The basalt cores containing fractures and vugs filled by carbonate phases were investigated macroscopically. The macroscopic observations on the core surface revealed a variety of carbonate internal sediments and cements characterized by complex paragenetic sequences. This study focuses on the origin of micritic sediment. Selected samples of representative textures were then chosen, slabbed, and made into thin sections for petrographic analyses. Samples for scanning electron microscope (SEM) study were broken from the thin-section chips and were not subject to selective dissolution.