Where: New Zealand (35.2° S, 173.5° E: paleocoordinates 46.0° S, 177.0° E)
• coordinate based on unpublished field data
• 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 90859: authorized by Austin Hendy, entered by Austin Hendy on 19.08.2009
Creative Commons license: CC BY (attribution)
Taxonomic list
Protozoa | |
Anthocyrtidium odontatum O'Conner 1994 radiolarian
Lamprocyclas matakohe O'Conner 1994 radiolarian | |
Dorcadospyris mahurangi O'Conner 1994 radiolarian | |
Siphocampe missilis O'Conner 1994 radiolarian | |
Phormocyrtis vasculum O'Conner 1994 radiolarian |