Fig. 5: Pore types of the sandstones.
From: Petrophysical and mechanical characterization of sandstones from different grottoes in China
a Microfractures in Yungang sandstone, b intergranular pores in Tianlongshan sandstone, c intragranular pores in Tianlongshan sandstone, d dissolution pores in Tianlongshan sandstone, and e micropores closely related to clay aggregates in Tianlongshan sandstone.
