Ferraz Shell Bed, Unit 2: Wordian - Wuchiapingian, Brazil

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Bivalvia - Pholadomyida - Pachydomidae
9 specimens
Bivalvia - Pholadomyida - Megadesmidae
3 specimens
Simões et al. 2010 1 specimen
1 specimen
1 specimen
2 specimens
5 specimens
Bivalvia - Carditida - Astartidae
Pinzonella illusa Cowper Reed 1932
144 specimens
50 specimens
Bivalvia - Mytilida - Mytilidae
6 specimens
see common names

Geography
Country:Brazil State/province:São Paulo
Coordinates: 22.3° South, 47.6° West (view map)
Paleocoordinates:32.1° South, 13.1° West (Wright 2013)
Basis of coordinate:estimated from map
Geographic resolution:small collection
Time
Period: Permian Epoch: Guadalupian - Lopingian
Stage: Wordian - Wuchiapingian 10 m.y. bin: Permian 4
*Period:Late/Upper Permian *Epoch:Zechstein
*International age/stage:Kazanian - Changxingian
Key time interval: Wordian - Wuchiapingian
Age range of interval: 266.9 - 254.14 m.y. ago
* legacy (obsolete) database fields
Stratigraphy
Geological group:Passa Dois Formation:Corumbataí
Stratigraphic resolution:bed
Stratigraphy comments: Originally given "Kazanian - Tatarian?" age. Corumbataí Formation is equivalent to the Serra Alta and Teresina Fm, and contains bivalves assigned to pre-Rio do Rasto zones in the Paraná Basin bivalve biochronology. The Teresina Fm yielded a radiometric date of 267 +/- 17 Ma, with the overlying Serrinha Mb (Rio do Rasto Fm) yielding an age or 266.3 +/- 4.6 Ma (Rocha-Campos et al., 2019). Bivalves correlated to the lower Serrinha Member were associated with U/Pb ages of 265 +/- 2.5 Ma in Namibia (David et al., 2011). This suggests a Wordian or earlier age for the Corumbataí Fm. However, the lower part of the Corumbataí Fm itself yielded an ID-TIMS age of 257.5 +/- 2.2 Ma (Rocha-Campos et al., 2019), which would suggest the Corumbataí is actually Wuchiapingian.
Lithology and environment
Primary lithology:lenticular,wave ripples,shelly/skeletal,brown,green lithified sandy,calcareous siltstone
Secondary lithology:lenticular,grading,intraclastic,shelly/skeletal silty grainstone
Includes fossils?Y
Lithology description: In the area, the deposits consist of about 130 m of brown-red, violet, green or varicolored siltstone and shale, with subsidiary fine sandstone, bioclastic sandstone, limestone, and thin, commonly silicified, coquinas. The outcrop includes intensely silicified sandstone beds that represent scarce intercalations within a monotonous sequence dominated by violet siltstones with wave and lenticular bedding. 'Unit 2' occurs as lenticular bioclastic bodies that are 10-15 cm thick and extend laterally from meters-10's meters. Basal contact with underlying siltstones sharp and erosive, upper contact more gradual or, less frequently, marked by shelly layers dominated by convex-up bioclasts. Silicified siltstone intraclasts occur. Bioclasts loosely to densely packed. Sediments often graded normally. Shells mostly disarticulated. Fragmented shells rare. Shells mostly convex up.
Environment:lacustrine - large Tectonic setting:cratonic basin
Taphonomy
Modes of preservation:body,replaced with silica
Size of fossils:macrofossils
Collection methods and comments
Collection methods:bulk,chemical,mechanical,field collection
Reason for describing collection:paleoecologic analysis
Metadata
Database number:10177
Authorizer:J. Alroy, M. Clapham Enterer:M. Sommers, M. Clapham
Modifier:M. Clapham Research group:freshwater
Created:2001-02-27 12:02:00 Last modified:2025-02-22 15:12:02
Access level:the public Released:2001-02-27 12:02:00
Creative Commons license:CC0
Reference information

Primary reference:
918. M. G. Simoes and M. Kowalewski. 1998. Shell beds as paleoecological puzzles: a case study from the Upper Permian of the Parana Basin, Brazil. Facies 38:175-196 [J. Alroy/M. Sommers]

Secondary references:

72171 M. G. Simões, L. E. Anelli, and J. M. David. 2010. Othonella araguaiana (Bivalvia, Megadesmidae) from the Corumbataí Formation (Midlle Permian), eastern margin of the Paraná Basin: systematic, evolutionary and biostratigraphic significances. Revista do Instituto Geociências - USP 10:45-55 [M. Clapham/M. Clapham]