Phakathi kolwakhiwo lwejoloji esilufumanayo kwiplanethi yethu sinazo craton. Igama elithi craton lisetyenziselwa ukwahlula isahlulo esizinzileyo sangaphakathi soqweqwe lwelizwekazi kule mimandla ye-orogenic, engamabhanti angqamene okuqokelelana kunye / okanye ukhukuliseko lwentlenga oluxhomekeke ekuthobekeni kunye / okanye ukunyuswa.
Kweli nqaku siza kukuxelela yonke into ekufuneka uyazi malunga necraton, iimpawu zayo kunye nokubaluleka kwayo.
Uqweqwe lwelizwekazi
I-continental crust indala kakhulu kwaye ikhukulisekile kwaye inamatye amandulo e-igneous kunye ne-metamorphic. Amatye e-post-archaic agcina umthwalo ogoqiweyo wamatye angaphezulu okanye angaphantsi kwe-metamorphic sedimentary. Ezokuqala zikwindawo ethe tyaba, ephantse ibethe tyaba, yaye ezokugqibela ziiNtaba. I-Craton okanye i-cratogen (isuka kwi-Greek Kraton, ethetha isitya esicaba kakhulu) sisingqimba somhlaba esifikelele kwimeko embi ngolo hlobo kwimbali yokwakheka komhlaba ekude. Ukususela ngoko, ayizange ihlupheke ngokuhlukana okanye ukuguqulwa ngenxa yokuba ayizange ichaphazeleke yintshukumo ye-orogenic. Ngesi sizathu, iicratons zithande ukuba mcaba, okanye zibe ne-bas-reliefs ezingqukuva, kwaye zikholisa ukuba ngamatye amadala. Icraton engaphantsi kwamanzi ibizwa ngokuba ziinesocratons.
Yintoni icraton
Igama elithi craton lisetyenziselwa ukwahlula iindawo ezizinzileyo zangaphakathi zoqweqwe lwelizwekazi ukusuka kumabhanti e-orogenic (imida yelizwekazi, intlenga kunye nezitya ze-orogenic), ezikukuqokelelana okulandelelanayo kunye / okanye iindawo zokhukuliseko lwentlenga (izitya) eziphantsi kokuthotywa. Kwaye / okanye ukuphakamisa (iintaba). Icraton ebanzi esembindini welizwekazi inokuqulunqwa ngamakhaka kunye namaqonga omhlaba, kunye neziseko zeglasi. Ikhaka yinxalenye yecraton, apho amatye ePrecambrian afumaneka kakhulu kumphezulu. Ngokwahlukileyo, iqonga elisisiseko ligutyungelwe ngama-horizontal sediments kunye ne-sublevels.
Ikhaka yindawo yelizwekazi eyenziwe ngamatye ayenziwe ngexesha le-Precambrian, awayengagqunywanga lulwandle. Ikhaka lenziwa ngawona matye amadala oqweqwe lomhlaba, igranitization kunye nemetamorphism. Ukususela kwimvelaphi yabo, baye bazinza kwaye bagcina ukuqina kwabo.
Inyaniso yokuba abazange bantywiliselwe ngenxa yolwaphulo-mthetho kungenxa yokuba baye babandezeleka ngokushukuma okuthe nkqo kwe-tectonic. Azizange zibe namava okusongwa kuba zazixhathise yonke into ethe tyaba. Izikhuselo ziqhelekile ukuba zingabikho kunye namatye e-metamorphic avele kwindawo enkulu, enezakhiwo ezizinzileyo kunye nemisebenzi embalwa ye-orogenic. Kuzo zonke iimeko, la matye angaphezulu kweminyaka engama-570 yezigidi ubudala, kwaye ezinye zisusela kwiminyaka engama-200 ukuya kwi-3,5 yezigidigidi eyadlulayo.
Ngenxa yozinzo, ukhukuliseko luwenza abe caba ubume bendawo yelizwekazi lonke. Nangona kunjalo, ziqhelekile ukuba nemigangatho eyiconvex kwaye zinokurhangqwa ziindawo ezigqunywe yintlenga ezibizwa ngokuba ziishelufa zelizwekazi. Iindawo ezingenanto, amaqonga agqunyiweyo kunye neziseko zecrystalline xa zidibene zenza inxalenye ezinzileyo yoqweqwe lwelizwekazi elenza ikhaka okanye icraton.
Amakhaka nokubaluleka kwawo
Ikhaka lidla ngokuba ngundoqo welizwekazi, kwaye uninzi lwayo lubotshwe ngebhanti egotyiweyo yeCambrian yamatye. La mabhanti adityaniswa adityaniswa emphethweni wekhaka lomhlaba elalikho ngaphambili, ngaloo ndlela enyusa ubukhulu belizwekazi lantlandlolo alenzileyo. Imiphetho yekhaka ichaphazeleka ngamandla etectonic, athi wona atshabalalise kwaye akhe kwakhona, kunye necraton apho akhoyo.
Icraton yiyunithi enkulu yolwakhiwo kuqweqwe lomhlaba, eyenziwe ngamatye amaninzi azinzileyo. ngokubanzi igneous kunye / okanye amatye metamorphic. Ngamanye amaxesha igutyungelwe yintlenga encinci. Icraton eqhelekileyo yiCanadian Shield (Precambrian). Iipasile zomhlaba ezibizwa ngokuba yi "oceanic" okanye "underwater" cratons zisenokungahambelani nale ngcaciso. Igama elithi "Craton" sisithethantonye sekhaka.
Icraton yinxalenye ezinzileyo kumbindi welizwekazi, ebonakala ngokuba yenziwe ngamatye asezantsi ekristale yamandulo. Igama elithi craton lisetyenziswa ukwahlula ezi ndawo kwimisele ehambayo. ezingamabhanti amgca wentlenga ediphozithiweyo. Icraton enkulu esembindini welizwekazi inokwenziwa zizinto ezimbini: ikhaka lomhlaba kunye neqonga. Ikhaka yinxalenye yecraton, apho (ngokubanzi) amatye e-Precambrian basement atyhileke kakhulu kumphezulu. Ngokwahlukileyo, eqongeni, umgangatho ongaphantsi okanye umgangatho ophantsi ugqitywe yintlenga.
IiCratons zaseParaguay
Icraton yenziwa yinucleus endala kakhulu. Ngenxa yobume bazo obushukumayo, bayadibana benze ilizwekazi. Nangona kunjalo, azisoloko zivela phezulu. IParaguay inomlambo iApa Craton (ukusuka emantla) kunye neTebicuary (ukusuka emazantsi). Ngezantsi kweChaco kukho i-Craton «Pampia», leyo yahlulwe kwiRío de la Plata kunye neCraton de La Plata.
I-Transbrasiliano Lineamiento yindawo ye-suture, yomanyano, yongquzulwano lwelizwekazi apho iicratons zidityanisiwe, kwaye inokuqhubekeka kude kube yiNtshona Afrika, idlula kumhlaba waseBrazil. Esi sakhiwo sodidi lokuqala, njengethunga, sisukela kwi-Lower Cambrian (iminyaka eyi-528 yezigidi) xa kwakusenziwa iGondwana.
Kukho iingxabano ukuba i-craton ye-Tebicuary River ye-Río de la Plata okanye ayikho, okanye ukuba i-Paraná (ngaphantsi kwe-basin ye-Paraná) ibhloko eyahlukileyo ukusuka kwi-Río de la Plata. Nangona kunjalo, imodeli ethandwa kakhulu ichazwe apha.
Umahluko phakathi kwecraton, isitya kunye ne fault
I-craton yindawo ezinzileyo ye-continental crust kunye akazange abe namava amaninzi e-orogenic tectonics okanye iipleyiti ixesha elide. Icraton iqulathe isiseko secrystalline sePrecambrian rock eqhele ukubizwa ngokuba likhaka kunye neqonga apho intlenga ethe tye okanye ekufutshane-ethe tyaba okanye amatye entlenga ajikeleze ikhaka.
Izitya zizidakumba kuqweqwe yenziwe ngumsebenzi weplate tectonic, apho intlenga iqokelelana khona. Ukuzingisa kokubekwa kuya kuvelisa iqondo elongezelelweyo lokugoba okanye ukuthotywa. Izitya zeSedimentary, okanye izitya ezimfutshane, zinokubunjwa ngumphanda okanye zondiswe kakuhle. Ukuba amatye omthombo we-hydrocarbon atyetyisiweyo adityaniswe phantsi kweemeko zexesha elaneleyo kunye nobunzulu bokungcwatywa, i-oyile kunye negesi inokuveliswa kwisitya.
Okokugqibela, ingxaki a uphazamiseko okanye umphezulu welaminar okhoyo kwilitye elinqabileyo apho kukho ukufuduka okuqaphelekayo. Ngokuxhomekeke kwisalathiso esihambelanayo sokufuduka phakathi kwamatye, okanye iibhloko zesiphoso, kumacala omabini esiphoso, ukunyakaza kwabo kuchazwa ngokuthe ngqo (okanye ngokuqhelekileyo), ukuguqula, okanye ukufuduka kwekhosi.
Ndiyathemba ukuba ngolu lwazi unokufunda ngakumbi malunga necraton kunye neempawu zayo.