Early mountain building Geologically the Fichtel massif consists mainly of
granite. The history of its
orogeny begins in the
Precambrian Eon about 750–800 million years ago. From that time only the
truncated uplands of the once-towering mountain chain are left. Subsequently, the area was covered by sea, and
rivers transported
sediments from the old eroding mountains on the coast. These sediments were deposited as layers of
clay,
sand and
limestone. At the beginning of the
Cambrian Period, about 570 million years ago, these beds were folded and raised up to form new mountains. High
temperatures and
pressure during this
mountain folding process, which lasted into the
Upper Carboniferous Period, created
metamorphic rock. The
shale layers were transformed into
phyllites and
schists, sandstones metamorphosed into
quartzite and limestone produced
Wunsiedel marble. These mountains, which may have been several kilometres high, were also eroded to
sea level again.
Variscan orogeny: mountains from the depths of the sea In the next phase, great, deep-sea sediments were laid down under the present-day Fichtel Mountains and the
Franconian Forest from the
Silurian,
Devonian and
Lower Carboniferous periods; these are especially well recorded in the Franconian Forest, whose rocks were only subject to very low-grade
metamorphism (associated with volcanism and
ore formation) and which contain easily dated
fossils. Finally, in the
Upper Carboniferous period 285 million years ago, the
Hercynian mountain building phase began and raised the Fichtel Mountains, Franconian Forest and
Münchberg gneiss plateau into high mountains – like almost all the
fold mountains formed during the Hercynian period. This mountain building episode was the
Variscan orogeny, named after
Hof's Latin name (and the tribe of
Varisci) of
Curia variscorum. At the same time, magma intruded in several phases into the
folds, where it solidified under the Earth's surface into the present-day granites. As granite formed, secondary rocks were only affected by slight
contact metamorphism. The rest of the molten rock with its
ore-containing fluids formed
pegmatite, as well as veins of ore and minerals – the basis of the
medieval mining industry and early
industrialisation of this region. During the
Upper Carboniferous and Lower
Permian (
Rotliegendes) large quantities of rock debris were deposited in intramontane basins and onto the foreland of the mountain range. These basins were formed by
extensional tectonics which were accompanied by an intermediate to acidic
volcanism. The
sediments of the
Rotliegendes are only exposed in a few places, but have been confirmed across a wide area by drilling beneath the
platform southwest of the
Franconian Line. Late Variscan
volcanic rocks occur in the Fichtel Mountains as layers of
rhyolite.
Alpine orogeny creates new pressures In the
neogene (
Upper Tertiary beginning 26 million years ago) period,
tectonic activity increased again – just as the
Alpine orogeny (
Alps,
Carpathians etc.) slowly came to an end. In that time, parts of this and other older massifs (such as the
Bohemian-Moravian Highlands or
Bohemian Massif in the
Alpine foothills) sometimes ended up underneath younger rock. In the Upper
Miocene (10 million years ago), molten
basalt broke through in northern
Upper Palatinate as the
Eger Graben was being formed. Through erosion, the remains of former
diatremes have been uncovered and may be seen e.g. on the
Rauher Kulm or at Parkstein near
Weiden. Basaltic surface layers, i.e. extensive flows of low-viscosity
lava, are visible e. g. on the Teichelberg near
Pechbrunn. These basaltic
nappes should not however be confused with the formation of
tectonic layers. The formation of the present
landscape finally took place in the younger
Pliocene about 5 million years ago: an earlier-formed
Franconian fault line came under pressure again and the Fichtel Mountains,
Franconian Forest, the
Münchberg Gneiss Massif and the northern
Upper Palatine Forest were uplifted along it. This last
uplift gave the forces of erosion more to do again and the rivers cut deeply into the already, almost levelled, mountain range. So the present day structure was created from a
plateau: a low mountain range which is being gnawed away at on all sides, with a long and varied history. Although often difficult to interpret, it is an 'Eldorado' for
geologists from a wide range of specialisms.
Predominant rock types Granite ( for
grain) and its derivatives make up about 40% of the area – its impact being all the more striking because this very hard, yet hydrous, rock forms the highest
peaks in the area. Its stark appearance and the early emergency of industry here have made their mark on
landscape and people. In detail there is: •
Porphyritic Granite of the
Bad Weißenstadt/Liebenstein massif (including the towns of
Marktleuthen/
Röslau) and extending into the
Czech Republic as far as
Haslau. The
porphyry contains
biotite (dark
mica) and
phenocrysts of
feldspar up to 8 cm across. •
Reut Granite near
Gefrees is, by contrast, finer with a bluish-grey hue.
Selb Granite (found northeast of the upper massif near Schwarzenhammer and running through the Selb Forest and the Czech Republic into
Saxony/
Elster Mountains) is fine-grained, but grey again. •
Holzmühl Granite occurs in just two small outcrops near Holzmühl, 3 km southeast of Marktleuthen and near Längenau on the Wartberg, east-northeast of
Selb; medium-grained with a higher biotite content, unevenly grained microstructure. •
Redwitzite is also called
Syenite Granite and occurs in the
Marktredwitz/
Arzberg/
Thiersheim triangle; medium- and also fine-grained, its variable mineral composition produces colourations from light grey, dark grey and dark green-grey to almost black. •
Rand Granite (Dach Granite) occurs in all the prominent massifs of the Fichtel Mountains (the Ochsenkopf, the southern part of the Schneeberg and the Haberstein, the Platte to the Hohe Matze, the
Kösseine and the
Großer Kornberg); its groundmass is small-grained with phenocrysts of
feldspar,
quartz and
biotite, sometimes sprinkled with
muscovite as well; •
Kösseine-Rand Granite occurs on the Kösseine, including the Burgstein, Haberstein and Schauerberg, and the southern part of the Großer Kornberg massif; small- to medium-grained, porphyritic structure weak or missing; low in phenocrysts. •
Kern Granite is found in the central Fichtelberg/Ochsenkopf/
Nußhardt block and on the eastern perimeter of the Schneeberg; it forms outcrops of in the shape of numerous rock formations; medium- to coarse-grained. •
Kösseine and Wolfsgarten Kern Granite. There are numerous pockets of Kösseine Granite containing hornfels, cm-large biotite-rich shreds and nodules of host rock, rounded or round quartz-feldspar rich pockets on the Kösseine massif: narrow band on the north, east and southern edge, small labyrinth, Kleinwendern quarry, Hirschensprung rock formation, Wolfstein, Hohenstein, Ochsenkopf, Hundslohe and Gregnitz valley; on the Kornberg: the Wolfsgarten forest and the south-southwestern part of the Großer Kornberg; relatively coarse, has an unusual appearance due to the blue feldspar, black biotite and richly sprinkled dark foreign bodies; Wolfsgarten Granite is somewhat lighter blue. •
Zinn Granite is restricted to the central massif and occurs on the Rudolfstein, on the Drei Brüder almost to the summit of the Schneeberg, western slope of the Seehügel, between Seehügel and Platte, Fuchsbau and Zufurt west of
Leupoldsdorf; very even, medium grain; little biotite, a lot of muscovite; lighter, brighter hue. •
Rand Granite of the Steinwald massif: in the western part of the Steinwald, e. g. on the Dachsfelsen, and the northwestern part of the Grandfelsen; small-grained. •
Steinwald Granite occurs in the centre, including the Weißenstein, Platte, Katzentrögel, Reiseneggerfelsen and Hackelstein; coarse-grained. •
Friedenfels Granite is the transitional
facies between the Steinwald Granite and the Falkenberg Porphyritic Granite; it forms the basement of the Pechbrunn basalt region and surfaces there at various places between the basalt nappes; porphyritic structure, especially rich in feldspar phenocrysts. == Mining industry ==