THE LATE JURASSICAMMONITE FAUNA OF NEW ZEALAND G.R. STEVENS Institute of Geological & Nuclear Sciences monograph 18 (New Zealand Geological Survey paleontological bulletin 74) Institute of Geological & Nuclear Sciences Limited Lower Hutt, New Zealand BIBLIOGRAPHIC REFERENCE Stevens. G.R 1997. The Late Jurassic ammonite fauna of New Zealand. Institute of Geological & Nuclear 1 Sciences monograph 18. 216 p. Lower Hutt, New Zealand. Institute of Geological & Nuclear Sciences Limited. I G R Ste\.ens Institute of Geological & Nuclear Sciences Limited, Lower Hutt, New Zealand Grateful acknowledgement is made to the Lottery Science Research Committee of the 'Vew Zealand Lottery Grants Board and to the Balivean Trust for financial assistance towards the publication of this monograph. Edited and prepared for publication by Geoff Gresory. Word Therapy, Paraparaumu Printed by Graphic Press & Packaging Ltd, Levin ISSN 11 72-028X ISBN 0-478-09583-X ii Cop!right Institute of Geological &Nuclear Sciences Limited 1997 Front cover: Representative New Zealand endemic ammonite taxa: Kossmatia nracnaughti n.sp. (left); Paraholiceraloides gr.ai?rmackiei n.sp. (middle); Subdichotoinoceras innmetaiense n.sp. (right). In the background is a detail of the sutures exposed in specimen CE2305 Calliphylloceras empedoclis (Gemmellaro) (see Plate 4, figs 4.5). Frontispiece: The shorelines of Kawhia Harbour, a large embayrnent on the north-westem coastline of the North Island of New Zealand, have been the prime sources of Late Jurassic ammonites since the first collec- tions by Hochstener in 1859. The illustrations show repre- sentative views ofthe south side of the harbour. (upper) Harbour entrance and Te Maika Peninsula top right. The other peninsula landforms are in succession: Totara Peninsula, Heteri Pe- ninsula and "Waikiekie Pe- ninsula", with Kowhai Point jutting out into the harbour at middle right. (middle) Nathan Point in fore- ground; Kowhai Point in mid- dle distance; in far distance: Totara Peninsula, Te Maika Peninsula and Albatross Point. (lower) Eastern shoreline of Mairi Point. Kinohaku Siltstone is exposed on the shore platform and the Mairi Ammonite Bed outcrops about half way along the coastline. Aerial photography by Lloyd Homer. ABSTRACT (iii) A~rlacosphinctoides zone: Middle Tithonian (iv) Subplaniles zone: Late Tithonian Late Jurassic ammonite assemblages are found primarily in strata of the Murihiku Terrane (= Hokonui facies) of the Ne\\, Zealand sedimentary sequence. This terrane, formed largely of volcaniclastic sediments, is interpreted as repre- senting an arc-trench system developed along the oceanward side of the Gondwana margin and separated from it by a marginal sea. Most of the ammonite collections from the Murihiku have been made from the west coast of the North Island. from strata of the Kawhia Regional Syncline, exposed around the shores of Kawhia and Aotea Harbours, and at Pon Waikato. Marokopa and Awakino. Three ammonite localities are known from South Island strata of the Younger Torlesse (or Pahau Subterrane). The Younger Torlesse rocks are interpreted as representing the deformed contents of an accretionary prism that was devel- oped along a trench-transform system flanking the Gondwana coastline. Ye\+ Zealand Late Jurassic (Kimmeridgian and Tithonian) macrofaunas are dominated by siltstoneimudstone bivalve assemblages, with ammonites being usually in the minority. Although ammonite assemblages occur at intervals throughout ihs New Zealand local stages of Heterian, Ohauan and Puaroan, numbers of individuals are generally low, and well preserved specimens are usually uncommon. Faunal sequences are often interrupted by barren zones. Large concentra- tions of specimens, to produce shellbeds, are very rare. l%e general paucity ofthe New Zealand ammonite record is in marked contrast to the richly abundant populations that lived in the tropical and sub-tropical shallow-water shelf seas of the Central Tethys. Climatic and facies conditions in New Zealand were substantially different from those of the Central Tethys. First, New Zealand was situated in mid- latitudes, probably between 40"s and 50% lat., and sea water temperatures were probably equivalent to those of the modem warm-temperate zone. Because the Late Jurassic world was probably ice-free, global climates were generally equable, with a very wide tropicallsub-tropical zone, occupied by the richly developed Tethyan faunas. In the Late Jurassic New Zealand was unequivocally marginal to this situation and, although Tethyan fauna1 elements were present, the cooler warm-temperate conditions then prevailing throughout New Zealand were undoubtedly less than optimal for their development. Nonetheless, the absence at this time of anti-Boreal ("Austral") elements, that appeared later in the Cretaceous in response to cooling conditions, provides a clear indication that sea water temperatures did not fall to reach levels equivalent to those ofthe modem cool-temperate zone. Second, New Zealand straddled a tectonically active plate margin, and the Murihiku sediments, in which almost all of the ammonites are preserved, were laid down in an arc-trench situation, adjacent to amajor subduction zone developed along the southeastern edge of the Gondwana continent. The fossiliferous components of the Murihiku sediments are therefore preserved in thick sequences of volcaniclastic sandstones, siltstones and tuffs that have undergone low-grade metamorphism, with any fossils present being overgrown and disrupted by the development of coarsely crystalline secondary minerals. Phylloceratidae are more richly represented in the Late Jurassic of New Zealand than might be deduced from the published records. Taxa include PhyNoceras salima Krumbeck, Partschiceras otekense n.sp., P strigoceriforme n.sp., 1 Calliphylloceras empedoclis (Gemmellaro), Holcop~lloceraspolyo[c~rm (Benecke), Holcophylloceraspassari (Boehm) mason; n. subsp. and Ppchophylloceras sp. indet. Tethyan affinities are particularly evident. Lytoceratidae includes Lvroceras taharoaeme Stevens, which ranges up to a diameter of 1.5 m. Oppeliidae are represented by Uhligites molutaran~rs (Boehm) and U. kevesin. sp.; Aspidoceratidae by Aspidoceras cf. erromphaloides Burckhardt: Aulacostephanidae by Epiceplralites marwicki n. sp, and Subneumoyria cf. ordonezi (Burckhardt). Ataxioceratidae are well represented throughout the Late Jurassic sequence, except for in the lower l Heterian. Taxa are: Idoceras heleriense n. sp., I. speighri(Marshall), Kossmatia macnauglrtin.sp., K. cf. desmidoppcha (Uhlig), K. aff. desmidoppcha (Uhlig). K. pilicosta n. sp., K. mairietrsis n. sp., K. cf. santarosana (Burckhardt), Pnraholiceras flemingi n. sp., R subspitiense n. sp., P aff. sabineanum (Oppel), P. aff. haugi Uhlig, l Pnrabnliceraloidesgrantmackiein. sp., Pachysphinctes cf. beyrichi (Futterer), Aulacosphinctoides brownei (Marshall), A. sisvphi (Hector), Kawkiasphinctes antipodus n. sp., Srihplanites hirri~vaiettsis n. sp., Subdichotomoceras l nraraetaiense n. sp. The following ammonite range zones can be recognised in the Heterian - Puaroan succession of New Zealand: (i) ldoceras zone, correlated with Early and Late Kimmeridgian (ii) Paraboliceras zone: Middle Tithonian The Early Tithonian is either absent or poorly represented in the New Zealand sequence. Based on an assessment of the validity ofthe tie-points that can be derived from the ammonite data, the New Zealand local stages have been assigned the following correlations: Heterian: Late Callovian-Early Kimmeridgian; Ohauan: Late Kimmeridgian-Middle Tithonian; Puaroan: Middle and Late Tithonian. The Late Jurassic ammonite assemblages ofNew Zealand show well-defined variations in the proportions ofLeiostraca and Trachyostraca and assessed values for faunal turnover, diversity and abundance. Such variations are interpreted as being responses to environmental factors and reflect sedimentological and ecologicalfluctuations resulting from local tectonic activity and eustatic changes in sea level. In general, there is a good match between biotic and sedimentological changes and published eustatic models. Mis- matches are probably related to contemporaneous local tectonic activity related to the early phases of the Rangitata Orogeny. Occurrences of giant ammonites appear to coincide with the major phases of rising sea level. Such occur- rences may be related to the generation of episodes of upwelling and general turnover ofthe water column that served to lift on to inshore shelf areas representative samples of populations that were normally resident in deeper waters some distance offshore. Strong Tethyan provincial affinities are shown by the ammonite assemblages of the Late Jurassic ofNew Zealand. The Leiostraca show circum-Gondwana links, but with some northwards extensions into Mexico, southern Europe, the Middle East and Asia Minor. The Trachyostraca show a more restricted, hut nonetheless also circum-Gondwana set of affinities, but without any direct links to southern Europe, the Middle East and Asia Minor. However, linkages to Mexico remain very strong. The circum-Gondwana affinities of both Leiostraca and Trachyostraca reflect faunal migrations that occurred along shorelines extending around the margin of Gondwana. Marked affmities exist with New Caledonia, Papua New Guinea, Indonesia, NW Himalaya, East Africa, Malaysia, southern South America and the Antarctic Peninsula. While such circum-Gondwana links are compatible with conventional Gondwana reconstructions, an even tighter fit can be achieved by the assumption ofan expanding earth thesis, making direct linkages between New Zealand and Central and South America even more of a physical possibility. Keywords. Molluscs; Ammonoidea; Phylloceratidae; Lytoceratidae; Oppeliidae; Aulacostephanidae; Ataxioceratidae; new taxa; Jurassic; Kimmeridgian; Tithonian; stratigraphic correlation; New Zealand; Kawhia Harbour; Aotea Har- bour; Port Waikato; Marokopa; Awakino; Morrinsville; Humnui; Metric Map Sheets (l :50 OOONZMS 260) M34, N33, R13, R14, R15, R16, R17, T14. CONTENTS ABSTRACT iv Chapter 1. INTRODUCTION Historical background Repositories of collections Acknowledgements Chapter 2. STRATIGRAPFIY Introduction Late Jurassic strata in New Zealand Ammonite occurrences in the Late Jurassic of New Zealand Murihiku Terrane Torlesse Terrane New Zealand Late Jurassic stages: Definition, subdivision and correlation Nomenclature Heterian stage Ohauan stage Puaroan stage Quantity, quality and state of preservation of ammonite material in the Late Jurassic of New Zealand Influence of climatic and tectonic environmental factors on the Late Jurassic successions of New Zealand Chapter 3. SYSTEMATICS Terminology and criteria for classification Suprageneric classification Systematic descriptions Measurement of specimens Sutural diagrams Polymorphism Order Ammonoidea Suborder Phylloceratina Superfamily Phyllocerataceae Family Phylloceratidae Subfamily Phylloceratioae Phylloceras salima Krumheck Phylloceras cf. salima Partschiceras ofekense n.sp . Partschiceras shigocerforme n.sp. cf. Partschiceras sp. indet. Subfamily Calliphylloceratinae Caliiphylloceras empedoclis (Gemmellaro) Holcophylloceraspolyolcum (Benecke) HolcophyNoceras cf. polyolcum Holcophylloceraspassati (Boehm) masoni n. subsp cf. HolcophyNoceras sp. indet. Ptychophylloceras sp. indet. Suborder Lytoceratina Superfamily Lytocerataceae Family Lytoceratidae Subfamily Lytoceratinae Lytoceras taharoaense Stevens Lyroceras sp. indet. ?Lytoceras sp. indet. Suborder Anunonitina Superfamily Haplocerataceae Family Oppeliidae Subfamily Streblitinae Uhligites motutaranus (Boehm) Uhligites keyesi n.sp. Incertae sedis Superfamily Perisphinctaceae Family Aspidoceratidae Subfamily Aspidoceratinae Aspidoceras cf. euomphaloides Burckhardt ?Aspidoceras sp. indet. Family Aulacostepbanidae Epicephalites marwicki n.sp. Subneumqvria cf. ordonezi (Burckhardt) Family Ataxioceratidae Subfamily Ataxioceratinae ldoceras heteriense n.sp. Idoceras cf. heteriense Idoceras speighti (Marshall) Idoceras sp. indet. Kossmatia macnaughti n. sp. Kossmafia cf. macnaughti Kossmatia cf. desmidoprycha Uhlig Kossmatia aff. desmidoptycha Uhlig Kossmatia sp. indet.? desmidoprycha Uhlig Kossmatiapilicosta n.sp. Kossmatia mairiensis n.sp. Kossmatia cf. mairiensis Kossmatia cf. santarosana (Burckhardt) Kossmatia sp. indet. ?Kossmatia sp. indet. Parabolicerasflemingi n.sp. Paraboliceras subspitiense n.sp. Paraboliceras cf. subspitiense Paraboliceras aff. sabineanum (Oppel) Paraboliceras aff. haugi Uhlig ?Paraboliceras sp. indet. Paraboliceratoides grantmackiei nsp. Subfamily Lithacoceratinae Pachysphinctes cf. beyrichi (Futterer) Subfamily Vigatosphinctinae Nomenclature of perisphinctid taxa Aulacosphinctoides brownei (Marshall) Aulacosphinctoides sisyphi (Hector) Aulacosphinctoides sp. indet. Kawhiasphinctes n.gen. Kawhiasphinctes antipodus n.sp. Subplanites huriwaiensis n.sp. Subplanites sp. indet. Subdichotomoceras maraetaiense n.sp. Incertae sedis "Perisphinctes" kawhiae n. sp. Chapter 4. BTOSTRATIGRAPHY Stratigraphic distribution of taxa Ammonite zonation Relationship of ammonite zonation to bivalve zonation Relationship of ammonite zonation to dinoflagellate zonation Page 37 37 37 37 37 39 39 40 40 40 40 41 41 41 44 45 45 46 48 48 50 51 53 54 54 54 55 56 57 57 58 59 59 60 62 62 62 62 63 64 64 65 65 68 72 78 78 79 8 1 83 84 85 87 Chapter 5. OVERSEAS CORRELATIONS Introduction Historical development Subdivision of the Tithonian Standard zones of the Kimmeridgian-Tithonian Oraka Sandstone Captain King's Shellbed, Ohinerurn Formation, Kiwi Sandstone and Waikutakuta Siltstone Kowhai Point Siltstone and Takatahi Formation Kinohaku Siltstone Waiharakeke Conglomerate Puti Siltstone Conclusions Chapter 6. PALAEOECOLOGY Faunal spectra Lithological changes accompanying Late Jurassic eustaq Relationship of ammonite biota to Late Jurassic eustasy Giant ammonites and eustasy Chapter 7. PALAEOBIOGEOGRAPHY AND FAUNAL AFFINITIES 110 Tethyan fauna1 links 110 Trans-Pacific fauna1 links: the Mexican connection 111 Paleoclimatology 113 REFERENCES 117 APPENDIX - Late Jurassic ammonite localities Geological Survey fossil localities University of Auckland fossil localities University of Canterbury fossil localities Canterbury Museum fossil localities University of Otago fossil localities Victoria University of Wellington fossil localities The Natural History Museum (London) fossil localities Abbreviations of collectors' names PLATES INDEX LIST OF TEXT FIGURES Fig. I Some major contributors to the study ofNew Zealand Late Jurassic ammonites. Fig. 2 Map of the Murihiku and associated terranes in New Zealand. Fig. 3 Map of the disposition of the Palaeozoic and Mesozoic terranes of New Zealand before continental break-up. Fig. 4 Cross-section through theNew Zealand Orogen in Early Cretaceous times. Fig. 5 Platr tectonic reconstruction, 1.atc Jurzs~c FIE. 6 Keclonal dlstrihution of Junccic rockc. Konh Island of Nca 7callnd Fig. 7 Fig. 8 Fig. 9 Fig. 10 Fig. l I Fig. 12 Fig. 13 Fig. 14 Fig. 15 Fig. 16 Fig. 17 Fig. 18 Fig. 19 U Generalised map of Jurassic lithological units, Kawhia Harbour. Detailed map of Jurassic lithological units exposed along the southern shore of Kawhia Harbour. Map of Jurassic lithological units, Port Waikato. Cross-section of an ammonite to illustrate the system of measurement. Phylloceras salima Kmmheck. Whorl cross-section. Phylloceras salima Krumbeck. Suture lines. Partschiceras otekense n.sp. Whorl cross-section. Portschiceras sirigoceriforme n.sp. Drawing showing spiral groove. Calliphylloceras empedoclis (Gemmellaro). Suture lines. Calliphyloceros empedoclis (Gemmellaro). Constrictions on internal mould. Calliphylloceras empedoclis (Gemmellaro). Whorl cross-sections. Holcophylloceraspolyo(cum (Benecke). Whorl cross-sections. Holcophylloceraspolyo/cum (Benecke). Suture line. Page 3 Ftg 20 /lolcopl~~llocero.~pnl~~~lcrn~ (Ilmc.ckc) (:oncrr~ct~ons on internal niould. 2'1 FIE ?I llol~~or,hillnceru~ noholr.um Illcncckc~. Granh ot'constr~c~~~ns ncr \rhorl. 29 . , . , ~ig. 22 Holcophylloceras passati (~oehm) maioni n.'subsp. Sketches of internal moulds. 32 Fig. 23.24 Lytoceras taharoaense Stevens. Suture lines. 35 Fig. 25 Hector's original illustration of Uhligites hectori Spath. 38 Fig. 26 Boehm's original sutural diagram for Uhligites molutaranus (Boehm). 38 Fig. 27 Aspidoceras cf. euomphaloides Burckhardt. Suture line. 40 Fig. 28 Epicephalites manvicki n.sp. Whorl cross-section. 43 Fig. 29 Epicephalites manvicki n.sp. Suture line. 43 Fig. 30 Subneumayria cf. ordonezi (Burckhardt). Whorl cross-section. 44 Fig. 3 1 Idoceras heteriense n.sp. Suture lines. 47 Fig. 32 fdoceras speighri (Marshall) Suture lines. 49 Fig. 33 Idoceras speighti (Marshall) Suture lines. 50 Fig. 34 Kossmatia macna~rghti n.sp. Ribbing pattern. 52 Fig. 35, 36 Kossmatia macnaughti n.sp. Suture lines. 53 Fig. 37 Kossmatia mairiensis n.sp. Ribbing pattern. 56 Fig. 38 Kossmatia cf santarosana (Burckhardt). Ribbing pattern. 58 Fig. 39 Parabolicerasjlemingi n.sp. and P himalayanum Uhlig. Suture lines. 6 1 Fig. 40 Aulacosphinctoides brownei (Marshall). Rib density curves and septation diagram. 70 Fig. 41.42 A~rlacosphinctoides brownei (Marshall). Suture lines. 7 1 Fig. 43 Aulacosphinctoides brownei (Marshall). Suture line illustrated by Boehm (191 l). 71 Fig. 44 Aulacosphinctoides sisyphi (Hector). Hector's original illustration. 74 Fig. 45 Aulacosphinctoides sisyphi (Hector). Rib density curves and septation diagram. 75 Figs 46,47 Aulacosphinctoides sisyphi (Hector). Suture line. 76 4 Fig. 48 Aulacosphinctoides sisyphi (Hector). Suture line. 77 Fig. 49 Perisphinctes marshalli Spath. Sutural diagram illustrated by Boehm (191 1). 77 Fig. 50 Strbplanites huriwaiemis n.sp. Ribbing pattern and whorl cross-section. 82 Fie. 51 Ammonites novo-zelandicus Hauer. Hauer's orieinal illustrations. 87 U Fig. 52 Ammonites aucklandicus Hector. Hector's original illustration. Fig. 53 Stratigraphic ranges of ammonites in the Late Jurassic sequence ofNew Zealand. Fig. 54 Ammonite zones in the Late Jurassic of New Zealand. Fig. 55 Relationship of Bivalvia zones to the standard Kawhia succession. Fig. 56 Relationship of dinoflagellate zones to the standard Kawhia succession. Fig. 57 Standard ammonite zones for the Tethyan Realm and their probable presence in New Zealand. Fig. 58 Faunal spectra for the Late Jurassic ammonite faunas of New Zealand, showing fluctuations in percentage proportions of Leiostraca and Trachyostraca. Fig. 59 Faunal spectra for Late Jurassic ammonite faunas of Northern ltaly Fig. 60 Relationship of lithology to eustatic fluctuations in the Late Jurassic of New Zealand. Fig. 61 Plots of first and last appearances, turnover, diversity and abundance for the Late lurassic ammonite faunas of New Zealand. Fig. 62 Occurrences of giant ammonites in the New Zealand Late Jurassic sequence. Figs 63. 64 Gondwana reconstructions. Figs 65. 66 Expanding earth reconstmctions. LIST OF Plate l Plate 2 Plate 3 Plate 4 Plate 5 Plate 6 Plate 7 Plate 8 Plate 9 plate 10 Plate 11 Plate 12 Plate 13 Plate 14 Plate 15 Plate 16 Plate 17 Plate 18 Plate 19 Plate 20 Plate 21 Plate 22 Plate 23 Plate 24 4 Plate 25 Plate 26 Plate 27 Plate 28 Plate 29 Plate 30 Plate 3 1 Plate 32 Plate 33 PLATES Figs 1-6 Phylloceras salima Kmmbeck Fig. I PhyNoceras salima Krumbeck Figs 2, 3 Partschiceras otekense n.sp. Figs 4, 5, 8 Partschiceras strigoceriforme n.sp. Figs 6, 7 Partschiceras aff partschi (Hauer) Figs 1-4 CalliphyNoceras empedoclis (Gemmellaro) Figs 1-5 Calliphylloceras empedoclis (Gemmellaro) Figs 1. 2 Holcophyllocerospolyolcam (Benecke) Figs 1-3 Holcophylloceraspol~volcum (Benecke) Figs 4, 5 Holcophylloceraspassafi (Boehm) masoni n, subsp. Figs 1, 2 Holcophylloceraspassati (Boehm) masoni n, subsp. Figs 1-7 Holcophylloceraspassati (Boehm) masoni n, subsp. Figs 1-4.6 Holcophylloceraspassali (Boehm) masoni n.subsp. Fig. 5 Ptychophylloceras sp. indet. Figs 1-3 Lytoceras faharoaense Stevens Fig. 1 Uhligifes mofufaranrrr (Boehm) Figs 1-3 Uhligites motutaranus (Boehm) Figs 1-3 Uhligites motutaranus (Boehm) Figs 4, 5 Uhligifes keyesi n.sp. Figs 6-8 Aspidoceras cf. euomphaloides Burckhardt Figs 1. 2 Aspidoceras cf. euomphaloides Burckhardt Figs 3-7 Epicephalifes marwicki n.sp. Fig. l Epicephalifes marwicki n.sp. Figs 2, 3 Subneumayria cf. ordonezi (Burckhardt) Figs 4-9 Idoceros hereriense n.sp. Fig. I ldoceros heteriense n.sp. Figs 2-4 Idoceras speighfi (Marshall) Figs 1-8 Kossmatia macnaugl~ti n.sp. Figs 1, 5 Kossmatia cf. desmidoptycha Uhlig Fig. 2 Kossmatia aff desmidoptycha Uhlig Figs 3.4 Kossmatio? cf. desmidoptycha Uhlig Fig. 6 Kossmatiapilicosta n.sp. Figs 1-6 Kossmatia mairiensis n.sp. Figs 1-5 Kossmatia cf. santarosana (Burckhardt) Figs 6-9 Parnbolicerasjlemingi n.sp. Figs 1-4 Parabolicerasfimingi n.sp. Fig. 5 Paraboliceras subspitiense n.sp. Figs 1, 2 Paraboliceras subspitiense n.sp. Figs 3.4 Paraboliceras atT sabineanum (Oppel) Figs 5-7 Paraboliceras aE haugi (Uhlig) Fig. 1 Paraboliceras aff haugi (Uhlig) Figs 2-5 Paraboliceratoides granfmackiei n.sp. Fig. 6 Pach.vsphinctes cf beyrichi (Futterer) Fig. 1 Pachysphinctes cf. be.vrichi (Futterer) Figs 2-1 1 Aulacosphincroides brownei (Marshall) Figs 1-8 Aulacosphincroides brownei (Marshall) Figs 1-2 Aulacosphinctoides sisyphi (Hector) Figs 1-4 Aulacosphinctoides sisyphi (Hector) Figs 1,2 Aulacosphinctoides sisyphi (Hector) Figs 1-3 Kawhiasphinctes antipodus n.sp. Figs 1, 2 Kawhiasphinctes antipodus n.sp. Figs 1. 2 Kawhiasphinctes anfipodus n.sp. Figs 1-3 Kawhiasphinctes antipodus n.sp. Figs 4-6 Subplanites huriwaiensis n.sp. Figs 1-3 S~~bplanites huriwaiensis n.sp. Fig. 4 "Perisphinctes" kmvhiae (Browne MS) n.sp. Figs 5-7 Subdichotomoceras marefaense n.sp. Page 144 [...]... good regional correlation Apart from being offset by 480 km on the Alpine Fault in the South Island, the Murihiku strata are continuous from the southeastern coast ofthe South Island, and thence along the western side of the country, to the north of the North Island The Cenozoic deformation of New Zealand has bent the Murihiku rocks overall into a lazy Z-shape They are concealed in places by younger rocks... margins of the Terrane have been subject to tectonic erosion, and as a consequence the basinal form of Murihiku rocks can only be deduced by reconstruction from the sediment fill The extensions of the Murihiku Terrane, in northerly and southerly directions beyond the present New Zealand landmass are based on inference In the southeast ofNew Zealand the Murihiku Terrane passes offshore, to underlie part of. .. The Captain Figure 9 (opposite) Although Jurassic rocks occur intermittently in the region between Kawhia Harbour and the mouth of the Waikato River (see Kear 1966) a distance of some 80 km the outcrops are often poorly exposed and deeply weathered Along the southern side of the mouth of the Waikato River an extensive headland region has exposed a series of outcrops extending across the strike of the. .. (1960), who defined the base of the stage as being the incoming of Retroceramus haasti On the basis of the first appearance of R haasti, Meesook (1 989) placed the base ofthe Ohauan stage atthe base ofthe Waikiekie Tuffaceous Siltstone Meesook (1989; see also Meesook & GrantMackie 1995) recognised three zones in the Ohauan Stage: (i) those strata deposited between the incoming ofR haasti and the last appearance... He defined the base of the Waikatoan on the first appearance of Belemnopsis aucklandica aucklandica (Hochstener) The Waikatoan includes the youngest marine rocks of the Kawhia Syncline, and the overlying non-marine Huriwai Formation At Kawhia Harbour the Mangaoran includes the uppermost 10 m of the Kinohaku Siltstone, the full thickness of the Waiharakeke Conglomerate and threequarters of the Puti Siltstone... on the venter and ventral flanks, and converge and fuse irregularly in twos and threes at the umbilical margin At the bottom of the umbilical wall, adjoining the seam, there is a small flange Although the New Zealand material consists of only fragmentary and corroded specimens, nonethelessthey are very distinctive when seen in the context ofthe entire New Zealand Late Jurassic ammonite fauna and therefore... separating the Rakaia and Pahau Subterranes in the South Island Although various plate-tectonic models have been proposed to explain the origin of the Esk Head Mtlange (cf Silberling et al 1988), it is likely that it is the product of tectonism associated with the renewal of subduction that led to the accumulation of the Pahau Subterrane, on the Pacific side ofthe Rakaia Subterrane, after the latter... original disposition ofthe terranes depicted in Fig 2 This simplified palaeogeographic map based on Bradshaw (1989, fig 1) shows his version of the disposition of the Paleozoic and Mesozoic terranes of New Zealand before the continental break-up phase of the midCretaceous and the dextral shear events oftheNeogene The Murihiku Terrane accumulated as arc deposits immediately offshore from the Gondwana continental... as to the plate tectonic situation in the Late Jurassic This interpretation, based on that of Wilson et al (1989) shows their version of the wider tectonic regime that was influencing the events in New Zealand, depicted in Figs 3 4 At this time progressive subduction ofthe lzanagi Plate was underway resulting in the progressive rafting in and suturing of the individual accreted components of the Torlesse... (1869-1950) was a versatile geologist who held the post ofprofessor of ~ e o & at Otago university from 1908 to 1916 (Waners 1996) His main claim to fame isas the originator of the name ienimbrite and of the concent of the "Andesite Line" (called bv later authors the "Marshall Line") which is now recopnised as defining the western boundary of the Pacific Plate in the SW Pacific region He also had a major . LIST OF Plate l Plate 2 Plate 3 Plate 4 Plate 5 Plate 6 Plate 7 Plate 8 Plate 9 plate 10 Plate 11 Plate 12 Plate 13 Plate 14 Plate 15 . 15 Plate 16 Plate 17 Plate 18 Plate 19 Plate 20 Plate 21 Plate 22 Plate 23 Plate 24 4 Plate 25 Plate 26 Plate 27 Plate 28 Plate 29 Plate