Prisojnik
| Prisank | |
|---|---|
| Prisojnik | |
 Prisank/Prisojnik | |
| Highest point | |
| Elevation | 2,547 m (8,356 ft) |
| Prominence | 547 m (1,795 ft)[1] |
| Listing | Alpine mountains 2500-2999 m |
| Coordinates | 46°15′N 13°28′E / 46.25°N 13.46°E |
| Geography | |
  Prisank Location in the Alps | |
| Location | Slovenia |
| Parent range | Julian Alps |
Prisojnik or Prisank is a mountain of the Julian Alps in Slovenia. Its summit is 2,547 m above sea level. It is located above the Vršič Pass, from where most climbs of the mountain start.[2] Geologically, the mountain is significant for its well-preserved Middle Triassic-era carbonate rocks that display a complete platform-to-basin cycle dating back approximately 240 million years. The mountain's structure makes it an important field locality for studying the geological development of the Julian Alps in relation to the opening of the Tethys Ocean.
Geology
[edit]Prisojnik is carved largely from Middle Triassic carbonate rocks that record a complete platform-to-basin] cycle. The lower slopes expose up to 200 m of massive grey limestone assigned to the Contrin Formation, deposited in a warm, shallow-marine setting roughly 240 million years ago. Above this limestone geologists have mapped thin, red, nodular layers of the Loibl Formation—deep-water lime-mud packed with radiolarians (microscopic plankton) and paper-thin bivalves—showing that the former platform suddenly drowned and was submerged beneath deeper water. Tiny fissures called neptunian dykes cut down into the Contrin limestone and are filled with the same red mud, confirming that faulting opened cracks while the new seafloor sediments were settling.[3]
Overlying the red pelagic beds are green tuffs and thin rhyolite lava flows that record short-lived volcanic activity connected with the same Extensional tectonics. These volcanic rocks grade upward into 25 m of thin-bedded grey limestone of the Buchenstein Formation, rich in re-worked algae and shell fragments transported downslope from neighbouring shoals. The summit wall is made of more than 500 m of massive, partly dolomitised limestone belonging to the Schlern Formation, which represents the renewed growth of a shallow-water carbonate platform during the Ladinian to early Carnian stages of the Triassic.[3]
The full succession shows that Prisojnik stood on the tilted margin of a small half-graben—a fault-bounded block that sank gently along one side while the opposite side rose. As the block subsided, the platform surface drowned, deep-water muds and volcanics accumulated in the depression, and finally the basin was rapidly infilled by carbonate debris as the platform prograded back across it. These structures make the mountain an important field locality for studying how the opening of the Tethys Ocean reshaped the geology of the present-day Julian Alps.[3]
Biology
[edit]Lepidoptera include Zygaena transalpina.[4]
References
[edit]- ^ "Prisojnik - peakbagger". peakbagger.com. Retrieved 15 February 2015.
- ^ "Prisojnik - summitpost". summitpost.org. Retrieved 25 March 2015.
- ^ a b c Celarc, Bogomir; Goričan, Špela; Kolar-Jurkovšek, Tea (2013). "Middle Triassic carbonate-platform break-up and formation of small-scale half-grabens (Julian and Kamnik–Savinja Alps, Slovenia)". Facies. 59 (3): 583–610. Bibcode:2013Faci...59..583C. doi:10.1007/s10347-012-0326-0.
- ^ Šašić, Martina; Nahirnić, Ana; Tarmann, Gerhard M. (31 December 2016). "Zygaenidae (Lepidoptera) in the Lepidoptera collections of the Croatian Natural History Museum". Natura Croatica: Periodicum Musei Historiae Naturalis Croatici. 25 (2): 233–248. doi:10.20302/NC.2016.25.19. eISSN 1848-7386.