Sample# 3, 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
unclassified
Trachypolia nodulosa
1 specimen
Gastropoda - Heterostropha - Pyramidellidae
Odostomella doliolum (Philippi 1844)
1 specimen
Gastropoda - Littorinidae
Melarhaphe neritoides (Linnaeus 1758)
28 specimens
recombined as Littorina neritoides
Gastropoda - Rissoidae
Alvania mediolittoralis
186 specimens
Alvania poucheti
6 specimens
Alvania sleursi
54 specimens
Cingula trifasciata
32 specimens
Manzonia unifasciata Dautzenburg 1889
2 specimens
Rissoa guernei
96 specimens
Gastropoda - Neogastropoda - Muricidae
Ocinebrina aciculata
1 specimen
Gastropoda - Neogastropoda - Mitromorphidae
Mitromorpha azorensis
1 specimen
Gastropoda - Neogastropoda - Columbellidae
Anachis avaroides
14 specimens
Gastropoda - Triviidae
Trivia sp. Broderip 1837
1 specimen
Gastropoda - Naticidae
Natica cf. prietoi
1 specimen
Gastropoda - Cerithiopsidae
Cerithiopsis sp. Hanley 1849
2 specimens
Gastropoda - Triphoridae
Triphoridae indet. Gray 1847
18 specimens
Gastropoda - Planaxidae
Fossarus ambiguus (Linnaeus 1758)
5 specimens
Gastropoda - Cerithiidae
Bittium latreillii
232 specimens
Gastropoda - Trochidae
Jujubinus pseudogravinae
6 specimens
Gastropoda - Phasianellidae
Tricolia pullus (Linnaeus 1758)
1 specimen
Gastropoda - Lepetellida - Haliotidae
Haliotis tuberculata 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
10 m.y. bin:Cenozoic 6
Key time interval:Late/Upper Pleistocene
Age range of interval:0.12600 - 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,mesofossils
Spatial orientation:random
Abundance in sediment:abundant
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: DBUA-F - the fossil collections is housed at the Department of Biology of 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: Modern nomenclature and species-resolution identifications.
Metadata
Database number:122285
Authorizer:A. Hendy Enterer:A. Hendy
Modifier:S. Ávila Research group:marine invertebrate
Created:2011-12-20 23:47:40 Last modified:2023-09-12 09:49:30
Access level:authorizer only Released:2013-12-20 23:47:40
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]