Vutivi bya Misava yale Cradle of Humankind

Ku Vumbeka ka Maribye

©David Fleminger

Maribye yale ndzhawini ya Cradle of Humankind yatelele ngopfu hi Dolomitic bedrock, lawa yanga vumbeka ehansi laha kunga entangiki, kambe kuri na mati yokufumela lawa yanga khumbarheta Witwatersrand Basin kwalomu ka 3 billion wa malembe lawa ya hundzeke. Maribye ya dolomite ya endliwe hi calcium carbonate (limestone) leyingana ti oxygen isotopes tintsongo letinga cheriwa leswaku tita endla ntirho wa kahle. Leswi swi endle leswaku kuva na xivumbeko xa Karstic xa misava, lexi kunga xona xikotaka leswaku kuva na mabaku eka misava yakona hikokwalaho ka nkhukhulo wa misava eka mintila leyinga hoxeka ehansi ka misava.
Maribye lawa yanga e Sterkfontein nale Krugersdorp ya tlhelela endzhaku kwalomuya kava 2.6 billion wa malembe naswona maribye lawa yanga evuhuma dyambu, kutshunelela e Hartebeespoort, yana kwalomu ka 2.2 billion wa malembe yarikona. Maribye lawa ya hetelele ya voyamile nyana naswona maribye lawa yanga eka vupela dyambu byale Cradle of Humankind, ku kongoma e Krugersdorp ya tlakukile, leswinga endla leswaku kuva na nkhukhulo wa misava xikanwe swi endla swintshabyani eka xiphemu xa Cradle of Humankind.

A hi Languteni swa vu Thekiniki

Loko u lava kutirhisa ngopfu vuthekiniki, naswona i mani anga swilaveki, ti fossil letinga cheriwa endzeni tikumeka eka ntlawa wa Chuniespoort, leyinga e hansi ka ntlawa wa Malmani, ya maribye ya Transvaal Supergroup, naswona yatumbulukile kwalomu ka 2.5 billion wa malembe lawa ya hundzeke. Ntlawa wa Malmani nawona wutlhele wu avanyisiwa hi swiyenge swinwana swa 5: laha kunga Oaktree, Monte Christo, Lyttleton, Eccles xikan’we na Frisco Formations. Ndzhawu leyi nayona yina masalela ya lead na koporo, leswi swinga ceriwa hi tinxaka leti atiri kona khale xikan’we na vahlampfa lavanga fika vatshama lahaya ka ndzhawu liya.

Tindlela to Cela na Masiku

©David Fleminger

Se, ntsena loko archaeologist kumbe palaeontologist a kote kuva a vona vukona bya maribye lawa yangana ti fossil, xana vakuma njhani swilo endzeni? Kahle kahle, ku handza swilava vukheta, switeka nkarhi naswona i ntirho lowu vavaka swinene lowu lavaka malembe ya vuleteri xikan’we nakunga heli mbilu. Leswi swatika swinene kuswihlamusela hi vuenti ngopfu ngopfu loko u fanele u switsala e hansi eka nxanxameto wa marito wuntsongo. Se swifambisa leswi…
Kumbexani xa nkoka swinene kungava ku twisisa ku handziwa ka misava, leswivuriwaka provenience. Kahle kahle, leswi swivula leswaku ulava ku kandziyisa hi vuenti xiyimo lexi ti fossil tinga kumekisa xiswona: LAha tinga kumeka kona? Leswi ati tshamise xiswona? Lexi ati tshame ekusuhi naxona? Xana akuri na yini e henhla katona? Xana akuri nayini ehansi ka tona? Vuxokoxoko lebyi hinkwabyo byinga kunyika voxokoxoko byo engetelela xikan’we naku pfuneta kutswisisa ku antswa hiti fossil, ndzhawu ya tona, laha tikumekaka kona xikan’we na mahanyelo yatona leswinga kotekaka loko wotiteka uti chela e bokisini.
Mhaka hileswaku maendlelo lawa yo handziwa i ndlela yo kavanyeta naswona, loko se kususiwe breccia kumbe ti fossil, ungaka ungaha koti ku vuyisela nakambe Humpty. Se, u fanele ku kunguhata ku cela kahle naswona u tsala ehansi vuxokoxoko hinkwabyo hivukona bya swipetlu swati fossils loko unga se tisusa kutani uya tihlayisa eka kamara ro hlayisela eka rona. LEswi swikatsa kuva u teka swinepe xikan’we naku hlayisa matsalwa lawa ya tekiwaka loko urikarhi u tirha, leswi lavekaka kuya hi nawu wa tiko ra Afrika Dzonga. Loko woka unga susi swotala kuya hi laha awu fanele hakona, naswona switekiwa tani hi maendlelo yakahle kuva u siya xiphemu xa vumbhoni leswaku vanwana lavangata tsakela ku cela vata kota ku cela siku rin’wana.

Ku Kandza Kumbe e-e

©David Fleminger

Ekusunguleni, ti archaeologists ati tirhisa maendlelo ya grid kukota ku vona ku phemekela ka ti fossils. Maendlelo lawa hi laha u vekelaka tintambu kumbe tidarata leti hingakanyanaka kuva ti endla grid ya swibokisani leswi vuriwaka ti spits.
Ti archaeologists tita sungula ku cela eka grid yinwana na yinwana eka swiphemu sweswo, kuringana kwalomu ka 100 centimetres hiku enta, va humesa ti fossils kutani vati chela endzeni ka nkwama lowu tsariweke grid na maentelo.
Lawa akuri maendlelo lawa aya tirhisiwa e Sterkfontein kuringana century leyi hundzeke, naswona tintambu ta khale taha cikinya laha kunga ceriwa kona. Xiphiqo hi maendlelo lawa hileswaku switirhisiwa hinkwaswo swisongasonganile naswona swastika kuvona swiphemu swakona hi xin’we xin’we.
Hiku tirhisa thekinoloji leyintshwa leyi kumekaka masiku lawa eka ti archaeologists, maendlelo ya grid ya sungule ku hundzeriwa. Sweswi, hiku tirhisa xichinani xa mangatsila lexivuriwaka Total Station (onge ku hlanganisiwe theodolite na GPS) ti archaeologists tikota ku kandziyisa ndzhawu na kuleha ka xin’wana na xinwana lexikumekaka. Leswi swivuyerisa swipetlu swa 3D leswi kandziyisiwaka eka ID tag kutani yi vekiwa eka plastic bag xikan’we nati fossil.

Maendlelo yaku Kula

Kuna maendlelo yambirhi yo cela: horizontal na vertical. Tani hi nawu wo angarhela, swilo leswi kumiwaka eka levele yinwe swi hanya eka nkarhi wunwe, kasi leswikumekaka eka vertical plane swi kombeta vukhale (yale henhla i yintsongo, yale ndzeni iya khale).
Se, ku hlawula leswaku u cela njhani swiya hiku u lava kukuma yini. Loko u lava xifaniso xo anama xa nkarhi wokarhi u cela u tsemakanya; loko u lava ku tiva kulandzelerisa matimu u cela uya e hansi.
Himpela, swilo swinge olovi kuswivona naswona emabakwini swinwana swa phemeleleka xikan’we nakuva swisuka endzhawini. Se vuhleri byokarhi bya stratigraphy ya ndzhawu byi tala kuva byi laveka loko unga se kuma vuxaka bya nkarhinyana bya swilo leswinga kona.
U tlhela u kuma na swipimelo swimbirhi swa tinxaka ta macelelo: laha kungana misava leyi vevukaka nalah yinga tiyela, swiphemu phemu swofana na breccias emabakwini. Eka misava leyinga tiyelangiki, switirhisiwa swankoka i thawula xikan’we na ti burachi to hlawuleka na tipiki ta matino yohambana hambana– hinkwaswo swa xiyimo xale henhla.
Thawula ritirhisiwa ku olovisa naku sula misava. Piki yitirhisiwa ku cela naku humesela handle ti fossil naswona burachi yitirhisiwa ku kukula sandi leyivevukaka. Kukuma mpimo wakahle, misava hinkwayo leyinga ekusuhi nati fossil yi hlengeletiwa kutani yi sefiwa leswaku kuta susiwa swirhambyani na swiphemu swa ti fossil, leswi cheriwaka e nkwameni kutani switsariwa leswaku switaya kambisisiwa e lab.

Ku Humesiwa

Loko u tirha hi breccias yo tsindziyela, hixitalo awu koti ku susa ti fossil kusuka eka ribye loko uri eku celeni. Ematshanwini, u fanele ku tsema xiphemu lexingana breccias leyingana ti fossil kutani uyiyisa e lab. Ku endla leswi, u fanele ku tirhisa borho yo khoma hi voko ku boxa mimbhovo eka block yaleyo. Kutani u nghenisa ti wedges timbirhi embhoveni kutani u endla stake exikarhi laha u hambanyisaka ribye kahle kusuka e hansi kumbe e khumbini. Tindzawu to pimanyisa hitona ta endliwa eka block leswaku kuta vekeriwa ti co-ordinates endzhaku ka nkarhi.
Loko se u tlhelele e Lab, unga susa hiku nonoka ti fossil kusuka eka rock matrix, kungava hiku tirhisa borho leyintsongo (like an engraver’s tool) kumbe hiku chela hivukheta acid leyingata n’okisa breccia loko yisiya ti fossil taha tshamisekile. Hivumbirhi maendlello lawa ya lava malembe yotala yo ringetela naku lehisa mbilu.
Kukuma vukhale byati fossils, kuna tinxaka timbirhi letinga landzeleriwaka: maendlelo lawa ya hundzeriwaka na lawa ya chronometric. Yosungula hi laha u ringetaka ku tirha ehenhla ka xilo lexinga xa khale swinene kumbe xiri xintsongo eka lexin’wana lexinga kumiwa eka ndzhawu yin’we, naswona leswi switala ku endliwa hiku tiva vukhale bya swiphemu swa misava laha kunga kumiwa ti fossil hiku langutisisa swin’wana (ngopfu ngopfu flora na fauna) leswi kumekaka eka leyara yin’we kutani swipimanyisiwa nale ka tindzhawu tin’wana. Loko kunga se fika 1960’s, kutiva vukhale aswi endliwa hindlela yoleyo. Maendlelo ya Chronometric ya fambelana naku tiva vukhale bya ti fossil hindlela yaku ‘kuve malembe yangani kunga se fika lawa ya sweswi’. Leswi swi endliwa hi nhlayo ya xinghana kambe leyitikaka leyitalaka kuva yi katsa ku hlayela leswaku kuna khemikali ya muxaka wihi (kufana na carbon) leyi kumekaka eka ti fossil, kutani swipimanyisiwa na nhlayo leyitivekaka yak u bola ka khemikhali yoleyo.
Maendlelo lawa ya radiometric yanga pima potassium-argon (K-Ar), carbon (loko kuriku xilo xexo xile hansi ka 50 000 wa malembe hi vukhale), xikan’we na swin’wana swati radioactive. Ku tlhela kuva na maendlelo lawa ya vuriwaka Palaeo-magnetism lawa ya langutisisaka ku tolovekiwa ka swipetlupetlu endzeni kati fossils kuva ku tiviwa leswaku ti magnetic field ta misava ti fambe kangani (swin’wana leswi yiswiendlaka nyana eka malembe ya magidigidi), kambe sweswo swindzi pandzisa nhloko swinene kuswitwisisa.

Translated by Ike Ngobeni