A yau zamuyi magana ne game da tsarin kasa wanda ake kiran sa shaida tudu. An kirkiresu ne sakamakon zaizayar kasa kuma galibi ana samunsu a cikin shimfidar wurare. Na dauke shi a matsayin shaidar wucewar lokaci koma baya da kuma canjin gangare ko dandamali. Yana da halaye da yawa waɗanda suka cancanci sanin kamar yadda yake bayani kaɗan game da tasirin tasirin ɓawon ƙasa.
A cikin wannan labarin za mu gaya muku abin da tudun shaida yake, halayensa da yadda yake da mahimmanci ga ilimin ƙasa.
Menene tsaunin shaida
Tsarin halitta ne wanda ya faru ne sakamakon zaizayar ƙasa tsawon shekaru. Muna magana ne akan sikelin lokacin ilimin kasa don haka ba za a iya kimanta shi a ma'aunin ɗan adam ba. Shaida ta uku ita ce wacce ke bayyana canjin caca ko dandamali a farfajiyar lebur. Wannan farfajiyar ya ƙunshi yadudduka masu kwance na dutsen mai taushi da wuya inda ci gaba da busawar iska ya haifar da zaizayar kasa wacce ta sauya fasalin kasar.
A cikin laushi masu laushi na ƙasa, yashwa yana faruwa akai-akai. Kogunan suna haifar da yashewa kuma suna yin tsaunuka daban-daban da sauran tsari. Idan tsaunuka sun lalace ta kowane bangare, abin da aka sani da tsaunin shaida yana samuwa. Waɗannan tsaunuka sun mamaye waɗannan wurare tsawon shekaru miliyan da yawa.
Yadda ake kafa shi
Wadannan tsarin ilimin kasa an sassaka su ta hanyar zaizayar kasa kuma ana kiranta sunan shaida saboda shaida ce ta dadaddiyar fadada wani shimfidar wuri wanda aka kebe dashi. Bambancin zaizayar kasa da ta faru saboda koguna da ramuka sune mafi mawuyacin laushi da laushi a jere. Wadannan tuddai masu shaida ana iyakance su ta hanyar kubucewar zaizayar da ke tattare da wani yanki wanda ya samu matsala ta hanyar dutsen mai karfi da kuma wani laushi mai taushi wanda aka kirkira da dutsen laushi. Mafi sashi mafi wuya shine ake kira mashi mai ƙwanƙwasa kuma ɓangare mafi laushi ana kiransa gangara.
Kare mai shaida yana da bayanin haɗin concave conx kuma ya bambanta dangane da juriya da ɓangaren duwatsu masu tauri da ɓangaren duwatsu masu taushi suka ba shi. Lokacin da zaizayar da kogunan suka samar ya karu, kowane bangare yana sanya tudun shaida ya bayyana tare da kololuwa masu fadi. Saboda haka, su shaidu ne na dandamali wanda ya wanzu a wannan wurin miliyoyin shekaru da suka gabata. Sauran taimakon da ya rage shine saiti mai laushi mai laushi waɗanda aka shirya su a kwance kuma wanda zaizayarwar ta iya sassakawa.
Ina tuddai masu shaida?
Suna da yawa gama gari a cikin kwandunan ruwa na koguna daban-daban. Wadannan hanyoyin ana iya samun su a tsaunin Pilot, a Arewacin Carolina, a cikin Cerro de la Teta (Guajira Peninsula) da kuma cikin Dori plateau (Burquina Faso). A cikin ƙasarmu kuma zamu iya samun sa a cikin ɗakunan talla daban-daban kamar su bakin ciki na kogin Ebro da kuma cikin kwandunan da ke tsakiyar yankin. A Madrid muna da Cerros de la Marañosa, a kan Cerro de los Ángeles da Buenavista, kuma a lardin Palencia, da Cerro del Otero.
Zamu bayyana halaye na Cerro de los Ángeles. Tana da nisan kusan kilomita 10 daga Madrid, a cikin garin Getafe. Wannan shine yadda ake la'akari da shi a matsayin yankin Yankin Yankin Iberiya. A saboda wannan dalili, yana da mahimmancin gaske duk da cewa babu wani ma'auni na kimiyya wanda ke tallafawa hakan. A kan tsubirin da ke saman dutsen nan sanannen kayan aikin ne na Misis De los Apóstoles. Wannan yana ba da damar farawa tun daga ƙarni na sha huɗu kuma kyakkyawan abin tunawa ne mai kyau.
A kan gangaren wannan tudun akwai bishiyoyin Pine na Aleppo, filayen wasanni, filin wasan ƙwallon ƙafa, hanyoyi daban-daban da kuma wurin shakatawa. Wannan ya sa Cerro de los Ángeles yawon shakatawa mai yawon shakatawa wanda ke cikin haɗuwa da yanayi. Tushenta ya kai mita 610 kuma ya kai tsayin mita 666. A mafi girman matsayi shine farkon yanayin ƙirar ƙasa. Yana da kyau kwarai da gaske ganin dukkan ra'ayoyin Getafe, Madrid da ƙauyukan da ke kewaye da karamar hukumar.
Babban fasali
Wadannan tsaunukan shaida za'a iya rarraba su azaman tsaunin tsibiri. Babban halayyar sa an kiyaye ta bayan yashwa wanda ya wargaza sauran kayan da ke kusa. Wadannan tsaunukan tsibiri an kiyaye su daga ƙazantawa saboda ingantaccen lithology. Suna da matukar amfani ga nazarin ilimin ƙasa tunda su kaɗai ne suka rage na sauran hanyoyin ilimin ƙasa waɗanda suka mamaye yankin a baya. Don yin taswirar lokaci na yadda duk fuskar duniya ta ci gaba bayan yashwa, yana da mahimmanci a san yanayin siffofin taimakon a wancan lokacin. Godiya ga kasancewar waɗannan tuddai masu shaida yana yiwuwa a sani.
Wadannan zaizayar kasa da kuma lamuran yau da kullun sune yanayin halittar duniyar mu. Wadannan tuddai masu shaida suma suna da halin kewaye da ruwa, wanda shine dalilin da yasa suke cikin yankuna kusa da rafuka waɗanda suke a mashigar teku. Dangane da wasu nazarin, waɗannan abubuwan sassauƙan dole ne suka kasance tsakanin agesananan shekarun Middle da Lower Miocene.
Wannan tsari ba galibi ana rufe shi da jan laushi tunda sun riga sun kasance a cikin ƙarancin Miocene. Idan kun ci karo da wasu lalatattun laka, zai kasance ne kawai a farkon mita 3 ko 4 na tsaunin.
Dole ne a banbanta tudun shaida daga shuɗa galibi ta girman. Murs suna daɗa faɗaɗawa a duk yankin kuma suna da yawa sosai. Babban banbancin sa shine cewa tuddai masu shaida basuda yawa kuma basu da yawa. Bugu da kari, páramo ya kunshi cikakken yanayin halittu tare da rinjaye na ciyawar shrub. Wannan yana sanya shi a sanya shi cikin yanayin ƙirar halitta a matsayin prairie saboda nau'in ciyawar ta. Koyaya, tudun shaida ba a kasafta shi a matsayin yanayin yanayin ƙasa ba.
Ina fatan cewa tare da wannan bayanin za ku iya koyo game da tudun shaida.