Daga cikin jerin wurare mafi zafi a duniya, hamadar Sahara a kasar Mauritania, tabbas Afirka na cikin jerin sunayen, inda yanayin zafi zai iya kaiwa digiri 57.7 a ma'aunin celcius. Iska mai tsananin zafi da zafi na mamaye yankin a duk shekara amma kuma akwai wani wuri mai ban mamaki a cikin hamada; kuma a duk duniya, ana kiranta da 'Idon Sahara'.
'Idon Sahara' - Tsarin Richat
Tsarin Richat, ko kuma wanda aka fi sani da 'Idon Sahara', wani kubba ne na ilimin geologic - ko da yake har yanzu yana da cece-kuce - yana dauke da duwatsun da suka riga sun bayyana rayuwa a duniya. Idon yayi kama da shuɗi karas kuma yana cikin Yammacin Sahara. Yawancin masana ilimin kasa sun yi imanin cewa samuwar Ido ya fara ne lokacin da babban yankin Pangea ya fara ja da baya.
Gano 'Idon Sahara'
Tsawon shekaru aru-aru, ƴan ƙabilar ƙauyuka ƙalilan ne kawai suka san wannan ƙaƙƙarfan samuwar. An fara ɗaukar hoto a cikin 1960s ta Gemini na aikin 'yan sama jannati, waɗanda suka yi amfani da shi azaman alamar ƙasa don bin diddigin ci gaban jerin saukowarsu. Daga baya, tauraron dan adam na Landsat ya ɗauki ƙarin hotuna kuma ya ba da bayani game da girman, tsawo, da kuma girman samuwar.
Masana ilimin kasa da farko sun yi imanin cewa 'Idon Sahara' wani rami ne mai tasiri da aka haifar a lokacin da wani abu daga sararin samaniya ya kutsa cikin saman duniya. Duk da haka, dogon nazari na duwatsun da ke cikin ginin ya nuna cewa asalinsa gaba ɗaya na duniya ne.
Bayanan tsarin 'Idon Sahara'
'Idon Sahara', ko kuma wanda aka fi sani da Richat Structure, wani tsari ne mai ma'ana sosai, ɗan ɗan leƙen asiri, ƙyalli mai zurfi mai zurfin mil 25. Dutsen sedimentary da aka fallasa a cikin wannan dome yana da shekaru daga Late Proterozoic a tsakiyar tsakiyar dome zuwa Ordovician sandstone kusa da gefenta. Bambancin yashi na yadudduka masu tsayayyar ma'adini ya haifar da babban madaidaicin madaurin abinci. Cibiyar ta ta ƙunshi siliceous breccia wanda ke rufe yanki wanda yakai aƙalla mil 19 a diamita.
An fallasa su a cikin ciki na Tsarin Richat akwai duwatsu masu ƙyalli iri -iri. Sun hada da rhyolitic volcanic rock, gabbros, carbonatites da kimberlites. Duwatsu na rhyolitic sun haɗa da kwararar ruwa da jujjuyawar duwatsun ruwa waɗanda ke sashi na cibiyoyi masu fashewa guda biyu, waɗanda aka fassara su ne ragowar ragowar biyu maharba.
Dangane da taswirar filin da bayanan aeromagnetic, duwatsun gabbroic sun zama dikes ringing guda biyu. Gwargwadon zobe na ciki kusan mita 20 ne a faɗinsa kuma ya ta'allaka kusan kilomita 3 daga tsakiyar Tsarin Richat. Gwargwadon zobe na waje yana da nisan mita 50 kuma yana kwance kusan kilomita 7 zuwa 8 daga tsakiyar wannan ginin.
An zana tasoshin carbonate da talatin da biyu a cikin Tsarin Richat. Gabaɗaya dikes kusan tsawon mita 300 kuma yawanci faɗin mita 1 zuwa 4. Sun ƙunshi manyan carbonatites waɗanda galibi basu da vesicles. An ƙaddara dutsen carbonatite kamar yadda ya yi sanyi tsakanin shekaru miliyan 94 zuwa 104 da suka wuce.
Sirrin da ke bayan asalin 'Idon Sahara'
An fara bayyana Tsarin Richat a tsakanin shekarun 1930 zuwa 1940, a matsayin Richât Crater ko Richât buttonhole. A cikin 1948, Richard-Molard ya yi la'akari da shi a matsayin sakamakon a laccolithic turawa. Daga baya an yi la'akari da asalinsa a takaice azaman tsarin tasiri. Amma wani bincike mai zurfi a tsakanin shekarun 1950 zuwa 1960 ya nuna cewa an samar da shi ta hanyar tsarin ƙasa.
Koyaya, bayan fage da bincike mai zurfi a cikin ƙarshen 1960s, ba a sami tabbataccen shaida ba. girgiza metamorphism ko kowane irin nakasa da ke nuna alamar hypervelocity bankwana tasiri.
Duk da yake coesite, wani nau'i na silicon dioxide wanda aka ɗauka azaman mai nuna alamar girgiza metamorphism, da farko an ba da rahoton cewa yana nan a cikin samfuran dutsen da aka tattara daga Tsarin Richat, ƙarin nazarin samfuran dutsen ya ƙare cewa an ɓata sunan barite a matsayin coesite.
An gudanar da aikin a kan danganta tsarin a cikin 1990s. Sabunta binciken da aka yi na samuwar Richat Structure ta Mattton et Al daga 2005 zuwa 2008 ya tabbatar da cewa lallai ba tsarin tasiri bane.
Nazarin bincike da yawa na 2011 akan Richat megabreccias ya kammala cewa carbonates a cikin megabreccias masu wadatar silica an halicce su ta hanyar ruwan zafi mai ƙarancin zafin jiki, kuma tsarin yana buƙatar kariya ta musamman da ƙarin binciken asalin sa.
Ka'idar gamsarwa ta asalin 'Idon Sahara'
Masana kimiyya har yanzu suna da tambayoyi game da Idon Sahara, amma masana ilimin ƙasa biyu na Kanada suna da ka'idar aiki game da asalin sa.
Suna tunanin cewa halittar Ido ta fara ne sama da shekaru miliyan 100 da suka gabata, yayin da babban tekun Pangea ya rabu da tectonics kuma abin da ke yanzu Afirka da Kudancin Amurka ana rarrabu da juna.
Dutsen da ya narke ya tunkuɗa zuwa saman amma bai kai ga haka ba, ya haifar da wani dome na yadudduka na dutse, kamar babban ƙura. Wannan kuma ya haifar da lalatattun layukan da ke zagaye da ƙetare Ido. Dutsen narkakken ya narkar da limestone kusa da tsakiyar Ido, wanda ya fado ya zama wani nau'in dutse na musamman da ake kira breccia.
Bayan shekaru miliyan 100 da suka gabata, Ido ya fashe da ƙarfi. Wannan ya rushe kumburin kwata -kwata, kuma zaizayar ƙasa ta yi sauran aikin don ƙirƙirar Idon Sahara da muka sani a yau. Zoben an yi su ne da dutsen iri daban -daban da ke lalata da sauri. Da'irar paler kusa da tsakiyar Ido shine dutsen mai aman wuta wanda aka kirkira lokacin fashewar.
'Idon Sahara' - alama ce ta sararin samaniya
'Yan sama jannati na zamani suna son Ido saboda yawancin saharar Sahara ruwan teku ne da ba ya karyewa. The Blue Eye yana daya daga cikin 'yan raguwa a cikin monotony wanda ake iya gani daga sararin samaniya, kuma yanzu ya zama babban mahimmin alama a gare su.
'Idon Sahara' wuri ne mai kyau don ziyarta
Yammacin Sahara ba ta da yanayin yanayi da ke wanzu a lokacin samuwar Ido. Duk da haka, har yanzu yana yiwuwa a ziyarci busasshiyar hamada mai yashi wadda idon Sahara ke kira gida -amma ba tafiya ce mai daɗi ba. Matafiya dole ne da farko su sami damar shiga biranen Mauritaniya kuma su sami mai tallafawa na gida.
Da zarar an shigar da su, ana ba da shawarar masu yawon bude ido da su yi shirye -shiryen balaguron gida. Wasu 'yan kasuwa suna ba da tafiye-tafiyen jirgin sama ko balaguron iska mai zafi a kan Ido, yana ba baƙi damar kallon ido. Eye yana kusa da garin Ouadane, wanda ke tafiya da mota daga ginin, har ma akwai otal a cikin Ido.
