Auchinleck Tip contains mixed Carboniferous mine spoil, historically attributed to the Scottish Middle Coal Measures Formation. Among the hard limestone blocks, shale can yield plant stems and roots, including stems of Calamites. Many pieces are barren or poorly preserved, but the original account records occasional better plant remains. The dumped rocks no longer retain their original bed order. Carboniferious, Spoil Heap, Rating: ♦♦♦