Eniwetok atoll, core E1, 2780-2790ft (Eocene of Marshall Islands)

Where: Marshall Islands (11.4° N, 162.4° E: paleocoordinates 4.0° N, 176.0° W)

When: Priabonian (38.0 - 33.9 Ma)

• Late Eocene, Tertiary b. Cole (1957, p. 749) places the top of the Eocene at 2,780 feet on the basis of the first appearance of a diagnostic smaller Foraminifera, Pseudochrysalidina. Todd and Low (1960, p. 807) place the top of the Eocene at 2,770 feet. The writer accepts 2,780 feet as the top because of the appearance of a different lithology. Chips that appear at this depth show strong solution features, such as molds, which indicate that a solution unconformity separates the rocks of Eocene and Miocene age, just as the Miocene e sediments are separated from younger rocks by a similar but better developed unconformity.

• group of beds-level stratigraphic resolution

Environment/lithology: perireef or subreef; lithified limestone

• Fore reef or open shoal water
• Below 2,560 feet the cuttings are coarser; they are mixtures of white rock fragments like those described from the interval above and angular fragments of unaltered coral and mollusks. Angular chips of white dense crystalline limestone appear at this depth. These chips are rare in the 2,780- to 2,790-foot sample but become abundant below 2,790 feet. Through the upper 20 feet of this interval the cuttings take on a white color as opposed to the tan of the overlying sediments. The white rock chips are composed largely of foraminiferal limestone with some mollusk molds.

Size class: macrofossils

Reposited in the USNM

Collection methods: core

Primary reference: P. M. Kier. 1964. Fossil echinoids from the Marshall Islands. United States Geological Survey Professional Paper 260-GG:1121-1126 [M. Clapham/M. Clapham]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 195885: authorized by Matthew Clapham, entered by Matthew Clapham on 29.08.2018

Creative Commons license: CC BY (attribution)

Taxonomic list

Show authors, comments, and common names
Echinoidea
 Clypeasteroida - Fibulariidae
Echinocyamus petalus
Echinocyamus petalus Kier 1964 sand dollar