Sample 13-5A-b, Yap (Miocene of Micronesia, Federated States of)

Where: Micronesia, Federated States of (9.5° N, 138.1° E: paleocoordinates 9.6° N, 138.2° E)

• coordinate estimated from map

• small collection-level geographic resolution

When: CN 3 nannofossil zone, Map Formation, Burdigalian (20.4 - 16.0 Ma)

• In addition to the abundant Cyclicargolithus floridanus, Sphenolithus heteromorphus is also abundant or common in these samples. Because of the presence of the latter species, the nannoflora observed in these samples are identifiable to that of the late Early Miocene Zone CN 3 or early Middle Miocene Zone CN 4 (Okada and Bukry, 1980). According to Berggren et al. (1995), these two zones range from 18.2 to 13.6 Ma in age. Short-rayed discoasters such as Discoaster deflandrei are more abundant than long-rayed discoasters such as D. variabilis in the CN 3 flora, Nannoflora observed in samples 13-5A-a, 13-5A-b, 14-a and 14-b in which D. deflandrei far exceeds D. variabilis in relative abundance, therefore, seem to belong Zone CN 3.

• bed-level stratigraphic resolution

Environment/lithology: basinal (); lithified lime mudstone

• Calcareous nanno ooze

Size class: microfossils

Collection methods: peel or thin section

Primary reference: K. Fujioka, H. Matsuoka, G. Kimura, A. Takeuchi, H. Matsugi and H. Okada. 1998. Age constraint on the obduction of ophiolitic rocks in the Yap Island, Philippine Sea, using nannofossils. Journal of the Geological Society of Japan 104:415-418 [M. Clapham/M. Clapham]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 191880: authorized by Matthew Clapham, entered by Matthew Clapham on 19.02.2018

Creative Commons license: CC BY (attribution)

Taxonomic list

Coccolithophyceae
  -
Cyclicargolithus floridanus Roth and Hay 1967
 Prymnesiophycidae - Prymnesiophycidae
Discoaster deflandrei Bramlette and Riedel 1954
Discoaster variabilis Martini and Bramlette 1963
Discoaster adamanteus Bramlette and Wilcoxon 1967
Coccolithus pelagicus Wallich 1877
  -
Sphenolithus moriformis Bronnimann and Stradner 1960