Dutsen bakin teku
 Dutsen bakin teku | |
|---|---|
| Bayanai | |
| Ƙaramin ɓangare na |
sedimentary rock (en)  |
.JPG)
Beachrock wani dutse ne mai laushi ga dutse mai laushi wanda ya ƙunshi cakuda mai laushi, yashi, da kuma dutse mai girman laka wanda aka rufe shi da ma'adanai na carbonate kuma ya samo asali ne a bakin teku. Dangane da wurin, turɓaya da aka yi amfani da ita don samar da dutsen rairayin bakin teku na iya kunshe da cakuda mai canzawa na harsashi, raguwar murjani, raguwar dutse na nau'o'i daban-daban, da sauran kayan. Hakanan yana iya ƙunsar kayan tarihi da aka warwatsa, katako, da kwakwa. Beachrock yawanci yana samuwa a cikin yankin intertidal a cikin yankuna masu zafi ko semi-tropical. Koyaya, ana samun dutsen rairayin bakin teku na Quaternary har zuwa arewa da kudu kamar 60 ° latitude.[1][2]
Bayani na gaba ɗaya
[gyara sashe | gyara masomin]Raka'o'in rairayin bakin teku suna samuwa a ƙarƙashin bakin bakin ciki na laka kuma gabaɗaya sun wuce yashi mara ƙarfi. Yawanci sun ƙunshi raka'a da yawa, wakiltar sassa da yawa na ciminti da fallasa. Ma'adinan ma'adinai na rairayin bakin teku shine galibi high-magnesium calcite ko aragonite . Babban hanyoyin da ke tattare da siminti shine : supersaturation tare da CaCO 3 ta hanyar kai tsaye evaporation na ruwan teku, ruwan karkashin kasa CO 2 degassing a cikin vadose zone, hadawa na marine da meteoric ruwa fluxes da hazo na micritic calcium carbonate a matsayin byproduct na microbiological aiki.
A kan iyakar bakin teku masu janyewa, ɓarkewar dutsen rairayin bakin teku na iya zama bayyananne a bakin teku inda za su iya aiki a matsayin shingen ga rushewar bakin teku. Kasancewar dutsen rairayin bakin teku na iya haifar da karancin laka a cikin rairayin kan teku da kuma fitar da tsarin raƙuman ruwa. Saboda bakin rairayin bakin teku yana cikin yankin intertidal kuma saboda yawanci yana samuwa a cikin 'yan shekaru, damarsa a matsayin mai nuna alamar matakin teku da ya gabata yana da mahimmanci.
Cementation da matsayi na bakin teku
[gyara sashe | gyara masomin]Dutsen rairayin bakin teku suna tare da bakin teku a lokaci guda kuma yawanci suna da 'yan mita daga bakin teku. Gabaɗaya ana raba su a matakai da yawa waɗanda zasu iya dacewa da ƙarni daban-daban na siminti na bakin teku. Don haka, yankunan da suka tsufa suna cikin ɓangaren waje na tsari lokacin da ƙananan suke a gefen rairayin bakin teku, mai yiwuwa a ƙarƙashin yashi mara ƙarfi. Har ila yau, suna da alama suna da sha'awar teku (50-150 [bayani da ake buƙata]). Akwai bayyanar da yawa na tsarin rairayin bakin teku waɗanda ke da alamun raguwa da gibin da yawa. Sakamakon wannan gaskiyar shine tsari mai katsewa na bangarori daban-daban na bakin teku, wanda zai iya kasancewa iri ɗaya.
Tsawon rairayin bakin teku ya bambanta daga mita zuwa kilomita, faɗin sa na iya kaiwa har zuwa mita 300 kuma tsayinsa yana farawa daga 30 cm kuma ya kai mita 3.
Bayan aiwatar da rushewar bakin teku, ana iya gano tsarin rairayin bakin teku. Rushewar bakin teku na iya zama sakamakon hauhawar matakin teku ko rashi a cikin daidaitattun ruwa. Ta wata hanya ko wata, yashi marar ƙarfi wanda ya rufe dutsen rairayin bakin teku ya janye kuma an bayyana tsari. Idan tsarin siminti ya ci gaba, za a kafa sabon bakin teku a sabon matsayi a cikin yankin intertidal. Matakan da suka biyo baya na canjin matakin teku na iya haifar da yankuna masu yawa na rairayin bakin teku.
Manazarta
[gyara sashe | gyara masomin]- ↑ Neuendorf, K.K.E., J.P. Mehl, Jr., and J.A. Jackson, J.A., eds. (2005) Glossary of Geology (5th ed.). Alexandria, Virginia, American Geological Institute. 779 pp. ISBN 0-922152-76-4
- ↑ Scholle, P.A., D.G. Bebout, and C.H. Moore (1983) Carbonate Depositional Environments. Memoir no. 33. Tulsa, Oklahoma, American Association of Petroleum Geologists. 708 pp. ISBN 978-0-89181-310-1