A red residual soil in humid tropical and subtropical regions that is leached of soluble minerals, aluminum hydroxides, and silica but still contains concentrations of iron oxides and iron hydroxides.

• 红土湿润的热带或亚热带地区的红色残留土，被雨水冲掉了可溶性矿物质、氢氧化铝和二氧化硅，但是仍保留了氧化铁和氢氧化铁