Kev sib tsoo ntawm nruab nrab
Magma nce siab raws txoj kab ncig tubular thiab hla ntawm qhov txoj kev ua qab nthab, uas yog hu ua qhov tawg nruab nrab. Qhov chaw no feem ntau nyob ntawm qhov kev sib tshuam ntawm ob pawg ntawm kev yuam kev, thiab yog txoj kev tseem ceeb ntawm kev ua hluav taws xob hauv thaj chaw Mesozoic, Cenozoic thiab txawm tias niaj hnub. Qhov kev sib tsoo hauv nruab nrab feem ntau yog nrog lub zog sib tsoo, uas thawj zaug ejects cov pa roj thiab khib nyiab ntau, thiab thaum kawg yauv magma.