Middle Ordovician

常见例句

The material source of the Carboniferous karst type bauxite in North China mainly came from the underlying Late Cambrian—Middle Ordovician carbonate rock.
华北石炭纪岩溶型铝土矿的主要物质来源为下伏的晚寒武世—中奥陶世碳酸盐岩。
From the suture line towards the north, an andesite line along Sharburti Mountain was the volcanic island arc developed from middle Ordovician to middle-late Silurian.
由缝合线向北，沙尔布尔提山安山岩线是中奥陶世至中、晚志留世发育起来的火山岛弧。
In the period from Middle Ordovician to Devonian, the central and southern Ningxia area is the back-arc foreland basin in the north continental side of North Qilianshan orogen.
宁夏中南部地区在中奥陶世至泥盆纪是作为北祁连造山带北侧的弧后前陆盆地靠大陆一侧而存在的；