List of Articles Late Devonian

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  1 - Facies analysis and sedimentary environment of the Jeirud Formation in Garmabdar section, central Alborz: with emphasis on paleoredox conditions during deposition of black shales
  Nahid Karimi Najmeh  Etemad-Saeed Aram Bayet-Goll Afshin  Zohdi Tomas Kumpan
  The late Devonian has been associated with major global climate changes, widespread anoxia events, and the Hangenberg Crisis. The main aim of this study is to explore the relationship between paleoenvironment and paleoredox condition during deposition of the lower Devon More

  The late Devonian has been associated with major global climate changes, widespread anoxia events, and the Hangenberg Crisis. The main aim of this study is to explore the relationship between paleoenvironment and paleoredox condition during deposition of the lower Devonian Jeirud Formation in the Garmabdar section, northeast of Tehran. The Jeirud Formation in the Garmabdar section, with a thickness of about 280 m, is composed of siliciclastics, carbonates, carbonate-siliciclastic hybrids and phosphorite deposits. Sedimentary facies analysis led to recognition of three siliciclastic facies associations related to estuarine environments under the influence of waves, shoreface and offshore and two carbonate facies associations related to intertidal and subtidal environments. Moreover, the geochemical paleoredox proxies (such as U/Th and V/Cr) also suggest prevailing anoxic conditions during deposition of black shales and phosphorites in the studied section. In overall, these results suggest that there is a good agreement between the depth of the depositional environment and anoxic conditions during deposition of black shales of the Jeirud Formation. Manuscript profile
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  2 - Biostratigraphy, biofacies and CAI of the late Devonian deposits in Kale-Sardar section, North-east Tabas, based on conodont fauna
  Mina Ramshini ٍٍElahe Sattari Ali Bahrami Hosyen Vaziri moghadam
  10.61186/ispg.41138.11.22.1
  Kale-Sardar section, is located at the vicinity of Niaz village, 15 kilometers east of Tabas town. This section consists of 80 m thick and from Late Devonian deposits as known as Shishtu formation that upper part of this section has cut by a fault by Frasnian’s deposits More

  Kale-Sardar section, is located at the vicinity of Niaz village, 15 kilometers east of Tabas town. This section consists of 80 m thick and from Late Devonian deposits as known as Shishtu formation that upper part of this section has cut by a fault by Frasnian’s deposits. The entire studied thickness is subdivided into 12 lithostratigraphic units and in order to study of conodont elements, 27 species and subspecies belonging to 7 genera were recognized, that due to these revealed conodont elements, Shishtu formation’s age in the studied section spans from Eifelian to late Frasnian. The Frasnian-Famennian bio event in studied section is located between two intervals linguiformis Zone and Lower to Middle triangularis zones which is located at the top of the dark Frasnian shales and at the base of the thin limestones of the Famennian layer. The microfacies determined in studied section are subdivided into siliciclastic-carbonate and carbonate facies, which were deposited from the shore to the deep part of the marine environment. Gradual changes in facies within stratigraphical sequence, sedimentological hiatus due to sudden change in sedimentary environment’s slope, absence of reef facies (related to Wilson’s 5th facies zone) and presence of discontinuous bioclastic barrier (existence of semi-enclosed lagoon), convey that studied sediments were deposited in a homoclinal carbonate ramp. Manuscript profile