Organic debris and allochthonous coal in Quaternary landforms within a periglacial setting (Longyearbyen Mining District, Norway) - A multi-disciplinary study (coal geology-geomorphology-sedimentology)
High volatile bituminous coal C and B is currently exploited at Spitsbergen-Svalbard, Norway. Several coal seams formed during the Palaeocene, of which some were reworked by mass wasting (MW), (glacial)-fluvial (GF) and coastal-marine wave-dominated (WM) processes under periglacial conditions during...
| Published in: | International Journal of Coal Geology |
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| Main Authors: | , , , , , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
Elsevier
2020
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| Subjects: | |
| Online Access: | http://hdl.handle.net/10261/233554 https://doi.org/10.1016/j.coal.2020.103625 |
| Summary: | High volatile bituminous coal C and B is currently exploited at Spitsbergen-Svalbard, Norway. Several coal seams formed during the Palaeocene, of which some were reworked by mass wasting (MW), (glacial)-fluvial (GF) and coastal-marine wave-dominated (WM) processes under periglacial conditions during the Quaternary. This supergene alteration resulted in different landforms and deposit bearing four different types of depositional environments in Svalbard: (1) Invisible floral and faunal remains, (2) visible floral remains, (3) drift wood, (4) coal placers s. The subaerial slow- and fast-moving MW was accompanied by chemical weathering giving rise to jarosite coatings indicative of acidic meteoric solutions, whereas the remaining subaquatic processes operated under neutral to slightly alkaline conditions. Fast-moving MW and WM are productive processes, whereas GF ones are destructive with regard to coal accumulation. The most efficient tools to study the origin of the OM-bearing coarse-grained deposits are the morphology and orientation of bioclasts while the LER/HER (= low exothermic / high exothermic reaction) ratio is used for finer-grained OM-bearing sediments. The maceral analysis revealed that the landforms accounted for by GF and WM were emplaced as a result of geogenic and anthropogenic processes and aged younger than 1900 CE, while MW is Quaternary and true geogenic. Driftwood is cast in the role of a marker for coal-bearing (fluvial-) marine environments different in age and rank of coalification. With this in mind it is an excellent tool to drawn the boundary in paralic settings between the marine and fluvial impact. In conclusion, coal fragments are markers for short-term, periodical and fast landform-building processes, whereas siliciclasts from the host and bedrock are markers for long-term and episodical geomorphological and sedimentological supergene alteration. Peer reviewed |
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