Data for: The effect of sediment lithology on oxygen isotope composition and phase transformation of marine biogenic opal.

These are d18O measurements of silica phases (biogenic amorphous opal, opal-A', opal-CT, and microquartz chert) from a set of drilled sediments from Ocean Drilling Program (ODP) sites 1049-1053. These measurements were made after separation of the silica phases from bulk sediment, cleaning, and measurements with laser fluorination mass spectrometry.