El Chacay Fm - Laguna La Oriental, Provincia de Santa Cruz: Burdigalian, Argentina

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Gastropoda - Neogastropoda - Volutidae
Proscaphella cossmanni Ihering 1907
Gastropoda - Struthiolariidae
Struthiolarella ornata
Bivalvia - Arcida - Cucullaeidae
Cucullaea marshalli Zinsmeister 1981
Bivalvia - Arcida - Arcidae
Barbatia sp. Gray 1842
Bivalvia - Pholadida - Myidae
Mya (Arenomya) nucleoides (Wilckens 1911)
Bivalvia - Cardiida - Cardiidae
Loxocardium puelchum (Sowerby 1846)
recombined as Trachycardium puelchum
Bivalvia - Carditida - Carditidae
Venericardia sp. Lamarck 1801
Rhynchonellata - Rhynchonellida - Notosariidae
Plicirhynchia plicigera (Ihering 1897)
see common names

Geography
Country:Argentina
Coordinates: 47.6° South, 71.8° West (view map)
Paleocoordinates:48.4° South, 66.1° West
Basis of coordinate:estimated from map
Geographic resolution:outcrop
Time
Period:Neogene Epoch:Miocene
Stage:Burdigalian 10 m.y. bin:Cenozoic 5
Key time interval:Burdigalian
Age range of interval:20.44000 - 15.98000 m.y. ago
Stratigraphy
Formation:El Chacay
Stratigraphic resolution:group of beds
Stratigraphy comments: STRATIGRAPHIC RELATIONS: From El Chacay Fm, which regionally overlies Basalto Posadas and is overlain by the Santa Cruz Fm (Eocene-Oligocene). THICKNESS: AGE: Eocene. No further detail provided. Justified on the basis of stratigraphic position and biostratigraphic correlation. This unit has more recently been dated as early Miocene (Burdigalian) by Sr isotopes (Cuitiño et al., 2015) and correlative units also as Burdigalian by U-Pb chronology (Cuitiño et al., 2012). STRATIGRAPHIC POSITION: Unknown stratigraphic position within section. Figure 3 (Chiesa et al. 1995) suggests that the collection is derived from multiple distinct beds within the formation at each section.
Lithology and environment
Primary lithology: lithified sandstone
Secondary lithology:shelly/skeletal lithified sandy "mixed carbonate-siliciclastic"
Includes fossils?Y
Includes fossils?Y
Lithology description: SPECIFIC LITHOLOGY: No specific lithology stated though Figure 3 (Chiesa et al. 1995) suggests that macrofauna are typically derived from sandstones and sandy coquinas at each section. LITHIFICATION: Lithified, based on figured specimens.
Environment:marine indet.
Geology comments: ENVIRONMENT: Shallow marine arenaceous platform, normal salinity, under a subtropical climate, with water temperatures between 19-22 degrees C.
Taphonomy
Modes of preservation:body
Size of fossils:macrofossils
Preservation of anatomical detail:poor
Articulated whole bodies:some
Collection methods and comments
Collection methods:selective quarrying,field collection
Reason for describing collection:biostratigraphic analysis
Collection method comments: COLLECTORS: Presumably collected by authors during broader lithostratigraphic study and geologic mapping (see Chiesa and Camacho, 1995). REPOSITORY: CIRGEO (Centro de Investigaciones en Recursos Geologicos), Argentina.
Taxonomic list comments:COVERAGE: Exhaustive for all macrofaunal groups (Brachiopoda, Bivalvia, Gastropoda). NOMENCLATURE: Authoritative paper using subgeneric and species-level designations.
Metadata
Database number:65184
Authorizer:A. Hendy Enterer:A. Hendy
Modifier:M. Clapham Research group:marine invertebrate
Created:2006-09-19 15:22:20 Last modified:2017-07-30 18:58:57
Access level:group members Released:2007-03-19 15:22:20
Creative Commons license:CC BY
Reference information

Primary reference:
18786. J.O. Chiesa, S.G. Parma, and H.H. Camacho. 1995. Observaciones estratigraficas en el Paleogeno del noroeste de la Provincia de Santa Cruz (Republica Argentina). Parte II: Invertebrados marinos de la Formacion El Chacy (Eoceno), Provincia de Santa Cruz, Argentina. Systematica y bioestratigrafia. Monografias de la Acadamia Nacional de Ciencias Exactas, Fisicas Y Naturales 11:17-68 [A. Hendy/A. Hendy]