About the trail
Between the Argenthaler Waldsee and the south-east located
Quartzite opencast pit a Geological nature trail leads on a length
of about 5,5 km through 20 stages describing the changeful history
of this old mining region. The information boards at the stages
cover a great variety of aspects, are multiple illustrated and
understandingly composed. The trip through all stages will take
about 2,5 to 3 hours. Start and end point is the parking area at
the Argenthaler Waldsee.
In Summer the Argenthaler Waldsee and the Biergarten are opened for
swimming and refreshing (with costs, but supervised) to relax and
recreate from the exhausting Geo adventure.
Smelting of ore
Modern ore mining occurs in the Rheinboellerhuette since 1598. At
first the ore was taken from the proximity of the Guldenbachtal,
later the radius was spread more and more. Until 1860 30 ore pits
supplied the Rheinboellerhuette.
In 1893 the last furnace of the Rheinboellerhuette was blown off
because the iron and steel production has been moved to Saar and
The ore pit 'Grube Neufund' was one of the suppliers of the
Rheinboellerhuette. Here Brown Iron Ore (Limonite) was mined in
open pit since 1824. It is located under a 2 to 10 meter sized
cover. Already in 1889 the mining was temporarily closed for lack
With the beginning of World War 1 in 1915 mining started again, but
to increase rentability it was changed to deep mining. Due to
improved machines and better profitability deep mining was changed
back to surface mining in 1918. Until 1925 the number of employees
of the Grube Neufund rose up to 60.
In 1930 the last mining company, the 'Gewerkschaft Neue Abendsonne'
went bankrupt and the technical equipment was removed. In 1935 the
last operating was suspended finally.
Iron ore in the Hunsrueck
The are three different deposits of ore in the Hunsrueck: Brown
Iron Ore (Limonite), Red Ochre (Hematite) and Magnetic Iron Ore
(Magnetite). Hematite and Magnetite basicallly differ from Limonite
and are rare. Limonite has been mined in the Hunsrueck in about 200
pits, like in Grube Neufund here, whereas Hematite and Magnetite
were dug in only 30 pits.
Limonite is a comparatively young rock, it originates in Tertiary
about 60 MBP. The continents had almost reached their current
position, but temperature was higher than today.
In Oligocene (32 ? 24 MBP) the sea level rose. The Variscan
mountains have been weathered strongly and were ablated mostly. So
a flat sea propagated here, where the Soonwald was one island in
it. Subtropical climate caused thick Laterite soils. Groundwater
had little depth and could be saturated with iron and manganese.
The acidic rivers transported the dissolved iron to the coast.
During the inflow into the sea the iron crystallized and
precipitated to the bottom where chunks of 5 to 60 cm were built,
containing less than 45% iron.
Limonite is not a true mineral, because of its building processes
it's called a 'weathering rock'.
Hematite and Magnetite
In contrast Hematite and Magnetite are very old rocks. Hematite has
been built by analogical processes like the Limonite but contains
up to 70% iron. Magnetite has volcanic origin and contains more
than 70% iron.
In Devonian (417 MBP) most mainland was located in the south of the
earth as the continent Gondwana and around Equator the much smaller
continent Laurussia (Old Red Sandstone continent).Between Gondwana
and Laurussia there were many islands, one of them was the
'Mitteldeutsche Schwelle'. It separated a strait, the Hunsrueck
Slate Sea, from the ocean. On Old Red and the Mitteldeutsche
Schwelle rose mountains near the coast and their rivers transported
much stones into the sea.
During a period of 60 mio. years the bottom of the sea saged, so
that strata of about 10 km thickness could be deposited. Because of
its own weight these strata compressed itself from Sand to
Sandstone and from Clay to Mudstone.
At the end of Devonian the sea went dry and was falted during
Carboniferous (325 MBP) to the Variscan Mountains. The two
continents Gondwana and Laurussia clashed to the super continent
Pangea. At the junction the 'Hunsrueck-Suedrand-Stoerung' occured
and in the south of it the 'Saar-Nahe-Basin'. The
'Hunsrueck-Suedrand-Stoerung' marks the ancient subduction zone,
where the 'Mitteldeutsche Schwelle' slid on Old Red.
The rocks have been compressed over a period of about 25 mio.
years, Sandstone to Quartzite and Mudstone to Slate. During the
folding they have been multiply relocated, so that even the oldest
strata of Colored Slate were put from the bottom to the top.
Dissolved iron infiltrated fissures an was deposited there by
The super continent Pangea drifted to the North and so the climate
changed from tropical-humid in Carboniferous to subtropical-arid in
Perm 280 MBP. In the region of the Saar-Nahe-Basin volcanism
occured. Credentials are the Donnersberg and the Kreuznacher
Rhyolitmassiv with the Rotenfels. During the volcanism the rare
Magnetite originated, it is ? compared with the Hematite ? a little
Information panels of the Geo-Erlebnis Argenthal. Further
information may be retrieved from Gemeinde Argenthal,
Thiergartenstrasse 2, D-55496 Argenthal, Phone +49.6761.965966, Web
Paleogeographic maps by Ron Blakey, Department of Geology, Box
4099, Northern Arizona University Flagstaff, AZ 86011, Web
- How thick is the Limonite stratus in the Grube Neufund?
- Which elevation has todays face of the Argenthaler Quartzite
- Which of today's unique fish species lived in the flat areas of
the Devonic sea and what was it's singularity?
- Wich cities were connected by the roman trunk road through the
- Where have the crude ore been smelted after the closing of the
- Which hourly wages were paid to the miners in the 1920
- To claim this cache as found you have to write an email
containing the GC-Code as subject, a valid return address and as
body text the answers to the questions to
GeoMops@web.de . You will receive an answer with the permission
to log if your answers are correct within a few days.
- Find the Hunsrueck Crocodile take a photo of you on or beside
it and attach the picture to your log.
Logs without permission and / or picture will be deleted.
I hope you will enjoy this cache ? have fun!
Nggragvba: gur Uhafehrpx Pebpbqvyr vf nobhg 5z ybat naq jngpuvat lbh!