Northern Harz Boundary Fault
Encyclopedia
The Northern Harz Boundary Fault is a geological fault where the Harz Block, which consists of rocks formed during the Palaeozoic Era and folded in the course of Hercynian mountain building, borders on the Subhercynian Basin or Harz Foreland. The fault is also known in English as the Harz North Rim Fault or Harznordrand Thrust (Fault).
The northern edge of the Harz is oriented in a Hercynian (WNW-ESE) direction and runs from Neuekrug-Hahausen
via Langelsheim
, Goslar
, Bad Harzburg
, Ilsenburg
, Wernigerode
, Blankenburg, Thale
and Gernrode
to the area of Ballenstedt
.
The Northern Harz Boundary Fault forms the southern border of the Northeast German Basin, a part of the Central European Basin. The Subhercynian Basin, also known as the Harz Foreland, is a small sub-basin of the Northeast German Basin. This intracontinental basin that has been subsided since the Permian
period was formed from the Hercynian foreland basins and accumulated sediments of the Mesozoic era. The basin was formed by a deformation or bulging of the Moho
. In the Cretaceous the basin was squeezed by Alpine orogeny
which also uplifted the Harz Block.
The Northern Harz Boundary Fault was activated in the Early Cretaceous
and the Harz was uplifted along the line of the fault. The Harz Block was thrust over the Mesozoic strata of the Subhercynian Basin, steeply tilting its Mesozoic
strata. The most intensive phase of uplift occurred in a period of about 2 million years during from the middle of the Santonian
age to the lower Campanian
. The completion of uplift is shown by the fact that the rocks of the Upper Cretaceous lie at a much shallower angle than those of the Lower Cretaceous, and that, in some places, they overlap discordantly. The uplift is still going on today.
Along the western part of the fault, the Harz was lifted by at least 5 to 7 km, which can be estimated from the thickness of the Mesozoic
rocks deposited in the Harz Foreland and eroded Paleozoic rocks. The Harz was partly thrust over the layers of Mesozoic rock to the north. Here, the Mesozoic strata were tilted steeply (70-80 degrees) or even overturned. A good example is at the Langenberg Quarry, but there are also many other outcrops that show the steeply sloping strata. In these strata, rocks of the Jurassic
are steeply inclined. Near Blankenburg and Ballenstedt there are rocks lying at steep angles from the Cretaceous
, which form the so-called Devil's Wall or Teufelsmauer
. They include, inter alia, rocks of Heidelberg Sandstone, a silicified quartz sandstone.
Springs rise along the entire fault system, both those with low quantities of minerals as well as mineral water
springs. The mineral waters are used, for example, in Bad Harzburg, by the spa industry.
The northern edge of the Harz is oriented in a Hercynian (WNW-ESE) direction and runs from Neuekrug-Hahausen
Hahausen
Hahausen is a municipality in the district of Goslar in Lower Saxony, Germany.It is situated northwest of the Harz mountains, between Seesen and Lutter am Barenberge. It is part of the Samtgemeinde Lutter am Barenberge....
via Langelsheim
Langelsheim
Langelsheim is a town in the district of Goslar, in Lower Saxony, Germany.- Geography :The municipality is situated between the river Innerste and its tributary Grane, on the northern edge of the Harz mountain range and the Harz National Park, located about northwest of Goslar.- City subdivisions...
, Goslar
Goslar
Goslar is a historic town in Lower Saxony, Germany. It is the administrative centre of the district of Goslar and located on the northwestern slopes of the Harz mountain range. The Old Town of Goslar and the Mines of Rammelsberg are UNESCO World Heritage Sites.-Geography:Goslar is situated at the...
, Bad Harzburg
Bad Harzburg
Bad Harzburg is a town in central Germany, in the Goslar district of Lower Saxony. It lies on the northern edge of the Harz mountains and is a recognised saltwater spa and climatic health resort.- Location :...
, Ilsenburg
Ilsenburg
Ilsenburg is a town in the district of Harz, in Saxony-Anhalt in Germany. It is situated under the north foot of the Harz Mountains, at the entrance to the Ilsetal valley of the small Ilse river, a tributary of the Oker, about six north-west of the town of Wernigerode. It received town privileges...
, Wernigerode
Wernigerode
Wernigerode is a town in the district of Harz, Saxony-Anhalt, Germany. Until 2007, it was the capital of the district of Wernigerode. Its population was 35,500 in 1999....
, Blankenburg, Thale
Thale
Thale is a town in the Harz district in Saxony-Anhalt in central Germany.-Geography:It is situated on the river Bode, approximately 8 km west of Quedlinburg. It is the terminus of the Magdeburg–Thale railway.- History :...
and Gernrode
Gernrode
Gernrode is a town and a former municipality in Germany, in the district of Harz, Saxony-Anhalt. The town was first mentioned in 961 and became a city in 1539. Since 1 January 2011, it is part of the town Quedlinburg...
to the area of Ballenstedt
Ballenstedt
Ballenstedt is a town in the Harz district, in the German state of Saxony-Anhalt. It is situated at the northern rim of the Harz mountain range, about 10 km southeast of Quedlinburg. The municipality includes the villages of Badeborn and Oppenrode...
.
The Northern Harz Boundary Fault forms the southern border of the Northeast German Basin, a part of the Central European Basin. The Subhercynian Basin, also known as the Harz Foreland, is a small sub-basin of the Northeast German Basin. This intracontinental basin that has been subsided since the Permian
Permian
The PermianThe term "Permian" was introduced into geology in 1841 by Sir Sir R. I. Murchison, president of the Geological Society of London, who identified typical strata in extensive Russian explorations undertaken with Edouard de Verneuil; Murchison asserted in 1841 that he named his "Permian...
period was formed from the Hercynian foreland basins and accumulated sediments of the Mesozoic era. The basin was formed by a deformation or bulging of the Moho
Mohorovičić discontinuity
The Mohorovičić discontinuity , usually referred to as the Moho, is the boundary between the Earth's crust and the mantle. Named after the pioneering Croatian seismologist Andrija Mohorovičić, the Moho separates both the oceanic crust and continental crust from underlying mantle...
. In the Cretaceous the basin was squeezed by Alpine orogeny
Alpine orogeny
The Alpine orogeny is an orogenic phase in the Late Mesozoic and Tertiary that formed the mountain ranges of the Alpide belt...
which also uplifted the Harz Block.
The Northern Harz Boundary Fault was activated in the Early Cretaceous
Early Cretaceous
The Early Cretaceous or the Lower Cretaceous , is the earlier or lower of the two major divisions of the Cretaceous...
and the Harz was uplifted along the line of the fault. The Harz Block was thrust over the Mesozoic strata of the Subhercynian Basin, steeply tilting its Mesozoic
Mesozoic
The Mesozoic era is an interval of geological time from about 250 million years ago to about 65 million years ago. It is often referred to as the age of reptiles because reptiles, namely dinosaurs, were the dominant terrestrial and marine vertebrates of the time...
strata. The most intensive phase of uplift occurred in a period of about 2 million years during from the middle of the Santonian
Santonian
The Santonian is an age in the geologic timescale or a chronostratigraphic stage. It is a subdivision of the Late Cretaceous epoch or Upper Cretaceous series. It spans the time between 85.8 ± 0.7 mya and 83.5 ± 0.7 mya...
age to the lower Campanian
Campanian
The Campanian is, in the ICS' geologic timescale, the fifth of six ages of the Late Cretaceous epoch . The Campanian spans the time from 83.5 ± 0.7 Ma to 70.6 ± 0.6 Ma ...
. The completion of uplift is shown by the fact that the rocks of the Upper Cretaceous lie at a much shallower angle than those of the Lower Cretaceous, and that, in some places, they overlap discordantly. The uplift is still going on today.
Along the western part of the fault, the Harz was lifted by at least 5 to 7 km, which can be estimated from the thickness of the Mesozoic
Mesozoic
The Mesozoic era is an interval of geological time from about 250 million years ago to about 65 million years ago. It is often referred to as the age of reptiles because reptiles, namely dinosaurs, were the dominant terrestrial and marine vertebrates of the time...
rocks deposited in the Harz Foreland and eroded Paleozoic rocks. The Harz was partly thrust over the layers of Mesozoic rock to the north. Here, the Mesozoic strata were tilted steeply (70-80 degrees) or even overturned. A good example is at the Langenberg Quarry, but there are also many other outcrops that show the steeply sloping strata. In these strata, rocks of the Jurassic
Jurassic
The Jurassic is a geologic period and system that extends from about Mya to Mya, that is, from the end of the Triassic to the beginning of the Cretaceous. The Jurassic constitutes the middle period of the Mesozoic era, also known as the age of reptiles. The start of the period is marked by...
are steeply inclined. Near Blankenburg and Ballenstedt there are rocks lying at steep angles from the Cretaceous
Cretaceous
The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...
, which form the so-called Devil's Wall or Teufelsmauer
Teufelsmauer (Harz)
The Teufelsmauer is a rock formation made of hard sandstones of the Upper Cretaceous in the northern part of the Harz Foreland in central Germany. This wall of rock runs from Blankenburg via Weddersleben and Rieder to Ballenstedt. The most prominent individual rocks of the Teufelsmauer have their...
. They include, inter alia, rocks of Heidelberg Sandstone, a silicified quartz sandstone.
Springs rise along the entire fault system, both those with low quantities of minerals as well as mineral water
Mineral water
Mineral water is water containing minerals or other dissolved substances that alter its taste or give it therapeutic value, generally obtained from a naturally occurring mineral spring or source. Dissolved substances in the water may include various salts and sulfur compounds...
springs. The mineral waters are used, for example, in Bad Harzburg, by the spa industry.