砾岩是一种由圆浑状的砾石（粒径大于2mm）胶结而成的岩石，是圆状和次圆状的砾石占岩石总量30%以上的碎屑岩。砾岩中碎屑组分主要是岩屑，只有少量矿物碎屑，填隙物为砂、粉砂、粘土物质和化学沉淀物质。

The conglomerate is a type of rock cemented by round gravel (diameter more than 2mm). It is a clastic rock with round and sub-round gravels accounting for more than 30% of the total rock mass. The clastic components in the conglomerate are mainly rock debris, with only a small amount of mineral detritus. Interstitial materials are sand, silty sand, clay material and chemical precipitates.