Quick note on the geomorphology of Cyrodil and its consequen
Posted: Sat Sep 12, 2009 2:08 amThis is the first of a series of article I gather on Cyrodilian studies. Please don't be afraid to read it...
There has been very few studies on the former climates of Cyrodil and on the impact on the landscape. The deep valleys, lakes and sea shores are giving important clues.
Our study on Brena, Corbele and Strid river are showing that the valley depth is between 200 to 500 meters from the surrounding plateau. The canyonisation process seems to have occured quite recently as most cliffs do not show any sign of erosion. This is a process that could have occured less than 10 000 years BP and could be the results of the geological uplift of the continent or a quick decrease in the sea level. However, the very deep fjord of the Nibernay and the Vvardenfell in Morrowind are typical of geological uplift.
I just want to give here a quick overview on the geology of this process and some hypothesis on the deglaciation.
1/ The Sancre Tor orogenesis
The Dragonfall, Colovian, Jerall, Velothi and Valus mountains are the recent consequences of a plate tectonic collision between the cyrodilian microplate and the "Hamskymor" plate (one should not see the name "cyrodilian plate" as a mark of imperialism toward our brothers argonians and elfs). This collision could have occured about 20 millions years BP and leads the raise of a highland barrier extending NW-SE through Tamriel
2/ The Bruma period (From the town Bruma, where it was first put in evidence)
This mountains were blocking the warm winds dominantly blowing from the south east. Consequently the northern part of Tamriel developped a colder climate and glaciers started to extend from these mountains toward the northern part, in Morrowind, Skymir but also to a lesser extent in Cyrodil. The whole Morrowind, Skyrim and Hammerfell and most of Cyrodil were covered by ice in same places up to 2700 m thick. The southern limit of the glacier were corresponding roughly to the present borders of Cyrodil. The Bruma ice age is classically ranging from 5 millions years BP to 10 000 years BP. One can see clearly that most of the recent Tamriel history is ice age.
3/ The deglaciation
What initiated the deglaciation is still an hypothesis and a geological mystery. This might have started 10 to 15 thousands BP. Our hypothesis is that it might be due to 3 concurring factors :
- Re-activation of a series of explosive volcanism : Imperial City is clearly built on the caldera of a quite recent origin, same applies to the southern coast of Hammerfell around the city of Taneth. This re-activation is clearly due to the tide effect of the surface crust of the moon. It is a known fact that the moon has some orbital eccentricity which brings it nearer to our world every 17 millions year. The crust is submitted to enormous tidal effects and thus re-activation of volcanism in weak points. The explosion of the caldera of Imperial City has occured about 17 000 years BP. The pressure of this explosion is responsible for the genesis of the famous imperfect and perfect diamonds of Cyrodil. Please note that the hypothesis of the meteor, creating an astroblem is obsolete. My distinguished elven colleague, Pr Eswellyn, will have to agree, as I did, with the volcanism argonian thesis.
- Early Ayleid civilization : It is believed that the early Ayleid civilization was using some organic liquid rocks as an energy source, thus increasing carbon dioxyde in the atmosphere and initiated a moderate global warming.
- This volcanism and early ayleid globlal warming provoked a very light melting of the giant glacier of Tamriel in the southern part of Cyrodil. The water started to flow south-east and created the argonian black marsh. In a cascade, this marsh became a major source of methan release in the atmosphere which increased the global warming.
This positive feed back cascade of events led to the melting of the ice covering most of Tamriel
4/ Isostatic readjustement or Post-Bruma period glacial rebound
The enormous weight of the ice caused the surface of the crust to deform and downwarp under the ice load, forcing the fluid mantle material to flow away from the loaded area. At the end of the Bruma ice age when the glaciers retreated, the removal of the weight from the depressed land led to uplift or rebound of the land and the return flow of mantle material back under the deglaciated area. Due to the extreme viscosity of the mantle, it will take many thousands of years for the land to reach an equilibrium level.(Adapted from Wikipedia).
Consequences :
1/ A detailled study of the volcanic activity of the caldera of Imperial City should be carried
2/ Study on the impact of Ayleid civilization needs urgently to be done
3/ Any draining or modification of Argonian black marsh should be regarded with the utmost attention to avoid further destabilization of sea level.
There has been very few studies on the former climates of Cyrodil and on the impact on the landscape. The deep valleys, lakes and sea shores are giving important clues.
Our study on Brena, Corbele and Strid river are showing that the valley depth is between 200 to 500 meters from the surrounding plateau. The canyonisation process seems to have occured quite recently as most cliffs do not show any sign of erosion. This is a process that could have occured less than 10 000 years BP and could be the results of the geological uplift of the continent or a quick decrease in the sea level. However, the very deep fjord of the Nibernay and the Vvardenfell in Morrowind are typical of geological uplift.
I just want to give here a quick overview on the geology of this process and some hypothesis on the deglaciation.
1/ The Sancre Tor orogenesis
The Dragonfall, Colovian, Jerall, Velothi and Valus mountains are the recent consequences of a plate tectonic collision between the cyrodilian microplate and the "Hamskymor" plate (one should not see the name "cyrodilian plate" as a mark of imperialism toward our brothers argonians and elfs). This collision could have occured about 20 millions years BP and leads the raise of a highland barrier extending NW-SE through Tamriel
2/ The Bruma period (From the town Bruma, where it was first put in evidence)
This mountains were blocking the warm winds dominantly blowing from the south east. Consequently the northern part of Tamriel developped a colder climate and glaciers started to extend from these mountains toward the northern part, in Morrowind, Skymir but also to a lesser extent in Cyrodil. The whole Morrowind, Skyrim and Hammerfell and most of Cyrodil were covered by ice in same places up to 2700 m thick. The southern limit of the glacier were corresponding roughly to the present borders of Cyrodil. The Bruma ice age is classically ranging from 5 millions years BP to 10 000 years BP. One can see clearly that most of the recent Tamriel history is ice age.
3/ The deglaciation
What initiated the deglaciation is still an hypothesis and a geological mystery. This might have started 10 to 15 thousands BP. Our hypothesis is that it might be due to 3 concurring factors :
- Re-activation of a series of explosive volcanism : Imperial City is clearly built on the caldera of a quite recent origin, same applies to the southern coast of Hammerfell around the city of Taneth. This re-activation is clearly due to the tide effect of the surface crust of the moon. It is a known fact that the moon has some orbital eccentricity which brings it nearer to our world every 17 millions year. The crust is submitted to enormous tidal effects and thus re-activation of volcanism in weak points. The explosion of the caldera of Imperial City has occured about 17 000 years BP. The pressure of this explosion is responsible for the genesis of the famous imperfect and perfect diamonds of Cyrodil. Please note that the hypothesis of the meteor, creating an astroblem is obsolete. My distinguished elven colleague, Pr Eswellyn, will have to agree, as I did, with the volcanism argonian thesis.
- Early Ayleid civilization : It is believed that the early Ayleid civilization was using some organic liquid rocks as an energy source, thus increasing carbon dioxyde in the atmosphere and initiated a moderate global warming.
- This volcanism and early ayleid globlal warming provoked a very light melting of the giant glacier of Tamriel in the southern part of Cyrodil. The water started to flow south-east and created the argonian black marsh. In a cascade, this marsh became a major source of methan release in the atmosphere which increased the global warming.
This positive feed back cascade of events led to the melting of the ice covering most of Tamriel
4/ Isostatic readjustement or Post-Bruma period glacial rebound
The enormous weight of the ice caused the surface of the crust to deform and downwarp under the ice load, forcing the fluid mantle material to flow away from the loaded area. At the end of the Bruma ice age when the glaciers retreated, the removal of the weight from the depressed land led to uplift or rebound of the land and the return flow of mantle material back under the deglaciated area. Due to the extreme viscosity of the mantle, it will take many thousands of years for the land to reach an equilibrium level.(Adapted from Wikipedia).
Consequences :
1/ A detailled study of the volcanic activity of the caldera of Imperial City should be carried
2/ Study on the impact of Ayleid civilization needs urgently to be done
3/ Any draining or modification of Argonian black marsh should be regarded with the utmost attention to avoid further destabilization of sea level.