Sediments in carbonate-rich intervals range from nannofossil ooze to nanofossil clay. In carbonate-poor intervals, sediments are clay, clay with silt, or clay with nannofossils. Colors range from light greenish gray to dark greenish gray alternating with reddish brown and reddish green intervals. This unit is well resolved on the downhole logs, with clear cyclic variations in gamma ray, bulk density, velocity, and resistivity. Unit I. Unit II sediments are nannofossil clay and clay with silt.
Colors show limited variations from light to dark greenish gray.
The sediments are predominantly composed of nannofossil clay, clay with nannofossil, clay with silt, and clay. Site 1061 has mixed magnetic polarity, with Hole 1061A ending in the Gauss normal chron. Several excursions within the Brunhes Chron are reproducible among the holes. As in previous Blake Ridge sites, pore-water chemistry shows a very thin sulfate reduction zone of about 13 m. Calcium and magnesium distribution indicate carbonate precipitation near the sulfate methane interface and within the methanogenic zone. No gas hydrate was directly observed, but chloride profiles freshen with depth, indicating gas hydrate may underlie Site 1061.