Geometry and Evolution of the Eastern Part of the Hercynian Orogenic System in Europe and its Transition to the Scythides

Abstract

Hersinyen orojenezi, geç Paleozoyik zamanında Pangea oluşumu sırasında meydana gelmiş büyük bir orojenik kuşaktır. Lavrasya ve Gondwanaland'in çarpışması sonucu meydana gelen Pangea'nın, geç Devoniyen zamanında başlayan dalma-batma ve büyük ihtimalle erken-orta Karboniferden Permo-Triyas zamanına kadar devam eden çarpışma süreçleri batıda mevcutken, daha doğuda bu zaman içerisinde çarpışma hiç gerçekleşmemiş ve dalma batma süreci devam etmiştir. Orojenezin bu kısmında geç Permiyen-erken Triyas zamanında başlayan riftleşme dalma-batma yayını dogudan batıya dogru (bugünki Helenik-Dinarik Sistem ve Panoniyen-Karpatlar Bölgesi) yay ekseni boyunca parçalayarak bir kenar havzası oluşturmaya ve oluşan bu havza erken Jurada kapanmaya başlamıştır.Anahtar metodolijisi karşılaştırmalı orojenez anatomisi olan bu makalede, sistemin en az bilinen ve Türkiye'den Avusturya'ya kadar olan Doğu Avrupa segmentine ait tektonik zonlarının jeolojik yapıları Karboniferden Jura- Kratese zamanına kadar çalışılarak Hersinyen Orojenezi'nin evrimindeki etkileri tartışılmıştır. Karpatlar, Balkanlar ve Anadolu bloklarının, ve diğer Akdeniz bölgelerinin palinspastik rekonstrüksüyonları yapılarak Paleozoyik-erken Mesozoyik zamanındaki orjinal yerleri için bir çözüm sunulmuştur.Sonuç olarak, dalma-batma zonuna ait magmatik yayın Doğu Pontidler'den Batı Karpatlar'a kadar Pelagonyen Zonu'ndan ve Rodop-Pontid Bloğu'ndan geçerek bir süreklilik izlediği görülmektedir. Bunun yanı sıra, bahsi geçen rift zonu Karakaya Karmaşığı'ndan başlayıp Pelangonyen Zonu, İç Helenidler ve Meliata'dan geçerek Batı Karpatlar'a kadar devam etmektedir.

The Hercynian Orogen, one of the best-known orogenic belts in the world, still hides many secrets concerning its evolution. This orogen formed through the collision between Laurussia and Gondwana-Land, which resulted in the supercontinent of Pangaea. Pangaea's formation began in the late Devonian with the onset of subduction and continued from the early-medial Carboniferous to the Permo-Triassic by means of collision. However, at the eastern part of this supercontinent, collision never happened and subduction continued in the Permo-Triassic. The coast of the Palaeo-Tethys known as Alpine-type Triassic succession was the scene of high mobility events in the core of the Pangaea in terms of Hercynian and Post-Hercynian stages. It is a fact that when the subduction process was still continuing, a rifting event began in the Permo Triassic at the eastern part of Pangaea by disrupting a magmatic arc. The results show a continuous arc goes from the Rhodope-Pontide Fragment in the north, through the Eastern Carpathians, Tisza Block, Western Carpathians, and Pelagonian Zone, to the Eastern Pontides in the south. Additionally, the lithostratigraphic charts of all the tectonic zones indicate the volcano sedimentary complexes, which show a rifting event as their most likely interpretation. As a consequence of this rifting, a marginal basin started to form beginning from the eastern part and tore westward by tracing the weak zones of the former arc. It began to take shape from the Karakaya Complex, goes through the Pelagonian zone and the Inner Western Carpathians namely Meliaticum into the Tisza Block in the Late Permian-Early Triassic. From the medial to the end of the late Triassic, the entire Hellenic-Dinaric System and Italy began to disintegrate, which started from the Pindos Zone in Hellenides and Sicily in Italy, and joined together into the Southern Alps by passing through all along the coast of the present Adriatic Sea. This presentation shows a reconstruction of the Mediterranean Tethysides at the time of the early Triassic. It was done by palinspastically restoring all the orogenic deformation for which data were to be had painstakingly and not just schematically. It is still incomplete, because it does not show the rift areas of the Sclafani-Imerese, Lagonegro and Pindos-Budva, except to show where they were. It also delineates the lie of the Karakaya and the Meliata rifts and shows that they were one and the same rift. Karakaya was later partly incorporated into the Vardar Ocean. Most of it closed during the earliest Jurassic, whereas the Meliata part was delayed until the late Jurassic. These closures are responses to two events: 1) Palaeo-Tethyan closure in case of Karakaya and 2) the opening of the South Atlantic in case of the Meliata. This paper addresses itself mainly to the solution of the Karakaya-Meliata problem.