Site 688 ODP Leg 112 Early Eocene Peru (Eocene of Peru)

Where: Peru (11.5° S, 78.9° W: paleocoordinates 22.2° S, 111.0° W)

• coordinate stated in text

• small collection-level geographic resolution

When: Early/Lower Eocene (55.8 - 48.6 Ma)

Environment/lithology: marine; lithified, shelly/skeletal, silty, calcareous lime mudstone

• The early Eocene Pseudolimea assemblage is associated with benthic foraminifers indicating deposition on the outer shelf; however most modern Limidae are distributed throughout the inner shelf. Calcareous nannoplankton above and below the shell bed indicate shallow water and the shell bed appears to be in situ. The presence of shallow water taxa suggests subsidence of approximately 4000 m for these early Eocene beds.
• At 3819.8 m water depth, a silty foraminifer-rich bioclastic limestone was recovered. Cores from above and below the concentration of mollusk shells can be placed at an early Eocene age in the calcareous nannoplankton Zone NP13 (Discoaster lodoensis Zone). Thin sections at 726 m sub-bottom reveal silty to sandy mudstone, pelitic and somewhat bituminous matrix with numerous angular quartz grains, as well as edged, sometimes clear stem-like unaltered plagioclase grains indicating volcanic activity in that region in the early Eocene. A pyritic impregnation of the matrix is present, glauconite grains are rare, and the mudstone is bioturbated.

Size classes: macrofossils, mesofossils, microfossils

Preservation: recrystallized, original aragonite, original calcite, replaced with calcite

Collection methods: core,

Primary reference: H. Hagn and E. Martini. 1990. A lower Eocene shell bed and some Quaternary mollusks from ODP Leg 112 off Peru. Proceedings of the Ocean Drilling Program, Scientific Results 112:329-333 [L. Ivany/C. Visaggi/C. Visaggi]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 42706: authorized by Linda Ivany, entered by Christy Visaggi on 04.08.2004

Creative Commons license: CC BY (attribution)

Taxonomic list

• Taxonomic list compiled from text and figures.
Show authors, comments, and common names
unclassified
  -
Echinodermata indet.
Gnathostomata
  -
Osteichthyes indet.
Bivalvia
  -
"Pelecypoda indet." = Bivalvia
"Pelecypoda indet." = Bivalvia Linnaeus 1758 clam
 Pectinida - Limidae
Limidae indet.
Limidae indet. Rafinesque 1815 file clam
Deuteropoda
  -
Ostracoda indet.
Ostracoda indet. Latreille 1802 ostracod
unclassified
  -
Porifera indet.
Porifera indet. Grant 1836
Coccolithophyceae
  -
Transversopontis sp.
Transversopontis sp. Hay et al. 1966
 Prymnesiophycidae - Prymnesiophycidae
"Discolithina sp." = Pontosphaera
"Discolithina sp." = Pontosphaera Lohmann 1961
Globothalamea
 Rotaliida - Gavelinellidae
Gavelinella sp.
Gavelinella sp. Brotzen 1942
Nodosariata
 Vaginulinida - Vaginulinidae
Lenticulina sp.
Lenticulina sp. Lamarck 1804
Foraminifera
 Rotaliacea -
Rotaliacea sp.
Rotaliacea sp. Ehrenberg 1839
 Buliminacea - Siphogenerinoididae
Siphogenerina sp.
Siphogenerina sp. Schlumberger 1882