Ko te Dolomite he kōhuke kōnukawate kore wai e mōhiotia ana, ko te koneki konupūmā konupāora warawhā te matū matua, e tohua ana e te tātai CaMg(CO₃)₂. Koia te wāhanga matua o te toka parataiao e kīa ana ko te ingoa kotahi (e kīa ana ko te dolostone hei karo i te rangirua) me te toka kēhua e kīa ana ko te mapere dolomite.Mai i te taha kōhuke, ka whakakikoruatia te dolomite ki te pūnaha tapatoru-rhombohedral, ka whakaputa i ngā tioata rhombohedral me ngā mata ānau, ngā whakaranu nohoanga, ngā whakaranu pūpū, kirikiri rānei. I tana āhua parakore, he korekore, he mā rānei te kōhuke; engari, ko ngā poke pēnei i te rino, te konupāora, te kobalt rānei e whakakapi ana i te anga tioata, e hoatu ana i ngā āhua māwhero, parauri, hina, kōwhai rānei.Ka wehewehea te Dolomite i te karetiki (CaCO₃) e tōna whakaritenga hanganga, e wehea ai ngā paparanga kōaro o te konupūmā me te konupāora e ngā papa o ngā rōpū warawhā (CO₃²⁻). Nā tēnei hanganga raupapa tiketike ka puta he kiato teitei ake (2.84–2.86 g/cm³) me te pakeke ake (3.5–4 i te tauine Mohs) i te karetiki, tae atu ki te āhua pōturi o te tauhohenga ki te waikawa pūhaumāota (HCl) mārire, me te pūhā kaha anake ina whakawerahia, puehutia rānei.
Ko te whakahuatanga ingoa me te whakaaetanga putaiao o te dolomite e mau ana ki nga tikanga whenua o Uropi o te rau tau 1800 whakamutunga. I whakaingoatia te kohuke hei whakanui i te tohunga taiao me te tohunga whenua Parani a Dieudonné Sylvain Guy Tancrède de Gratet de Dolomieu (e mohiotia ana ko Déodat de Dolomieu), nana i whakaahua tuatahi nga toka waro ahurei i nga Alps Tyrolean o te raki o Itari i te tau 1791. I kite a Dolomieu ko enei toka, ahakoa he rite ki te kiripaka, kare i pakupaku kaha ki nga waikawa ngoikore. Kare i roa, i te tau 1792, ka tirohia e te tohunga matū Swiss a Nicolas-Théodore de Saussure te matū o te rawa, ka whakaingoatia mana te kohuke ko “dolomite.” Ko tenei kitenga o mua i puta mai ehara i te ingoa o te kohuke anake, engari ko te whakaingoa o nga Dolomites, te pae maunga whakamiharo, taratara i te raki-rawhiti o Itari e hanga ana i te nuinga o tenei toka. Ko te rangahau o mua o te dolomite i whanau mai i muri tetahi o nga raru roa rawa o te whenua: “Te Raru o te Dolomite.” I mohio wawe nga tohunga whenua o mua, ahakoa kei nga waahi katoa o nga toka tawhito nga hanganga dolomite nunui (mai i te Precambrian ki te Paleozoic), he tino uaua nga hoa hou e whakaheke kaha ana i nga taiao moana o naianei.
Ko te takenga mai o te dolomite he tukanga matū whenua uaua, he mea nui ki te tautohetohe pūtaiao. Ko te whakaputanga tuatahi o te dolomite i roto i te wai moana i raro i ngā āhuatanga noa o te mata o te whenua (25°C, 1 atm) e āraitia ana e te pūmārō. Ka puta tēnei āraitanga nā te mea he tino whakamākūkū ngā katote konupora (Mg²⁺) i roto i ngā wairewa wai, e pupuri ana i ō rātou rāpoi wai a tawhio noa me te kaha nui, e kore ai e uru ki roto i te whakatakotoranga tioata warawao whakariterite i ngā pāmahana iti. Nō reira, ko te nuinga o te dolomite whenua he mea tuarua, nō te take diagenetic.
Ko tēnei hanganga tuarua e puta ana mā te dolomititanga, he tukanga whakakapi e heke haere ai ngā waipiro whai konupora i roto i ngā parataiao pākaukau konupūmā (CaCO₃) o mua, i ngā kōhatu pākaukau rānei. Ko te tauhohenga matū whānui e whakaaturia ana pēnei:
2CaCO3 (kāraitī) + konupūmā2+ → CaMg(CO3)2 (dolomite) + Ca2+
E tika ana tēnei tauhohenga matū whenua matatini ki ngā āhuatanga whakamaoritanga me te hāora wai tino motuhake hei whakakore i tōna ārai nekehanga. Tuatahi, ko ngā pāmahana tiketike—e hono ana ki te tanumanga parataiao hōhonu me te mahi waiariki—he mea nui hei whakapōraru i ngā kiri whakamākū kaha e tiaki ana i ngā katote konupora. Waihoki, e hiahiatia ana he ōwehenga Mg²⁺/Ca²⁺ teitei hei whakahauhau i te tukanga, he āhuatanga e whakaōritea ana i te nuinga o te wā e te whakaetoeto nui o te wai tai i roto i ngā riu kua rohea (te tauira parataiao whakaetoeto), e te whakaranu rānei o te wai whenua hou ki ngā wai tai o te one (te tauira whakaranu-whakarewa a Dorag). I tua atu i ngā ara parakōrehu noa, e whakanui ana ngā rangahau parataiao hou i te mahi a te takawaenga moroiti, e whakaatu ana he kaha ngā huakita whakaheke pūngāwhā me te whakaputa māhu ki te whakahaere i te parataiao o te dolomite i ngā mahana iti i roto i ngā moana tote nui, kawa rānei, mā te whakarerekē i te matū wai o te rohe me te whakakore i ngā ārai nekehanga pēnei i te pūngāwhā rewa. Hei whakamutunga, nā te mea he tino kikii te whakatakotoranga tioata o te dolomite i tōna kākaraka taketake, ko te whakakapinga whenua nei te take o te 13% whakaheke i te papatipu toka. Nā tēnei whakaheke rahi e whakaputa ana i te kōpaka me te urutanga o waenga tioata tuarua, e whakamārama ana he aha ngā papahanga dolomita tawhito e noho ai hei waihāpai rōhe mō ngā wai whenua, me te rarangi ki te ao tāngata hei mahanga hanganga matua mō ngā putunga hinu me te hau.
Te Hanganga Kiripiri me te Hangarite
Ko te Dolomite, me te tātai matū pai ko CaMg(CO₃)₂, ka whakakatokato i roto i te pūnaha tioata tapatoru, ā, nō te roopu whakatakotoranga rewa-whakawhiti R-3. Ko tōna hanganga tioata e mōhiotia ana e te whakaritenga tino raupapa o ngā paparanga kōpapa-kīroka me te konupora-kīroka e wehea ana e ngā rōpū warawao (CO₃²⁻), he āhuatanga e tino rerekē ai te dolomite i te kāratiti me ētahi atu kohuke warawao māmā. I te taha o te tuaka tioata-c, ka whakakikoruatia ngā whārangi warawao katia e ngā paparanga katote e noho ai te konupora me te konupōma ki ngā tūnga tioata motuhake, kaua e tōrapa noa ki te whāriki. Ko tēnei whakaritenga katote i ahu mai i te rerekētanga nui o te pūtoro katote me te whanonga here i waenganui i te Ca²⁺ me te Mg²⁺, e whakaputa ana i tētahi hanganga he iti ake te ōrite i tō te kāratiti, engari e whakapiki ana i te pūmau hanganga. Kua whakaatuhia e ngā rangahau whakatairā-X me te hīraurau irahiko ka rerekē te tohu o te whakaritenga katote i runga i te mahana, te matū waipū, me ngā āhuatanga tipu, ā, he mea noa te whakaritenga kore-katoa i roto i ngā tauira māori. I roto i ngā taiao parataiao e tere ai te parataiao o te dolomite, e hanga rānei i raro i ngā here nekehanga, ka puta pea he matū e whakaatu ana i te haupori-whauriki konupora–konupōma, he āhua pūmau-kore e kīia ana ko te protodolomite. Ko te takenga mai o ēnei wāhanga haupori e hono tonu ana ki te "raru dolomite" kua roa e rangahaua ana, tētahi o ngā kaupapa tino mātātoa i roto i te mātai parataiao warawao me te matūwhenua, e pā ana ki te rerekētanga i waenga i te nui o te dolomite i roto i te pūrākau matawhenua me te uaua o te whakaputa i te dolomite tino whakarite i raro i ngā āhuatanga mata o nāianei.
Ngā Tāhu me ngā Āhuatanga Whatu
Ko te dolomite parakore he kore tae, he ma, he ata kōruarua rānei; heoi, i te nuinga o te wā, ka puta ngā tauira māori i te whānuitanga o ngā tae e ahu mai ana i te whakakapinga o ngā huānga tohu, ngā hētanga o te tukutuku whakatakotoranga, me ngā whakaurunga pāhekoheko i riro i te wā e tipu ana te tioata. Ko te rino te mea e whakaputa i te kōrewa, te kirīmi, te kōwhai-parauri, te parauri rānei; ko te konupora kei te whakaputa i ngā tae māwhero ngāwari ki te whero; ā, ko te kānara iti nei te kaha e whakaputa i ngā momo tae waireti me te hākūareti e tino hiahiatia ana e ngā kaikohi kōhatu. Ko te dolomite he tiaho kotakota ki te tiaho peara, ā, he mārama ki te kōruarua i runga i te rahi o te tioata me te nui o te paruparu. Ki te tirohanga whatu, he uniaxial negative, me ngā taupātata whakaata i te nuinga o te wā mai i nω = 1.679–1.681 ki nε = 1.500–1.503, e whakaputa ana i te birefringence kaha e kitea ana i raro i te miihini tirohanga whakamārama polarised. Nā tēnei huringa whatu kaha e puta ai ngā tae tīwhana teitei me ngā huringa āhuatanga motuhake i te hurihanga o te atamira, e waiho ai te dolomite hei tohu petrographic nui i roto i ngā toka waro. I te wāhanga angiangi, e kitea ana te aratohu rhombohedral, ngā hanganga tipu whakarōpū, me te pākākā ararewa i ētahi wā; ā, e whakaatu ana ngā rangahau cathodoluminescence i te whakarōpū o ngā huānga e pā ana ki ngā rerekētanga o te kaha o ngā huānga tohu. Ko ēnei āhuatanga whatu e whakarato ana i te mōhiohio nui mō te hītori diagenetic, ngā tauwhitiwhiti wai, me te kukuwhatanga geochemical o ngā parataiao waro me ngā toka puna.
Ngā Momo Mātātoka
E maha ngā momo me ngā whakaputanga tito o te dolomite kua mōhiotia i runga i te āhua o te karaihe, te matū o te tohu kōnuka, me ngā hononga whakarewa-tōtika i roto i te rōpū dolomite. Ko tētahi o ngā kupu kohinga tino mōhiotia ko te Pearl Spar, e tohu ana ki ngā whakahuihui o ngā karaihe rhombohedral kopiko e whakaatu ana i te tīaho peara, ā, he maha ngā wā ka tupu hei āhua noho noho hōiho hei tohu mō ngā taiao hydrothermal. Ko te whakaki i te haeana ki roto i te hanganga dolomite e ārahi ana ki te kohuke ankerite, he waro haeana-tino nui nō te rōpū dolomite, ā, e hanga ana i ngā raupapa tito whānui mā te whakakapinga Fe–Mg. Waihoki, ko te whakakapinga manganihi ahu whakamua e puta ai te whakawhiti ki te kutnohorite, te mema manganihi-tino nui o te rōpū. Ko ngā kukū tohu o te kobalta ka puta pea te momo cobaltoan dolomite tino ataahua, e rongonui ana mō tōna kara mākatea kaha me te noho ki roto i ngā putunga kōwhenua kua whakaheketia e te kobalta. Kua tuhia ētahi atu rerekētanga tito e pā ana ki te konutea, te nīkera, me ētahi atu kākāti hauwaru-rua i roto i ngā āhuatanga whenua motuhake, e whakaatu ana i te ngāwari o te whakapaparanga dolomite ki te whakaawe i te whakakapinga i te wā e pupuri ana i tōna hanganga karaihe taketake. Ko ēnei momo he whakaatu nui hei whakahou i ngā tukanga hanga kōwhenua, te whakarerekētanga hydrothermal, te whanake o te wai, me ngā āhuatanga matū whenua ā-rohe, e waiho ana ngā kohuke rōpū-dolomite hei tohu whai take i roto i te whenua ohaoha me te rangahau parataiao waro.
Ngā Āhuatanga Tinana me te Matū
Ko te pakeke Mohs o te tāwatawa (dolomite) kei te 3.5–4, ko tōna taumaha whārite e 2.84 ki te 2.86 g/cm³ te nuinga, ā, he wehenga rhombohedral tōna hei whakaputa i ngā kongakonga me ngā koki āhua tata ki te 73° me te 107°. Ko ngā tioata takitahi he rhombohedral, he paparahi, he āhua noho whaiaro rānei, ahakoa he nui ake ngā whakaminenga kirikiri i roto i ngā toka parataiao me ngā toka hurihanga. I runga i te āhuatanga miihini, he mārō noa iho te kōhuke, ā, he mā tonu tōna kiri ahakoa te tae o waho. I runga i te āhuatanga matū, he warowaihā rua kore-wai te tāwatawa e ū ana ki te whānuitanga o ngā taiao āraiwhenua, ā, ko ia tētahi o ngā kōhuke hanga toka matua o ngā papa warowaihā me ngā kōwhatu tāwatawa puta noa i te ao. Ahakoa tōna ūnga pūngoi, he pōturi rawa ngā tauhohenga o te kōhuke ki ngā pāmahana iti, he āhuatanga e whai wāhi ana ki te uaua o te hanganga tāwatawa hou me te whai pānga nui ki te whakawhitinga toka warowaihā. Kāore i rite ki te kārata (calcite) e tauhohe kaha ana ki te waikawa māota hauhā (hydrochloric acid) mātao, he ngoikore, he roa rānei te tukupū o te tāwatawa ina whakamātauria ki te ringaringa. He kaha ake te tauhohenga ina whakapaura te kōhuke, ina whakamahanatia rānei te waikawa, he āhuatanga e whakamahia nuitia ana e ngā kaimātai whenua me ngā kaimātai kōhuke hei whakaingoa i te taunga. I tua atu i tōna hiranga āraiwhenua, he kōhuke ahumahi nui te tāwatawa e whakamahia ana ki ngā rauemi ārai ahi, ki ngā rerenga whakarewa, ki ngā whakaranu hanga whare, ki te whakapai oneone, ki te hanga karaihe, me ngā tukanga matū maha, e whakaatu ana i tōna nui whānui me tōna hiranga ōhanga puta noa i ngā wāhanga maha.
Ngā Whakamahinga me te Hiranga Ōhanga
Ko te Dolomite he kohuke warawī awhiwhi whānui e whai hiranga nui ana i roto i te ahumahi, te pūtaiao whenua, me te kohinga kohuke. I roto i te ahumahi, he matū whakapūmau matua i roto i te hanga whare, e whakamahia ai te dolomite kōrapa me te dolostone hei whakaranu mō te raima, te uku, te hanga huarahi, me te kōhatu whare. I roto i te mahi whakarewa, ka mahi te dolomite hei rewa e tika ana i te whakaputa rino me te tīra, e āwhina ana ki te tango i ngā poke, te hanga para, me te tiaki i te oumu, i te wā e whakamahia nuitia ana te dolomite tunua ki te hanga i ngā rauemi pārūrū e kaha ana ki te ātete i ngā pāmahana tino nui. Ka whakamahia hoki te kohuke ki te ahuwhenua hei kaihāora i te waikawa o te oneone me te whakarato konupūmā me te konupora, ā, he wāhi anō tōna ki ngā whakamahinga taiao pēnei i te maimoatanga wai, te whakaora i te waikeri waiwā kōruki, me te whakaweto whakahawea paipa. Ko ētahi atu whakamahinga ko te whakaputa karaihe, karamika, peita, tongawiti, pūhui konupora, me ngā momo matū matū. I tua atu i āna whakamahinga ahumahi, he hiranga pūtaiao nui te dolomite nā tōna wāhi ki te rangahau parataiao warawī, te whakahoutanga, ngā pūnaha waiwhenua, me ngā rangahau hinu papa, inā koa e pā ana ki te "raru dolomite" ā-ao roa. Ko ngā tauira kohuke tino hanga, tae atu ki te dolomite kobaltoan me ngā momo whakaaturanga tera motuhake, e whakahōnoretia ana hoki e ngā whare taonga me ngā kaikohi kohuke, e waiho ana te dolomite hei kohuke whai tikanga ōhanga me te kohuke kaupapa.