J. D. Campbell

The stratigraphy of the Torlesse rocks of the Mt Somers area (S81) mid-Canterbury

Abstract Pre-Cretaceous basement in the Mt Somers area consists of Torlesse Supergroup rocks of prehnite-pumpellyite facies which are here subdivided into the Mt Taylor Group (Middle-Late Triassic; new group), the Clent Hills Group (Middle-Late Jurassic; amended group), and undifferentiated Torlesse Supergroup. Mt Taylor Group is further subdivided into three new formations: (a) Fingers Formation (Kaihikuan-?Oretian (Ladinian-?Carnian) of late Middle to perhaps early Late Triassic age) of medium-coarse-grained sandstone and minor interbedded alternating sandstone-siltstone sequences containing the key fossils Daonella sp., Praegonia sp., and Spiriferina cf. abichi Oppel. Part of this formation consists of distinctive massive, white, micaceous, coarse-grained feldsarenite with dark calcareous spheroidal concretions. (b) Pudding Hill Formation (Middleearly Late Triassic) a flysch-like sequence of alternating dark grey, fine sandstone and siltstone turbidites, and contains the tube fossil Torlessia mackayi B...

An association of Torlessia and late Middle—early Upper Triassic fossils at Pudding Hill Stream, central Canterbury

Abstract Marine invertebrates of late Middle-early Upper Triassic age are associated in redeposited sediments with tubes of Torlessia at Pudding Hill Stream near Mount Hutt, central Canterbury. Bryozoans, taxodont bivalves, Plicatula, brachiopods including Mentzeliopsis, gastropods and crinoids are preserved in more or less fragmentary form in the coarse (granule-sized) bases of graded units, some of which contain Torlessia tubes in their finer-grained upper parts. The mode of occurrence suggests emplacement by subaqueous flow of both the tubes and the shelly remains. Contemporaneity of the tubes and the other fossils is certain and time equivalence of Pudding Hill Formation and Fingers Formation to the west is established. An east-facing palaeoslope seems likely for the Rangitata-Ashburton catchment area for at least part of Triassic time.

Triassic Radiolaria from Kaka Point Structural Belt, Otago, New Zealand

Abstract Triassic Radiolaria are documented from phosphatic nodules obtained from the Karoro Formation and Potiki Siltstone from Kaka Point Structural Belt, Otago, New Zealand. There are abundant Glomeropyle and Spumellaria, and rare Nassellaria and Entactinaria. By comparison with radiolarian faunas from Japan, Thailand, European Tethys, and other Triassic strata in New Zealand, the Karoro Formation is correlated with upper Lower Triassic (Olenekian), older than the Potiki Siltstone. We believe that the fauna is strongly affected by non‐Tethyan radiolarians based on the abundance of Glomeropyle, rare occurrence of Tethyan taxa, and the presence of many undescribed forms. Three new species are described herein: Glomeropyle bispinosa, G. campbelli, and Poulpus (?) caveaformis.

Angiosperm fruit and leaf fossils from Miocene silcrete, Landslip Hill, northern Southland, New Zealand

Abstract Impressions of fruits and leaves of angiosperms recovered from Landslip Hill near Gore, eastern Southland, include some showing features attributable to Corynocarpus, others that may belong to Avicennia, Pomaderris, and Pouteria as well as the already described Fagaceae and Casuarinaceae. These, along with araucariacean fossils, allow the reconstruction of a warm temperate Early Miocene vegetation in eastern Southland, which may have been coastal.

Willsher Group and geology of the Triassic Kaka Point coastal section, south‐east Otago, New Zealand

Abstract Willsher Group (new) and component formations in the Kaka Point Structural Belt are defined and described: Karoro Formation (Nelsonian, late Early Triassic), Potiki Siltstone (?Malakovian, late Early to early Middle Triassic), Bates Siltstone, Kaka Point Volcanic Sandstone, Tilson Siltstone, and Steney Voe Formation (Etalian, Middle Triassic), Pilot Point Sandstone (Etalian or Kaihikuan), Short Bay Formation (late Etalian or Kaihikuan), Port Molyneux Siltstone and Waituti Siltstone (Kaihikuan, latest Middle to early Late Triassic). Sparse body fossils include ammonoids, bivalves, gastropods, brachiopods, and crustacean, crinoid, and rare bone fragments. Bentonitic and zeolitised ash beds are copiously developed in thick sequences of laminated siltstones with subordinate mostly highly felsic volcaniclastic sandstones; a laharic origin is suggested for some. Sedimentary structures indicate current directions and slope directions from an easterly quarter. Analcime‐quartz and albite are progressively advanced dehydration products of heulandite and clinoptilolite replacement of glass with accompanying movement of mobile elements. Some analcime has formed without heulandite precursor. Differences from coeval rocks in the Southland Syncline of the Murihiku Terrane in inferred source directions, sedimentary facies, very low‐grade metamorphism, and geochemistry imply distinct provenances and tectonic histories, although sources were probably parts of the same volcanic arc complex. The Kaka Point Structural Belt is fault‐bounded and was displaced relative to the Southland Syncline sequence during accretion or later. Its relationship to the Dun Mountain‐Maitai Terrane is at present unclear. The belt may be regarded as a displaced splinter of either the Murihiku Terrane or the Dun Mountain‐Maitai Terrane, or it may be a fragment of a separate but related suspect terrane.

Cenozoic records of the genus Lingula (Brachiopoda: Inarticulata) in New Zealand

Abstract Lingula occurs in the New Zealand Cenozoic in horizons of Paleocene, Eocene, Oligocene and Miocene age. The geographie and stratigraphie distribution of Lingula waikatoensis Penseler through the Tertiary is described, and the significance of the genus as an indicator of paleoshorelines and paleodimate is discussed.

Heterastridium (Hydrozoa) from Norian sequences inNew Caledonia and New Zealand

Abstract Globular bodies with vermicularly-sculptured surfaces and cellular internal structure, identified as the hydrozoan Heterastridium conglobatum Reuss, are found in late Triassic rocks of New Caledonia in a Monotis shellbed on lIle Hugon. Less wellpreserved specimens, identified as Heterastridium cf. conglobatum and Hererastridium sp., occur in rocks of the Richmond Group in Nelson and the Taringatura Group in Southland, New Zealand. These occurrences seem to demonstrate the presence of the Suessi Zone in New Caledonia and New Zealand Upper Norian sequences. Correlation of the New Zealand local stages late Otamitan and Warepan with the Suessi Zone suggests a Norian age for part, perhaps all, of the Halobia zone in New Zealand.

Fossil legumes from the Manuherikia Group (Miocene), Central Otago, New Zealand

Abstract Leguminosae fossils are prominent in the Nevis Oil Shale Member of the Manuherikia Group in Central Otago, New Zealand. Valves from legumes up to 74 mm long are found as compressions in laminated mudstone along with other plant macrofossils and freshwater mussels.

Systematics and evolution of the brachiopod genus Rhizothyris in the Oligocene—Miocene of New Zealand

Abstract The terebratellid genus Rhizothyris Thomson, 1915, has been restudied. The genus spans the period represented by Landon, Pareora, and Southland Series (OligoceneMiocene). Individual populations show a wide range of variation in trivial characters, making it difficult to delimit species. Of the 18 previously described species, 13 are placed in synonymy because they lack statistically significant differences from other species. One new species R. kokoamuensis is described, and five previously named species are reaffirmed. The stratigraphic history of the genus is presented and an interpretation of its evolution is attempted.

A woody shrub from the Miocene Nevis Oil Shale, Otago, New Zealand ‐ a possible fossil divaricate?

Fragments of a shrub preserved in the Miocene Nevis Oil Shale in Nevis Valley, Central Otago are described Leaf size and arrangement, and stem architecture appear similar to divaricate growth forms in the modern New Zealand flora