Tazareh Section, Alburz Mts, Outer shelf facies 2 (Jurassic to of Iran)

Where: Iran (36.4° N, 54.5° E: paleocoordinates 13.8° S, 47.7° E)

• coordinate stated in text

• outcrop-level geographic resolution

When: Shemshak Formation, Early/Lower Aalenian to Early/Lower Aalenian (175.6 - 171.6 Ma)

• group of beds-level stratigraphic resolution

Environment/lithology: transition zone or lower shoreface; lithified, bioturbated, gray, argillaceous siltstone

• The monotonous facies clearly corresponds to the deepest part of the shelf, well below the influence of storms. Sedimentation rates were low enough for the sediment to become totally bioturbated.
• Facies of the outer shelf are fairly monotonous, dark grey in colour, highly bioturbated, and range from silt to argillaceous silt with plant debris. Scattered small concretions with a calcareous or ferruginous cement occur in parts of the section.

Size class: macrofossils

Primary reference: F. T. Fürsich, M. Wilemsen, K. Seyed-Emami, F. Cecca, and M. R. Majidifard. 2005. The upper Shemshak Formation (Toarcian–Aalenian) of the Eastern Alborz (Iran): Biota and palaeoenvironments during a transgressive–regressive cycle. Fazies 51:365-384 [M. Aberhan/T. Schossleitner/T. Schossleitner]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 141261: authorized by Martin Aberhan, entered by Thomas Schossleitner on 23.03.2013

Creative Commons license: CC BY (attribution)

Taxonomic list

Malacostraca
 Decapoda - Glypheidae
Glyphea sp. Von Meyer 1835 decapod
Rhynchonellata
 Terebratulida -
Polychaeta
 Sabellida - Serpulidae
Serpulidae indet. Rafinesque 1835
Bivalvia
 Arcida - Arcidae
"Arca (Eonavicula) sp." = Eonavicula
"Arca (Eonavicula) sp." = Eonavicula Arkell 1929 clam
 Myalinida - Kolymiidae
"Parainoceramus sp." = Kolymia
"Parainoceramus sp." = Kolymia clam
 Myalinida - Inoceramidae
Pseudomytiloides sp. Koschelkina 1963 clam
 Pectinida - Pectinoidae
Chlamys sp. Röding 1798 scallop
 Pectinida -
"Entolium corneolum" = Entolium (Entolium) corneolum
"Entolium corneolum" = Entolium (Entolium) corneolum Young and Bird 1828 scallop
 Ostreida - Posidoniidae
"Bositra buchii" = Bositra buchi
"Bositra buchii" = Bositra buchi Roemer 1836 oyster
 Pholadida - Pleuromyidae
Pleuromya sp. Agassiz 1845 clam
 Cardiida - Cardiidae
 Pholadomyida - Pholadomyidae
 Trigoniida - Myophorelloidae
Crinoidea
  -
Crinoidea indet. Miller 1821 Sea lily