scholarly journals Wildfire Events at the Triassic-Jurassic Boundary of the Tabas Basin, Central Iran

2020 ◽  
Author(s):  
Majid M Alipour ◽  
Bahram Alizadeh ◽  
AmirAbbas Jahangard ◽  
AhmadReza GandomiSani
Keyword(s):  
Major Change ◽  
Lower Jurassic ◽  
Upper Triassic ◽  
Central Iran ◽  
Sharp Boundary ◽  
Depositional Settings ◽  
Run Off ◽  
Clastic Sediments ◽  
Nayband Formation ◽  
Microscopic Charcoal

Abstract This paper presents organic geochemical evidence pointing to the occurrence of wildfire events at the Triassic-Jurassic boundary in Central Iran. The studied outcrop section (the Kamarmacheh Kuh section) is comprised of the Upper Triassic Nayband Formation which passes conformably into the Lower Jurassic Ab-e-Haji Formation with no sharp boundary. Organic petrographical studies reveal a higher concentration of semi-fusinite macerals and microscopic charcoal at the boundary between studied formations. This observation can be an evidence for widespread wildfire events at the Triassic-Jurassic boundary of the studied area. Following these fires, vast areas of land were exposed for erosion and large volumes of clastic sediments were provided due to increased run-off. This agrees well with previous sedimentological and stratigraphical studies suggesting a major change in the depositional conditions from marine to non-marine at the Triassic-Jurassic boundary of the Tabas Basin. These findings can have important implications about paleo-depositional settings of the studied formations and the nature of the associated organic matter.

Stenolaemate bryozoans from the upper triassic (Norian-Rhaetian) Nayband Formation, Central Iran

Facies ◽  
2003 ◽  
Vol 48 (1) ◽  
pp. 135-150 ◽  
Author(s):  
Priska Schäfer ◽  
Baba Senowbari-Daryan ◽  
Ali Hamedani
Keyword(s):  
Upper Triassic ◽  
Central Iran ◽  
Nayband Formation

First hexactinellid sponge reported from the Upper Triassic Nayband formation of central Iran

2007 ◽  
Vol 81 (6) ◽  
pp. 1538-1542 ◽  
Author(s):  
J. Keith Rigby ◽  
B. Senowbari-Daryan
Keyword(s):  
Scleractinian Corals ◽  
Upper Triassic ◽  
Central Iran ◽  
Hexactinellid Sponge ◽  
Nayband Formation ◽  
Hexactinellid Sponges

Sponges, along with scleractinian corals, are among the main reef-building organisms in Triassic reefs. Hypercalcified groups, including the chambered sphinctozoans, and the unchambered inozoans, chaetetids, and spongiomorphids, represent the most abundant Triassic reef-building sponges. Earlier workers have described elements of the latter group as “hydrozoans.” Hexactinellid sponges, abundant in some Permian reefs (e.g., in Texas, Finks, 1960), are rarely known from similar Triassic deposits, in general (Tichy, 1975), and particularly from Upper Triassic stratigraphic units. Hexactinellid sponges have been sporadically reported from well-investigated Upper Triassic reefs in the western Tethyan region (e.g., Keupp et al., 1989). However, a variety of hexactinellid sponges have been reported from Upper Triassic deposits and reefal limestones of the northern and central Tethyan realm (Boiko, 1990; Wu, 1989; Wu and Xiao, 1989; Rigby et al., 1998).

Depositional history and sequence stratigraphy of central Tethyan from the Upper Triassic Nayband Formation, Central Iran

2020 ◽  
Vol 35 (1) ◽  
Author(s):  
Asghar Etesampour ◽  
Asadollah Mahboubi ◽  
Reza Moussavi-Harami ◽  
Nasser Arzani ◽  
Hoseinali Bagi
Keyword(s):  
Sequence Stratigraphy ◽  
Upper Triassic ◽  
Central Iran ◽  
Depositional History ◽  
Nayband Formation

The palynology of the Nayband Formation (Upper Triassic) of the Tabas Block, Central Iran

2020 ◽  
Vol 282 ◽  
pp. 104308
Author(s):  
Hossein Sabbaghiyan ◽  
Mohammadreza Aria-Nasab ◽  
Ebrahim Ghasemi-Nejad
Keyword(s):  
Upper Triassic ◽  
Central Iran ◽  
Nayband Formation

scholarly journals MESOZOIC RADIOLARIANS FROM RHYTHMICALLY LAYERED SEDIMENTS OF THE RIMSKY-KORSAKOV ISLANDS (PETER THE GREAT BAY, JAPAN SEA) AND THEIR SIGNIFICANCE FOR DETERMINING THE TRIASSIC-JURASSIC BOUNDARY

2021 ◽  
pp. 39-54
Author(s):  
O.L. Smirnova ◽  
◽  
E.A. Bessonova ◽  
T.A. Emelyanova ◽  
◽  
...  
Keyword(s):  
Peter The Great Bay ◽  
Japan Sea ◽  
Research Area ◽  
Lower Jurassic ◽  
Upper Triassic ◽  
Peter The Great ◽  
Great Bay ◽  
The Pacific ◽  
Stratigraphic Division ◽  
First Time

The results of the biostratigraphic study based on the radiolarian analysis of the rhythmically layered terrigenous deposits from the Islands of the Rimsky-Korsakov Archipelago (Peter the Great Bay, Japan Sea) have been presented. These deposits are most similar to the medium-grained turbidites. For the first time the distribution and stratigraphic division of the boundary sediments of the upper Triassic and lower Jurassic separated by a marking layer were substantiated in the research area. On the basis of comparisons with isochronous zonal units of the Pacific and Tethyan areas in the upper Triassic sediments of the studied sections, layers with Globolaxtorum tozeri (upper Rhaetian) were established, and in the lower Jurassic zone Pantanellium tanuense Zone (Hettangian) was traced and layers with Parahsuum simplum (Sinemurian – Pliensbachian) were established.

An ichthyosaur forefin from the Triassic of British Columbia exemplifying Jurassic features

1991 ◽  
Vol 28 (10) ◽  
pp. 1553-1560 ◽  
Author(s):  
C. McGowan
Keyword(s):  
British Columbia ◽  
North America ◽  
Lower Jurassic ◽  
Upper Triassic ◽  
New Material ◽  
Important Site

New ichthyosaur material is reported from an Upper Triassic locality on Williston Lake, northeastern British Columbia. The paucity of ichthyosaurs from the Triassic of North America make this a potentially important site. An isolated forefin is described, which is unlike that of any Triassic species from North America but which compares closely with certain Lower Jurassic species from England and Germany. The new material suggests that the transition in the ichthyosaurian fauna at the close of the Triassic may have been less abrupt than was previously supposed.

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