This report presents new data on chemical and mineralogical composition and density of altered and fresh igneous rocks from key Deep Sea Drilling Project (DSDP)/Ocean Drilling Program (ODP) holes drilled on the following main tectonomagmatic structures of the ocean floor:
1. Mid-ocean ridges and abyssal plains and basins (DSDP Legs 37, 61, 63, 64, 65, 69, 70, 83, and 91 and ODP Legs 106, 111, 123, 129, 137, 139, 140, 148, and 169);
2. Seamounts and guyots (DSDP Legs 19, 55, and 62 and ODP Legs 143 and 144);
3. Intraplate rises (DSDP Legs 26, 33, 51, 52, 53, 72, and 74 and ODP Legs 104, 115, 120, 121, and 183); and
4. Marginal seas (DSDP Legs 19, 59, and 60 and ODP Legs 124, 125, 126, 127, 128, and 135).