England in the west to Poland in the east; it's nothern border were the Iro-Scottish highlands, then still connected with northern America.

New vistas around every bend

Well, back to the hiking. We had to ascend a pretty steep path until we reached the plateau, but from there it was nice going through the beech forest, with several pretty views at the surrounding landscape. Those spots are well protected by rails and offer benches for a rest. Some of them are connected with historical events or interesting rock formations.

The Salt Woman

Another geological feature are the salt deposits of the Zechstein Sea which have come close to the surface in some spots thanks to the geological changes. One of these deposits can be found nearby - the town Bad Sooden-Allendorf is named for it. The spot on the photo above was either a resting place for women carrying salt along the ridge path, or the guardpost of the wives of salt smugglers who could see far into the valley below and warn their men of patrols.

View from the Horse Cave towards the village of Hitzelrode

Another interesting spot is the Horse Cave or Horse Hole (Pferdeloch). The Horse Cave is a ravine with several musselkalk pillars and chimneys (you can see a photo of the cliffs above). It is said that the ravine has been used as hiding place for the villagers' horses and cattle during the Thirty Years War.

The Wolf Table

The Wolf Table (Wolfstisch) is a musselkalk plate on a boulder of similar material - the combination looks pretty much like a table. It is only a few metres away from another cliff and may have been used as sacrifical place during the Iron Age and perhaps as a secret meeting place in the Middle Ages. It surely is the sort of natural feature that would have been interpreted as having been created by the gods.

Wolf Table, seen from a different angle

It were not the gods, of course, but erosion. The cliff once had been a larger plateau that eroded over time. Besides the Wolf Table, there are several more rocks that have withstood erosion a bit better than the surrounding material. But some - likely far - time in the future, the edge of the cliff will reach the table and it will slide down into the valley.

Closeup of the Wolf Table

The inner German border after WW2 ran directly across the Gobert. The American occupied part in Hessia became part of the BRD in May 1949, while the Sovyet occupied land in Thuringia was part of the GDR since October 1949. For 40 years, this part was inaccessible for us though we lived in Eschwege in the 80ies.

View from the Wolf Table into the valley

There is a second loop of the way on the Goberg plateau on the Thuringian side, which runs directly on the Green Belt for some part. The Green Belt is the result of the former border which had been depopulated and served as refuge for rare species of fauna and flora. After the German reunion, large parts of the belt have been turned into nature parks and biosphere reserves where hiking is allowed, but no building projects and such.

View from the Wolf Table, different angle

We plan to do the second circular route as soon as the weather will allow it. For now, I'll leave you with another pretty view.

The Lost Fort is a blog based on my travels in Germany, the UK and other places, with essays on Roman and Mediaeval history illustrated with lots of photos of old castles, cathedrals, Roman remains, and beautiful landscapes. You may also find the odd essay about geology or Mediaeval literature.

All texts (except comments by guests) and photos (if no other copyright is noted) on this blog are copyright of Gabriele Campbell.

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Location: Germany

I'm a blogger from Germany with a MA in Literature and History which doesn't pay my bills, so I use it to research blogposts instead. I'm interested in everything Roman and Mediaeval, avid reader and sometimes writer, opera enthusiast, traveller with a liking for foreign languages and odd rocks, photographer, and tea aficionado. And an old-fashioned blogger who hasn't yet gotten an Instagram account. :-)