鐵質石英砂岩主要分布在小門國小西側及北側，一部分發育在島嶼東側，呈塊狀零星分布，岩塊中石英砂的粒度均勻，約在2公厘左右甚或更細，膠結物為褐鐵礦，因岩石堅硬，居民常採集做為圍築防風牆或屋牆的材料，所以整個岩層被破壞非常嚴重。鐵質石英砂岩暴露在地表時，受到氧化作用，褐鐵礦風化而剝離，會殘留一片石英砂粒在地表上。本標本採集自小門嶼。
鐵質石英砂岩主要分布在小門國小西側及北側，一部分發育在島嶼東側，呈塊狀零星分布，岩塊中石英砂的粒度均勻，約在2公厘左右甚或更細，膠結物為褐鐵礦，因岩石堅硬，居民常採集做為圍築防風牆或屋牆的材料，所以整個岩層被破壞非常嚴重。鐵質石英砂岩暴露在地表時，受到氧化作用，褐鐵礦風化而剝離，會殘留一片石英砂粒在地表上。本標本採集自小門嶼。
The iron silica sandstone is mainly distributed in the westnorth of Hsiaomen Elementary School,part of it develops in the east of the islet, sporadically distributed in blocks. The grain size of silica sand in the rock block is uniform, about 2 mmeven finer,the cementitious rock is limonite. Because the rock is so solid, residents often collect it as a material for building windbreakshouse walls. As a result, the entire rock formation is damaged very seriously. When exposed to the earth surface, the iron silica sandstone is oxidizedthe limonite is weatheredpeeled off, leaving silica sand to cover the entire area. This specimen was collected from Hsiaomen Islet.
