MORDENITE DEPOSITS AND ZEOLITE ZONATION IN TI-IE I-IORN MOUNTAINS AREA. SOUTH-CENTRAL ALASKA
Occurrence ol'morrlenite, /~e~ilandite,und 1aun.lontite lbr-nzecl by burial nzetar71orptzisn1 of'tnurine ~~itrictu/]s. T11e esterlsioc mortlenitc drposils nzay lzuvc f~c.onomic1niporlat1c.e. STATE OF ALASKA
Jay S. IIamrnond, C;ovc~t.~lor.
(;LI~ 11. hIartin, C'o~tl~~~issiot~c'r,I)rp(. (I/' :Vulut.cll ll'cso~r~.cc~s
Itoss (:. Schat't', Slalc Gcologisl CONTENTS
.\l)stt-:Ic.t...... Illt rotluclio~i...... P~1rl)Osc...... '\cl S:lnll)lillg...... -...... M;illl)ing ...... I,;~l)or;llorys[.~l(lic-s ...... MORDENITE DEPOSITS AND ZEOLITE ZQNATION IN THE HORN MOUNTAINS AREA, SOUTH-CENTRAL ALASKA photomicrograph ;~ndllis h(~lpfultlisc-nssions duritlg the‘ cc:llrsr of this work. hIy thanks art, also txstrntit~dto M.S. Extc.nsivc5 mortlcnit.ci-rich I~~l'l'soc.c~c~.ring wit11 t11(~ Itoh~riso~~for proparalio~l of thin soclions. Fillally, I 'I'alhe,ctn;~ I'ormution in lh(, Horn hIount;~ins;irt>;c 01' ~vish lo thank Irly so~ls.Mikc a~idHill II:~wkins, \rrho south-central Alaska ;irtS ol' cornn~c,rcial gr:itlcs. '1'111. stln~rdas my I'icbld i~ssist~~~lts. 1)rolwrties ol' tlir ~nortlrnitr~with rc.gurtl to cornnicrc.i;~l rccl~~irc,~ncntsnc~cltl I'urlh(>r st.~icly. l'hc zc~olitc~sin thcb arcs;1 wcBrc*l'orn~t,tl 1)) I)i~riiil tliagc~nc~sis;lntl rcx~ion:~l nic~t.;unorphism ol' lav:t ant1 Tllv zcolitcs ~ni~lcbr;~lsarc, of intt'rc,sl as important volcanic elc~lritustlcspositc~cl in a r~ugt~osynclin:rltrou~h. i~lcll~strial~nincbrals of' us(> ill a varic>l>.of fit,lcls. 'l'llc3 IIculandil(~:tntl I;~~~montitc~zonc%s suggcxst Illat. tll(' scltl- minc,relogical, c~homic~al,and inrluslrial propc,rtirls of thc irncnts wc>rc1sul),i~~ctc~d to :I tnaxiln~1111t(xnll)(bri~turcb ncl;lr %OO°C at watc,r I)rclssurc.s I'rom 0.5 to :i kilol)ars, wliic*h zc,olitcxs wrlro t)ric~fl~\.cl(~scribrcl hy Ilawkins (1973) 2nd corrc,spontls to I~uriuldcptlis ol' I to 10 hilomr~tc~rs. more r(bcc,~ltlyill two dr~tnilcclgct~c,ral rcvicw artic~ltxson Thcl occurrcLncc, of mortlc~nit.c~will~in tho li~~ill:~ntlitc~ thc usr and ~)rol~~~rtic~sof' ~c~olit(,s: hlu~npton ( 1973) and zonch is prol)al)ly tlucl lo lli(s I'ino-gr;~inc~tl11:1turc, 01' 11118 AIunson an:! Shtlppiirtl (197.1). 'l'liosc1 articl(~sshould br parent t.ul'fs, which c:ausc~d a high(.r silica ;tctivity th;~n co~~sult(~clI)!, t111:scb it~l(~rt~stotlill an ovcrvicw of' the‘ rlsewh(,rc in this /.o~ic,,Lht~rot)y 1)rotlucing ~mortic~tiitr. utility :uld (lc~onoi~iicv:~lut' of zc'olitc~s. i\nalcimc>, which occurs locally within the, mord(~nitc~ zoncb, may 1i:ivc~ I)c~clnSortn(,cl from t~iorclvnit(~01- I~(SII- lantlite lul'l's by the action 01' solictic,n:, IIi:tt wcsr1>marc, alkaline, Locally than c~lst~whcrc~in t.11c. /.oII(~. 'I'hcs l'ic.l(l I.cast I)y (:ull':c~ ulitl ot.ht.rs ( 1'17:;) giv(*h rtt- li;rI)l(. rcsults and sl~oultlI'incl uscx in zc.olit(1 ~)rohl)tscting. 'I'h(1 art,:t st~~tlic~ti(pl. 1) is localotl ul,out 12 ~nilcls INTRODUCTION north of' 'l'ahnc>t.ii Pass 1,otlgt~at mil? 12.1 of lhc5 (;lomi ilighway. 'l'l~cb arcs;l is ac~c~rssihlc~11y c~itht~roff-thcl-road PLJKPOSLC vc~liiclc3s,via roads to nclarby placc'r mincs; or hy float- c~quippc~tlfiscad-\ving airc*raft, \vhic41 can 1;wcI at So~~th 'l'htl primary purpost, of tllis stutly wah to invcstigat~' 1,akc on thc S~LI~~ICL~II~stro~iiiL>~ of tllc, stud) arc?I. thr ~nordcnitcdtlposits of tllc, IIorn hlount;~irls artha, upper Malanuska Valley, Alaska. A suhorcli~latopur- pose was lo preparc' a rcco~lllaissa~~ccgcbologic Inap of the arca sl~owi~lgthe geologic srtti~lgof tlic ~nord(b~~ittx 'I'hr sti~dyc.onsistvd of' invcbstigatit~gtht, zcolitization deposits. A final purposcl was to samplr otl1c.r arclas in of th(> lowor Juri~ssic'I'alkt~c>t~la formation in thcs IIorn lhr vicinity of lhcl study arra in stlarch of otllcr zcwlitcs hIounlai11s. 12s showll by (irantz (1965), splay faults drposits. This study is a conli~l~tatio~lof thi~l rr,portcld associaltld with thv Caribou l:ai~lt have‘ isolatcd ant1 previously (Hawkins, 1973). cssposcld a triangular sclction ol' thv 'I'nlkt~c~tn:~formation ill tiit> IIorn hlounl.ai~~sarc.:i. l'hc Talkcrtna forlnatioll in this arcLac,onsists lnainly of thick ~111itsof pyrocl;istic S;III~S~OIIOS,siltsto11(~, i111d I would likv to thank I).C. llarlman. 'I'.k:. Smith, ~untl claystono (co:rrsc, a11d fill(, watcr-laitl tuffs); a~idr~sitic N.C. Vtlach of ll~rAlaska Stat(%1)ivisioll of (;c5ologic;ll ;111d basaltic 1ava.c art3 also prc~sc~nt(pl. 2). Altho~~ghtllr and Grophysical Survrys for funding, logistic.al, iuitl formation is mostly marincl, ilo marinc, fossils wc3rc' zunaly tical support of this study. I also wish lo tl~a~~kIny found. LVood fragmt,~itsand casts wcro ol,st~rvotlill sointl coll(~aguc~,1)onaltl (:r?;brck, for his assii;tanc.c~ \r.illl LIII~~S.'rhv 'l':~lk~( locating and mapping tliis u~iit.The tuff, which supports little or no vrgclalion, forms an easily visible wliilr cap 'I'lle primary purposti of thc1 study was to detcrminrl on the ro~undvdhills at thr hratl of Albert Crrvk. In the extent and grade of 111(' mordrl~iitt>deposit in thc outcrop, tho tuft' co~lsislsof flat or partly c*onchoiclal area. To this end, fist-sized samples wrrr collrctc~clfrom fragmctits about 5 cm it1 tliamolt~r. IJnit ,Jlk-2 appears the numerous outcrops of tuffs, tuff:rcc~ous lvackes, and to br discontin~~ouslydistribut.rd \vithin map unit Jtk-3. lavas in the area. Plates 1 iuid 2 show thc localities Carcful srarcli rrvt,alcd no rxposurcs of tliis unit ~iortll- from which samples wrrt collectt>d. cast of the fllbert Crrrk cXxposures.IIowever. thc unit may rxtthnd to thr southwest side of Alfred Crrck, wllert> sample localitic,~79 :uicl 83 may be part ol' it. Morc tlrtailcd mapping is nredt~dhcrr. Because general mapping was of secondary im- Map unit Jtk-l consists mostly of volcmiic sandstones portance, the grologic map ihown in platc 2 is in- and basalt atid ;undvsilc flows. 'I'uffs are prrst~ntbut arts complete. Salient feat~~resof tht' map arc bast~don not as abutidiunt as in othor units. IJnit Jtk-1 forms tht) Grat~tz (1965)---particularly thc contact bc~lwc~c~nthc cliffs and the summits of tticb mounlai~lsat th(, hc,ad of Talkretna formation and thc 'I'~~xcdniformation, ;uid Alfrc,d and Albt.rt Cr(1t.k~. 'I'hr unit is c~stensivt~ly the faults ((lither mapped or infrrrcd): this rcport also zeolitizrd, iuicl contains abundant veins of chalky-wliitcx contains details of (J~1ater11at-ydcposits ~iotshown in lai~montitt,and largr~ 2- to 3.~111 vug fillings of pink plate 2. Mapping of the units within thtl 'Salk('clna Ilc~ul:uiditc~.ilt the head of Alfred Creek basil1 is a formation was done as part of tht, study. 'Sllr, map 25-foot-thic*k layer of 11iortlt~nilt~-richtuff; altho~lgh units shown in plate 2 arr based on hand-spccimr~i mapped as brlonging Lo 111iit Jtk-1, this tuff has brt>n properties and topographic c,xprr,ssion of thc units. dtsignated Jtk-2 LO draw attts~ltion to its ~norctenitc Map unit Jlk-5, lhc casternmost unit. consists mainly t~nriclimtxnt. of volcanic sandstont, (with some tuffs), and basalt and Zcolitv zonation (tliscussc~don p. 6) indicates that alidesite flows. Thr unit ii ~nodcratrlyallrrcd lo clay nit Jtk-l was tho most drrply buricd unit and is mirierals. Zcoliti~alion is not pronounced, although stratigrirphically t.h(> lowchsl unit of thosc mapped. Unit Jtk-5 is consid(~rc~dlo bc. the uppermost unit. 'rhis in- sands1onc.s. Unit Jtk-5 forms a st)rics of low, t~orthr~ast- forencr is supporter1 by lhc gelir.ral 20-degree south- trending ridges at thtx mo~~tllsof Albr,rt and North r~irstt~rlydip of Lhc litl~ologicutiits mapped. Creeks. l:i~ially, tllrl contact botwecln thc 'I'alkc~clna formation Map unit Jtk-4 is cl~aracterized b>, pu~i~ic~t~ousi~tltl utiits mapped I~c,rc ancl thcb 'I'~~srdniformalioli mapped vitric* tuffs with suborditlatc tuffaceo~~swackcs, t~nsalt, I)y (irantz (1965) was not dclerminrd in the prcssrnt and andesite flows. Zeolitization is morc tlxlcnsivr than st.~~tly.Conscquc'ntly, tho area in platc 2 bctwerti tho in unit Jtk-5, with h~~ulaliclilcvoid filli~lgsanti vcinlc.1~ norlllc~astc~rlylimits of tliis study and tllc 'l'~~scd~ii especially common in exposures of coarser lithologies formatio~lcontact of Ciralltz has brcn Irlfl blank. in tllc upper parts of Albert and North Creeks. Unit Jtk-4 is a swale-forming unit; that is, it forms the low, LABORATORY STUDIES rolling, gently sloping hills crossing the tnidsrctio~lof Albert Creek and is characterized by a thi~i-bedtled,tali- wcatliering tuff capping thrse hills. Map unit Jtk-3 consists of pumicrous ant1 vitric t~ll'fs X-ray diffri~ction pattrrns of thc. samplrs wtlre 01,- generally altered to mordenitr,. 1,ocal sections consist ol' taincd using tht. procc~durcs prc>viously d(~scribc~tl(Haw- ~nordcnitc-rich vitric tuffs. Unit Jtk-3 wcalhers to ir kins, 1973). Samples containing zrolitcs of the hcu- buff color and comprises much of thr illfrc~d (hek landitr-clinoptilolitc~ group \vrrtl hratc>ci following th(1 basin and the low hills dividing thr headwaters of Albert mclllod giwn by Alictti (1972). 'Sliis was tlont, lo dis- and Alfred Creeks. A purple and light-grwn luff hori~on tinguish bctwt~en hculaliditc a~idclinoptilolitc inid to of this unit oftrn forms the conlac-t hrtwtvn map nits obtain informatioti on thts chemical composition of thrx Jlk-3 and -4. 'I'opographically, 111lit Jtk-3 occ~~piclstht. hc~ulanditr,inaslnucl~ as its thermal stability varies with break in slope separating the cliff-forming unit Jtk-l its cllrmical composition (Alirltti, 1972). FIt~i~landitt~ant1 (below) from the swalr-forming unit Jtk--1. ~nordt~nitctogtltlicr artb clil'fic~~ltto dt~lt~ctl)y mt3atis of Map unit Jtk-2 is a fine-grained, mord(.~iite-richtuff. X-ray diffractioli brcausr~ tlicy share Inany peaks. Al- 'She tuff wrsathrrs to tannish white and it1 some loc*alitics though it was 11ot ust~cl ill tliis stucly, thc lechliiy~~c~ has the appearance of porcellanitr. Wood fragrnclnts atid dvsc,rib(d by Sudo ;uid others (l963), which relics on casts can be found in some exposures of this nit o11 th~sc>lec-live clissolution of Ileulanditr (clinoptilolite) ill Albert Creek. Ofte11, thin rosc5ttc.i of radiating tnordt~~nito 6S IICI, may I)(, i~sr~fulit1 subseyut>ntst~~tlit~s. Sa~nples crystals, 112 lo 1 cm ill diameter, art1 prrlset~tin tht~tuff cont:~iliillg 10A clay 11rinr~ralswere treated with rtllylcnt~ partings. These crystals are r~xc~c~llontI'icld guid('s in glycol and X-rayed again to drl(1rminc thrs prrsrsncc of landilc I'rom t)otli Lhtb h(~~~lanclilt~atitl niordrnilr, zones lo srcL if lIt(1 polyluorpllisni ol 11it1 1icul:uidilr could br ilscd as a basis oi' cotnpnrisoli. 'l'he li~~~li~lltlit~~c~xliibit~d similar polg,~nl.)rpl~ihni,bcilig tr;ulsfortnrtl to IIculandile- 13 when Iioatc~d I'or 18 lioi~rsul .150~)C;ill sornc cases, Cull'i~z and ollit~rs (1973) proposcbtl :I simplv field samplcs from ho~lizolirs sliowt~dlhr ilil(~rlnrdiatt~pliasc test lor zt,olittls hasrcl upon llir c~ntlialp\~of Iiytlratioli ol' FIoula~tdilr-I,dis~:usscd by Alicatli (1972). On thr basis tl(1Iiydratcd zrolite,~.I)cliydralt~tl zt~olittbs rcsact c~rollirr- of this ttbst, it is conclud~~tltliat no gross compositional malty wli(sn liydraltd ancl cbshibit a r:~pitl ~uldpro- diffrrt~~icc~sc3sist I~rt\vrrntliv h(~~ila~idilr~sfrom tlic two nouncrd ternpt~ral~irc~i11c:rcascs. 'l'11(~ amoullL of thc zo~los. tr~mpt~rati~roincrcasc' dcpctids ot~tlio typr ittiti quatilit! 'I'lir zotlc3s distiligi~isllc~dhr~rcb cwrrcspond to Lliost~ of 1111> zeolite prc5sctnt. 'I'liis lt>st was ctarrit,d 0111 ilndcr ot~sclrvtdc~lst~v;hc~rc~ throilglio~ct Lhcx world iilld co~istit~itt~ laboralory conditions using a mi~t't'lv I'urnacc, it1 wllic,h the, zeolites fac,icas (Scki, 1969; Coolnbs, 1970). Figurt. 1 5-g samplcs of powdcrthd zeolit.izt~ti luff c~ol~laillrdill shows possibl(8 I)rcbssLlrcx(1') vs trlnl~rralurc ('1') fitllds 35-mm film c~atiistrrs wt,rtl Iiratc~ct for 1 hour. 'l'lit~ ~ltidrr w11ic.h tlio various asst~lnblagc~sarr stable. As samplcs wt'rc> cappcsd and c.oolt~Ito room tc~rnpc~ralurc~. sliowti by %(%II (19(il) al~dI~ricfly disc~~tssotl prclvioilsly 'St,n millililrrs of walthr a1 room tt~mpc~ri~tiirt~\vcbrtb tticln 1)) IIawkilis (1973), 11111 c*lit~micalpol(1ntial of water added to :I sampltl and thcs slurry was rapidly slirrcstl with ill 1111, s).sl(lln i> pt,rtiaps tlich most c.ritic*al variable ;I laboratory th(~rmoi~ictor.'1111(> tc51npt'raturct of Lhcs :tl'l't~ctitig zoolitc, stai)ilil> rc~latiolis.'l'ht, morr hydrous siumplc brforcb 1110 acitlitioti of thc~watvr allti th(3 111as- zcoliltbs mortlonilo (CaAI,Si, 002,1.711,0) and lirulan- itnutn tt3mpc,rati~rcbof tho hydr:~tt~tls;urnplo \r.rrcz 01)- tlitcl ((~i~A12Si7()lX.(i~~20~rrc~stablrx irndrr a Iiigli clicmi- sc1rvc>tl, slid A 'L'. 111(1 diff(~ro~icc~t)r>l\vc~tan tlic~sc~ two c,al pototitial 01 wattir, whr1roas Lhc I(sss hyclro~~szrolilcb tvlnpc'raturrs, was rcbc~ordt)d.'i'l~is I)roccbss was rt,pc~at(stl 1u~inlo1ilit.r((:aAI,Si,iOl.j..lII,)C))) is Irss slablt> ilntlrr lor cacll samplr. 'l'llc. rcs~iltsof this k~starts shown in LIi~~st~ctonditions.-'1'1lc c.~r'lnici~lpotrlilial of water in tat~lt,1. (Cornpart, with IIawkins, 1973, t:~blc 3.) thcs s\.slrtn varicbs with tl~vpartial prrssurr of water and s:tlitiit\.. Illc~rcbasilig salitiity of intrastrntal waters at dt~plhhas 111(, same' cll'lcc~las incrrasing tr~nipcralurcin 'I'llo activil), of silica in th(> systcni is another im- port:uit varial~lc~.111 going from mordrllitc1 Illrough 22s showl~ill ~I':~hl(>1, mosl oI' thv s;tmpl~~sc~oll(~c.t(~tl Ilt.ularlclit(~ to la~~~no~itilt~tllcrc, is a progrrssivc de- \vclrcl zoo1itc~-ht,ari~ig;rnortlt.liitt3 anti lic~uliuldiLC \st,rcbtlic, silicalioll. I'ossit):~, reactions I'or calciurn end-~n~mbcr mosl al)irritliu~l zc~olit(ls,iuitl lau~iio~rtit(~iultl atial(,ilnc> \tcsrt>tliv lt~i~st:~b~~~itl:i~it. %t>olitrloc~currc.tictcls for loc~alilit>ssIio\v~~ ill plato :! arti cxspc~c~inllyititcxrc,sting. 'I'll(, ty1)~ ol' ~e~olitt~(ti('- tor~iiiti(~tIl~y X-ri~y tliI'fr:~(~tio~i)o(b(,t~rri~ig ill :I givt~ti Iocalily \vns plolt(d oli a si~m~)lc~-loc-~rlit!.rnap. 1;roln tliis plot it LV:I~ ~(~t~tithat hc~i~lu~clitooccurrctl ill two ~ot~c~s,~nordt~nitc~ ill ollc, zonts, lai~molltit(~it1 ~111ot1it.r zollrL. ;rut1 a~~alc.inlcxin t\+o localitic~s tr'ithill thts Inor- d(stiilt3zo~io. 'l'lits zc~olitr,zolicts art, tl(~li~~c~al~~tll)y bollntl- ar) (.ilrvt5s c~~ll(~(l~(aolitt~ isogratls (pl. 2). :l~ioLl~t~rzotitb cl(bsig~ii~tcb(lill pliitc 2 IS 111~~quitrt~ LOIIO IS tt~titittiv(~1) ()u;~rlz \V:tlrsr suggc~stt~cl.'I'llis zoticb('!) is l~asc~tloli 1n.o siimplc3s in :i~i0.)- 2 lI'>O nliicli zc~olitt~s\vcsrcb absc,t~lallti quart/ Iintl I'illc~tl 111~~ Otiior rc~actioltsartx possiblt, slid Ilavc' l)t.rn c~slt~nsively I'racturc.~:u~d cc~mc~nletl thc grains. studitad by Svki ( 1969, 1972, 1973). 'I'lic positio11 of [lit. Iai~~iio~ilil(~xo11~~ 15 11oL LV(>II Rrnctioll 2, or ;I variant itl\,olvilig plagioclasc~,srcms ~~stal)lislietl.01iIy I)e~l\vt.c~~lsiutiplt. localilirbs :iH iitlti 39 to ha\$(! occi!rrt~tl itt tli(3 arc5:l sti~ditad, inasmilch as (pl. 2) is tlicb I)oi~lltlorywell knoivn. Nt~vc~rtlrt~le~ss,tlial a si~iiiplc~s76 :~iitl :;(i,hot11 appart~llllysi111iIar Iapilli l~iffs, lai~nionlitczolic) c~sislsis t~uscdon lllis 1oc.alioii. OII thc l~avtl I~rsc~i;~ll(arcltl to Iit~ulatitlitr':inti quartz-laumolititr- ~~t)~~~id;uilIn~irnolitilc float c~ncoi~tilf~rc~tlat (II~, Iltnad of c:tl(.i to, rt~sl)c~c~li\(,I?.. Allrtid (:rcoIc. atld oli tl~t~abst~~ic~~ of tllc, assoc.iiiLioii t\s rcbac.tioti I shows, thtb I';)rmation of niortlcnitc la~~montil(~-~i~orrio~iilt~.'I'Ii(5 c9virltinc~t~ s~cp[)orls tlics cay- rcbq~~irclsa higlic,r :tc%tivity ol' silica Iliati dot's lit~~ilanditc. istt~tlccof 21 I:u~tno~itit(% zoncb tliiit is apparcblitly scsp:~ralt.d 'I'hch ~x)siliot~occ.upicd 1)). mordtbnit(' ill the ~oolitc t'rotr~thrl ~nortlt~t~itc~~olit, by a Ii~~i~liuiditt~zollt.. I'acicbs is prtSsclill>. a sill)jrc.l of dc1hutcx. Ulnda (1970, 'rho uiltlior c~x~t~iiinc~d---t,!.Llit~rniitl stal)ilit! ---II(~LI- 1971), for c~xanlpl(~,shows Illat n~ordenit(>occ-ilpirs TABLE 1. Sanlplc, Itartd-sprcirr~crltlcsc.r.ipIior~, czrtrl rttirzc,ralo#.y (1s tl(~lor~~ir~ctlh,v S-ray tli/'/'racliort artti rc,sulls o/'/'icltl Icsl Tufl'accous wachc Quartz, fc.ltlspar, h(~ul:rntlitt~ Tufl' Quartz, l'c~ltlsj);ir,chloritcx, mortlcnitc Tuf'facc,o~~sw;~chc, Qugrrtz, fc~ltlsp:rr,chloritt), h(~ul;tntlitc~ Tul'faccous wachc Quartz, I'ttl(lspar, hc~uliintlitc Volcanic irrcxnitc, Quartz, I'oltlspar, chlorite,, hc~u1;intlitc Siltstone Quartz, niontmorillonit(~ Basalt Fc.ltls[':lr Pumicr~ol~s1 ul'i' Qu;irtz, I'c~ltlspar,hcul;inditc~ B;ls:llt 1''0ltlsl)ar, nlontlnorillo~~itt~ L)acitc%('!) Qu;irtz, I'c~l(lsl)ar Basalt, ;tltc,rc~l Quartz, I'cbldspar, mortlc~nit.<~ 'Tuff:tccous w;ickcy Poltlspar, chloritc~ Basalt Q~~artz,l'cltlsl,ar, n~ontmorillonik Vitric tul'f Qu;rrtz, l'c~ldspnr,hrul;tndit(~ Antlesibc~ Fc,ltlspar, chloritr 'l'u l'f'nccwus wackr Quartz, I'c~ltlsl)ar,hc~~llantlit' Vitric tufl' Quartz, I'eltlspiir, hc~ul~lnditc~ Vitric tufl' Q~lartz,I'c.ltlspar, mortlcnitc, Vitric tlll'f Quartz, l'eltlslxir, morclcnitcs Tul'l'~~cc~ousw;tchc, Quttrtz, I'oltlsl)ar TLII'f~ic~~c~us witcko Quartz, l'(~ltlsl)ar,lrc~~~lantlitc. 'TLI I'l'acc~ouswacko C;tlcitc, ;~nalcinic~ TLIfl' Quartz, I'cltlspar, tnordcnitc, T~~l'l'acc~ouswncko Quartz, l'cltlspar, hc~ulantlite Tu l'l' Quartz, l't~ltlspar,hculantlitt. 1,apilli tuff Qu;~rtz,l'c~ltlsp;rr, hc~ulantlitt~ Tuffaccous wackr Quartz, fclltlsp;rr, hculanclitc Tu ff Quartz, I'c,ltlsl)ar, mordenitc. Vein filling C;rlcitc,, 11t~ul;rntlitc~ Vitric tufl' Quartz, I'c~ltlspar,tnortlcnitc Tu l'l'acc,ous wac kc Quartz, fc,ltlspar, montmorillonite 'rul'l'acc~ousw:ickc~ Quartz, l'c~ltlspar,hculnntlitc Quartz-hc~ul;intlikvein Qu;irtz, lic~ulan(litc~ Tu I'f Q~~artz,Scldspar Vitric tul'l' Quartz, Sc,ldspar, hc~irlantlitc~ Vcsicul;~rI):is;ilt Tul'l'acrous wackc, Quartz, I'eltlspar, hculantlitr Tu fl'ac<~ouswac kc Quartz, I'cltlspar, chlorite Tu l'l':~ceo~~swac kc) Quartz, l'(~ldsp;n,heulantlitcl Tuffaccous w;icke Quartz, feldspar, 1ic~ul;intlite L:tpilIi t~il'l' Quartz, calcil.c~,1;tutnontitc. 'Tu l'l'accous woc kc, Quartz, I'cltlsp;rr, heulanditc Basalt Fcltlspar, chlorite,, hculandite Vitric tul'f Quartz, I'f,ltlspar, niortlcnite 'Tufl'accous wackts Quartz, I'cldspar, montmorillonite L;ipilli ~LII'S Quartz, I'c.ltlspar, mortlcnite TLIl'l'acc~ous w;tchc~ Quartz, I'cltlsp;ir, hculanditc~ Tu 1'1' Quartz, I'cltlspi~r,mordenitcl Tu fl' Quartz, l'olds~)ar,morclrnite Ilculantlitcl vvin IIculantlitc Lapilli tul'l' Quartz, I'eldsl);tr, mordenite Tu rl' Qu:~rtz,I'c~lcls~)nr, mortlenite L:tpiIli tul'l' Quilrtz, ht~ulantlitc L;rpilli tul'l' with ht~~~l:tntlitc~,1lo Quartz, I'c~ldsl)ar,hrulantlitc Lapilli tul'l' Quartz, I'eltlspar, mortlenitt, ;\ntlesite MOK1)15NI'l'b: I)I~:P0SIrI'SAN11 ZEOLITE %ONArrI0N IN 'l'lIfS IIOltN bIOIJNrl'AINS AltKA, SOLJ'l'~I-C1~~Nf~~tAIJi11,ASKA ------'I'LI~'~',l'Io:1t Quartz, t't~lcls1)ar,montmorillonitc. 'r'ul'l', l'l0:1t Quartz, feltlsl)ar, hculantlitc rr'~ll'l',l'lO21t Quartz, c:ilcitc T~~l'lhccwuswnc kc, Quartz, feltls~)nr TLIfl' Quartz, frltlspar, montmorillonilc Clayslonc, Quartz, I'ctltlsl>ar 'r~~l'fwith zc~olitr(?)vc~inlot Quartz, fcltlspar, mortlc,nitc. 'I'ul'l' Quartz, hculatlclite Tul'l' Quartz, fc,lclsl)ar, hrulanclitc Tul'l'ncr~ousw;~ck(a Quartz, l'eltlspar, mortlcnitc, 'I'lll'l' Quartz, fcltlsl)ar, I:~umontitc F(slsic tu l'l' Quartz, fcldspar Fcalsic tul'f Quartz, fc~ltlsl)ar P(1lsic lul'l' Quartz, feltisp:~r Pclsic tul'l' Quartz, l'rl(1spor Fc,lsic tu l'l' Quartz, I'cltlspar, niuscovitr Fe~lsic1~11'1' Quartz, Sc.ltlspar Vrlsic tul'l' Quartz, fc.l(lspar, niuscovitc~ Fclsic ~LII'I' ('1,r dbb. . Fcllsic tul'l' Quartz, l'c~ltlspar,n~ontmorillonite Vug fillin2 in I'rlsic tufl' Hculandite L;ipilIi ti~l'f Quartz, L'c~ltlspar,hc~~tlantlitc Vitric t~ll'l' Quartz, hculantlitr '1'11 l'l'~tcc~o~~sw;lc kc, Quartz, feltlsl~ar,heulanclitc '1'~1t'l';lcc~o~1sw:lc kt, Quartz, l'clcls~~ar,hculan(litt~ Vitric tul'l' Quartz, l'rltlsi)ar, mordt~nitc~ Pumice, with ht~~~l;~ntlitt~ 1 Iculanditc Vitric tul'l' Q~lartz,feltlspar, mortlenitc Lapilli t~~l'l' Quartz, ft,lclspnr, hc~ula!iditc. Vitric tul'l' with mortl(~nit(~crystals Quartz, l'eltlsp;cr, niordenitc. Vitric t~lff Quartz, l'c~ltlspnr,mortlenitc~ Vclsicul:~r I):ts;~lt, I'lo:it Quartz, l'cltlsr>ar, I;lumontitc, 'I'11 fl', l'Io;1t Quartz, hc~ulantlitc~,mont.morillonitc TII~'~',l'loat Quartz, I'clclsl~ar,niontmorillonile 'rlll'l', I'IO~lt Quartz, l'c~ltlspor,Iaumonlite Vesicul;ir I)asi~lt Pcldsl~ar,motitmorillonitc Lai)illi t11l'l' Quartz, I'cltispar, mortlc~nitc~ Lapilli tufl' Fc~lclspar,montmorillonitc~, hc~nlandite Quartz, opaline silica vcsin quart^ Tul'l' Quartz, fcltlspar Vitric tul'l' Quartz, mortlc.nite Hrulandite vug l'illing Hculanditc, Tuf l'acc~usw:lc kc, Fcxldspar, hr~~lal~tlitc* L:ipiIli ti~l'l' Quartz, I'cltlspar, monlmorillonitr~,heulanditck Vitric tuff Quartz, l'clclspar, tnortltsnitr Tul'l', I'lont Quartz, l'cltlsl>ar, hvula~lclilc TLI~'~',l'loat Quartz, l'eltlspar, mordc~nitc~ Vitric tuff Quartz, l'cltlspar, mordcnite Basalt Feltlspar, montrnorillonitc~ Putniccs with zewlitci:') I'loat Quartz, l'c~ltlspar,Iaumontite Tufl' Quartz, f~ltlspar,n~orclcl~itc~ Tul'l' witti h~~ulanditc~vc,inlrt Quartz, feldspar, heulantlile Lapilli ti~l'l' Feltlspar, monttt1ori1lo11it.r Hcbulantlitr co1)I)lc~ He~~lantlito l'ul'l' Lost sample, Vitric tuff Quartz, l'c~ltlspar Tu t'l'acc,ous war kc, Quartz, l'c~ltlspnl 6 SPECIAL REPORT 9 the lowest P-'I' rclgion of thr3 zeolite facics (fig. I), drawn arc, very Lrntativc. Both calcite and analcitiie whereas Seki and others (1972) have1 shown that occur in t.his samplt.. As is evident frotn tabltl 1, calcite mordenite can occupy a P-'r region extending well into is 11ot a colnmon constitut'nt of the rocks studird, and the laumontitc1 zonc. Srki observed that mordenite in thc occurrc~nct~ot' calcite, in this rock is very likely as- these cases is confined to finr-grained pumice tuffs, sociatr~dwith the occurrc>nce of analci~nc'.In samplr. 21, where it was forrnrd by devitrification of glass shards c,alcilv occurs as matrix and as ccment for the 'frame- The relatively coarse-grainrd, morv permeahlc tuff brec- work' grains of analcilnr and as psc1~1domorplisafter cia~associated with the1 puniicr tuffs were1 allrrcd to plagioclasr. Where frcsli, unaltcrrd-appearing plagio- laurnontile or prelinite. Apparently the restrictrtl pcsr- (*lase (An45) grains are abundant it1 many otlitlr san~plcs, meability and tlir greater reactivity of the pumice only calcitr, pseudomorphs remain in the plagioclasr in tuffs permitted thr rrquirtltl rlc>vatr>dsilica activity to be samplr 21. In this saniplr, ;unalcimc seem.; to have reached for mordenite formation in rocks that othcrwisc f'ormcd from p~i~nictfragmrlnts but, ~uilikemordcnil~~ alter to tlie lau1nontitc~-pre1hnilrasseinblage. or hc~ulanditt~,whicli replace thc1 glass sliards and prrx- sc'rvck thr texturc. of thc sliarcts, no sliardliktl tc,xt~~rc rr,mains and thc analcime forms aggrc'gatrs of cvstals. Chlorite 13oltls (1972) cliscusst~d thr formatioli of analcimt, from Iit~ulanditc~atid c~linoptilolite,and pointed out that --. - this modr~of formation is favorrld by alkalintl solutions. -.- - kIc~ sLatt,s that in t.lits hlurikiku Supergroup, Soulhl;uid Nt8w %t~al;uld, both calinoptilolitt~ho~~lantlitr uncl an- -0 alcimr ocacur in alttxred tuffs---locally in the s;unt3 bed. F~~rlliermorc,as hr, disci~sses marine sediments, lhr rt.qi~isilo high ptI for analcime formation can he ob- tained by loss of CO,,- from sea water isolated from thc "**, Heulandite atniosphrre. An ;u~alogoussituation may have prrvailt1d *** : I'or the analcime formation in sa~nplr21. 'l'l~r>calcite)- *$ Analcirne- ::- " analcimtx asse~nblagc,could l~avrfor~nrd by the' altc,ration * Q~~~~~ 34)2 ~airak;te ~otdenite 2 "3 of a mord(~~iitetuff in a locally alkalinc eni~ironmclnt, I which was crc>atptl by isolation of i~ntrastratal fluids fro111 t11t. ~~trnospht~rt~,loss of C02 to form calcittx, ~uld finally lhr prc>cipitation of analcimc. Again, tl~iscon- Temperature (OC) clusion is Lc~nt:~tivc~ancl lnorc3 tlctailctl ch(~mic~~liuld pc~trograpliicstuclic~s arc1 ncscdt~tl. FIGURE 1. Possihlc ~)rc~ssure-vs-te~n~)c~raturc.I'ic,ltls I'or low-gracie mineral facies. Arrows ~.cxprescnl I':~cic,s 'I'hc, ~~biquilo~~soccurrellccy of quartz in tht, s;i~npl(~s series as follows: (1) high pressure, low tem- rc,quires com~nr,nt.With tlnr few c~xct~ptionsof siumplt~s perature; (2) intermcadiate; (3) low prc,ssure in- 92a, 92b, 77, :uid tliv quartz-lau~no~ititc~rocks (samplc>s termediate; (4) lowest pressure. [Diagram from 3.1 and 74), q~iartzis not rradily c'videlnt pelrogra- Coomhs (1970).] l~llically.'rhea fr;~~ii(>w~rkgrains in tlic, t~~ffacro~~sw:~ckcs arcs plagioclascl, pumice‘, and lava fragrncnts. 'l'hr, X-ray With few exc:eptio~ls, mordrnitr occurrclnces are diffraction study clrarly sliows that the pumicr frag- confined to tuff's with 1ie~1l:uiditr~occurring colnmonly ~iic~ntsand the, matrix of thcsc rocks liavcx hcscbn nltvrcd to in the coarser-grained tuffacrous wackcs (table 1 ). 'l'his zeolites ant1 ~nicrocrystallinc, q~~artz.Vitric tuffs arc, observation is also evident frotn figurcl 2, wl~ercit is similarly altt~rc~tl.'l'hc quartz-zc~olittlassociation suggr,sts seen that tlie mordenite zo~iris more or lrss confined to thr followi~lggt~nc~ralizcd rr,action: map unit Jtk-3, a map unit dominated hy tuffs. Pt,lro- Auclvsitc~('!)Glass + 1Vatt.r + %c~olitrs+ Quartz graphically, mordenite is not a cornmoll void filler in tllr coarser lithologies but is confined to pumictt fragrnrnts. ,I111(, appar(1nt sy~igc~nolic~association of quartz iuid the' vitric tuffs, and voids within thtlsc> fin('-graint'd rocks. ztwlitt's mordcnit(> and hoi~landitt~itiiplic~s Illat Ihr From these obscbrvations, tht, mordclnitc occurre,lic.c ill activity of silica in the di:~gcnc>ticssystem in wllicl~tho this area may be similar to that dcscribc~dby Stbki (l97:I; zrtolitrs Sortntd was controll(d by the solubililj. of and othclrs, 1972), and the formation of mordo~iitvin quartz. this area is controlled mainly by thrl nature, of tlir l'hr prtsse3ncc>of q~~artzas vcsi~i filling iuid crment in reactants and secotndarily by the‘ P-'I' c,o~iditionsof sampl(ss 92a and 92b is striking. This may bt~a strictly burial. local occ*urrcancc>of quartz; howc~vr~r,tlic absc)ncc, of Analcinie occurrc,ncc,s sr,thnito be localizc~tlwitllitl tho zc~olitosatid tli(x oc-cburrt1nc.tLof quartz it1 thcir slcatl niay mordenite zone. 'l'o datrl, only onex sa~nplr(No. 21) has suggest tht. c~xistc~ncc~oT a possiblr quartz zo~ic'(pl. 2). been petrograpliically studird; Iirnccl tlle cor~c-lusiotls If this ~o~nc~is valid, it rc~prc~sc~ntthrl lowe~stI'-'I' zotic' of diagcnc~sisand burial ~nt~ta~iiorpl~is~~~. more carc>ful c~x;iminatio~lof thcsc tuffs should bt. 'I'licrr appear lo bcl two zrolilc zontLs,lieulaliditr~ a~lcl carrird out; Ilowovtlr, yet-~~ninvt~stigatrdosposurcs of I;u~monlitc, indicalivr of diffrrt~tititlte~lsitg of rnt'ta- the Talkc'rtna fornlation in tllr gcncral area should br ~norpllism, and thrsr zonrs prohably for~nt>dill re- studied first. sponsc3 lo low-gradr niclalnorphism of volciuiir dtbtritus in a t3ugcosynclirial trough. '1'111~ ~nordr~litt.tollt3 rc- prc~scntshculandilo subf;~cirspressurt3-t~mpt~ral~~rt' co~l- ditions kuid its occurrcncch in this zo~lc~is d~1t8to tht, 'I'tie mordt~nitt~-richtuft's tlrsignated Jtk-2 are of conlrol c~sc~rlt~dhy lh(1 rc,actants. 'l'llt, ocCnrroncc~of potential economic valutl. 'l'he areal rstent and thick- arlalcinlc is tlucb lo local clichmic:~l contlilions c~sistr~llill nc>ss of tlir~srbluffs arr sl~ownin plate 2. 'I'he eslrnt of lhcs mordonitr zoncl. 111t, morde11itc.-tuff horizon ill the upper hclulanditc Bt,causc, thc~ posilioli of thci l~o~~lantlil~~-li~~~~~~o~itit~~zone at the Iwad of Alfrr,ci Creek retnairls lo be dc- ho~~ndarydc~prnds on thcl salinity of tht' s\.stt1m irl which tt~rminrd. 'I'his Ilorizon is certainly more t.xtensive nietamorphism occurred. the> irolcanic st~dimenlsin thc~ tllan is sliowu in the plaltb: t~owc~vcr,time did not plrmit ctud?; arrb:i coulrl Iiavc brthn subjt~clcd to mnsilnu~ii tilt, horizon to bv traccd 1'~1rtht,r. lvrnpc~rat~~rcsaround 200~)~and ivatvr prvssurrs pro- An cstimatt~of' tlio gratlc of tlic mordrnitr tuffs can bably aro~cnd0.5 lo :I kilot)ars. l~lcrt~ast~tlsal~nit!' of I)(, tniidt> from tilr rcsults of thr zr'olile ficld test (table LII(> sysl('~nwoultl 1owt.r Lhcx l.c~lnpc3ral~rrr~of tllt3 11t~u- 1). 'l'he samples shown in tablth 2 (clsct1rpted from lablt, Iiuiditr-la~~~no~~lil(~boundan. Sodimc~nts in Lhc II~XLI- I) art1 from ~niitJtk-2. 'l'lit, ~nordetiit(l-ric.11samplvs 79 Iiuidilc zoncb wcrc Irss drcpl?; t~uricdthan we3rcxtllosci ;uitl 83 may also t)tb from this unit, but lnortl dillailed napping is nrr~dedLo Platc3 1 sllows tl~ta 1oc.atio11 from \\llicli sa~~lplt,s wtsrc' takc,n lo in\t~slig:~lt~possit)ltx tt$olitcl localitit.5 in o1lic.r parts oI' th(, Ilorn Rloilntains (:;~ril,o~~('rtbok arcw. %t.olitt>s arc prtbsr3ntin sampltls (Nos. 50.58) morcl or It~ss c*onfint>tlto tht' prt3vio~lsl\.~nt~ntiont~d scbg~nt~nt (1). 2) ol' t11o 'l'alk~~c~t~~:~I'orni:~tion. 'l'l~is:lrtba slio~~I(lIw inccbsLigal(d t'urlhtbr to rit~tc~rn~int~if xcsolitt' d(,posits ol' possil~lvtlconomic* value' are prt~stant. 'I'hc~ lack of zt~olitcssin samples from localitic~s60-6.1 kcas disappointing. 'l'tlc~st,s;~mplcs arc, from :I lllick. ~vcll- clsposcd sclqiltxncr of Tertiary fclsic luffs at thc~Ilcbad- bIrs;~n 10.8 ivatcrs of Caribou Crcvk. Ksc-ttpt for a fr>w zc~olitcsin St;~nclnrcltlcviation 2, 3-1 vugs in \rcsict~~larIavas associat(~tl with lhcs tuffs, no Synthetic sutliu~n ztwlitcs wtLro found in this iiroa. %~~olitiz;~tionof local mordc,nitca' I 6. :'I bvds within lht, l11t'f srbyucnct, m;q. I)(% prc,st,nt. but largo-scaltl zc.oIitizatio11 of Illr, lypc shown hy Lhct 'I'alkt~t~lnaformation dotss 1101 sescbln to htn prc~sc~nt.il 1)y IJnion Carbide :und Norton, rc~spc~ctivcly(Mumpton. diagc1nc'sis and regional n~tltamorphismof volcanic de- 1973). 'l'horc arc scvcaral patc,ntrd processrs (Hawkins, tritus dr,positrd in a rugrosynclinal trough. The ex- 1973, Appendix I) for t.ht. brnc,ficiation of zc,olitc, orc,s. istrnce of hc.ulanditc1 and laumot~tilez0nt.s indicates a In ;~ddition, Norton h;~s dt~vcllopcd :I Ivac*hing procac5ss differc~ncein mclamorphic gradcl of the rocks in the I.1iat yickltls a zc,olitcs procl~rclwill1 atlsorption propc,rlics arm, with liculanditcl being the lower grade mineral similar to thoso of sg~ntllc~lic~nordrnilc (Sand, 1968). and laumonlitr the higlirr grade mineral. 'Phis difference (An idcia of tilt, propcrlic,~01' 1110 ~nordc,nitr tl(,posit in grad(, lnay he du(> to thcl difference in depth of sludic~tlI~t.rc, can ht, obtainc,cl from tl~t,data shown in burial, that is, the volcanic srdirnents of Horn Mountains 1.;11)1~~:I of Ilawki~~s.1!173.) It1 arltlitio~i.a rapid ~ncbtllod and thosc~at lli(3 head of Albc~rtCreek werc morr deeply for tI1(1 c>valuation of adsorptive propc~rtit's of zt9olitos buric1cl than wrrtl thosr at the mouth of Albert Creek II:IS bcvn d(~vc3lopi~dby Landolt (1971). and North Cretxk. 'I'lic sedimcnts wrrtb subjected to 'I'hr tnordrnitc. dt,posit studivd ht'ro is of com~nr~rcial tnaxitnum tt>mpc1raturrisaround 200~~and water pres- grade and cxtcnt. a11d furthrr study of (I~tspropc,rtics surfs around 0.5 to 3 kilobars, which corresponds to of the mordt,nitr sl~o~ildI)? citrri(5d 0~11.'1'11t, nianucLrill burial depths of 1 to 10 kilomrters. 'l'hr temperature of which tI1cb ~nordc~nil(~might I)() nst,d in Alaska rcmains to thc l~c~ulandilc~-laiimo~ltiteboundary was probably less t)t, dc~lcrnlinc~d.Applications involving large, quantities than 200°~hr~causc~ of the effect of salinity of the of zeolil.c>s whtlrrl itniformily of th(\ propt~rtic~sof tht, iutrastratal waters on tlic activity of water during zc~olil.o is not criticaal sho~~ld1x1 soi~glit. Synthtlti(t mrtamorphism. zc~olitc~s,which I~avc, i~tiifortn propt,rtit,s (ol'tt,~~for a h,lordtlnitc occurred within tl~c~hculandite zone be- particular application), :ire, not likrly to br dirrctly ctauscl of the, fine-grained nature of the luffs, causing a c~c*onomicallycompctitivrl. liighrlr silica activity in the, intrastratal fluids than in the '1'110 hortic~~lturalusc~fulnt~ss of Ia~~rnotltitt~tuffs from rest of the, zonr. Analcimtl may have formed locally Shcrp Mo~~ntaitl(fIawkins, 1973) \bras tostcd b). 11.11. from a mordrtiitr or llc~ulanditctuff by solutions locally 1)inkrl of tht. IJnivrrsity of Alaska, Agricultural 14:x- morc alkalinc' that1 lliosr throughout thr mordenite pc,rimtlnt Station. 'l'l~(~dtltails of this Lrst arcs not ZOllt'. availahlr at this tirnc,, but I)ink(,l (pcsrsonal c-o~tp~lnica- 'I'ht, fic,ld tclst of Culfaz and others (1973) gives tiotl, 197 1) conclucl(~tlthat Lhts 1:~ulnontitc. tuffs 11:1d 110 rc~liablr~rc,sults and should br ust'd. nolicc~ablocffc~t in hydroponic, c~spc~rimt~ntsinvolving thsults of initial (,x- p. 1448-1462. pc,rimcnls arc, disappointing. f3olcs, J.kt., 1971. Synlhrsis of analcime from natural Ilr~~ilanditeand clinoptilolite: Am. Min. 56, p. 1724- 173.1. Coombs, I).S., 1970, Present status of the zeolite facies, 'l'htl field tvst for zc,olitcs publislit~dby (:ulfaz and irl Prclprints of tht. Sec. Int'l. Conf. on Molecular otlic~rs(1973) gavcs rr~sultsin good agrr~r3~nt~nlwill1 thosr sit,vr> zc~olitc.~:Worcclstrr Polytrctinic Instilulrs, p. ob1aint.d by X-ray difl'raction. 'l'llcl trst sc,t,ms lo b(' 556-566. much lrss stibjrct to int(~rft~rc~ncc~Ily clay rninc~ralsth:ul Culfaz, A., Kirsling, C.H., and Sand, L.H., 1973, A firld is thc tc'st of H(~lfft~ric11(1961), whic4i was clvalu:~trd 1)y trst for molecular sir,ve zeolitcls: Am. Min. 58, Hawkins (1973). 'I'hc' trlst Lvas no1 c~valuatrtl under p. 1044-1048. ficld conditions. 'l'llc, grt~;~lt~stutility of thtl trxst may litx Grantz, A.M., 1965, Geologic map and cross sections of in complcmcnting the X-ray data iuid quickly eslin~ating tllr Nrllchina arca, south-central Alaska: I1.S. (;pol. atsolilt, graclts in monozrolilic tuffs. 'l'lltt test should find Survey opcn-file report. considtlrablr us?. IIawkins, D.B., 1973, Scdime11tat-y zeolitc1 dcposils of tht. upper Malanuska Vallry, Alaska: Alaska 1)iv. CONCLUSIONS Gc.01. ant1 Gcopllys. Surveys, Spec. Itpt. 6. Hrlffericlt, Y., 1964, A simple identification reaction for 'I'lic ~nordtlnitc-richtuffs invc~stigntc~din this study ztwlites (molecular sieves): Am. Min. 49, p. 1753- art, ot' comnic~rcial gradc. 'l'ht, propt,rtic,s of the Inor- 1754. drnites should be i~ivt~stigatr~dfurthtlr lo drtt~rmint~if it [,andolt, (;.kt., 1971, Method of rapid dctc'rmination of meets currc>nt i~~dustrialrrquircmclnts. hlordcnitc dc- adsorption properties of lnolccular sicves: Anal. posits in othclr parts of thts 'ralkcc'tna for~nationin the, Chem. 43 (4),p. 613-615. gt'lleral study arc,a should bc sought. Mumpton, F.A., 1973, Worldwide deposits and utiliza- 'rhc. zc>olitrs in tht, arcla wchrc) formc~tl bv burial tion of natural ztlolites: Industrial Minrrals 73, Octobcr. p. 2-1 1. t;~ins.ctl~~[r;~l ,I;III;III: - 1973. lotlie suhstitl~tiolland the) sti~l)ilit>of Inor- - 1!)71. Sole, 011 111o 'c~olilic. i.onillg 01 t11ts Noogt~~~c~ dtl~~iltl:J. (;t1ol. Soc. .lapiin, 7:) (10). p. titi!)-ti7ti. ~)>.roc~l;istic-rot~ks ol' .lapit~l:klt~ln. (;t,oI. Soc*.Jal~all. Srki. Y.. Oki, Y.. Odaka. S.. iuld O~anii ti.. 1972. ti. 1). 195-200. Stability of nlordcnitc' in ~tloliltbL'ircit's nlt,ta~norphisl~l Zt>n, P:-~III, I9ti1, '1'110 /.t~oIittxki(>itss: ill1 i~~tt~r[)rt~li~lio~~: of tilt, Oynnla-Ist,lli~ri~distric.1. cli~st I'iirl~i~\v;iSIou11- .\III. J. Sci., 259, p. {Ol-109.