(Table 1) Mineralogy at DSDP Leg 62 Holes

Sixty-nine sediment samples of Deep Sea Drilling Project Leg 62 were mineralogically examined by X-ray diffractometry, and gasometrically for their carbonate content. Most sediments were found to be carbonate-rich; some have up to 97% CaCO3. Many chalk or limestone samples contain chert, accounting for high quartz percentages in some analyzed samples.

(Appendix A) Oxygen and carbon isotope results of detrital carbonate grains of Heinrich layers from HU90-013-028 and IODP Sites 303-U1302/U1303/U1308 in the North Atlantic Ocean

We report oxygen and carbon isotope results of detrital carbonate grains from Heinrich layers at three sites in the North Atlantic located along a transect from the Labrador Sea to the eastern North Atlantic. Oxygen isotopic values of individual detrital carbonate grains from six Heinrich layers at all sites average - 5.6 ppm ± 1.5 ppm (1sigma; n = 166), reflecting values of dolomitic limestone derived from source areas in northeastern Canada. The d18O of bulk carbonate at Integrated Ocean Drilling Program (IODP) Site U1308 (re-occupation of Deep Sea Drilling Project (DSDP) Site 609) in the eastern North Atlantic records the proportion of detrital to biogenic carbonate and d18O decreases to - 5 ppm during Heinrich (H) events 1, 2, 4 and 5 relative to a background value of ~ 1 to 2 ppm for biogenic carbonate. Bulk d18O also decreases during H3 and H6 but only attains values of - 1ppm, indicating either a greater proportion of biogenic-to-detrital carbonate or a different source. Because the d18O of detrital carbonate is ~ 9 ppm lower than foraminifer carbonate, any fine-grained detrital carbonate not removed from the inner test chambers will lower foraminifer d18O. We conclude bulk carbonate d18O is a sensitive proxy for detrital carbonate and may be useful for identifying Heinrich layers in cores within and near the margins of the North Atlantic ice-rafted detritus (IRD) belt.

Description of manganese deposits from the Oriente province in Cuba

Deposits of manganese ore have been found in five of the six provinces of Cuba and have been reported from the sixth. Only Oriente and Pinar del Rio provinces have more than a few known deposits and only the deposits of Oriente have yielded any appreciable amount of ore. In this area the Cobre formation, of late Cretaceous(?) to middle Eocene age, overlies the Vinent formation but their stratigraphie relations are unknown. The Cobre overlies unconformably the Habana(?) formation. The Cobre formation consists of andesitic, basaltic, and dacitic tuff, agglomerate, and lavas with minor amounts of marine clastic and limestone deposits, and a prominent limestone bed, the Charco Redondo limestone member, at the top of the formation. All productive manganese deposits of Oriente are in the Cobre formation, usually within a few tens of meters above or below the base of the Charco Redondo limestone member.