Xa abantu bethetha ngeemeteorites, phantse wonke umntu ucinga ngamatye asesibhakabhakeni awela esibhakabhakeni ngaphandle kwemfihlakalo engaphezulu. Kodwa eneneni, emva kweqhekeza ngalinye kukho ibali elimangalisayo lejoloji kunye nelomkhathi. Kwimeko ye uqweqwe lweemeteorite ezingezizo eze-CI kunye nee-lithologies zohlobo lwe-CI1Singena kwenye yezona ndawo zintle nezintsonkothileyo ze-meteoritics: ukuqonda indlela eyona nto iqinileyo yamandulo kwiNkqubo yeLanga eyakheka kwaye yaguquka ngayo.
Kweli nqaku siza kuchaza ngokuzolileyo oko kuthethwa ziimeteorite ezingezizo eze-CI, oko kuzichazayo Ii-chondrites ze-carbonaceous zeklasi ye-CI1Ingqimba yangaphandle yakheka njani, edla ngokutsha xa ingena emoyeni? Kwaye izifundo zakudala ze-petrographic, iikhemikhali, kunye ne-mineralogical (uhlobo olufumana kwiingxelo zakudala zejoloji kwifomathi yePDF) zinegalelo lini ekuqondeni kwethu kwangoku? Ingcinga kukudibanisa olu lwazi lobuchwephesha kunye neenkcazo ezicacileyo kunye nolwimi olufikelelekayo, ukuze ukwazi ukulandela ngaphandle kokuba yingcali.
Zithini iimeteorite zeCI kwaye kuthetha ukuthini ukuthi "ezingezizo zeCI"?
Ngaphakathi kusapho olukhulu lweemeteorite, ii-chondrites ze-carbonaceous zezinye zezona qela zibangela umdla kakhulu kuba zigcina iimpawu zakudala kakhulu. Phakathi kwazo, ii-chondrites ze-carbonaceous zohlobo lwe-CI (ngamanye amaxesha zibizwa ngokuba yi-Ivuna-type) ziyindlela eqhelekileyo yokuqwalasela ukwakheka okuqhelekileyo kweNkqubo yeSolar yasekuqaleni, ngaphandle kwezinto eziguquguqukayo ezilula.
Ii-chondrites ze-CI zibonakaliswa ngokuba ne ukwakheka kwezinto ezisisiseko kufana kakhulu neLanga (kwakhona, singayithathi njenge-hydrogen, i-helium, kunye nezinye izinto eziguquguqukayo), kunye nobuninzi obuphawulekayo bezinto eziguquguqukayo kunye namanzi adibene neeminerali ezimanzi. Zingamatye amnyama, aguqulwa kakhulu ngamanzi emzimbeni wawo, kangangokuba awagcini ii-chondrules eziqhelekileyo ezichazwe kakuhle ezibonakala kwezinye ii-chondrites.
Xa sithetha ngeemeteorite "ezingezizo eze-CI", siyazahlula kuzo zonke ezinye ii-chondrites kunye neemeteorite ezingezizo ezo qela. Ngamanye amazwi, nayiphi na i-meteorite engenazo utyikityo lwe-geochemical kunye ne-mineralological lwe-CI Iwela kudidi olukhulu "olungekho kwi-CI": i-CM, i-CO, i-CV, ii-CR chondrites, ezinye iintlobo ze-carbonaceous, ii-chondrites eziqhelekileyo, kwanee-meteorites ezahlukeneyo.
Olu mahluko lubalulekile kuba ii-chondrites ze-CI zisebenza njenge ipateni yokuthelekisaUbuninzi bezinto ezikwezinye iimeteorite budla ngokubonakaliswa ngokunxulumene namaxabiso e-CI. Ke ngoko, ukwahlula phakathi koqweqwe lweemeteorite ze-CI kunye noqweqwe lweemeteorite ezingezizo ze-CI kunefuthe elithe ngqo ekutolikeni imbali yokungena kobushushu kunye nomoya wesampuli.
Imisebenzi yakudala evela kwizikhungo zejoloji kunye neenkonzo zikarhulumente idla ngokugxininisa olu thelekiso nomgangatho we-CI. Xa uhlalutyo lubonisa ukuba i-meteorite ine-"non-CI fraction" okanye "non-CI crust," igxininisa ukuba iimpawu zayo ziyahluka kuloo mgangatho. imodeli yekhemikhali yelanga, ebonisa ezinye iinkqubo zokwakheka nokuguqulwa.
I-CI1 lithologies: inqanaba eliphezulu lokuguqulwa kwamanzi
Ngaphakathi kwi-CI chondrites, kukho ulwahlulo olusekelwe kwinqanaba le-metamorphism kunye notshintsho. CI1 Oku kubonisa inqanaba eliphezulu lotshintsho lwamanzi ngaphakathi kwesikali se-carbonaceous chondrite (inombolo 1 ihambelana nenqanaba eliphezulu lokufuma kunye nokutshintsha kobushushu obuphantsi). Ngokwenyani, ii-chondrites ze-CI1 zibonisa ubume obuphindaphindeneyo kakhulu kunye nobukho obuqinileyo beeminerali ezifumileyo.
Kolu hlobo lwe-meteorite, ngokucacileyo imatrix entle iyalawula ngaphezu kwayo nayiphi na isakhiwo esiphambili. Ii-Chondrules azibonakali lula, kwaye uninzi lwelitye lwenziwe zii-phyllosilicates, ii-sulfides, i-magnetite, kunye nezinye iiminerali ezibonisa ukusebenzisana okukhulu namanzi olwelo kwi-asteroid engumzali. Olu hlobo "luthambileyo" noluguqulwe kakhulu lwahlukile kakhulu kolwamanye ama-chondrites e-carbonaceous angachaphazeleki kangako.
Izifundo zembali ze-petrographic, ezifana nezo zigcinwe kwiindawo zokugcina imibutho yelizwe yejoloji, zichaza olu hlobo lokwakheka ngokweenkcukacha: iinkozo ezincinci, i-complex mineralogy, kunye nobuninzi bezigaba ze-microcrystalline. Kwiindawo ezikhazimlisiweyo, umphezulu ubonakalisa i- inkangeleko efanayo kakhulu, ngaphandle komahluko omkhulu phakathi kwee-chondrules kunye ne-matrix, ngokungafaniyo nee-CV okanye ii-CO chondrites apho izakhiwo ezingqukuva zibonakala kakhulu.
Olunye uphawu olucacileyo lwe-CI1 kukuba umxholo ophezulu wekhabhoni kunye neekhompawundi eziguquguqukayoZidla ngokuba nezinto eziphilayo ezintsonkothileyo kunye neentsalela zeekhompawundi ze-carbonaceous eziye zavuselela umdla we-astrobiology kuba zinika izikhokelo malunga neemolekyuli zezinto eziphilayo ezifumaneka kwidiski yokuqala ye-protoplanetary. Olu buninzi bee-volatiles lukwachaphazela indlela i-meteorite eziphatha ngayo ngexesha lokungena emoyeni kunye nokwenziwa koqweqwe lwe-fusion.
Iinkcazo zeekhemikhali zezi meteorites zibonisa ukuba izinto ezininzi ezilandelelanayo zinobuninzi obufana kakhulu namaxabiso elanga. Ke ngoko, xa kuthelekiswa iimeteorites ezingezizo ze-CI kunye ne-CI1 lithologies, ziyathelekiswa. iindlela ezimbini ezingaqhelekanga zokuguquka kwezinto zakudala: enye iguqulwe kakhulu ngamanzi kwaye isondele kwisakhiwo selanga, kwaye enye isenokuba idlule kwiinkqubo zobushushu eziqatha kakhulu, iimpembelelo okanye umahluko.
Yintoni uqweqwe lweemeteorite kwaye lwenziwa njani?
Xa i-meteorite ingena emoyeni woMhlaba, ifumana ubushushu obukhulu ngenxa yokungqubana nomoya. La mandla obushushu anyibilikisa ngokukhawuleza umaleko ongaphandle welitye, nto leyo evelisa oko kwaziwa ngokuba yi-meteorite. uqweqwe lokudibanisa okanye nje uqweqwe. Yifilimu elingana neeshumi ezimbalwa zemilimitha ubukhulu, ngamanye amaxesha ilingana neeshumi ezimbalwa zemilimitha, egubungela umphezulu ize iqine ngemizuzwana ngexesha lokwehla komoya.
Eli xolo lidla ngokuba mnyama okanye libe mnyama kakhulu, linembonakalo yeglasi okanye engacwebezeliyo, kwaye lihlala libonakala iimpawu ze-aerodynamic njengee-regmaglypts (iingontsi ezincinci, ezimile okwesithupha) kunye nezinye izakhiwo eziqingqiwe kukuhamba komoya ofudumeleyo. Ubukho bazo yenye yezona zikhokelo zisetyenziswa rhoqo ngabaqokeleli kunye neengcali zejoloji ukuze ukwahlula i-meteorite yokwenyani ukusuka kwilitye elilula lomhlaba.
Ukwakheka kweekhemikhali kolu qweqwe akufani noko kwangaphakathi kwe-meteorite. Ngexesha lokunyibilika ngokukhawuleza, ezinye izinto ziyaguquguquka, ezinye zixinene, kwaye kwakheka izigaba ezithile zeeminerali. Umzekelo, kuqhelekile ukufumana iiglasi ezenziwe nge-silicateKukho ii-iron oxides, i-magnetite, kunye nezigaba ze-metal ezityebileyo kunye ne-sulfide ezicwangciswe ngokutsha ngobushushu. Ubukhulu kunye neempawu ze-crust zixhomekeke kakhulu kwisantya sokungena, i-engile, ubungakanani bento, kunye nokwakheka kwayo kokuqala.
Kwi-meteorites ezibuthathaka kakhulu okanye eziguqukileyo kakhulu, ezifana ne-CI1 lithologies, i-crust inokuba yinto engahambelaniyo okanye eqhekekileyo. Ubuninzi beeminerali ezimanzi kunye nezigaba eziguquguqukayo zibangela ukwakheka kweempendulo ezithile zeekhemikhali ngexesha lokungena. ukukhupha igesi ngequbulisoUkuqhuma okuncinci kwangaphakathi okanye ukwahlulwahlulwa kwamaqhekeza kutshintsha kancinci umphezulu onyibilikisiweyo. Iingxelo zobugcisa zakudala zichaza iisampulu ezineengqakumba eziqhekekileyo, zibonisa umahluko phakathi komaleko wangaphandle omnyama kunye nowangaphakathi okhanyayo okanye ongwevu.
Ngokwahlukileyo koko, kwiimeteorite ezincinci ezingezizo eze-CI, njengee-chondrites ezininzi eziqhelekileyo, uqweqwe lwe-fusion luhlala luqhubeka ngakumbi kwaye lufana. I-matrix yangaphakathi enganyangekiyo ivumela le filimu yeglasi ukuba igcinwe ngcono, inika umfanekiso ocacileyo we-aerodynamic kunye nesigqubuthelo esimnyama esifanayo. Lo mahluko obonakalayo phakathi kweengqukuva zeemeteorite ezingezizo eze-CI kunye neengqukuva zezinto zohlobo lwe-CI1 yenye yeenkcukacha ezibonwayo xa kuthelekiswa iingqokelela ze-petrographic.
Umahluko phakathi kwe-non-CI meteorite crust kunye ne-CI1 lithologies
Nangona xa uqala ukujonga zonke iingqukuva ze-meteorite zinokubonakala zifana, izifundo ezineenkcukacha zibonisa iingongoma ezibalulekileyo xa kuhlalutywa uqweqwe lwe-fusion kwiimeteorites ezingezizo ze-CI ngokuchasene ne-CI1 lithologiesUmahluko wokuqala, nobonakalayo, bubume bomphezulu. Kwiimeteorite ezininzi ezingezizo eze-CI, ii-regmaglypts, ii-striations, kunye neefom ezithathwe kwi-ablation ziyabonakala ngokucacileyo, ngelixa kwiisampuli zohlobo lwe-CI1, uqweqwe lunokubonakala lungaqhelekanga, kunye neendawo ezinamaxolo okanye ii-microfissures ezinxulumene nobuthathaka belitye.
Ngokwembono ye-petrographic, ukuba kulungiselelwe icandelo elicociweyo eliquka uqweqwe kunye nolwangaphakathi, kuyabonwa ukuba utshintsho kwiimeteorites ezingezizo ze-CI ludla ngokuba kucace phakathi kweglasi okanye iikristale ezincinci zesikhumba kunye nezinto ze-matrix, apho kukho ii-chondrules kunye neenkozo zesinyithi ezichazwe kakuhle. Ngokwahlukileyo koko, kwi-CI1 i-matrix yangaphakathi incinci kwaye iyafana kangangokuba umgca wokwahlukana ne-crust awusoloko uphawulwa kangako, ngaphandle kotshintsho kumbala kunye nophuhliso lwezigaba ze-oxidation ezinamandla ngakumbi kuloo filimu yangaphandle.
Uhlalutyo lweekhemikhali lwe-crust lukwabonisa ezinye izinto ezahlukileyo. Kwii-meteorites ezingezizo ze-CI ezine-iron kunye ne-nickel eninzi, i-crust ibonisa i- ubukho obutyebileyo bee-iron oxides kunye ne-magnetiteOku kubangelwa kukunyibilika ngokukhawuleza kwesinyithi ngexesha lokufudumeza komoya. Kwi-CI1, apho isigaba sesinyithi sele singaninzi kakhulu kwaye umxholo wamanzi uphezulu, uqweqwe lulawulwa kakhulu zii-silicates kunye neemveliso zokuphelelwa ngamanzi emzimbeni zeeminerali zodongwe.
Omnye umba onomdla yindlela yokuziphatha kwe-mechanical. Kwi-CI1 lithologies, umahluko phakathi kwe-cortex yeglasi kunye nengaphakathi eliguqulwe kakhulu unokuxhasa ukwahlukana kunye nokulahleka kweqhekeza Kungekudala emva kokuwa, ngenxa yotshintsho lobushushu okanye iimpembelelo ezincinci ngexesha lokuthuthwa. Amatyala amaninzi eziqwenga ze-CI, apho uqweqwe lungaphelelanga okanye kubonwa i-mosaic yeepleyiti ezincinci ezihlukanisiweyo, abhalwe kwiingqokelela zeemyuziyam nakwiimpapasho zakudala.
Kwi-meteorites ezincinci nezingengo-CI, i-crust idla ngokugcinwa ngcono, ngaphandle kokuba isampuli ivezwe kwizinto eziphilayo ixesha elide. Kwiindawo ezimanzi zomhlaba, kuzo zombini iintlobo ze-CI1 nezinye, i-crust ichatshazelwa yi iinkqubo zotshintsho lwesibini: i-oxidation, ukwakheka kwee-crusts ze-iron oxide, ukunyibilika okungaphelelanga, njl. Olu tshintsho lulandelayo lunokufihla umahluko wokuqala phakathi kwee-crusts, nto leyo enokwenza kube nzima ukutolika kwazo ukuba i-meteorite ayiqokelelwanga emva nje kokuwa.
Iindlela zokufunda: ukusuka kwiingxelo zakudala ukuya kwi-meteoritics yanamhlanje
Uninzi lwezinto esizaziyo namhlanje malunga neengqukuva zeemeteorite ezingezizo ezeCI kunye ne-CI1 lithologies zivela kumsebenzi oqokelelwe kwiminyaka emininzi edlulileyo kuphando lwejoloji, kwiindawo zokujonga izinto, nakwiimyuziyam. Olu lwazi luvela kumaxwebhu ePDF askeniweyo agcinwe kwiindawo zokugcina ulwazi zikawonke-wonke. iinkcazo ezineenkcukacha zamacandelo amancinci, uhlalutyo lweekhemikhali ezimanzi, i-optical microscopy ekukhanyeni okudlulisiweyo nokubonakalayo, kunye neendlela ze-electron microprobe kamva.
Ezi ncwadi zichaza indlela yokufunda uqweqwe: ukulungiswa kwamacandelo acwebezelayo aqala kumphezulu ongaphandle ukuya kwiimilimitha ezininzi ngaphakathi; uhlalutyo lwezigaba zeglasi kunye nekristale zoqweqwe; ukuqinisekiswa komxholo wesinyithi, i-nickel, isalfure, kunye ne-trace element; kunye nokuthelekiswa kwale datha nezinto zangaphakathi ezinganyibiliki. Konke oku kuvumela ukwakhiwa kwakhona koqweqwe imbali yobushushu be-meteorite ngexesha lokungena kwaye uqikelele iiparameter ezifana nobushushu obuphezulu obufikelelweyo okanye izinga lokuphola.
Ekuhambeni kwexesha, ezi ndlela ziye zancediswa luhlalutyo olunesisombululo esiphezulu: i-X-ray diffraction, i-Raman spectroscopy, i-X-ray microtomography, kunye neenkqubo ze-laser ablation kunye ne-mass spectrometry. Ezi zixhobo zivumela ukuchongwa izakhiwo ezincinci kwi-cortex, ukuzoniwa kweekhemikhali okucokisekileyo kakhulu kunye nokuba khona kwezigaba ezingabonakaliyo okanye ezi-nanocrystalline ezenziwe phantsi kweemeko eziqatha.
Kwimeko ye-CI1 lithologies, ezi ndlela zityhile iinkcukacha malunga nokuguqulwa kweeminerali ezimanzi xa zifudunyezwa ngokukhawuleza. Utshintsho ukusuka kwi-phyllosilicates ukuya kwi- izigaba eziphelelwe ngamanzi emzimbeni nezingenawo ulwelo kwi-crustal band, enika idatha malunga nemida yozinzo lobushushu bezo zimbiwa. Oku kusinceda siqonde ukuba kwenzeka ntoni kwizinto ezifanayo kwimizimba emincinci evezwe kwiziqendu zobushushu.
Kwiimeteorites ezingezizo eze-CI, izifundo zanamhlanje ziye zajonga nzulu kwintsebenziswano phakathi kwesinyithi kunye nesigaba se-silicate ngexesha lokunyibilika komphezulu, zilinganisa ukwakheka kwee-oxides, ii-sulfides, kunye nee-alloys ezityebileyo kwi-crust. Ezi zifundo ziqinisekisa, ngokuchanekileyo okukhulu, iindlela ezichazwe kwi izifundo zakudala ze-petrographic ezifumaneka kwiincwadi zamandulo: ukutyetyiswa kwee-iron oxides, ukuhlelwa ngokutsha kwee-sulfides, kunye nokubonakala kweeglasi ezinobume obuphakathi phakathi kwe-matrix kunye nee-chondrules.
Ukubaluleka kwesayensi kwe-crust kunye ne-lithologies CI1
Ingqimba ingabonakala ngathi "ngumaleko otshisiweyo" ongenamdla kangako, kodwa eneneni yingqokelela yolwazi malunga iimeko zokungena emoyeniUbukhulu, ubume, kunye nezigaba zeminerali ze-crust zinceda ekuqikeleleni amandla alahlekileyo, ukususwa kunye nokwahlukana kwamandla, kwanemiba efana nokujongwa ngexesha lokuwa. Kwiimeteorite ezibonwa xa kubhabha, olu lwazi lunokujongwa kunye neerekhodi ze-bolide ukuze kwakhiwe kwakhona iindlela kunye nesantya.
Xa kuthelekiswa ii-crusts zeemeteorites ezingezizo eze-CI nezo ze-CI1 lithologies, umahluko kwindlela izinto eziziphatha ngayo ezine-porosity eyahlukileyo, umxholo oguquguqukayo, kunye namandla oomatshini nawo unokufundwa. I-CI1, ngokuba ityebile kakhulu ngamanzi kunye neeminerali ezimanziZibonelela ngemeko egqithisileyo yezinto ezilahlekelwa ziintsholongwane kwaye ziphelelwe ngamanzi emzimbeni kakhulu kwimizuzwana embalwa. Oku kunika ulwazi oluxabisekileyo malunga nendlela izinto ezifanayo eziguquka ngayo kwezinye iimeko, njengokusondela kwiLanga okanye impembelelo yomphezulu kwi-asteroids.
Ngaphezu koko, ii-lithologies ze-CI1 zihlala ziyindlela esisiseko yokubhekisela kwi-cosmochemistry. Ukwakheka kwazo, kufutshane nepateni yelanga, kuzenza zibe luhlobo "lwekhowudi yomthombo" yobuninzi bezinto kwiNkqubo yelanga yokuqala. Nakuphi na ukuphambuka okubonwa kwiimeteorites ezingezizo ze-CI kutolikwa ngokunxulumene iinkqubo zokuqhekeza: ukufuma kumaqondo obushushu ahlukeneyo, ukufuma okukhethayo, ukwahlulwahlulwa kwesinyithi, ukwahlulwa okungaphelelanga kwemizimba yabazali, njl.
Ukudibana kwe-crust kunye nengaphakathi kunika umfanekiso opheleleyo ngakumbi: i-crust ityhila inqanaba lokugqibela lohambo (ukungena komoya), ngelixa ingaphakathi ligcina imiqondiso yeminyaka yezigidi zembali yendalo. Kwiimeteorites ezingezizo ze-CI, loo mbali ingabandakanya iinkqubo ze-thermal metamorphism ukuqina ngakumbi, ngelixa kwi-CI1, utshintsho lwamanzi kumaqondo obushushu aphantsi ludla ngokuba yinto ephambili. Ukuthelekisa zombini ii-lithologies kuvumela inkcazo engcono yoluhlu lweendawo kunye neenkqubo ezichaphazele imizimba emincinci yeNkqubo yeSolar.
Okokugqibela, ukubakho kwezinto eziphilayo kwi-CI1 kunye nokusabela kwayo ekufudumaleni ngexesha lokwakheka kwe-crust nako kuyathakazelisa kwi-astrobiology. Abaphandi bafunda indlela ezi zinto zibola ngayo, ziguqula, okanye zigxile ngayo kumaleko otyhidiweyo, nto leyo enceda ukuqonda ukuba zeziphi iintlobo zee-molecule eziphilayo ezinokubakho. ukusinda kwimpembelelo yoMhlaba wasekuqaleni kwaye ukuba iimeteorites zinegalelo elingakanani kwizithako kwiinkqubo ze-prebiotic.
Xa zizonke, uhlalutyo olucokisekileyo lwe-crust yee-non-CI meteorites kunye ne-CI1 lithologies, ezixhaswa ziingxelo ze-geological zeminyaka emininzi, iingqokelela ze-petrographic, kunye neendlela zanamhlanje zohlalutyo, zisivumele ukuba sivelise umfanekiso oqinileyo wendlela eziziphatha ngayo ezi zinto ukususela ekudalweni kwazo kwi-protoplanetary disk ukuya kwimizuzwana yazo yokugqibela njengoko zidlula emoyeni woMhlaba. Lonke olu lwazi lubonakala lunobuchwephesha ekugqibeleni luqhagamshela kumbuzo olula kakhulu kodwa onomdla: Ngawaphi amatye amadala esiwaphetheyo ezandleni zethu kwaye aphuhliswe njani?.