Nzira yeRadioactive Carbon muArchaeology
Nzira yeradioactive carbon — inowanzonzi radiocarbon dating kana kuti Carbon-14 (C-14) dating — ndeimwe yenzira dzakakosha mukuchera matongo kwemazuva ano. Iyi nzira inobvumira vanochera matongo kufungidzira makore ezvinhu zvakamborarama, zvakaita sehuni, marasha, mapfupa, mhodzi, machira, uye kunyange zvasara zvekudya. Nekuziva kuti chipenyu chakafa riini, vanochera matongo vanogona kunyatsoongorora tsika dzekare, kuyedza fungidziro dzenhoroondo, uye nzvimbo dzinowanikwa mumamiriro avo etsika. Kunyange zvazvo isiri iyo chete nzira yekuferefeta, radiocarbon dating yave "chiyero chegoridhe" chenguva dzekare nedzekare, kunyanya mumakore ezviuru apfuura.
Nheyo dzekutanga dzeCarbon-14
Kabhoni ine ma isotopu akati wandei, ayo ari maumbirwo eatomu ane nhamba dzakasiyana dzema neutron. Ma isotopu akajairika i carbon-12 (C-12) uye carbon-13 (C-13), ayo akagadzikana. Panguva iyi, kabhoni-14 (C-14) ine radioactive. C-14 inoumbwa mumhepo kana mwaranzi ye cosmic ichibatana nemaatomu e nitrogen, ichigadzira C-14, iyo inobva yabatana ne oxygen kuti igadzire kabhoni dioxide (CO₂). Kuburikidza ne photosynthesis, zvirimwa zvinotora CO₂ ine C-14, uye mhuka dzinowana C-14 nekudya zvirimwa kana dzimwe mhuka.
Chero bedzi chipenyu chiri chipenyu, kuchinjana kwekabhoni nenzvimbo yakapoteredza kunoramba kuripo, saka chiyero cheC-14 mumuviri wacho chakaenzana nemhepo. Zvisinei, kana chipenyu chafa, kuchinjana uku kunomira. Kubva ipapo zvichienda mberi, C-14 iri muzvisaririra zvechipenyu inotanga kuora zvakare kuita nitrogen nemwero wakafanana. Mwero uyu wekuora unoratidzwa mu "hafu yehupenyu," inova nguva inodiwa kuti hafu yeC-14 yekutanga ipere. Hafu yehupenyu hweC-14 inenge makore 5.730. Nekuyera kuti C-14 yasara yakawanda sei, vaongorori vanogona kufungidzira kuti chipenyu chakafa riini.
Zvinhu Zvinogona Kushandiswa NeRadiocarbon
Chinhu chikuru chekuongorora nguva yeradiocarbon ndechekuti inoshanda chete pazvinhu zvakasikwa—zvinhu zvinobva kuzvinhu zvipenyu. Semuenzaniso:
– Marasha anobva pahuni dzinopfuta (anowanzo kuwanikwa panzvimbo dzekugara kana pamoto)
– Huni, mashizha, shinda dzemiti, mbeu
- Mapfupa, mazino, collagen
– Magoko nezvimwe zvinhu zvine carbonate (kunyange zvazvo zvakaoma zvikuru nekuda kwemigumisiro yemugodhi)
– Machira akagadzirwa neshinda dzechisikigo, bepa, dehwe
– Marara ezvekudya, zvasara zvezvipenyu zviri muhari dzehari
Kusiyana neizvi, matombo chaiwo, simbi, uye zviumbwa zvesimbi hazvigone kutsanangurwa zvakananga kuti zvine musi we radiocarbon dating nekuti hazvisi zvinhu zve organic. Zvisinei, zvisaririra zve organic zvakabatana nezvinhu izvi dzimwe nguva zvinogona kuongororwa.
Maitiro eKutora Samples uye Kuongorora muLaboratory
Kuti zvive nechokwadi chekuti mhedzisiro yekuyera nguva chaiyo, kutora sampuli kunofanirwa kuitwa nokungwarira. Kusvibiswa ndiwo muvengi mukuru. Kana sampuli ikasanganiswa nekabhoni yemazuva ano (semuenzaniso, kubva pakubata maoko, guruu, utsi, midzi yemiti, kana zvinhu zvinochengetedza), kuverenga zera kunogona kuva kudiki. Kusiyana neizvi, kusvibiswa nekabhoni "yekare" (semuenzaniso, kubva kune mamwe ma carbonate deposits) kunogona kuita kuti mhedzisiro yacho ikure.
Murabhoritari, sampuli dzinowanzo shandiswa kurapwa kuti dzibvise tsvina. Semuenzaniso, mapfupa anogadziriswa kuti abudise collagen; marasha anobviswa tsvina; uye huni dzinogona kutorwa kuti dzisarudze sampuli dzinonyatsoenderana.
Kune nzira mbiri huru dzekuyera C-14:
1. Nzira yekuora kweBeta (kuongororwa kweradiometric)
Kuyera mwaranzi inobuda kana C-14 yaora. Nzira iyi ndeyekare uye ichiri kushandiswa, asi inoda saizi yakakura yemuenzaniso.
2. Accelerator Mass Spectrometry (AMS)
Tekinoroji yemazuva ano inoyera huwandu hwemaatomu eC-14 zvakananga pachinzvimbo cheC-12 neC-13. AMS inoda masampuli madiki, inokurumidza, uye inowanzova yakanyatsojeka pazvinhu zvinokosha zvikuru kana zvidiki.
Mhedzisiro yekuyerwa inowanzo tsanangurwa se "makore eradiocarbon asati asvika" (BP), ne "yazvino" yakatarwa pa1950.
Kuenzanisa: Kuchinja Makore eRadiocarbon kuita Makore eKarenda
Vanhu vazhinji vanofunga kuti mhedzisiro yekutsvagisa kweradiocarbon inoenderana zvakananga negore rekarenda. Zvisinei, mwero weC-14 wemhepo haugari nguva dzose nekufamba kwenguva. Kuchinja kwekushanda kwezuva, kusiyana kwesimba remagineti rePasi, kuputika kwemakomo, uye mafambiro emhepo anogona kukonzera kuchinja kweC-14 ratios. Nokudaro, mhedzisiro yekutsvagisa kweradiocarbon inofanirwa kuenzaniswa uchishandisa calibration curve yakagadzirwa kubva padata rakazvimirira, kunyanya dendrochronology (miti yakakura), ice cores, uye sedimentary records.
Kuenzanisa kunoita kuti pave nemakore akasiyana-siyana ekarenda (semuenzaniso, mukana we95%) pane nhamba imwe chete. Mukuchera matongo, huwandu uhwu hwakakosha nekuti hunoratidza kusava nechokwadi kwesainzi uye hunobvumira kududzirwa kwakanyatsochenjerera.
Nguva uye Miganhu Yenzira
Kuverenga nguva yeRadiocarbon kunonyanya kushanda pakutsanangura nguva yemakore angangoita 50.000–60.000 apfuura. Kupfuura izvozvo, huwandu hweC-14 hwasara hushoma zvekuti haugone kuyerwa nenzira yakavimbika. Munguva dzekare, vanochera matongo vanoshandisa dzimwe nzira dzakadai sepotassium-argon (K-Ar), argon-argon (Ar-Ar), kana luminescence dating.
Kune zvimwe zvipingamupinyi:
– Mhedzisiro yedhamu: Zvipenyu zvemugungwa zvinogona kuratidzika se "zvakakura" nekuti kabhoni iri mugungwa ine simba rakasiyana neremhepo. Mhedzisiro yakafanana inogona kuitika muzvipenyu zvemumvura yakachena, zvichienderana nekwazvinobva kabhoni.
– Dambudziko re "matanda ekare": Matanda anoshandiswa sehuni anogona kubva mumiti yekare. Kana mukati mematanda ekare mukabviswa, mhedzisiro yacho inogona kunge yekare kupfuura chiitiko chaicho chekutsva.
– Mamiriro ekare: Mienzaniso yakafamba panzvimbo (semuenzaniso, marasha anotakurwa nemvura) inogona kupa mazuva asingamiriri mabasa evanhu muchikamu chacho.
Saka, vanochera matongo havawanzo vimba nemuenzaniso mumwe chete. Kuverenga nguva kunowanzoitwa pamienzaniso yakawanda kubva mumamiriro ezvinhu akanyatsotsanangurwa uye zvichienzaniswa nematanho ekuvaka, mhando dzezvinhu zvakagadzirwa, uye data rezvakatipoteredza.
Basa reRadiocarbon muKuunganidza Nhoroondo Yevanhu
Kubva payakagadzirwa naWillard Libby mukupera kwema1940, kuverengwa kwezviwanikwa zveradiocarbon kwakachinja manzwisisiro atinoita nguva yakapfuura. Iyi nzira inobatsira kuyedza nguva yekurima kwekutanga, kutama kwevanhu, kuvandudzwa kwetekinoroji yematombo nesimbi, uye kunyange makore enzvimbo dzekugara. Nhaurirano dzakawanda dzekuchera matongo dzaimbovimba nefungidziro dzinogona kutsigirwa nedata rakazara.
Semuenzaniso, kutsvagisa kweradiocarbon kunoita kuti vaongorori vagone kusiyanisa kana zvikamu zviviri zvekugara zvakatevedzana kana mazana emakore, kuongorora kana shanduko dzekudya dzaive dzakabatana nekushanduka kwemamiriro ekunze, uye kutevedzera mafambiro ekutengeserana kana mafambiro ehuwandu hwevanhu nekubatanidza mazuva kubva kunzvimbo dzakasiyana.
Mhedziso
Nzira yeradiocarbon mukuchera matongo chishandiso chakakosha chesainzi chekuongorora nguva yezvisaririra zvechisikigo uye kugadzira nguva chaiyo yehupenyu hwemunhu wekare. Nheyo yacho iri nyore—kuyera kuora kweC-14 mushure mekunge chisikwa chafa—asi kushandiswa kwayo kunoda kungwarira kukuru, kubva pakusarudzwa kwemuenzaniso uye kudzivirira kusvibiswa kusvika pakuongororwa kwemhedzisiro. Nekunzwisisa zvakanakira zvayo nemiganhu, vanochera matongo vanogona kushandisa radiocarbon dating kwete sechiratidzo chezera chete asi sewindo rinojekesa nyaya yekushanduka-shanduka kwetsika, shanduko yezvakatipoteredza, uye nhoroondo refu yebudiriro yevanhu.
Kana muchida, ndinogona kugadzirisa chinyorwa ichi kuita basa rechikoro (riri nyore), basa redzidzo (rine zvirevo nezviratidzo), kana kuwedzera mienzaniso yeongororo yeradiocarbon muIndonesia.
