silcretes造句

• Groundwater silcretes typically formed in more localised, topographically lower settings such as valley bottoms and slopes, whereas pedogenic silcrete tended to form extensive sheets over very large areas.
• Detailed studies of ganisters, which occur either as seatearths or elsewhere within coal-bearing strata, have found them to be ancient paleosols, which are equivalent in both physical characteristics and origin to modern silica-cemented soils, called silcretes.