Glossary

A | B | C | D | E | F | G | H | I | M | O | P | Q | R | S | T | V | W |

A:

Andalusite
aluminium silicate mineral

B:

Biotite
sheet silicate, also known as dark mica – has a flaky structure and is easily cleaved

Butte
isolated hill that has been preserved because of its hardness or resistance against weathering

C:

Caldera
large depressions often several kilometres in diameter formed when the roof of an (partially) empty magma chamber collapses

Cambrian to Ordovician
periods of the Palaeozoic around 541 to 444 million years ago

Carboniferous
time of coal formation, period of the Palaeozoic around 359 to 296 million years ago

Clam shrimp
up to 2 cm long crustaceans ("bivalved branchiopods")

Contact metamorphism
high temperature of magma causes transformation of the surrounding rock

Cut stone
a rock that has been cut to be processed for construction or to produce sculptures, articles of daily use or construction components

D:

Dike
usually a linear sheet of rock within another rock

Drumlin
rounded hills formed by the action of continental glaciers

E:

Elster-Glaciation
oldest of the three large-scale Nordic continental glaciations around 400,000 to 320,000 years ago

Erosion
(latin = "eating away"), removal of soil and rocks by flowing water, ice and wind

Erratic boulder
a rock that differs from type found in the area, usually transported from the place of origin by glaciers

Eruption
(latin eruptio = “to burst out “), expulsion of magma, rocks, gasses or ash from a volcanic vent

F:

Feldspar
silicate mineral, one of the most important rock-forming minerals

Fine-grained rocks
the faster a rock melt cools and solidifies, the smaller the crystals formed in the rock. In fine-grained rocks the crystals are usually < 1 mm

Flint line
the southernmost limit of the continental ice sheets is marked by distribution of glacial till containing flints

G:

Geology
science concerned with the composition, structure and development of the Earth

Geopark
a designated area where geology can be experienced

Geotope
(Greek ge = earth and topos = location), geological component of nature that provides an insight into the geological development of the Earth including the evolution of life

Glacial striation
scratches cut into the bedrock by rocks embedded in a moving glacier

Granulite
a type of schist formed by the exposure to very high temperatures and pressure (metamorphic rock)

Greywacke
Palaeozoic sedimentary rock, a grey to greyish-green sandstone with a high proportion of feldspar and a clay matrix

H:

Holocene
current geological epoch began around 12,000 years ago

I:

Idiomorphic
well-formed minerals with typical crystal faces

Ignimbrite
formed during explosive volcanic eruptions deposited in a pyroclastic flow: a current of huge volumes of hot gas carrying rock fragments, ash and lava fragments, which are so hot that they fuse together when deposited (“welding”)

Intrusion
emplacement of liquid rock (magma) in an existing rock

M:

Magma
hot, liquid rock melt, whose flow property varies according to its composition (silicate content, iron-magnesium content)

Menhir
standing stone, (maen = “stone “, hir = "long"), stones erected by prehistoric humans

Metamorphism
transformation of rocks by changes in temperature and/or pressure

Micro-syenogranite
granite (quartz and feldspar rich magmatite) variety where at least 65 % of the total feldspar content is alkaline feldspar content

microcrystalline
the crystals in the rock are so small that they can only be seen under a microscope (in contrast to macrocrystalline = visible to the naked eye)

Mountain formation
long-term geological process by which mountains are formed through the movement of the Earth’s crust

Myriapoda
group containing the millipedes, subphylum of the Arthropods

O:

Ostracodes
class of crustaceans, up to three centimetre long shrimp-like animals with a calcium carbonate shell

P:

Palaeozoic
a stage of geological change lasting from 541 to 252 million years ago, also includes the Permian period during which the volcanic rocks of the Geopark Porphyry Land were formed

Pangea
the most recent supercontinent, a landmass of around 138 million square kilometres that existed between 300 and 150 million years ago

Pleistocene
ice age, a period of the Quaternary from 2.6 million to 12,000 years ago

Porphyry
volcanic, usually silicate-rich type of rock with a porphyritic texture (large individual crystals of quartz, feldspar etc. in a very fine-grained matrix). In geology the correct term for quartz-rich porphyry is rhyolite

Proterozoic
early geologic eon around 541 million years ago

Pyroclasts
individual crystals, crystal or rock fragments that are ejected during an explosive volcanic eruption

Pyroxene
Silicate mineral, usually dark prismatic crystals mostly occurring in magmatic rocks with a low quartz content

Q:

Quartz
mineral with the overall chemical formula SiO2 and the second most abundant mineral in the Earth’s crust following feldspar

Quaternary
Period of the Cenozoic, from 2.6 million years ago until today, divided into the Pleistocene (ice age) and Holocene (post- ice age, includes the present)

R:

Rhyolite
volcanic rock with a fine-grained to porphyritic texture, mainly composed of quartz and feldspar. The colloquial name for a Palaeozoic rhyolite quartz-porphyry

Rochlitz-Caldera
a caldera in the Geopark Porphyry Land that was formed around 298 to 289 million years ago

S:

Saale-Glaciation
the middle of the three great Nordic continental glaciations around 300.000 to 126.000 years ago

Shale
sedimentary rock mostly containing clay and deposited in fine layers

Silicates
group of minerals that constitute around 90% of the Earth’s crust and includes all silicate minerals

Stock
a steep intrusion of a homogenous mass of magmatic rock into an existing rock

Supervolcano
a volcano that has deposited more than 1000 cubic kilometres of ash lava and rock fragments in a geologically short time

T:

Tertiary
the lignite period, a period in the Cenozoic around 66 to 2.6 million years ago

Tertiary quartzite
Lignite quartzite, fresh water quartzite formed by the precipitation of silica and cementation of Tertiary sand and gravel deposits, often redistributed by glaciers during the ice age

Trench/pit
ditch dug to examine the soil profile and/or sample the material

Tuff
a volcanic rock containing more than 75% pyroclastica usually very porous due to the gases ejected with the pyroclastica during an eruption

V:

Ventifacts
rocks and stones with grooves or polished surfaces produced by the abrasive action of wind-blown sand, often found in the regions near the margin of the ice age glaciers

Volcano/volcanism
geological structure formed by the ascent of magma through the Earth’s crust onto the surface, volcanism describes all the phenomena associated with the ascent of magma

W:

Weichsel-Glaciation
most recent of the three great Nordic continental glaciations around 115,000 to 12,000 years ago

Wurzen-Caldera
caldera formed around 287 to 285 million years ago in the Geopark Porphyry Land