The porosity and permeability of typical basaltic rocks have been analyzed. Four effusive facies basalt layers and two volcanic necks with rockoutcrops can be identified.
牛头山古火山历经四期喷发,地表可见四层喷溢相玄武岩层和两处火山颈相岩石出露。
3
"Small amounts of carbonate minerals have been detected on Mars before, " he explained. "[But this time] we're seeing a couple of large outcrops of rock poking through the soil of the Columbia Hills."