Loc. 9-30 [Esmeraldas Fm]: Zanclean, Ecuador

List of taxa
Where & when
Geology
Taphonomy & methods
Metadata & references
Taxonomic list
Globorotaliidae
Globorotalia humerosa Takayanagi and Saito 1962
recombined as Neogloboquadrina humerosa
Globorotalia ungulata Bermudez 1961
Globorotalia limbata (Fornasini 1902)
Globorotalia tumida (Brady 1877)
Globigerinidae
Globoquadrina continuosa
Nodosariata - Polymorphinida - Plectofrondiculariidae
Plectofrondicularia advena
Plectofrondicularia californica
Nodosariata - Nodosariida - Stilostomellidae
Stilostomella lepidula
Nodosariata - Nodosariida - Nodosariidae
Nodosaria anomala Reuss 1866
Buliminidae
Virgulina cornuta
Globobulimina glabra
Bulimina pagoda
Praeglobobulimina spinescens
Glandulinidae
Glandulina laevigata (d'Orbigny 1826)
Cassidulinidae
Globocassidulina subglobosa
Uvigerinidae
Uvigerina proboscidea
Uvigerina peregrina
Uvigerina hispidocostata
Uvigerina hispida
Bolivinidae
Bolivina argentea
Bolivina fimbriata
Bolivina mantaensis
Chilostomellidae
Pullenia bulloides
Globothalamea - Rotaliida - Discorbidae
Eponides umbonata
Globothalamea - Rotaliida - Nonionidae
Melonis affinis
Globothalamea - Rotaliida - Gavelinellidae
Gyroidina zelandica
Gyroidina soldanii
Globothalamea - Rotaliida - Cibicididae
Cibicides floridanus
Protozoa - Spumellaria - Coccodiscidae
Didymocyrtis tetrathalamus
Protozoa - Spumellaria - Spongodiscidae
Spongaster tetras Ehrenberg 1860
Protozoa - Entactinaria - Saturnalidae
Axoprunum angelinum
Protozoa - Nassellaria - Ultranaporidae
Pterocanium trilobum
Protozoa - Nassellaria - Pterocorythidae
Lamprocyclas nupitalis
Theocorythium vetulum
Lamprocyrtis heteroporos
Protozoa - Nassellaria - Eucyrtidiidae
Theocorythium trachelium (Ehrenberg 1861)
original and current combination Eucyrtidium trachelius
Protozoa - Nassellaria
Lychnodictyum audax
see common names

Geography
Country:Ecuador
Coordinates: 1.0° North, 79.8° West (view map)
Paleocoordinates:0.8° North, 79.0° West
Basis of coordinate:based on nearby landmark
Geographic resolution:outcrop
Time
Period:Neogene Epoch:Pliocene
Stage:Zanclean 10 m.y. bin:Cenozoic 6
Key time interval:Zanclean
Age range of interval:5.33300 - 3.60000 m.y. ago
Stratigraphy
Formation:Esmeraldas
Stratigraphic resolution:bed
Stratigraphy comments: STRATIGRAPHIC RELATIONS: From the Esmeraldas Fm, which regionally overlies the Borbon Fm (Middle-Late Miocene). AGE: Zanclean, on the basis of microfossil biostratigraphy. STRATIGRAPHIC POSITION: From unknown position within formation.
Lithology and environment
Primary lithology:tuffaceous,green unlithified mudstone
Includes fossils?Y
Lithology description: SPECIFIC LITHOLOGY: Greenish tuffaceous mudstone, containing interbeds of white volcanic ash, graded sand, and in some places graded shell debris. LITHIFICATION: Unlithified, as stated in text.
Environment:deep-water indet.
Geology comments: ENVIRONMENT: Microplanktonic fauna is fairly diverse, which sug- gests water depths in excess of 200 m. The benthonic fora- minifera suggest depths in the 240 to 900-m range. The mol- luscan fauna contains many discrepancies, in the combined presence of shoal-water and deep-water forms. Olsson (1964), strongly influenced by the presence of the "unusual" deep- water species, estimated the depth at 200 fathoms or 365 m. Rosenberg (1981) plotted a histogram of depth distributions, which peaked at 64 m.
Taphonomy
Modes of preservation:body
Size of fossils:mesofossils,microfossils
Collection methods and comments
Collection methods:bulk,chemical,hydrochloric,sieve,field collection
Reason for describing collection:biostratigraphic analysis
Collection method comments: COLLECTOR: Presumably the authors. REPOSITORY: Not stated, but presumably Princeton University, New Jersey. PREPARATION: Eighty-five gram samples were crushed and boiled with Calgon, then washed through 420-,m, 177-Am, 74-,m and 63- ,m screens. A cut of the fines was saved for nannofossils. The two largest fractions and half of the 74-gm fraction were dried, floated on CC14 and picked for foraminifera. The re- maining half of the 74-um fraction and the 63-,um fraction were decalcified with HC1 and washed again, then dried and floated on CClI, before mounting on slides for study of ra- diolarians. The flotation in this case was found to enrich radiolaria by a factor of about 30, and to raise the proportion of unbroken specimens. Nannofossils were concentrated from the fines that passed the 63-um mesh, in two steps: settling for 1.5 minutes in a 1-liter beaker separated a coarser fraction, to be discarded. The poured-off liquid was then settled in a similar beaker for 30 minutes, which settled out such nannofossils as could be handled by optical microscopy, while the ultra-fine ma- terial was discarded. Radiolaria and nannofossils were pre- pared for study as strewn slides mounted in balsam. Nan- nofossils were identified by optical phase contrast and polarized microscopy, at 1200 x.
Taxonomic list comments:COVERAGE: Exhaustive for foraminifera, nannofossils, and radiolarians. NOMENCLATURE: Not an authoritative publication, but with modern nomenclature and species-resolution identifications.
Metadata
Database number:90838
Authorizer:A. Hendy Enterer:A. Hendy
Modifier:A. Hendy Research group:marine invertebrate,micropaleontology
Created:2009-08-18 20:21:51 Last modified:2013-11-25 13:37:23
Access level:the public Released:2009-08-18 20:21:51
Creative Commons license:CC BY
Reference information

Primary reference:
30557. P. F. Hasson and A. G. Fischer. 1986. Observations on the Neogene of Northwestern Ecuador. Micropaleontology 32(1):32-42 [A. Hendy/A. Hendy]