The Middle and Upper Ordovician carbonate reef and shoal assemblae originally formed in a rimmed shelf system , and then reworked by multi phases diagenesis and structural fracturing.

• 塔中中上奥陶统碳酸盐岩储层是在一发育良好的镶边陆棚体系中形成的礁、滩组合,并经过后期多次成岩和构造破裂作用改造而成。