Üledékföldtaniés szerkezetföldtani megfigyelések a gorba-hát keleti lejtőjén ("Gyökér-völgy", Nyugati-Gerecse)

Translated title of the contribution: Sedimentological and structural geologic observations at the eastern slope of the gorba high ("Gyökér Ravine", Western Gerecse Mts, Hungary)

Horányi Anna, Takács Ágnes, Fodor László

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

The deposition of the Jurassic - Lower Cretaceous sequence in the Gerecse Mts was defined by differentiated palaeotopography likewise in other parts of the Transdanubian Range (GALA ́CZ & VÖRÖS 1972, GALA ́CZ 1988, VÖRÖS & GALA ́CZ 1998). The most characteristic element of the palaeomorphology was the uplifted Gorba High (CSA ́SZA ́R 1995) where condensed, discontinuous sedimentation occurred. The studied section is situated in a small valley called Gyökér Ravine in the eastern flank of the Alsó-Látó Hill (Figure 1) where multiple recurrence of an approximately 5 m thickJurassic-Berrriasian condensed succession can be observed (Figure 3). The lowermost Jurassic beds are crinoid-bearinglimestones containing thin calcareous turbidite layers of Liassic age overlain by Saccocoma- and Calpionella-bearing Upper Jurassic - Berriasian limestones and Lower Cretaceous sandstones (Figure 6). The Middle Jurassic is missing, apart from a local appearance of condensed variety of the Tölgyhát Limestone Formation (Bositra limestone) which related to the coeval sediments of the Asszony and Szél Hills. The sedimentary sequence suggests deposition in the upper part of the palaeoslope of the Gorba High. This marginal position of the profile is also indicated by the presence of Hierlatz Limestone and a Liassic fault or dyke margin at the western end of the southern part of the Gyökér Ravine. In contrast with the former olistolithic models (LANTOS 1997, FODOR & LANTOS 1998, BA ́RA ́NY 2004) low angle, west tonorth-west dipping normal faults can explain the repeated occurrence of the Mesozoic series. The tectonic reconstruction (backtilting) suggests that the normal faults formed due to ESE-WNW extension, before the tilt of the sequence, which was induced by NE-SW compression. The normal faults supposed to be Aptian to early Albian, while the tilt itself could beAlbian.

Original languageHungarian
Pages (from-to)223-234
Number of pages12
JournalFoldtani Kozlony
Volume140
Issue number3
Publication statusPublished - Jan 1 2010

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ASJC Scopus subject areas

  • Geology
  • Geochemistry and Petrology
  • Stratigraphy
  • Palaeontology

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