Geyserland - a guide to the vokanoes and geothermal areas of Rotoru1 (2002) by 8NCe Houghton and Bradley Scott. Geological Society ofNew l.ealand Guidebook No. 13. 48 pp. ISBN 0-908678-92-4

lntroducClon

The publication in November 200:? of1he second edition of the Society's 'Geyserland' guidebook is most welcome. The firsl edition was by far lhe best seller of the OSNZ guidebook series (although the special Japanese edition never really loOk off, figuratively or liten.lly) and this updated version is sun: also lo be popular. The new guide is v1..-ry atlractive lhankli to the wide use of colour photographs IIJld lismes, an infonnative yet readable (and occasionally witty) text, and a pleasing layout and design. The authors Hruce Houghton 1111d Brad Scott are 10 be congratulated for their hard work and insight. So, too, is Simon Nathan who contributed many of lhe new, mosdy lop-quality pho1ographs that make lhe book especially attractive (there are more than 30 colour photographs in the book, some spectacular). Simon also helped maintain the momennun that ensured the book was published after various delays. The editor and designer, Hlleen McSaveney, Is also commended fot het work. As well u the lntcteStl.ng, content and auraclivc design. the booll. appeals because it Is printed on good quality paper (the ·silky' covm even feel good) and ii is perfect in si:ze (BS) for IISCI in the car and ror packing in the suitcases or overseas visitors. Finally, it is very reasonably priced (SNZl7.9S incl. OST and puatage and packing in New Zealand). for all lhese misons, it then:lfore deserves lO sell well.

Coatenl

After a very short introduction about the special character of the Rotorua di&tricc. the firgt ran

of the book is divided into appropria1.e sections dealing "ith (I) volcanism and associated nomenclature, (2) calderas (including descriptio11t1 af Rotorua and Okataina caldera systems), ( 3 J geothermal activity and associated features. and (4) Rotorua City and associRled volcanic features and hazards. '11,e second par1 provides descriptive notes and figures for three tours in the Rotorua area. Tour I covers �olhcrmal fields soulh ofRotorua (Wairakei. Waiotapu. Waimangu). Tour 2 encircles Lake Rotorua and Includes descriptions of the Whakattwarewa geyser field. and Tour J deals wi1b a trip ro Mr ramwcra. Maps and photographs illustrate the text for each of these lours. Unfortunately. Tour :1 suffers in comparison with the 01her lwo in that lhe proposed stops arc no longer readily acce!ISiblc: the Crater Rd section (Stop 1. p.45) is badly ov,rgrown, as is the comparable cunlng directly across the n,11d: and Stops 2-6 {pp.46-48) on Mt Tarawera itself are now closed to the public. being atcainnble only via (cxpcntlive) guided tours.

In my view, there are some deficiencies in the book. 11) Nomtncla111rt. M11ny of1hfo fnrm11l str1t1il!,"Jphk n11mes used for the depc,�its. although ,1111 valid, prc-da� the proposals nf' Froggat1 & Lowe ( 1990). For example. the authors refer to the

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Rotoiri 'Hrcccia., Taupo ·Pumice', and Whakaumc 'Ash', etc. (e.g.. see table p. 10). Most publica1lons now use the nomenclalun: of Frogptt &. Lowe (1990) or a leu formal but none-the· less sys1ema1ic system (e.g., 'Rotorua tephra').

Cl) Ages. The authors mis.•ed an opportunity to use calibrated (calendar) ages thmughout lhe guide. lnstead, a mix of calendar, radioCIIJbon and radiometric: ages is WICd. Radiocarbon asi:s can be calibnued 10 c. 24,000 cal. yr RP using [NTCAL91 (S1uivereta/,, 1991), and the use of11uch calibrated ages for eruptives is now common (e.g.., Lowe el al., 1999; Sandiford f!/ al., 200 I; Newnhllm et al., 2003). f'or example, the Rc:rc:whakaaiw eruption occurred c. 17,600 cal. yr BP, equivalent 10 14,700 I"(" yr BP, and the Mamaku eruption occurred e. SOSO cal. yr BP, oquivalen1 lo 72SO I 4C yr BP. There an: some Inconsistencies in usage. For example, ROIOid eruptives are recorded al 65,000 years old io lhe te,n but on p. 11 (map of paleo-lakc: levels) the) arc evldcmLly 42,000 years old. In fairness, the actual age of these eruptives is cummtly unc:ertain, and estimates range from around 43,000 to 62.000 cal. yrs BP (e.g., Lowe & llog, I 99S; Berryman el al., 2000: l.ian & Shane. 2000; Sandos el ul., 2001: Cbarlier el al., 2003). Nevertheless, tho same (estimated) age should be used throughout the guide. Similarly, Kaharoa eruptives are llsu.-d variously as 600, 600 700, or 700 years old. A wiggle-match date has been obtained recenlly for the Kaharoa eruption, the initial explosive plinian phases occurring in the winter of A.D. I 314 ( 12 (HOBS et al., 2003), equivalent to 636 ( 12 cal. yr BP ('BP' by conviintion being A.O. 1950). l'o avoid the endless problem of the Tarawera eruption occurring 11 !i years ago (p.10) or 116 Yf!81'11 lliO (p.4S) depending on when 'present' is defined, I would 11uggest using ·np• (i.e., before A.l>. I 9!i0) or 'before A.O. 2000', or simply list the calendar date or lhe fflli,tion, leaving the n:ader to calculate the nwnbcr or years that has elapsed aiDQe the even I.

(J) Canography. On p. 45 units A to E arc listed in the key but are not shown in the accompanying lisun:. This figure also uses the out-of-favour term 'airfall' (Lowe & Hunt, 2001 ). On Lhc route map on p.37 the roads are shown as dashed lines, a personal dislike (I prefer full lines).

(4) Disputable statements. (a) Page 3: A description or1he process ofvolt'BDism is followed by the sentence "Volcanoes are the re11Uhing landfonns." This is far too l'CSlriclive because volcanistn and its products modify landforms In various ways other than simply producing 'volcanoes•. (h) Page 9: The Rowiti Brcccla (lgnimbri1e) is described as lhe youngest lgnimbrite In 'the di!§trkt'. The validity or1hb, statement dq,ends panly on where the 'district' boundaries lie, but I suspect Man[laone Subimu1, units. Onlanul lgnimbrite, Taupo lgnlmbrite, or even Kaharoa crup1ivc uni111 might quullry for this chronological distinction. (c) Page n: The phrc111ic erur1ion in Kuirau Parl< (Rororua) of26 January. 2001. is reported to huvc lasrcd 10 to 15 minutes. ,\hhnugh a louristsign at rhe site also slates this. witnesses to the nenl reported a duration ot"\e�s lhun, minutes (one wilncss limed the eruption at four 1snd a h1dfmin111es) (Rn1.1er Bril!l.ls & :\�hie) C'ody. pers. comm. :?00�).

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(d) Page 34: In the figuR!, lhe entin: line of crateni fonned on the massif of Mt Tarawera in the A.D. 1 886 eruption is labelled 'cha.11m'. However, only \he sc1ulhweslem-most crater, visible at a distanu from the wc:st and south, strictly should bear this 111111JC (Kearn, 1 988; Lowe et ul .. 2002). (c) Page 44: It is stated that very fine ash from the A.O. 1 886 Tarawm eruption was blown south and eat to n:ai:b l lawke's Bay. Accordin1 U> Thomas ( 1 888), effectively no ash Wiiii deposited in Hawkc's Ray, all being blown north and east (the southernmost locality Ilona the east coast to Meive ashfall was near Tolap Bay) (sec aleo Keam, 1 988). The basis for 1he delineation of the southeasterly part of rhe map of the Tarawcra fallout zone shown in Pullar & Birrell ( 1 973) is uncenain.

Condmioa

The new edicion of 'Oeyserland' Is ui excellent publlcalion. lhe points noted above beillf or rdatively minor concern. lllc pideboolc Is IIICf'id bo1h fbr the sene,al public and•• J!1X1C1 S1811ing polm for siudents. It ls an Ideal sift ror ovcneas Kldemics and SIUdents who law visited the area. ([ hive sfven several c.:oples all'eldy 10 JaplllleR ,·lsllUrS.) ·n.c new colour pbolclpaphs and figures. lhe updlled and alllhoriiativc text. and the pleuing layoUI and production all providt for a well,priced and useful purchase.

References

Berryman, K.; Marden, M.; Eden, O. ; Mu,enprb. C' . ; Ota, V.; Moriya, l. 2000. Quaternary riv�, terraces of the WaipllC.la River, l!ast C"oast, New Zc:aland, and their tectonic and palaeoclimalic significance. New aaland ,/ournal of Getnuw untl Geuphysi,·s 43. 229-245.

Cbarlier, 8.L.A.: Peatc. D. W .; WillOII. C.J.N.: l.owc11stem, J .B. : Storey. M.: Brown. S.J .A. Z!!Q1. Cryslllllisation ages in COC\'II 1Uidc ma,ma bodies: 11 1ll _ :unTh disequilibrium e\'idence from the Rotoiti and Eanhqmkt Fiii enap&ion deposlti;. TaUJ'IO Volcanic: Zone. New kaland. 1':artlt and PIOMtary Scit11'-t Lltttm,; 206, 44 1 -457.

frol!Plt. P.C.: Lowe, D.J . 1 990. A review of llltC Quaternary silicic and some: other rephra formarions from New Zealand: lhoir straligtaphy. nomenclature. disrribution. volume. and age. New Zlmland J1111n1of o[G,11/u,o• u,,d CJeoph)�id 33. 89- 1 t>9.

Hogg, A.G., Higham. T.F.G.; Lnwe. DJ .. Palmer. J.G.: Reimer, l>.J.: NC\\nham. R.M. 201>3. A wiggle-march date for Polynesian settlement of New 7.ealand. A111iq11ify 71 I I ) in press.

Keam. R. 1 988. ··Tarawera: the Volcanic Eruption or 1 0 June 1 886'". R.F. Kearn, Auc:klar1d.

Lian O.B.: Shane P.A. '.!000. Optical datins or pale011ols bracketing the widespread Rotoehu tephl'll, Nonh Island. New Zealand. Q11u1rrna1:v .'il!le11c:a Re, •iews 1 9, 1 649- 1 66'.!.

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I .owe, DJ.; Hoy. A.G. I 9'JS. Ase of 1he Rotoehu Ash - comment. New Zealand Jm,rnaJ of

(ieolo,o, r"•" Geophy1lcJ; 38, 399-402.

I.owe, DJ.; Hunt. J .B. 200 1 . A sUlllmuy of lerminology used in lephra-relaled studies. In: Juvigne, E.T . .t Rayna!, J.-P. (eds) .. Tephras: Chronology, Archaeolol)"'. Le$ Doi,.,iers de I ifrche11·lo/l;8 I : 1 7-22.

Lowe. DJ.; Newnham, R.M.; Ward, C.M. 1 999. S1n1tlgraphy and chronology nfa IS lea sequence of multi-soun:ed silicic tephru in a montane peat bos, eUlem North Island, New Znlaod. New Zealand J1111rnal nf Ge11lofJ' and Geophy,ies 42, 565-579.

Lowe, D.J .; Newnham, R.M.: Mccraw, J .D. 2002. Volcanism and early Maori in New Zealand. Pp. 1 26- 1 6 1 in Tomnce. R. & Orattan, J. (eds) "Natural Disasters arid Cultural Chlln11e", R.nulledge, London.

Newnham, R.M.; Eden, D.N.; Lowe, D.J ,; Hendy, C.H. 2003 . Rerewhakaaitu Tephra, a land-tea rnarker for the l .ast Termination In New Zealand. with Implications for global climate cbanse, (Jualtrnu,:v Sci11nc11 Revle�· 22. 219-308.

Pul lKT, W. A,; Birrell. K. S. 1 973 , Age and distribution of late Quaternary pyroclastic and associated covtr deposits of the Ratorua and Taupo area, North Island, New Zealand. New Zt!nlunrl .\'r11l S11rw:y Rtf1(1rt I .

Sandiford, A.; Alloway, B.V . ; Shane, P. 2001 . A 28,000-6600 cal yr record of local and clisllll volcanism pm;erved in a paleolake, Auckland, New l..ealand. N�w Zealand Jo11rnal ,,JGe11lt1fJ' a,ld CJcophyrlcs 44, 323-336.

SandCls, G.M.: Bird, M.I.: Pillans, R.; Fifield, L.K.; Alloway. B. V � Olappcll, J.; Hausladen, P.A.: Ameth. A. 200 1 . Radiocarbon dnllng or wood using different pretrentmcnt procedures: applii:.111lu11 tu tlu: chrurwllugy or Ro1oehu Ash, New Zealand. Radiocarbon 4.J, 239-248.

Sruiver, M.: Reimer, PJ.; Bard, E.: Dcck, J ,W.: Burr. G.S.; Hughen. K.A.: Kromer, B.; McC'onnac, Cr.; v1n der Plicht. J.: Spurk. M. l 998. INTC AL98 radiocarbon ase calib111tion. 24.000-4) cal AD. Radiocurh,m 40, 1 04 1 - 1 083.

Thomas. A.P. W. 1 888, .. Repnrl on the Eruption ofT11111wera and Rotomahana, New Zealand'', Ciovc:nunent Printer. Well in111on.

David J. Lowe Depanment of Eanh Sc:icnce!o. I n i , ,m,ily of Waikato, Prh'!lte Bag 3 1 05. Hamilton

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