Meliata Ocean

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Paleogeography of the Northern Hemisphere in the Upper Jurassic (Modified after Plasienka) shortly before final closure of the Meliata Ocean, which is located in the lower left of the diagram in darker blue, with the subduction zone on its SE side. MWestCarpJ-Meliata.png
Paleogeography of the Northern Hemisphere in the Upper Jurassic (Modified after Plašienka) shortly before final closure of the Meliata Ocean, which is located in the lower left of the diagram in darker blue, with the subduction zone on its SE side.

The Meliata Ocean (also referred to as the Meliata-Hallstatt Ocean) was a short-lived oceanic rift basin in the Mesozoic which lay in the NW part of the Tethys Ocean as an eastward opening oceanic embayment to Adria. [1]

Timing and location

The Meliata Ocean has been interpreted as a back-arc basin related to northward subduction of Palaeotethys. [2] The main basin-forming rifting began during the Anisian stage of the Triassic. Seafloor spreading ended at the beginning of the Middle Carnian. Subduction of the basin began in the latest Triassic with the final closing of the ocean, accompanied by uplift of the adjacent marginal areas, dated as basal Oxfordian. [3]

Fragments of the ocean floor were later obducted. Those fragments, along with some of the marine sediments which were deposited in the basin, can be found in the Western Carpathians. They include the Meliata Mélange which is particularly well exposed in the Muráň river in the small village of Meliata in southern Slovakia. [4] The Meliata nappe of the Western Carpathians includes fragments of upper Jurassic blueschist-bearing ophiolite which are interpreted as evidence for the subduction of the Meliata ocean. [5]

The closure of the basin caused deformation beyond the Carpathians and it has been argued that the Eoalpine orogeny in the Cretaceous, which led to the assembly of the Austroalpine nappe system, [6] was related to the collisional event that caused the closure of the Meliata Ocean. [7]

The Meliata suture zone itself is obscured by the Upper Austroalpine nappes. [7]

References

  1. Schmid, Stefan M.; Bernoulli, Daniel; Fügenschuh, Bernhard; Matenco, Liviu; Schefer, Senecio; Schuster, Ralf; Tischler, Matthias; Ustaszewski, Kamil (2008). "The Alpine-Carpathian-Dinaridic orogenic system: correlation and evolution of tectonic units". Swiss Journal of Geosciences. 101: 139–183. Retrieved 3 September 2025.
  2. McCann, Tom, ed. (2008). The Geology of Central Europe: Mesozoic and Cenozoic Volume 2. Geological Society. p. 1185. ISBN   9781862392656 . Retrieved 22 July 2025.
  3. Kozur, H. (1991). "The evolution of the Meliata-Hallstatt ocean and its significance for the early evolution of the Eastern Alps and Western Carpathians". Palaeogeography, Palaeoclimatology, Palaeoecology. 87 (1–4): 109–135. Bibcode:1991PPP....87..109K. doi:10.1016/0031-0182(91)90132-B.
  4. Aubrecht, Roman; Gawlick, Hans-Jürgen; Missoni, Sigrid; Plašienka, Dušan (2012). "Meliata type locality revisited: Evidence for the need of reinvestigation of the Meliata Unit and redefinition of the Meliata Mélange" (PDF). Mineralia Slovaca. 44. ISSN   0369-2086 . Retrieved 1 September 2025.
  5. Dallmeyer, R.D.; Neubauer, F.; Fritz, H. (2008). "The Meliata suture in the Carpathians: regional significance and implications for the evolution of high-pressure wedges within collisional orogens". Geological Society Special Publications. 298 (1): 101–115. Bibcode:2008GSLSP.298..101D. doi:10.1144/SP298.6 . Retrieved 1 September 2025.
  6. Rudmann, J.; Tanner, D. C.; Stipp, M.; Pomella, H.; Brandes, C. (2025). "2-D Kinematic Restoration of the Western Tauern Window, Eastern Alps Using Thermochronological and P-T Constraints". Tectonics. 44 (7) e2024TC008371. Bibcode:2025Tecto..4408371R. doi:10.1029/2024TC008371 . Retrieved 22 July 2025.
  7. 1 2 Schmid, Stefan M.; Fügenschuh, Bernhard; Kissling, Eduard; Schuster, Ralf (2004). "Tectonic map and overall architecture of the Alpine orogen". Eclogae Geologicae Helvetiae. 97: 93–117. doi:10.1007/s00015-004-1113-x.