Ibethano Ngamandla Elingezelelweko le-Terrestrial Impact
Ngephandle kwe-Vredefort crater, ibethano ngamandla le-colossal latjhiya ngemva iminye imitlhala eminengi erikhodwe ematjeni. Imitlhala le sele itholwe kwezinye iindawo ezimbalwa lapha yabetha khona ephasini loke, sele kwanjesi kuqatjangwa bona imitlhala yayo itjengisa ibethanongamandla lama-terestrial elenzekako.
Kokuthoma, kunaleya edege esalele kumetheriyali owawa lokha kuna izulu khulu phakathi kwe-radius esemakhilomitheni amakhulukhulu. Amatje ahlangahlangeneko kanye ne-shrapnel idege hlangana nendawo esifundeni esine-dome, aphelako lokha nase ziyela esentha.
Elinye itjhwayo elisepepeneneni lamandla amanengi la matjhuguluko enzeka ematjeni ngokwawo. Lokha nakubetha i-bolide, ingaletha amazinga womtjhiso ahlangana kwe-10 degree centigrade afike ku-hundred yama-gigapascal. Amandla amanengi la kanye nomtjhiso kubanga kobana amatje azombelezileko kobana atjhuguluke abematjha. Indlela le yeziwa ngokobana yi- ‘shock metamorphics’. Nokungelinye ibanga elisepepeneni lokobana kungebanga lani kunama- metamorphic features.
I-Shattercone
I-shattercone akusingilokhu okuthola nawuwisa irhwabalaza. Kunokobana kube njalo kuyiphetheni ethize erhatjhekela phezu kwamatje lokha nakudlula i-shock wave. Lokhu kuba nomphumela wokobana kuphindaphindeke isenzwesi endaweni yinye.
Ama-shattercone la avela enarheni ezimbalwa ezise- Vredefort Dome, begodu kuthiwa nange uwabeka kuhle woke ama-shattercone ngendlela engiyo, ungathola ilayini le-bolide. Ngebhadi, abavakatjhi besimanjemanje bathoma ukungasabi nendaba nokuthola i-shattercones babuyele nayo ekhaya. Le sekwaba yinjwayelo ekutlhogeka kobana iliswe ukwenzela bona kuvikelwe i-shattercone, ekuzoba ngezinye izinto ekutlhogeka kobana zenziwe yimenenja etja etlhogomela i-Dome.
I-Metamorphosis Yamatje
Amanye amatjhwayo aqakathekileko atholakala ematjeni we-Vredefort imithambo yemethirali enzima ebonakala ematjeni anzima. Ziyahlukahluka ngobude kanye nobudege ,kodwana ezinye ziqakathekile. Umhlobo welitje elisa rhalasi,elibizwa bona yi-pseudotachylite’ eyenzeka lokha amazinga womtjhiso aphezulu abanga kobana ilitje lincibilike bese litjhugulula amakhemikhali akilo. Amanye afanako womhlobo we-tachylite utholakala magega ne-volcano eduze kwamalayini anama-fault ( lapha ukuhlikihlana hlangana kwamapleyidi we-tectonic kukhipha umtjhiso ). Ibizo elithi- ‘pseudo’lifakwa lokha nakunganabufakazi bokobana kune- volcanic.
Amazinga womtjhiso aphezulu kanye negandeleleko elikhitjhwa yibethano ngamandla elenza enye i-metamorphosisi ematjeni,ebizwa bona yi-‘granophyre’. La mamatje afeyini abutheleleke ndawonye atjhuguluka aba lilitje linye, amatje adweni ancibilikileko, afika emakhilomitheni ambalwa. I-Radiometric dating yenqhetjhana ze-zircon ebethwaneni ngamandla elenzekakweli, amatje onakalako la, arhelebha ama-geologist kobana aphe isehlakalo se-Vredefort lesi ilanga elithize eliyi- 2.023 billion yeminyaka.
I-Shock-Deformation
Hlangana kwamanye ama- shock-deformation features ajayelekileko eendaweni ezinengi ezinebethano ngamandla yi-coesite kanye ne-stishovite. La mabizo aphiwe imihlobo emibili we-quartz (ekuyiminerali ejwayelekileko ematjeni). Enzeka lokha ama-quartz agandeleleke bekafuthumala aze afika kutheni atjhuguluke ijamo layo le-crystal lattice. Imitlhala yamaminerali amabili la, atholakala kuma-impact crater, kanye nendawo zokuhlola amabhomu we-nuclear. Ibizo elijwayelekileko lomhlobo we-deformation le yi-‘shocked quartz’.
Ubufakazi bokugcina be- shock metamorphism ayibonakali ngamehlo wenyama. Irhubhululo elenziwe ngokutjheja, lapha amatje asikwa bese ahlolwa ngaphasi kwe-elecron microscope, sele atjengise bona kunomonakalo ngaphasi kweleveli ye-atomic.
Ibethano Ngamandla Lamadayimani
Elinye ibethano ngamandla elithusako elonako litholakala e-Vredefort yibethano ngamandla lamadayimani. Amatje amancani la amahle, eliyimilimitha yinye ngobukhulu, abumbeka lokha i-meteorite nayibetha ilitje elizele i-carbon. Umtjhiso owaphuma ebethwaneni ngamandla eline-carbon latlama amakhulungamakhulu wamadayimani, kodwana akekho umuntu okhabe azi bona angenzani ngawo. I-Popigai crater ese-Siberia imumethe amakhulungamakhulu wamatani wedayimani evele ngemva kwebethano ngamandleli, kodwana akekho umuntu okhabe azi bona angenzani ngawo
Ihlanganisela yama-shattercones, pseudotachylite, yathusa ama-quartz kanye namanye ama- metamorphic sele kutholwe e-Vredefort kanye nakwamanye ama-impact craters. Sele zihlangene zithathwe njengesitlikitlo lebethanongamandla begodu sele lisetjenziselwa ukukhombisa iindawo lapha kwabakhona ibethano ngamandla kodwana zingaziwa ephasini loke.
Translated by Busisiwe Skhosana