Gulf of California section 2 "unconformity (upper)" fauna: Late/Upper Pleistocene, Mexico

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Thecostraca
Cirripedia indet. Rafinesque 1816
Listed as "barnacle plates"
Bivalvia
Bivalvia indet. Linnaeus 1758
Listed as "unidentifiable bivalves"
Bivalvia - Ostreida - Ostreidae
Ostrea sp. Linnaeus 1758
Bivalvia - Pectinida - Pectinidae
Pectinidae indet. Wilkes 1810
Listed as "scallop fragments"
Bivalvia - Cardiida - Cardiidae
Trachycardium sp. Mörch 1853
Bivalvia - Cardiida - Veneridae
Chione gnidia (Broderip and Sowerby I 1829)
recombined as Chionopsis gnidia
Chione californiensis (Broderip and Sowerby I 1835)
Gastropoda - Neogastropoda - Columbellidae
Columbella sp. Lamarck 1799
Gastropoda - Tegulidae
Tegula rugosa
see common names

Geography
Country:Mexico State/province:Sonora
Coordinates: 31.8° North, 114.1° West (view map)
Paleocoordinates:31.8° North, 114.1° West
Basis of coordinate:estimated from map
Geographic resolution:outcrop
Time
Period:Quaternary Epoch:Pleistocene
10 m.y. bin:Cenozoic 6
Key time interval:Late/Upper Pleistocene
Age range of interval:0.12600 - 0.01170 m.y. ago
Stratigraphy
Stratigraphic resolution:bed
Stratigraphy comments: Pleistocene fluvial, eolian, and deltaic deposits exposed in sea cliffs, overlain by coquina bed (dated at 125,00 bp)
Lithology and environment
Primary lithology:"cross stratification",planar lamination,deformed bedding,burrows,bioturbation,fine,medium unlithified sandstone
Secondary lithology: siltstone
Includes fossils?Y
Includes fossils?Y
Lithology description: massive fine- to medium-grained sands; bedding almost obscured by bioturbation; bedding mostly planar or low-angle corss-stratified, rare wavy beds and reactivation cross-beds; Ophiomorpha and Thalassinoides burrows common; burrows backfilled with shelly debris; Skolithos rare to common
Environment:transition zone/lower shoreface Tectonic setting:rift
Geology comments: active trans-tensional rift basin
Taphonomy
Modes of preservation:body
Degree of concentration:concentrated
Size of fossils:macrofossils
Spatial orientation:random
Articulated whole bodies:none
Disassociated major elements:all
Fragmentation:extreme
Bioerosion:occasional
Encrustation:occasional
Spatial resolution:parautochthonous
Collection methods and comments
Collection methods:bulk,field collection
Reason for describing collection:taphonomic analysis
Collection method comments: No comments on collection metholodolgy
Taxonomic list comments:No abundance data given on collection due to poor preservation
Metadata
Also known as:Section 2 - unconformity (upper) shell bed type
Database number:34936
Authorizer:A. Hendy Enterer:A. Hendy
Modifier:A. Hendy Research group:marine invertebrate
Created:2003-10-20 14:01:10 Last modified:2013-11-25 13:37:23
Access level:group members Released:2004-10-20 14:01:10
Creative Commons license:CC BY
Reference information

Primary reference:

9379.1% 4820K.H. Meldahl and A. H. Cutler. 1992. Neotectonics and taphonomy; Pleistocene molluscan shell accumulations in the northern Gulf of California. Palaios 7(2):187-197 [A. Miller/A. Hendy/A. Hendy]