Tazareh Section, Alburz Mts, Deltaic facies 1: Early/Lower Bajocian, Iran

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Gastropoda - Pseudomelaniidae
Pseudomelania sp. Pictet and Campiche 1862
Bivalvia - Ostreida - Bakevelliidae
Bakevellia sp. King 1848
Bivalvia - Pholadida - Ceratomyidae
Ceratomya sp. Sandberger 1864
Bivalvia - Pholadomyida - Pholadomyidae
Pholadomya (Bucardiomya) sp. (Rollier 1912)
unclassified
Rhizocorallium irregulare
see common names

Geography
Country:Iran
Coordinates: 36.4° North, 54.5° East (view map)
Paleocoordinates:14.0° South, 47.6° East
Basis of coordinate:stated in text
Geographic resolution:outcrop
Time
Period:Jurassic Epoch:Middle Jurassic
Stage:Bajocian 10 m.y. bin:Jurassic 4
Key time interval:Early/Lower Bajocian
Age range of interval:170.90000 - 168.60000 m.y. ago
Stratigraphy
Formation:Shemshak
Stratigraphic resolution:group of beds
Lithology and environment
Primary lithology:"cross stratification",medium,coarse lithified sandstone
Secondary lithology:fine lithified carbonaceous siltstone
Lithology description: One facies association is composed of finely interlayered silty clay and fine-grained ripple-laminated sandstone, coal, highly carbonaceous silt, in some cases associated with ferruginous concretions, root horizons, channeled, immature (arkosic), large-scale cross-bedded, medium- to coarse-grained, fining-upward sandstone sequences. In addition, 1–3-m thick coarsening upward sequences of silty clay to fine sand occur... Plant debris is ubiquitous, whereas larger wood fragments are restricted to the sandstone bodies.
Environment:deltaic indet.
Geology comments: ...represent various subenvironments of the delta plain with small distributaries, swamps, freshwater lakes, and marine embayments with a moderately diverse molluscan fauna. The latter may be evidence of a delta abandonment phase, which was either due to switching of delta lobes or eustatic sea-level rise. Tidal influence and sedimentation on mud flats is indicated by thinly interlayered clay-silt beds and lenticular bedding (e.g. at 3,565 m), but appears to have been of minor importance.
Taphonomy
Modes of preservation:body
Size of fossils:macrofossils
Collection methods and comments
Collection methods:field collection
Reason for describing collection:biostratigraphic analysis
Metadata
Database number:141259
Authorizer:M. Aberhan Enterer:T. Schossleitner
Research group:marine invertebrate
Created:2013-03-23 03:36:32 Last modified:2013-03-22 11:36:32
Access level:the public Released:2013-03-23 03:36:32
Creative Commons license:CC BY
Reference information

Primary reference:
45909. 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]