GEOPARK PORPHYRY COUNTRY – formed by supervolcanism and inland ice glaciers

Geoportals: Visitor & Experience Centres

Geoportal Museum Steinarbeiterhaus
A journey back in time to the life of a family of quarry workers around 1910; technical exhibition on stone quarrying, stone transport and stone processing in the open-air area. – Kirchgasse 5, 04808 Lossatal, OT Hohburg

Geoportal Mügeln railway station
„The World of Kaolin“ with multimedia exhibition on the most important raw material for porcelain production and Europe’s largest narrow-gauge railway network. – Bahnhofstrasse 2, 04769 Mügeln

Geoportal „Erden der Keramik“ („Clay for Ceramics“)
Creative centre all about the raw material clay in the artists‘ house Schaddelmühle; open-air gallery with ceramic sculptures – Zur Schaddelmühle 5, 04668 Grimma, OT Schaddel

Geoportal Porphyry House
Visitor and exhibition centre dedicated to the quarrying of the Rochlitz porphyry tuff on Rochlitzer Berg; Gleisberg quarry and porphyry nature trail – Rochlitz Mountain, 09306 Rochlitz

Geoportal Röcknitz
Supervolcano exhibition with fire-breathing volcanoes; evidence of the Ice Ages in the geo-adventure garden; „Fred Porphyrstein“ volcano playground – An der Wasserburg 1 and 3, 04808 Thallwitz, OT Röcknitz

GeoExperienceWorkshop
Stone & Earth Raw Materials Competence Centre with exhibitions „Porphyry, Tuff & Co“ and “ Precious Stones in Saxony – Treasures in Porphyry“, creative and show workshop – Thomas-Müntzer-Gasse 4c, 04687 Trebsen

 

Outstanding National geotopes

1 – Glacial striations on the Spielberg
2 – Gaudlitzberg
3 – Spitzberg Quarry
4 – Wolfsberg Quarry
5 – Wind and glacial striations on the Kleiner Berg
6 – Wachtelberg Quarry and Plant Protection Area
7 – Beucha Kirchbruch quarry
8 – Rock face Haselberg
9 – Quarry at Collmberg
10 – Gattersburg porphyry at the Grimma suspension bridge
11 – „Petrified lake“ Börtewitz
12 – Millstone quarry at Hasenbach
13 – Alluvial pond quarries
14 – „Large Monolith“ and „Devil’s Stone“
15 – Red porphyry wall at Mildenstein Castle
16 – Parthe Spring „Gossenborn“
17 – Gleisberg quarry on the Rochlitz Hill
18 – Eulenkluft rock face

 

National Geotopes – Impressive Windows into the Earth’s History

The Geopark and its geologists are proud to point out geotopes of international importance.

Granite porphyry in the Beucha Kirchbruch quarry
Rising magma solidifies deep in the earth’s crust, where it slowly cools to form the granite porphyry. It was used, for example, in the Battle of the Nations Monument in Leipzig. 

Glacier and wind striations near Hohburg
The porphyry layers, many hundreds of metres thick, were elevated to the surface over millions of years of earth’s history. During the ice ages several hundred thousand years ago, they were abraded by the inland ice and scarred by sandstorms.

Rochlitz porphyry tuff in the Gleisberg quarry on Rochlitz Mountain
About 290 million years ago, the region was dominated by supervolcanoes. Lava, ash and pyroclastic deposits such as the Rochlitz Porphyry Tuff collected in caleras. As an „IUGS Heritage Stone“, it is one of the world’s most important construction stones.


Legend

Geoportals
Döllnitz Railway (Mügeln Region)
National Geotopes
Outstanding Geotopes
other geotopes
active mining
historical mining

 

 

GEOPARK PORPHYRY LAND – On the trail of the supervolcanos

290 million years ago, during the Permian period, the area of today’s Geopark Porphyry Land was located close to the equator on the supercontinent Pangaea. Immense forces from deep within the earth unleashed their power here in two supervolcanic events. Multiple rivers of lava poured out of fissures and volcanic vents which constantly changed the landscape over a period of more than ten million years. Ash clouds obscured the sun. From volcanic calderas, hot mixtures of rock debris, ash and gases known as pyroclastic flows spread rapidly across the region. Their deposits solidified to form porphyry rocks (rhyolites, Greek for ‚flow‘ and ’stone‘). They have been used as versatile building blocks for thousands of years.

A caldera (Spanish for ‚cauldron‘) is a huge depression formed by the collapse of the roof over a (partially) emptied magma chamber. The Rochlitz and Wurzen calderas formed around 298 and 285 million years ago respectively over a magma reservoir up to 15 kilometres deep. In the millions of years of geological history that followed – most recently by Nordic glaciers in the Ice Age – both calderas were eroded down to the current level of the earth’s surface.

The motto „Saxony’s wealth of rocks“ refers to the heritage of the volcanoes in the Geopark Porphyry Land. Rock has characterised the architecture, industry and culture of the Mulde Valley region since the early Middle Ages. Rochlitz porphyry tuff is listed by the International Union of Geological Sciences as a globally unique building stone. During the warm and humid Cretaceous and Tertiary periods, the exposed volcanic rocks weathered to form white porcelain clay called kaolin the raw material for ceramics production. The ice ages in particular left behind gravel sands, clays and loess loams – more important raw materials in the Porphyry Land Geopark.


Captions

  • Eruption columns of magma-gas mixtures rise kilometres high into the atmosphere. Volcanic ash often rains down to earth for years.
  • Pyroclastic flows of rocks, ash, lava rock fragments and gases at temperatures of up to 400 degree centigrade are produced when eruption columns collapse.
  • Viscous lava emerges from the earth’s surface at temperatures of up to 800 degree centigrade, often accompanied by lava rock and ash eruptions.
  • Geological map of the Permian layers in the so-called Northwest Saxon Volcanic Complex illustrating the chronology of the two calderas.
  • Diagram showing the development of a caldera with various volcanic formations within the caldera and in the earth’s crust as well as the current erosion level.
  • The Rochlitz and Wurzen calderas are considered to be super-volcanic events in Earth’s history due to their surface area and the mass of volcanic ejecta they produced.
  • The caldera collapse produces very thick volcanic rocks. In the Wurzen and Rochlitz calderas, boreholes have revealed porphyry layers at least 600 metres thick.
  • Present-day bedding of the Permian volcanic rocks (volcanites) with younger cover layers of unconsolidated rocks and the position of important quarries.
  • The granite porphyry in the Beucha quarry was formed from magma that cooled below the earth’s surface. It was used for the Leipzig Monument to the Battle of the Nations.
  • Grey quartz porphyry (solidified pyroclastic flows) was once used to make paving stones. Today they are crushed into gravel and asphalt aggregates – here in the Lüptitz quarry.
  • Reddish-brown Rochlitz porphyry tuff has been used as a building stone throughout Europe for over 900 years. The portal of St Kilian’s Church in Bad Lausick is an early example of this.