Where: Ecuador (1.0° N, 79.8° W: paleocoordinates 0.8° N, 79.0° W)
• coordinate based on nearby landmark
• outcrop-level geographic resolution
When: Esmeraldas Formation, Zanclean (5.3 - 3.6 Ma)
• 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.
• bed-level stratigraphic resolution
Environment/lithology: deep-water; unlithified, tuffaceous, green mudstone
Size classes: mesofossils, microfossils
Collection methods: bulk, chemical, hydrochloric, sieve,
• 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.
Primary reference: P. F. Hasson and A. G. Fischer. 1986. Observations on the Neogene of Northwestern Ecuador. Micropaleontology 32(1):32-42 [A. Hendy/A. Hendy]more details
Purpose of describing collection: biostratigraphic analysis
PaleoDB collection 90839: authorized by Austin Hendy, entered by Austin Hendy on 18.08.2009
Creative Commons license: CC BY (attribution)
Taxonomic list
Protozoa | |
Sphaeropyle langii Dreyer 1889 radiolarian | |
Theocorythium vetulum radiolarian | |
Pterocanium trilobum radiolarian | |
Spongaster pentas radiolarian
Spongaster tetras Ehrenberg 1860 radiolarian | |
Globothalamea | |
Foraminifera | |
Buliminella subfusiformis Cushman 1925
Buliminella curta Cushman 1925
Bulimina marginata d'Orbigny 1826 | |
Nodosariata | |
Foraminifera | |
Orbulina universa, Globigerinoides immaturus, Globigerinoides ruber, Globigerinoides elongatus, Globigerinoides obliquus, Globigerina bulloides, "Globigerinoides sacculifer" = Trilobatus sacculifer
Orbulina universa d'Orbigny 1839
Globigerinoides ruber d'Orbigny 1839
Globigerinoides elongatus d'Orbigny 1826
Globigerinoides obliquus Bolli 1957
Globigerina bulloides d'Orbigny 1826
"Globigerinoides sacculifer" = Trilobatus sacculifer Brady 1877 | |
"Globorotalia humerosa" = Neogloboquadrina humerosa, Pulleniatina praecursor, Pulleniatina primalis, Globorotalia multicamerata, Globorotalia tumida, Globorotalia limbata, Globorotalia ungulata
"Globorotalia humerosa" = Neogloboquadrina humerosa Takayanagi and Saito 1962
Pulleniatina praecursor Banner and Blow 1967
Pulleniatina primalis Banner and Blow 1967
Globorotalia tumida Brady 1877
Globorotalia limbata Fornasini 1902
Globorotalia ungulata Bermudez 1961 | |
Glandulina laevigata d'Orbigny 1826 | |