Fin (geology)

Fin wani ilimin tarihin ƙasa ne, sauran bango na sedimentary dutse cewa ya kasance tsaye bayan da ke kewaye da dutse da aka rushe tare da parallel joints ko karyewa. Ana samar da fili lokacin da wani kunkuntar butte ko tudu ya samar da tsagewa da yawa a tsaye, a layi daya. Akwai manyan hanyoyi guda biyu na bin lalacewa. Na farko shine lokacin da ruwa ke gudana tare da haɗin gwiwa da karyewa kuma yana buɗe su da faɗi da faɗi, a Ƙarshen yana haifar da rushewa. Na biyu shine inda nau'in dutse (stratum) ya fi wuya kuma ya fi tsayayya da rushewa fiye da duwatsun makwabta, yana haifar da dutse mai rauni ya fadi.

Ana ɗaukar fins a matsayin matsakaici na wasu siffofin geologic kamar windows, arches, da hoodoos. Samun irin waɗannan fasalulluka tsari ne mai sauƙaƙe na matakai huɗu. Mataki na farko shine ɗagawa wanda ke haifar da zurfin layi daya, fashewar tsaye a cikin tudu. Mataki na biyu shine yanayin yanayi da rushewa wanda ke fadada fashewar, yana samar da fuka-fuki. Mataki na uku shine rushewar da ke kai hari daga ƙasa, yana haifar da windows da arches. Mataki na huɗu yana ci gaba da yanayin da ke fadada ramuka, yana haifar da arches da ramuka su rushe, suna haifar da spires ko hoodoos.

 Sandstones 
Fins za su samo asali ne a cikin duwatsu masu laushi, galibi sandstone. Sandstone yana kwance, wanda ke samar da yankunan rauni, tare da yanayin yanayi da rushewa. Iron oxide da calcium carbonate siminti sandstones suna samar da fins.Harvey, Adrian (2012). Introducing Geomorphology: A Guide to Landforms and Processes. Dunedin Academic Press Ltd. Wadannan galibi ana ganin su a matsayin ciment mai rauni, idan aka kwatanta da ciment mai tsayayya da rushewa, amma a yankuna masu bushewa da semi-arid sun fi tsayayya. Wannan ya faru ne saboda rashin ruwa a cikin waɗannan yankuna wanda in ba haka ba zai iya yin amfani da sinadarai na iron oxide cements da calcium carbonate cements.

Saboda sandstones suna da dutse mai laushi, suna da manyan haɗin gwiwa da jiragen gado wanda ke ba da tashoshi da yawa don magudanar ruwa. Lokacin da alamu na ruwa ke bin waɗannan hanyoyin, yana haifar da kusurwa, alamu na dendritic a cikin yanayin ƙasa. Rashin murfin ƙasa a cikin waɗannan yankuna masu bushewa yana ba da haɗin gwiwa matsakaicin iko akan tsarin magudanar ruwa wanda ke haifar da alamu na kusurwa, yanayin da ya fi dacewa, da gangaren da ke da tsawo.Hinds, Norman E. (1943). Geomorphology: The Evolution of Landscape. New York: Prentice-Hall, Inc.

 Abubuwan da suka faru 
Fins yawanci yana faruwa a yankuna masu busasshiyar ƙasa zuwa yankuna masu tsaka-tsaki, kamar kudu maso yammacin Amurka. Gidan shakatawa na Arches a Utah gida ne ga Navajo Sandstone,  wani sandstone na siminti na ƙarfe, kuma yana nuna duk matakai na fin zuwa rushewar ƙwanƙwasawa da tsarin tsari. Tsarin Entrada Sandstone  , dutsen siminti na calcium carbonate, ana iya samunsa a cikin wannan yankin, tare da Wyoming, Colorado, New Mexico, da Arizona.

 Gidan wasan kwaikwayo 

 Manazarta