Dingxi Prefecture is located in the foothill of the Loess Plateau climate is arid or semi - arid.位于黄土高原丘陵沟壑干旱半干旱区的甘肃省定西地区,面临生态恶劣和经济贫困的双重危机.The scent of pine and the sound of crickets floated down from the foothill Appala...
When deposited , 70 - 80 % of the volume of muddy sediments may be water.泥质沉积物沉积后, 体积的70-80%是水.Loose sediments may be changed into solid sedimentary rocks.松散的沉积物可以变成坚硬的沉积岩.The sediments are detrital.沉积岩为碎屑质.Larix pollen ...