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Geology ntawm Indonesian Pumice

Pumice los yog pumice yog ib hom pob zeb uas muaj xim xim, muaj ua npuas ncauj ua los ntawm iav-walled npuas, thiab feem ntau hu ua silicate volcanic iav.

Cov pob zeb no yog tsim los ntawm acidic magma los ntawm kev ua ntawm volcanic eruptions uas eject cov khoom mus rau saum huab cua; ces undergo kab rov tav thauj thiab sib sau ua pyroclastic pob zeb.

Pumice muaj cov khoom sib txawv, muaj ntau lub hlwb (cov qauv cellular) vim qhov nthuav dav ntawm cov pa roj carbon monoxide muaj nyob rau hauv, thiab feem ntau pom muaj cov khoom xoob lossis cov khoom tawg hauv volcanic breccia. Thaum cov zaub mov muaj nyob rau hauv pumice yog feldspar, quartz, obsidian, cristobalite, thiab tridymite.

Pumice tshwm sim thaum acidic magma nce mus rau saum npoo thiab dheev los rau hauv kev sib cuag nrog huab cua sab nraud. Ntuj iav ua npuas ncauj nrog / roj uas muaj nyob rau hauv nws muaj lub cib fim khiav dim thiab lub magma freezes dheev, pumice feem ntau tshwm sim raws li fragments uas ejected thaum lub sij hawm volcanic eruptions xws li loj los ntawm gravel mus rau pob zeb.

Pumice feem ntau tshwm sim raws li yaj los yog dej ntws, cov khoom xoob lossis cov khoom tawg nyob rau hauv volcanic breccias.

Pumice kuj tuaj yeem ua los ntawm cua sov obsidian, kom cov pa tawm. Cov cua kub ua rau obsidian los ntawm Krakatoa, qhov kub yuav tsum tau hloov obsidian rau hauv pumice nruab nrab 880oC. Qhov tshwj xeeb lub ntiajteb txawj nqus ntawm obsidian uas yog Ameslikas 2.36 poob rau 0.416 tom qab kev kho mob, yog li nws ntab hauv dej. Lub pob zeb pumice no muaj cov khoom siv hydraulic.

Pumice yog ib tug dawb mus rau grey, yellowish mus rau liab, vesicular kev ntxhib los mos nrog orifice loj, uas txawv nyob rau hauv kev sib raug zoo rau ib leeg los yog tsis mus rau ib tug scorched qauv nrog oriented orifice.

Qee zaum lub qhov yog ntim nrog zeolite / calcite. Lub pob zeb no tiv taus cov dej khov dej khov (Frost), tsis yog li hygroscopic (nqus dej). Nws muaj cov khoom siv hluav taws xob tsawg. Lub zog siab ntawm 30-20 kg / cm2. Lub ntsiab muaj pes tsawg leeg ntawm amorphous silicate minerals.

Raws li kev tsim (deposition), kev faib tawm ntawm qhov loj me (fragment) thiab cov khoom ntawm lub hauv paus chiv keeb, pumice deposits raug cais raws li hauv qab no:

Sub cheeb tsam
Sub-aqueous

Tshiab ardante; i.e. deposits tsim los ntawm kab rov tav outflow ntawm gases nyob rau hauv lava, uas ua rau ib tug sib tov ntawm fragments ntawm ntau qhov ntau thiab tsawg nyob rau hauv ib tug matrix daim ntawv.
Qhov tshwm sim ntawm kev tso nyiaj rov qab (redeposit)

Los ntawm cov metamorphosis, tsuas yog cov cheeb tsam uas yog volcanic yuav muaj kev lag luam pumice deposits. Lub hnub nyoog geological ntawm cov deposits yog nyob nruab nrab ntawm Tertiary thiab tam sim no. Lub roob hluav taws uas tau ua haujlwm thaum lub hnub nyoog geological no suav nrog Pacific Dej hiav txwv fringe thiab txoj kev coj los ntawm Hiav Txwv Mediterranean mus rau Himalayas thiab tom qab ntawd mus rau Is Nrias teb sab hnub tuaj.

Pob zeb zoo ib yam li lwm yam pumice yog pumicite thiab volcanic cinder. Pumicite muaj tib yam tshuaj muaj pes tsawg leeg, keeb kwm ntawm kev tsim thiab iav qauv raws li pumice. Qhov sib txawv tsuas yog nyob rau hauv particle loj, uas yog me dua 16 nti nyob rau hauv lub cheeb. Pumice pom muaj nyob ze rau nws qhov chaw ntawm keeb kwm, thaum pumicite tau raug thauj los ntawm cua rau qhov kev ncua deb, thiab tau muab tso rau hauv daim ntawv ntawm cov hmoov tshauv loj loj los yog ua cov pob zeb tuff.

Lub volcanic cinder muaj reddish rau dub vesicular fragments, uas tau muab tso rau thaum lub sij hawm tawg ntawm basaltic pob zeb los ntawm volcanic eruptions. Feem ntau ntawm cov cinder deposits yog pom raws li conical txaj fragments xws li 1 nti mus rau ob peb nti inch.

Muaj peev xwm ntawm Indonesian Pumice

Nyob rau hauv Indonesia, lub xub ntiag ntawm pumice yog ib txwm txuam nrog ib tug series ntawm Quaternary mus rau Tertiary volcanoes. Nws txoj kev faib khoom suav nrog thaj tsam ntawm Serang thiab Sukabumi (West Java), cov kob ntawm Lombok (NTB) thiab cov kob ntawm Ternate (Maluku).

Lub peev xwm rau pumice deposits uas muaj qhov tseem ceeb ntawm kev lag luam thiab cov peev nyiaj loj heev yog nyob ntawm cov kob ntawm Lombok, West Nusa Tenggara, Ternate Island, Maluku. Tus nqi ntsuas reserves nyob rau hauv cheeb tsam yog kwv yees li ntawm ntau tshaj 10 lab tonnes. Hauv cheeb tsam Lombok, kev siv pumice tau ua txij li tsib xyoos dhau los, thaum nyob rau hauv Ternate qhov kev siv tsuas yog ua rau xyoo 1991.

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