Two rock samples were collected at Site 1161 as soon as the core liners were split to characterize the microbial community inhabiting this environment (Table T3). One sample is a breccia fragment (Sample 187-1161A-4R-1 [Piece 10, 57-60 cm]), and one is a pillow basalt fragment composed of partially altered glass rind and crystalline basalt interior (Sample 187-1161A-3R-1 [Piece 24, 141-143 cm]). To sterilize them, the outer surfaces of the rocks were quickly flamed with an acetylene torch, and enrichment cultures and samples for DNA analysis and electron microscope studies were prepared (see "Igneous Rocks" in "Microbiology" in the "Explanatory Notes" chapter).