A strip of Kaihikuan Sediments between the Otematata and Otamatapio Rivers, North Otago.

Author:

Ryburn, RJ

Year:

Project type:

Advisers:

Abstract:

INTORDUCTION The Triassic f o ssi l loc a lity a t Corbie s Creek, North Otago was discovered i n 1958 by E . 8 . Gair and D. R. Gregg of the New Zeal an.d U·eological Survey. , 'l'his wa s recollect ed later in 1958 and a paper by Gair, Gregg and Speeden desm:i bing t he occurrence was published in 1962. The primary aim of this investi gation was to map the fossil locality tog ether with any extension of' the f ossili ferous horizon that might exist. Prom t his it was hoped that stratigraphy, structure and relationship with surrounding lithologies mi ght be elucidated. Field Work, Dat es and Procedure. F ield work was started on the 3rd of December 1963, twelve da~,rs ·being s pent on a geological traverse t hrough the ori ginal :fos sil locality and on reconnaisance of t he surrm_m ding rocks. Nurner ous :fossil localities were d:LscovePed over• an area of sevePal square miles. A brief / I - 2 - visit with Prof essor · Coombs on the 20th and 21st of December was followed by ·16 days in the area starting :from the 1st of J·anuary, '196L+. This period was s pent in est ablishing , measuring and extending ma ppable units within t he fossiliferous sediments, particularly in the area several miles south-ea st of the Corbies . Creek locality. Fossil collections were made over much of this area. Mr J.D. Campbell accompanied the writer on a three day v:Lsit towards the end of F ebruary. Starting on February the 29th, three days were spent in the area immediately to the south and south-east of the ori ginal Corbies Creek locality and a fourth on the north-west side of the Otrunatapio River. Possils found there served to esta.blish the nol~th-west con tinuation of the Triassic sediments. Work was continued in the Ntay vacation from the 20th to the 31st, mainly on extending the mapping as far as the Otematata River. Several days were used in attempting to correlate the area containing the Corbies Creek locality with the separate fossiliferous area to the south-east . Assistance was given to Professor J .· B~ .'_Mackie and party in establishing grolmd control points on the first weekend of Au gust. In the field, mapping was drawn directly on to the air-photos. Sections were measured with a tape compass and clinometer. - 3 - .Aclmowledgements:- 'rhe project was supervised by Mr J .• D. Camp bell to whom I am indebt ed f' o:e assistance and direction, particularly in :fossil identifications. I a~ grateful to Prof'essor Coombs :for suggestions and guida.YJ.ce in :fieldwork, and to Professor Maclde, O.A. Evans and C. ', . Garlick of the Surveying Department :for the f' irst class base map prepared f'rom air-photos. In :formation on surr01mding geology was obtained from Ivlr A.R. L1utch of the Geological Survey and :from :fellow student Y. K. Shu. I am indebted to Messrs W. P . and J.B. C~neron of Otematata Station and particularly to Mr and Mrs 'l'aylor of the Backyal"ds Homestead, Otematata Station :for their generous hospitality. Ge ographic Setting:- 'rhe position and exten t of' the ar•ea mapped is shown on the map of' the Otematata Region. A prominent fault angle depression trending northwest, south-east between the Otamatapio River and Otematata River provides the natuEal axis to the area studied ( see F i gure 1). Boundaries are provided by the two rivers mentioned above and by the crestal ridge of Middle Range to - LJ. - the north-east. 1\ line rou ghly pal'allel to Mi ddle Range 3 miles to t he soutb-west def'ines the r•emaining boundary. Tot a l area is appr•oxi::nt'l. tely 20 square miles. •rop ograJ2h.Y and Drainage:- •'rom the base of' the scarp f'orming the south-west f'ace of' Iii i ddle Range an extensive diss ected surf'ace slopes u p to the crest o:f HawkduJl Hange some 9 miles south-west. This is drained by both the Otematata and Otamatapio Rivers. The south-east third of' the area is drained by a series of' deeply incised gullies of' which Long Gully is promi n ent. These converge on the Otematata River just above the point where it cuts through Middle Range in a r et1!DI'kable meandering g oPge. 'l'he north-west t vvo-thirds is drained ma inly by Corbies Creek and tributaries. 'l'his stream is lmovm locally as tl i dclle Stream whj.le the name Glen Bouie Creek appears to apply to its upper rea ches. A larg e expanse of all1.1.v:Lal f'lood-plain and ter races between t he Otamat apio and Corbies Creel<:. will be referred t o as CoPbies Cr eek Basin. Back;yards Basin is the name given to the much smaller area of alluvium and outwash f'ans between the Backyards IIomest ead and the base of' / I - 5 - Middle Range near' the centre of the area. The low hillocky ground between the two, roughly square in plan, is called Rabbiter' s IIut Block. South-east of Backyards Basin the name Long Gully Blocl;: is intended to refer to the strip rmder'lain by fossiliferous Triassic rocl<:: s that extend as far as the Ote~ nata ta River . Culture; Vegetation and Outcrop. Acces s to the l:3ackyards Homest ead is via a pr ivate road from a gate on the Ote:natata - Omarama road about a mile beyond .Ahuriri Pass. Alternatively a rough venicle tr a ck leads directly across Middle Range f'rom tDtematata Station Homestead near Otematata t ownship. Another vehicle trEtck winds down Long G ull ~r to the Otematata River which it follows for ten miles upstream . within Ot ematata Station. 'l'he area lies wholly Ground cove1, in the lower parts tend s to be rather sparse, consisting ma inly of sorrel and scabweed with some scat t ered tussock. Some areas, particul arl y in Rabbitel,, s Hut Block, are almost devoid of vegetat ion, this being undoubtedly due to the infestation of rabbits. Hi gher ground is clothed in tussock while gulleys and sunny steep slopes are often choked with matEtgouri and sweet briar. Isolated and clumped willows are present in some wat er cmJ.r ses. / - 6 - Rainfall is reported to be 1211 a year. Outcrop is gen erally alnmdant particularly in Rahbi t er ' s Hut Block; but tends to be r'a t her low and broken there. In Long Gully Block outcrop is often rarer.1..'b1..lt better exposed due to grea t er relief'. /

Thesis description:

70 leaves. Ill, photos, diagms, Map (folded in pocket); 30 cm.

Department:

OU geology Identifier:

1964Ryburn

Author last name:

OURArchive handle:

OURArchive access level:

Location (WKT, WGS84):

POLYGON ((170.227976466000086 -44.614158441999962,170.235481647000029 -44.616908047999971,170.300628977000088 -44.640733886999953,170.302055533000043 -44.641257718999952,170.329489930000022 -44.663181296999937,170.357380513000066 -44.685450170999957,170.365829093000116 -44.697842068999933,170.367115240000089 -44.701216147999958,170.3717349530001 -44.713340813999935,170.371560619000093 -44.7196216899999,170.37152122800012 -44.721079451999969,170.371193667000057 -44.733020377999935,170.371190275000117 -44.733096835999959,170.370833066000046 -44.746059014999958,170.370274747000053 -44.766323322999938,170.231722366000099 -44.763630177999971,170.231249769000101 -44.763330808999967,170.182843634000051 -44.731379043999937,170.182399727000075 -44.731084654999961,170.146386634000123 -44.707996932999947,170.012058319000062 -44.597831035999945,170.011967538000022 -44.597756652999976,170.002768160000073 -44.589873528999931,170.001705176000087 -44.588963499999977,170.003805001000046 -44.561959933999958,170.026097023000034 -44.56254271399996,170.087135314000079 -44.564109433999931,170.134899980000114 -44.565312124999934,170.18367937700009 -44.56651943199995,170.217959510000014 -44.567354888999944,170.230148658000076 -44.567650770999933,170.230080440000052 -44.569112434999965,170.230076661000112 -44.569193387999974,170.229802283000026 -44.575071521999973,170.229500341000062 -44.581538810999973,170.228890802000024 -44.594590296999968,170.228395141000078 -44.605199652999943,170.228320536000069 -44.606796225999972,170.22827829400012 -44.607700199999954,170.228203263000069 -44.609305766999967,170.228201582000111 -44.609341745999984,170.228120662000038 -44.61107323799996,170.228054451000048 -44.61248991399998,170.227977937000105 -44.614126959999965,170.227976466000086 -44.614158441999962))

Files

http://download.otagogeology.org.nz/temp/Abstracts/1964Ryburn.pdf

Collection

Citation

Ryburn, RJ, “A strip of Kaihikuan Sediments between the Otematata and Otamatapio Rivers, North Otago.,” Otago Geology Theses, accessed May 22, 2024, https://theses.otagogeology.org.nz/items/show/17.

Output Formats