Sample# 7, Lagoinhas, Santa Maria (subunit B1): Late/Upper Pleistocene, Portugal
collected by Ávila et al 2003

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Gastropoda - Planaxidae
Fossarus ambiguus (Linnaeus 1758)
6 specimens
Gastropoda - Cerithiidae
Bittium latreillii
752 specimens
Gastropoda - Triphoridae
Triphoridae indet. Gray 1847
30 specimens
Gastropoda - Cerithiopsidae
Cerithiopsis sp. Hanley 1849
8 specimens
Gastropoda - Littorinidae
Melarhaphe neritoides (Linnaeus 1758)
61 specimens
recombined as Littorina neritoides
Gastropoda - Rissoidae
Alvania mediolittoralis
404 specimens
Alvania poucheti
10 specimens
Alvania sleursi
70 specimens
Alvania cancellata (da Costa 1778)
1 specimen
Pusillina inconspicua
19 specimens
Rissoa guernei
158 specimens
Cingula trifasciata
37 specimens
Manzonia unifasciata Dautzenburg 1889
25 specimens
Gastropoda - Neogastropoda - Mitridae
Mitra cornea
1 specimen
Gastropoda - Neogastropoda - Columbellidae
Anachis avaroides
30 specimens
Gastropoda - Neogastropoda - Muricidae
Stramonita haemastoma (Linnaeus 1767)
1 specimen
recombined as Stramonita haemostoma
Ocinebrina aciculata
3 specimens
Gastropoda - Neogastropoda - Mitromorphidae
Mitromorpha azorensis
8 specimens
Gastropoda - Trochidae
Calliostoma sp. Swainson 1840
1 specimen
Jujubinus pseudogravinae
5 specimens
Gastropoda - Patellidae
Patella sp. Linnaeus 1758
1 specimen
see common names

Geography
Country:Portugal
Coordinates: 37.0° North, 25.1° West (view map)
Paleocoordinates:37.0° North, 25.1° West
Basis of coordinate:based on nearby landmark
Geographic resolution:outcrop
Time
Period:Quaternary Epoch:Pleistocene
Stage:Late/Upper Pleistocene 10 m.y. bin:Cenozoic 6
Key time interval:Late/Upper Pleistocene
Age range of interval:0.12900 - 0.01170 m.y. ago
Stratigraphy
Local section:Lagoinhas Local bed:B1
Local order:bottom to top
Stratigraphic resolution:bed
Stratigraphy comments: STRATIGRAPHIC RELATIONS: From unnamed Late Quaternary marine deposits. AGE: early Late Pleistocene. Dated on the basis of U series. recently, Ávila et al. (2008a) dated the basal conglomerate of the Prainha outcrop (subunit A1 of Ávila et al., 2002) as Marine Isotopic Substage 5.5 (MIS 5.5), based on U/Th ages on shells of Patella spp. As explained by Ávila et al. (2008a), due to taphonomic problems and the wet climatic conditions prevailing on the island, the U-series measurements from their fossilized remains can only help constrain the age of the uranium taken up diagenetically. U-series data from Santa Maria Island indicate. an open system, providing mean 230Th ages that are much younger than the true age of the unit. They suggest relatively steady, more or less continuous, diagenetic U-uptake by the fossils since their deposition in the Pleistocene. Thus, accepting an age of 130–120 ka for the deposits, Ávila et al. (2008a) estimated that within the embedded biogenic carbonates U-uptake rates varied from c. 2.5 to 5 μg g CaCO−31 kyr−1. This was based on 230Th-ages in the 60–70 ka range, for shells that would have started accumulating diagenetic U some 130–120 ka ago (i.e. during the MIS 5.5) (Ávila et al., 2008a). STRATIGRAPHIC POSITION: Succession comprises cemented and bored carbonate sands, overlaind by 0.5 m beach sands with concentrations of shell debris.
Lithology and environment
Primary lithology:shelly/skeletal,yellow unlithified sandstone
Includes fossils?Y
Lithology description: SPECIFIC LITHOLOGY: Yellow uncemented lithic sands (dominated by the 250–500 μm [Lagoinhas] fraction), apart from the volcanogenic grains consisting almost exclusively of small mollusc fragments (carbonate contents ranging from 56.2 to 67.3% in the samples investigated). LITHIFICATION: Unlithified, as described in text.
Environment:foreshore
Geology comments: ENVIRONMENT: Sediments correspond to beach foreshore (intertidal) facies and show marked similarities to the recent beach sands both in grain size and composition.
Taphonomy
Modes of preservation:body,original aragonite
Degree of concentration:concentrated
Size of fossils:macrofossils
Fragmentation:frequent
Feeding/predation traces:drill holes
Temporal resolution:time-averaged
Spatial resolution:allochthonous
Collection methods and comments
Collection excludes:some macrofossils
Collection methods:bulk,sieve,field collection
Minimum sieve size:0.250
Reason for describing collection:paleoecologic analysis
Collectors:Ávila et al Collection dates:2003
Collection method comments: COLLECTOR: S. Ávila and others, Febuary 17, 2003. REPOSITORY: Not stated in text, but presumably the Universidade dos Açores. METHODS: Ten bulk samples of approximately 1 kg each were collected from the sand facies of the Lagoinhas deposit in a standardised sample spacing (about 50 cm laterally between contiguous samples). Sampling was restricted to fresh material, obtained from in-situ deposits after removal of weathered residues. Samples were disaggregated by short ultrasonic treatment and gentle wet-sieving. A mesh width of 0.250 mm was chosen, allowing the retrieval of almost all determinable remains of the macrobenthos (including fragments). Molluscs were the most abundant group recovered, accompanied by rare brachiopods and echinoderm debris.
Taxonomic list comments:COVERAGE: Exhaustive faunal list for gastropods. Bivalves omitted from sample faunal lists. NOMENCLATURE: Not an authoritative publication, but with modern nomenclature and species-resolution identifications.
Metadata
Database number:122289
Authorizer:A. Hendy Enterer:A. Hendy
Modifier:A. Hendy Research group:marine invertebrate
Created:2011-12-20 23:48:49 Last modified:2013-11-25 13:37:23
Access level:authorizer only Released:2013-12-20 23:48:49
Creative Commons license:CC BY
Reference information

Primary reference:
30051.fossil record S. P. Ávila, P. Madeira, C. Zazo, A. Kroh, M. Kirby, C. Marques Silva, M. Cachao and A. M. Frias Martins. 2009. Palaeoecology of the Pleistocene (MIS 5) outcrops of Santa Maria Island (Azores) in a complex oceanic tectonic setting. Palaeogeography, Palaeoclimatology, Palaeoecology 274:18-31 [W. Kiessling/U. Merkel/S. Ávila]