Soil/Geology Report on Blackreach

Sorry, this one is kind of long. I had to just make some information up in regards to the geology of the region, since no current info on it exists. Specifically, I just picked what I thought would be the most interesting option would be for the geologic material of Blackreach.

Delvin Gaerston

Agricultural Advisor to the Elder Council

Soil and Geologic Report on Blackreach

This report is being compiled on the orders of the Elder Council. After the recent discovery of the massive cavern known as “Blackreach”, I have been commissioned to put together a study of the soils above the cave system as well as the geology of Blackreach itself. Blackreach stretches over a large area. Starting at the Dwarven ruin of Mzinchaleft in the northwest it expands south to the Tower of Mzark. From there it goes southeast towards Lake Yorgrim and another Dwarven ruin known as Raldbthar. The cavern stretches north then, towards the next Dwarven ruin of Altfand in Winterhold Hold. It then stretches back to west to Mzinchaleft. A map of the region is attached here.

This region is comprised mainly of mountains and valleys. Though they can still be seen in the lands near Winterhold, the glaciers of northern Skyrim once extended into these regions. These glaciers left their mark on the regions soils. The parent material (the material from which the soil formed) of these soils are glacial tills and glacial-fluvial soils. Till is unsorted, unconsolidated material deposited by glaciers as they advance or retreat. There is little stratification (layering) of the soil and there tends to be high levels of clay and boulders may even be found amongst the soil. Some till deposits show limited organization of the fragments: large numbers of stones may lie with their long axes parallel to the flow direction of the glacier. This could provide more accurate information about flow direction than other glacial indicators. Although difficult to distinguish by appearance, there are two types of till, basal and ablation. Basal till was carried in the base of the glacier and commonly laid down under it. Ablation till was carried on or near the surface of the glacier and was let down as the glacier melted. Glacial-fluvial sediments are deposited by glacial meltwater in a floodplain environment. These deposits consist of coarse to medium grained sand and gravel, poorly to well sorted and bedded, with numerous cobbles, boulders, and lenses of till. They were deposited in ice contact or near-ice positions by glacial meltwater during the last phase of glaciation, when glaciers were stagnant or retreating. The glacial-fluvial soils are found in the southeast portion of our study area, near Lake Yorgrim.

The soils of this region are all Gellisols (as opposed to the Alfisols and Mollisols that were seen in Cyrodiil). Gelisols develop in climatic regions where temperatures continuously are at or below 0° C. They occur in arid regions and areas with effective precipitation. Permafrost (i.e., permanently frozen soil) is a characteristic environmental factor for the development of Gelisols. The distribution of permafrost comprise two zones: (i) continuous permafrost: the zone at the highest latitudes and elevations where permafrost is ubiquitous; the southern boundary corresponds to the -7 °C isotherm. (ii) discontinuous (sporadic) permafrost: the zone in which permafrost occurs only in some materials; the southern boundary corresponds to the 0 to -2 °C isotherm. The other characteristic of these soils is the force cryopedogenesis, or all the different actions imposed upon the soils by freezing and thawing. These forces can mix soils so that the horizons are no longer stratified and bring organic content to lower parts of the soil. Cryopedogenesis can also lead to the formation of fragipans within the soil. Fragipans are brittle and hard, compacted regions of soil that restrict water and root movement. They are common in these colder regions due to the freeze-thaw actions. The most fascinating feature of this region is, of course, the cavern of Blackreach. This massive underground is, amazingly, one large cavern and not a system of smaller caves. What is most interesting about the cavern is that it does not seem to have been formed by the same forces that have formed caves elsewhere in Tamriel. Typically, as rainwater falls it mixes with carbon dioxide in the atmosphere and then even more so in the soil. As the water mixes with carbon dioxide it becomes the acidic compound carbonic acid. Carbonic acid is then capable of chemically eroding the underlying bedrock, but only if the bedrock is limestone or dolomite. When enough of the bedrock is eroded, larger amounts of water can flow into it, now physical eroding it as well. However, the caverns of Blackreach are not limestone or dolomite. Furthermore, there does not seem to be enough organic matter in the soils to create the carbon dioxide necessary for carbonic acid development. Therefore, it seems there must be something else resonating throughout the region’s soil that is causing the water to become acidic to the bedrock. A recent expedition into Balckreach confirmed the rumors of the presence of the almost mythically rare material known as Aetherium. Current experiments are being run on the material to discover its properties. Could this be the source of the strange characteristics seen in the geology of the area? I, personally, believe it is no coincidence that this is one of the few places that soul gems can be found. One of the other known sources has been on Solstheim, where the rare “Heart Stone” deposits have been found. If the theories on Aetherium are true, that it does have a direct relation to the gods like ebony, then it could be that soul gems are tied to the Aedric influence as well. Blackreach is also the only known location of the rare Crimson Nirnroot. If my theory on Aetherium resonating some sort of energy into the surrounding soil is correct, it could explain why this plant cannot be found elsewhere.

Blackreach and its overlying lands is a mysterious region that warrants further exploration. It is the opinion of this researcher that the study of Aetherium should be a top priority. Blackreach is certainly a place that life has flourished; from the Crimson Nirnroot to the massive mushroom-like plants found in the cavern. If it is Aetherium that has allowed these plants to grow in an otherwise inhospitable location, perhaps it can be used to increase food production elsewhere in the Empire.