Ib txheej ntawm cov khoom zoo-grained detrital, feem ntau yog av nplaum, tuag tam sim hauv qab lub coalbed lossis tsim hauv pem teb ntawm cov coal seam. Nws sawv cev rau cov av qub uas cov nroj tsuag (los ntawm cov thee tau tsim) tau rooted, thiab nws feem ntau muaj cov hauv paus hniav (piv txwv li ntawm genus Stigmaria).
Yuav ua li cas underclay tsim?
hluav taws av nplaum. … Hauv Carboniferous thiab lwm yam coal-bearing strata, fireclay feem ntau muaj ntau underclays. Kev hloov pauv ntawm cov sediments los ntawm huab cua, nroj tsuag, thiab lwm yam txheej txheem av suav nrog underclay ua rau muaj feem ntau ntawm fireclay uas muaj underclay.
Dab tsi yog underclay?
: txheej av nplaum hauv qab lub txaj thee feem ntau muaj cov hauv paus hniav ntawm cov nroj tsuag thee thiab tsim cov hluav taws kub.
Puas yog av nplaum?
INTRODUCTION FLINT av nplaum txhais tau tias yog a sedimentary, micro- crystalline rau cryptocrystalline av nplaum (pob zeb) com- posed dominantly ntawm kaolin, uas tawg nrog ib tug pronounced conchoidal puas thiab resists slacking hauv dej. Qhov kev txhais no, ib txwm ib txwm muaj, qhia txog qhov yuav tsum tau muaj tab sis tsis txaus txaus.
av nplaum yog dab tsi?
Nws yog ib txoj kev tsim muaj cov coal seamsthiab yog ua los ntawm av nplaum thiab shales. … Clay ironstone, sib tov ntawm av nplaum thiab siderite (hlau carbonate), qee zaum tshwm sim raws li txheej ntawm tsaus-grey rau xim av, nplua-grained nodules overlying thee seams.
