Focused ion beam scanning electron microscopy(FIB-SEM) is a dual beam system which combines focused ion beam (FIB)
and scanning electron microscopy (SEM) to cut samples and display real-time images at nanometer scale. This study observed several
kinds of microfossils from the Lungmachi Formation (Llandovery, Silurian) with FIB-SEM. The results reveal that submicron-nano
pores, which provide valid space for shale gas reservoirs, are well-developed in conodonts, chitinozoans and acritarchs. Disparities of
micro-pores in different fossil groups shown in this study will help to explain the cause of organic pore heterogeneity in shales.