Leg 67 sample sediments are mainly composed of biogenic carbonate and biogenic siliceous materials. Apart from calcite, crystallized minerals are scarce; however, they are better represented in sites near the continent and in all Quaternary sediments. These minerals are: quartz, feldspars, smectite, and, rarely, chlorite, dolomite, and zeolite.

Supplement to: Latouche, Claude; Maillet, Noelle (1982): X-ray mineralogy studies, Leg 67 (Sites 494–500): The Middle America Trench transect off Guatemala. In: Abouin, J; von Huene, R; et al. (eds.), Initial Reports of the Deep Sea Drilling Project (U.S. Govt. Printing Office), 67, 529-535