Where: New Zealand (36.1° S, 174.2° E: paleocoordinates 46.7° S, 178.1° E)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Mahurangi Limestone Formation, Oligocene (33.9 - 23.0 Ma)

• STRATIGRAPHIC RELATIONS: From the Mahurangi Limestone, for which lithostratigraphic relationships are not discussed. AGE: Whaingaroan-Duntroonian, on the basis of nannofossil evidence; placed in Oligocene by enterer to avoid stratigraphic orphaning. STRATIGRAPHIC POSITION: From unknown position within formation.

• group of beds-level stratigraphic resolution

Environment/lithology: marine; lithified, bioturbated, gray, white, argillaceous limestone

Size class: microfossils

Collected by O'Conner

Collection methods: bulk, chemical, hydrochloric, sieve,

• COLLECTOR: B. O'Conner, c. 1980's. REPOSITORY: Dept of Geology, Auckland University. COLLECTION METHODS & ABUNDANCE: Samples of about 100g were weighed, crushed to approximately lcm size and treated with 10% hydrochloric acid (HC1). When reaction ceased the residue was boiled for a few minutes in 33% HCl, washed and then gently boiled in a mixture of 10% hydrogen peroxide (H202) and 35g/l tetra- sodium pyrophosphate (Na4P207.10H20) for about an hour. After washing thoroughly through a 63gm sieve, residues were dried, weighed and picked for mounting on stubs ready for SEM examination and photography. Strewn slides were prepared (using Entellan New (RI 1.49-1.50) and 22mm x 40mm cover slips) for examination under a transmitted light microscope, photography and estimation of abundances. Samples with a high radiolarian density were split into a coarse (150- 300gm) and a fine (<150gm) fraction and separate slides made from each fraction for ease of viewing. Estimates of true radiolarian abundance in each sample are ex- pressed as the number of Radiolaria per gram of sediment and are as follows: D (deluge >800); A (abundant 301-800); C (common 101- 300); F (few 20-100) and R (rare <20). Abundances of each new taxa on a strewn slide are noted as: D (>60); VA (very abundant 41-60); A (21-40); C (11-20); F (5-10); R (1-4).

Primary reference: B. O'Conner. 1994. Seven New Radiolarian Species from the Oligocene of New Zealand. Micropaleontology 40(4):337-350 [A. Hendy/A. Hendy/A. Hendy]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 90858: authorized by Austin Hendy, entered by Austin Hendy on 19.08.2009

Creative Commons license: CC BY (attribution)