ALBERT

Description: Igneous rocks were recovered from three sites on Hess Rise during Deep Sea Drilling Project Leg 62: altered basalt at Site 464, at the northern end of Hess Rise; and altered trachyte from Site 465, and rounded basalt pebbles in upper Albian to middle Miocene sediments from Site 466, both at the southern end of Hess Rise. Major-, minor-, and trace-element data for basalt from Hole 464 are consistent with these rocks being transitional tholeiites that have undergone low-temperature alteration by reaction with sea water. Trachyte from Hole 465A exhibits as many as three generations of plagioclase along with potash feldspar that are flow aligned in groundmasses alterted to smectites and random mixed-layer clays. Textural evidence indicates that these rocks were eruped subaerially. Chemical data show a range of values when plotted on two- and three-component variation diagrams. The observed variations may result in part from differentiation, but they also reflect the high degree of alteration. Several oxides and elements show strong correlation with H2O+: K2O, SiO2, Rb and Lu decrease and MgO increases with increasing H2O+. These trends, except for that of Lu, are consistent with experimentally determined changes in chemistry that accompany alteration. The trend for Lu has not been previously reported; it may result from a more-intense alteration of the HREE-rich mafic minerals than of the LREE-rich feldspars. Despite their alteration, the trachytes compare favorably with alkalic differentiates from oceanic islands. We interpret Hess Rise as a volcanic platform formed by eruption of off-ridge volcanic rocks onto MORB oceanic crust during the Aptian and Albian stages, after the basement had migrated away from the spreading center. By analogy with present oceanic islands, we propose that early tholeiitic basalts were followed by alkalic basalts and their differentiation products (trachytes), producing a volcanic archipelago of islands and seamounts. Subsequent tectonism and subsidence led to the present state of Hess Rise.

Description: Atomic-absorption spectrophotometry and instrumental neutron activation analysis were used to determine concentrations of SiO2, Al2O3, FeOt, MgO, CaO, Na2O, K2O, MnO, La, Ce, Sm, Eu, Tb, Yb, Lu, Sc, Co, Cr, Th, Hf, and Ta for 14 basalt samples from the lower portion of Hole 462A in the Nauru Basin. The basalts are similar to normal midocean ridge basalt (MORB) for the elements analyzed, and light rare-earth elements (LREE) are depleted relative to heavy rare-earth elements (HREE). Two samples are extensively altered to smectites and show significant reductions in Al2O3, CaO, MnO, Na2O, REE, Sc, Co, and Hf and gains in MgO and FeOt relative to unaltered samples. The increase in MgO and decrease in CaO indicate that alteration was caused by hydrothermal solutions.

Description: At Deep Sea Drilling Project (DSDP) Site 462, from mudline to 447 meters below the sea floor, Cenozoic nannofossil oozes and chalks have acoustic anisotropies such that horizontal sonic velocities are 0 to 2.5% faster than those in the vertical direction. In laminated chalk, anisotropy of 5% is typical, and in limestones, radiolarian oozes, porcellanites, and cherts, the anisotropies range from 4 to 13%. Middle Maestrichtian volcaniclastics from 447 meters to 560 meters below the sea floor have an acoustic anisotropy of 2 to 32%; 4 to 13% is typical. Basalt flows and sills occur between 560 meters and 1068 meters, and have no apparent anisotropy, but minor interbedded volcaniclastics have anisotropies from 0 to 20% (5% is typical). These volcaniclastics frequently have very small anisotropies, however, compared with the volcaniclastic sequence above the basalt section. Data in cross-plots of the laboratory-measured compressional sound velocity versus wet-bulk density, wet-water content, and porosity of sediments and sedimentary rock typically lie between the equations derived by Wyllie et al. (1956) and Wood (1941); the Wyllie et al. (1956) equation has a fair fit with similar basalt velocity cross-plots. Crossplots of thermal conductivity and sound velocity indicate only a fair correlation. Cross-plots of thermal conductivity versus porosity, wet-water content, and wet-bulk density correlate well with equations derived by Maxwell (1904), Ratcliff (1960), Parasnis (1960), and Bullard and Day (1961). Electrical formation factor versus porosity for sediments and sedimentary rock agrees with the Archie (1942) equation, with m values of 2.6; for basalt, an m of about 2.1 is typical. Basalt pore-water resistivities do not appear to be greatly different from sea water. Formation factors are greater than those derived from equations in Maxwell (1904), Winsauer et al. (1952), Boyce (1968), and Kermabon et al. (1969). An "apparent interstitial water resistivity" (Rwa) curve was derived from the density and induction logs. This Rwa curve indicated an anomaly, at 393.5 to 396.5 meters, which could be interpreted as (1) 76% hydrocarbons, (2) relatively fresh pore water (1.8 per mil salinity), or (3) low-grain-density (2.2 g/cm**3) semi-lithified porcellanite-chert. Porcellanite-chert is the most plausible interpretation. In situ temperatures measured by the Uyeda temperature probe were about 2 to 5°C (50%) higher than the equilibrium temperature (Lachenbruch and Brewer, 1959) extrapolated from two Gearhart-Owen continuous temperature logs; this discrepancy probably arises because the hole was washed out in this depth interval, so these extrapolated temperatures are probably not reliable. If one ignores all precautions as to temperature artifacts, then the equilibrium temperatures of the Gearhart-Owen temperature logs suggest that hydrothermal circulation is occurring in at least the upper 40 meters of the basalt section and heat is transferred by convection and not conduction. Hydrothermal circulation is probably not indicated, however, and the temperature anomalies probably result from excessive artificial cooling of the fractured basalt zones by circulation of water during drilling.

Description: The stratigraphic position of the glacially transported 'Scholle' (large-size erratic block) at Schobüll near Husum (Schleswig-Holstein) is now considered to be Devonian rather than 'Rotliegendes'. The 'Scholle', consisting of red clay and dolomite, is overlain by red-colored till without any flint but with up to 90% carbonate clasts (containing 15% dolomite), which indicates an eastern Baltic origin. The relationship of the 'Scholle' with the glacial till also points to an eastern Baltic origin for it, with up to 1 000 km transport distance.

Description: Available data on composition of sediments from the inner and outer continental shelves of the Southwest Africa, and on currents and variations of sea level in the Upper Quaternary are examined to elucidate the process of phosphate material concentration. Sand and gravel fractions in diatom oozes from the inner shelf have much higher phosphorus contents than adjoining sediments. This is due to presence of diagenetic phosphate nodules. As sea level varies, fine sediments are eroded by waves or currents that leads to formation of coarse-grained phosphate sediments.

Description: Ferromanganese nodules in the deep-sea and in freshwater lakes usually accrete layers rich in manganese oxides alternating with layers rich in iron oxides. The mechanism producing these alternating layers is unknown; indeed, the mechanism producing the nodules themselves is unknown. In Oneida Lake, New York, precipitants from the lake water and the surfaces of nodules at the sediment-water interface are enriched in Mn, whereas nodules buried in lake sediments have surface layers enriched in Fe. It is hypothesized here, using field and laboratory evidence, that reduction and mobilization of Mn from the nodule surface during periods of anoxic sediment cover produce the high Fe layers observed in the nodules.

Description: Since 1954 the Blake Plateau has interested the geophysical group at Woods HOle. Early cruises gathered data on this region incidental to other work. It became apparent that the area was worthy of more intense study. Questions about the bathymetry and underlying structure had been raised. This is a report of the most recent cruise undertaken to study the northern portion of the Plateau. It is intended to summarize the data collected and to be useful as art aid to investigators in preparation of manuscripts for publication.

Description: This report is Volume 3 of Descriptions of WHOI rock dredge samples. This series represents a major effort to catalog the rock dredge samples in the WHOI Sea Floor samples collection, and to disseminate this information throughout the scientific community. Volume 3 contains sample descriptions and station data for the dredge stations from five cruises during the period September 1978 through December 1980. The material in this and subsequent volumes of rock descriptions was largely prepared onboard ship by the participating scientists. Volume 3 was printed prior to volumes 1 and 2 because of the excellent documentation of the samples represented in this volume.

Description: The minor-element composition of concentric layers within a single ferromanganese nodule from the eastern North Pacific exhibits strong correlations with Fe and Mn contents but appears to be independent of pronounced mineralogic variations. On the basis of these correlations, the elemental composition of individual layers apparently is controlled by the relative contribution of two sources: seawater, and interstitial water of associated sediment. In contrast, the mineralogy of the nodule, consisting of birnessite in the outer few layers and todorokite in the inner layers, is considered to be a function of nodule diagenesis.

Description: The cores and dredges described in this report were taken on the ARIES Expedition from November 1970 until October 1971 by the Scripps Institution of Oceanography from the R/V Thomas Washington. A total of 65 cores and dredges were recovered and are available at Scripps for sampling and study.

Description: Compositional data for coexisting manganese nodules, micronodules, sediments and pore waters from five areas in the equatorial and S.W. Pacific have been obtained. This represents the largest study of its type ever undertaken to establish the distribution of elements between the various phases within the sediment column. The composition of manganese nodules, micronodules and sediments (on a carbonate-free basis) shows marked differences between the equatorial high productivity zone and the low productivity region of the S.W. Pacific. In the case of the nodules, th is reflects an increased supply of transition elements (notably Ni, Cu and Zn) to the nodules as a result of the in situ dissolution of siliceous tests within the sediment column in the equatorial Pacific high productivity zone. Micronodules display similar, but somewhat different, compositions to those of the associated nodules in each area. Micronodule composition is therefore influenced by the same basic factors that control nodule composition, but is modified by dissolution of the micronodules in situ within the sediment column. Locally, as in the area immediately south of the Marquesas Fracture Zone, the micronodule population is contaminated by small, angular volcanic rock fragments; this leads to apparently anomalous micronodule compositions. Micronodules appear to be a transient feature in the sediment column, especially in the equatorial Pacific. Dissolution of micronodules in the sediment column therefore represents an important source of elements for the growth of manganese nodules in the equatorial Pacific. Sediment composition is markedly influenced by the carbonate content. On a carbonate-free basis, the sediments from the equatorial high productivity zone are quite distinct in composition from those in the S.W. Pacific. This reflects differences in the lithology of the sediments. In the Aitutaki Passage, the local influence of volcanoclastic material in sediment composition has been established. The major cations and anions in pore waters measured here show no major differences between equatorial and S.W. Pacific sediments. Silica is, however, higher in equatorial Pacific pore waters reflecting the dissolution of siliceous tests in these sediments.

Description: At Sites 47 and 48, impenetrable and cherty Upper Cretaceous chalks were found. The upper part of what infer to be lower Cretaceous is even more reflective, and likely to be very cherty (and was found to be cherty in the Vema core). It became clear that basement could only be reached where the Upper Cretaceous and the upper part of the lower Cretaceous are absent. However, west of Site 48, the R/V Argo record showed an area in which the Upper Cretaceous has wedged out down dip, and the Lower Cretaceous is thinning out by loss of the strongly reflective beds at the top. This area appeared to offer the best chance for sampling the lowermost transparent layer. Two holes were drilled: Hole 49.0 and Hole 49.1 after Hole 49.0 stopped at 18 m. Beds near the base of sedimentary sequence revealed by the seismic profiles are found to be of early Cretaceous (Neocomian) or latest Jurassic (Tithonian) age, and of pelagic facies. The crust under the Shatsky Rise is latest Jurassic or older.

Description: Site 49 had been selected to investigate the basal part of the sedimentary sequence as revealed by the acoustic profiles, and to sample the underlying opaque material. However, the cherty nature of the sediments prevented penetration of the section at Site 49, and the only recourse appeared to be to move to a spot of even thinner sedimentary cover. Such a place existed, just downslope from Site 49, where Horizon B' comes very close to the surface, this is where Site 50 was selected.

Description: Having been stopped by chert in the Maestrichtian at Site 47, a site was looked for which would give an adequate Cenozoic thickness for satisfactory spudding-in, yet promised to lead from this into an older part of the section. This is the first record of Middle Maestrichtian in pelagic carbonate facies from the Northwest Pacific and surrounding lands, a matter of paleontologic-biostratigraphic importance.

Description: During the fourth and fifth legs of Scan Expedition, drill Sites 53 and 60 were surveyed and Site 59 was traversed. In addition to the drill site surveys, several other areas across the Mariana Arc System were investigated in some detail, guided by reconnaissance work aboard the R/V Argo from the previous year. The remarkable similarities in the occurrence and relative positions of a wide range of structural features in western Pacific arc systems strongly suggest a common mechanism of origin. The area in which crustal deformation related to island arc tectonism is occurring, more extensive and complex than generally recognized, is defined as the active island arc system; this includes not only the trench and volcanic chain, but also the deep basin and submarine ridge on the concave side of the active volcanoes.

Description: The results at Site 59 suggested that Mesozoic sediments are present beneath a thin Tertiary cover in the region north of the Caroline Ridge near the Mariana Trench. Since one of the principal objectives of the drilling program was to find old Pacific crust, and since the section at Site 59 was not fully penetrated, it seemed worth a determined effort to go beyond the level reached at Site 59, somewhere in the same general area, in an attempt to reach basement. As the reflection profile taken by Argo (SCAN Leg V) through Site 59 shows the section above thesmooth basement reflector (Horizon B?) thinning northwestward from about 0.3 to 0.15 second, by loss of part of the lower "transparent" layer, this is were Site 61 was located.

Description: The sedimentary section at Site 62 on Eauripik Ridge can be traced eastward into the East Caroline Basin. It was decided to drill a hole to basement in the eastern part of East Caroline Basin to determine the age of the upper strong reflectors and to test the hypothesis that sediments older than any at Site 62 are present. A nearly complete section was obtained from middle Oligocene to Quaternary, unconformably overlying basalt containing middle Oligocene chalk xenoliths. The sediments consist of chalk and chalk ooze in the Oligocene and Miocene, and of marl ooze and calcareous clay in the Pliocene and Quaternary.

Description: The interstitial water received at UCLA from Leg 7 (Guam to Hawaii) consisted of forty-two samples of approximately 5 milliliters each, three samples of approximately 10 milliliters each, and three samples of approximately 100 milliliters each. These pore waters had been squeezed from sediments consisting primarily of biogenic ooze, and had been collected at five different drilling sites along the route. High cobalt value were observed at Site 66 and were accompanied by a relatively high manganese concentration, but more normal iron, nickel and copper concentrations. This apparent cobalt enrichment could not be explained at the time of procedure. The line Islands area were Site 66 is situated was later notoriously known for its high Co values in manganese crust deposits (see, He, G., Ma, W., Song, C., Yang, S., Zhu, B., Yao, H., Jiang, X., Cheng, Y., 2011. Distribution characteristics of seamount cobalt-rich ferromanganese crusts and the determination of the size of areas for exploration and exploitation. Acta Oceanologica Sinica 30, 63–75. doi:10.1007/s13131-011-0120-9).

Description: Site 67 is on the Hawaiian Arch, in the general region selected for one of the Mohole Project sites. Therefore, intensive geophysical surveys have been made in the area. The objectives were to penetrate the entire sedimentary sequence to basement in order to learn the petrology and ages of the sediments and of the seismic reflectors, and to obtain samples of the underlying basement rocks. Well consolidated and bedded volcanic sandstone and mudstone, and claystone were found to extend from the sea floor to a depth of 60 meters, where a layer of hard brown porcelanite stopped the bit. Displaced radiolarians in mud from a core at 60 meters indicate sediments of early Eocene or late Paleocene age are present somewhere above that depth.

Description: An acoustically very transparent layer is present over much of the deep basin—here termed the Central Basin—between the Gilbert and Marshall Islands on the west and the Line Islands on the east. The Pacific Panel recommended drilling in this region to sample at least the upper transparent layer, and the first opaque layer beneath. Several possible sites were considered by the panel and by the shipboard party. Of paramount importance in choosing a particular site was a concern that sufficient sediments be present to bury the bottom-hole assembly (the drill collars and bumper subs) before the bit struck hard rock. A set of nearly continuous cores of an apparently uninterrupted section of radiolarian ooze ranging in age from middle Eocene to Recent was obtained, but the bit did not reach the deepest seismic reflector. Below depths of 127 meters, in the Oligocene and Eocene, thin chert and turbidite beds are sparsely interbedded with ooze.

Description: One of the principal objectives in the Central Pacific Basin was to elucidate the Paleobathymetric history of the region, which is located amidst groups of atolls and guyots that have subsided as much as 2 kilometers since mid-Cretaceous times. After failure to penetrate the entire sedimentary section and to sample basement at Site 65, on the west side of the Central Basin another site in the Basin where basement rocks might be sampled was searched. Likely places were known from unpublished reflection profiles on the east side of the Basin near the Line Islands by the Hawaii Institute of Geophysics. Finally it was decided to drill a transparent section once again in this area acoiding turbidites formations.

Description: Site 70 is located about 20 miles north of the northern boundary of the Clipperton Fracture Zone near 140° W. It is the northernmost of the N-S line of sites drilled during Leg 8 to investigate the east-west trending accumulation of sediment centered at about 2°N near 140°W. It lies about 500 miles south of Site 42 of Leg 5, the southernmost of a line of sites continuing to the north. The R/V Argo SCAN survey indicated that the area was one of low, broad abyssal hills, 2 to 10 miles in width on E-W profiles, with relatively thick sediment cover.

Description: Site 74 is located 250 miles northeast of the Marquesas Islands and lies 270 miles south of Site 73 and 400 miles north of Site 75. It is one of the sites along the N-S line drilled during Leg 8 to investigate the east-west trending accumulation of sediments centered about 2°N near 140°W. Site 74 is located near the center of a relatively flat area about 3 miles across. There is some indication of minor deformation at the site.

Description: Site 75 is located 300 miles southeast of the Marquesas Islands; 400 miles south of Site 74. It is the southernmost of the sites along the N-S line drilled during Leg 8 to investigate the east-west trending accumulation of sediments centered about 2°N near 140°W. This site is a replacement for the site at 31°S originally chosen by the JOIDES Pacific Advisory Panel (PAP Site 27). The original site was not drilled since a preliminary R/V Argo SCAN survey indicated insufficient sediment thickness.

Description: This report contains the field data obtained during the February to April 1960 oceanographic expedition of the USC&GS ship Explorer, together with such results from the analyses of these data as are completed to date. As additional studies are completed, the results will be published by the U.S. Coast and Geodetic Survey or by the other Government agencies, private oceanographic institutions, or individual scientists who are primarily concerned. The USC&GSS Explorer is a 1,900-ton, 220-foot Ocean Survey Ship (OSS 28). During the winter of 1960, the ship was scheduled for a routine transfer from her original home port of Seattle, Wash., to be based in the future out of Norfolk, Va. With the current accelerated demand for oceanographic information, it was felt that this transfer offered a unique opportunity to obtain useful oceanographic information along the route from Seattle to Norfolk.

Description: Initial data on the hydrogen-isotopic compositions in hydrous Mn minerals from various occurrences fall in a wide range from -298 to -84 per mil, relative to SMOW. DeltaD-values of todorokite and cryptomelane from Tertiary deposits show -89 and -150 per mil. 10 Angström-manganite and Delta-MnO2 from deep-sea nodules have relatively restricted DeltaD-values ranging from -96 to -84 per mil. The DeltaD-values for manganese bog ores from recent hot springs show almost -105 per mil. It is recognized that the isotopic values obtained for the deep-sea nodules and recent bog ores are slightly different ranged. Manganite and groutite are unique in their hydrogen-isotopic compositions, having the most depleted DeltaD-values ranging from -298 to -236 per mil. MnO(OH) minerals are more deuterium-depleted hydrous minerals than any other hydrothermal minerals from various ore deposits. Hydrogen-isotope fractionation factors between manganite and water were experimentally determined to be 0.7894, 0.7958 and 0.8078 at 150°, 200° and 250°C, respectively. the present experimental results indicate that if manganites were formed at temperatures below 250°C, under isotopic equilibrium conditions, most of the manganite mineralization in the Tertiary manganese deposits must have precipitated from meteoric hydrothermal solutions.

Description: This report is Volume 1 in the series of reports entitled "Descriptions of W.H.O.I. rock dredge samples". This series represents a major effort to catalog and prepare initial descriptions for all rock dredge samples in the W.H.O.I. Sea Floor Samples Collection, and to distribute this information throughout the scientific community. Volume 1 contains sample descriptions from approximately 382 dredging stations executed during the period 1960 through 1977. It also represents a digitized listing of all dredge station data for the entire W.H.O.I. Dredge Collection through 1980. This data is sorted by Marsden Square and can serve as a regional index for all rock descriptions included in Volumes 1-3.

Description: Five of 34 dredge hauls taken in the Atlantic Ocean recovered a material tentatively described on shipboard as a salmon-colored clay. X-ray diffraction analysis showed the clay material to consist principally of palygorskite. Occurring with the palygorskite are quartz, calcite, and dolomite. It is suggested that the palygorskite (and sepiolite) is the result of chemical precipitation brought about by the reaction of hydrothermal solutions with sea water.

Description: A submersible study has been conducted in February - March 1978 at the axis of the East Pacific Rise near 21°N. The expedition CYAMEX, the first submersible program to be conducted on the East Pacific Rise, is part of the French-American-Mexican project RITA (Rivera - Tamayo), a 3-year study devoted to detailed geological and geophysical investigations of the East Pacific Rise Crest. On the basis of the 15 dives made by CYANA in the axial area of the Rise, a morphological and tectonic zonation can be established for this moderately-fast spreading center. A narrow, 0.6 to 1.2 km wide zone of extrusion (zone 1), dominated by young lava flows, is flanked by a highly fissured and faulted zone of extension (zone 2) with a width of 1 to 2 km. Further out, zone 3 is dominated by outward tilted blocks bounded by inward-facing fault scarps. Active or recent faults extend up to 12 km from the axis of extrusion of the East Pacific Rise. This represents the first determination from direct field evidence of the width of active tectonism associated with an accreting plate boundary. Massive sulfide deposits, made principally of zinc, copper and iron, were found close to the axis of the Rise. Other signs of the intense hydrothermal activity included the discovery of benthic fauna of giant size similar to that found at the axis of the Galapagos Rift. We emphasize the cyclic character of the volcanicity. The main characteristics of the geology of this segment of the East Pacific Rise can be explained by the thermal structure at depth below this moderately-fast spreading center. The geological observations are compatible with the existence of a shallow magma reservoir centered at the axis of the Rise with a half-width of the order of 10 km.

Description: Of numerous island-arc systems in the western Pacific, the Mariana arc-trench system and the basins and submerged ridges lying west of them in the Philippine Sea seemed to be best suited to answer questions regarding arc-trench and back-arc basin formation. Three years of planning by the JOIDES Active Margin Panel, Ocean Crust Panel, and Planning Committee resulted in a proposed transect of drill sites aligned more or less along the 18th parallel. This South Philippine Sea transect was designed to investigate each major basin and ridge between the central part of the West Philippine Sea and the Mariana Trench and the Pacific Ocean plate immediately to the east.

Description: The goal of Site 462 was to study the paleontologic, sedimentary, petrologic, tectonic, and magnetic histories of that area through Recent to Late Jurassic time by drilling a deep re-entry site into the Nauru Basin west of the Ralik Chain of the Marshall Islands. This area formed at a fast-spreading Pacific Plate boundary 145 to 155 m.y. ago, in the Late Jurassic. Cores from this area allow to better understand the biostratigraphic evolution and sedimentary processes in a Mesozoic open-ocean environment, the petrologic nature of fast-spreading oceanic crust, the tectonic history of the Late Jurassic Pacific Plate, and the nature of the Jurassic magnetic quiet zone.

Description: The four sites drilled during Leg 62 were needed to establish better regional coverage of the North Pacific Ocean. Although paleoenvironments were to be stressed on Leg 62, studies of igneous rocks from acoustic basement were planned, to determine ages, petrogenesis, alteration effects, rock magnetism, and Paleomagnetism of old parts of the Pacific crust. These studies were emphasized in order to establish the early history of oceanic plateaus and whether they are the result of midocean-ridge or intraplate volcanism.

Description: A primary objective of Leg 63 was to investigate the fluctuations of this eastern boundary current along a north-south transect off the Gulf of California. This information would aid in biostratigraphically correlating open-ocean planktonic zones with local California zonations. Spanning the last 30 m.y., the complicated tectonic history of the continental margin off California and Baja California comprises changes from a subduction zone to a transform boundary and then to an inactive margin. A second objective of Leg 63 was to define and clarify this history using information on sedimentation, unconformities, basement ages, and paleomagnetic reconstructions gained from drilling, in conjunction with geophysical data and pre-existing bottom samples.

Description: Undamaged deep-sea manganese nodules were retrieved from a box core from the central North Pacific and quickly preserved in formaldehyde solution. Light and scanning electron microscope studies of the nodule surface reveal the presence of a variety of fragile filamentous and coccoid bacterial morphotypes, associated with an organic film that covers the botryoid surface.

Description: Testing of a continuous bucket-line dredging system was carried out in the South Pacific August 23 through September 14, 1970 by Japan Resources Association aboard the vessel "Chiyoda Maru No. 2". Fifteen dredge stations were occupied, and the system was tested at depths of 1080, 3755, and 1220 meters. The system is designed to recover manganese nodules, and the tests helped to verify its feasibility. A brief discussion of the merits of the continuous bucket-line compared to other continuous systems is made.

Description: The unusual petrological diversity of abyssal lavas erupted along some segments of the Galapagos spreading center is a direct consequence of the propagation (elongation) of these segments into older oceanic crust. With increasing distance behind propagating rift tips, relatively unfractionated MORB erupted close to the tips are joined first by FeTi basalts (bimodal assemblage) and then by a wide range of basaltic and siliceous lavas. Further behind propagating rift tips, this broad range diminishes again, approaching the narrow compositional range of adjacent normal ridge segments. These compositional variations reflect the evolution of the subaxial magmatic system beneath the newly forming spreading center as it propagates through a pre-existing plate. We envisage this evolution as proceeding from small, isolated, ephemeral magma chambers through increasing numbers of larger, increasingly interconnected chambers to the steady-state buffered system of a normal ridge. Throughout this evolution, magma supply rates gradually increase and cooling rates of crustal magma bodies decrease. High degrees of crystal fractionation are favored only when a delicate balance between cooling rate and resupply rate of primitive magma is achieved. At other propagating and non-propagating ridge-transform intersections the degree to which the balance is achieved and the length of ridge over which it evolves control the distribution of fractionated lavas. These effects may be evaluated provided a number of tectonic variables including transform length, spreading and propagation rates are taken into account.

Description: The southernmost part of the Sohm Abyssal Plain in the Northwest Atlantic Basin is geographically distal with respect to the major source of Quaternary terrigenous material transported from the Canadian Maritime Provinces. An assessment of the proportion of more locally introduced sediment relative to that derived from distal sources is based largely on size and compositional analyses of Quaternary piston core samples. These data are supplemented by radiocarbon dating of selected core samples, bottom photographs, conductivity-temperature-depth profiles, and seismic records. The premises of the study are that (a) locally derived sediment should be most abundant near high-relief bathymetric features such as seamounts and abyssal hills, and (b) such material should contain enhanced proportions of reworked volcanic debris and alteration products. Core analyses reveal that the amounts of these are directly related to proximity of volcanic ocean-bottom features, and that a significant, although not total, amount of such volcanic materials recovered from cores are derived from submarine weathering of basalt. Associated with this assemblage are nannofossils, dating from the Quaternary to the Upper Cretaceous, reworked from older strata. This increased proportion of volcanic and related products and reworked faunas near seamounts and basement rises strongly implies that such topographic features continue to serve as major source terrains. Locally derived volcanic materials, however, are usually disseminated and masked on the Sohm Abyssal Plain, particularly in sectors receiving large amounts of terrigenous turbidites and biogenic suspensates, and/or undergoing reworking by bottom currents. We propose that the volcanic fraction can serve as a useful index, or "yardstick," to interpret the role of locally derived material in abyssal plain sedimentation. A sedimentation model is developed to illustrate the premise that as access to land-derived sources diminishes, the proportion of terrigenous components is reduced while pelagic and volcanic fractions are enhanced. Thus, sediment accumulating in abyssal plains almost totally isolated from terrigenous sources would comprise significant amounts of pelagic (including wind-blown) and volcanic components.

Description: Nine nodules collected from throughout the deep North Pacific were analyzed for their mineralogy and major-element composition before and after leaching with Chester-Hughes solution. Data indicate that the mineral phillipsite accounts for the major part (〉 75%) of the aluminosilicate fraction of all nodules. It is suggested that formation of phillipsite takes place on growing nodule surfaces coupled with the oxidation of absorbed manganous ion. All the nodules could be described as ternary mixtures of amorphous iron fraction (Fe-Ti-P), manganese oxide fraction (Mn-Mg Cu-Ni), and phillipsite fraction (Al-Si-K-Na), these fractions accounting for 96% of the variability of the chemical composition.

Description: Crusts composed of nontronite and ferromanganese oxides were recovered from Explorer Ridge, a spreading ridge segment in the northeastern Pacific Ocean located off the west coast of Canada. The chemical and mineralogical composition of the crusts closely resembles that of the mound-like hydrothermal deposits recently discovered at the FAMOUS site on the Mid-Atlantic Ridge and on the Galapagos spreading centre. Compositional anomalies suggest that the crusts are precipitates of hydrothermal vent solutions which were ejected discontinuously and subsequently mixed with seawater.

Description: The purpose of the data file presented below is twofold: the first purpose is to make available in printed form the basic data relating to the samples collected as part of the joint U.S. Geological Survey - Woods Hole Oceanographic Institution program of study of the Atlantic continental margin of the United States; the second purpose is to maintain these data in a form that is easily retrievable by modern computer methods. With the data in such form, repeated manual transcription for statistical or similar mathematical treatment becomes unnecessary. Manual plotting of information or derivatives from the information may also be eliminated. Not only is handling of data by the computer considerably faster than manual techniques, but a fruitful source of errors, transcription mistakes, is eliminated.

Description: Submersible exploration on the eastern Pacific Ridge near 21 ° N has revealed an active hydrothermal system. It is manifested by the emission in the marine environment of hot and Highly mineralized fluids (370 ° C maximum). These fluids precipitate on contact with seawater and deposits of massive sulphides are built at the outlet of their sources. The mineralogical and geochemical study of the products associated with the emissions of hot fluids provides an initial evaluation of this type of deposit and leads to a comparison between the hydrothermalism responsible for the formation of sulphides and the hydrothermalism responsible for the formation of metal rich crusts formed of iron smectites and manganese oxides. This study is carried out with conventional mineralogical and geochemical investigations (optical and electronic microscopy, X-ray diffraction, X-ray fluorescence spectrometry, electron microprobe, neutron activation and mass spectrometry).

Description: A geophysical survey was conducted off Vancouver and Queen Charlotte Islands over a four-week period (July 12 to August 5, 1970) as part of HUDSON-70 expedition. The HUDSON-70 expedition was organized as part of the Canadian contribution to the International Decade of Oceanographic Exploration. The geophysical survey was conducted to study the subsurface structure across the continental margin off the British Columbia coast and in the deep ocean basins. The present report contains descriptions of the various measurements made during this cruise and the data collected.

Description: Manganese encrustations from two adjacent sampling sites in the Gulf of Aden display markedly different compositional characteristics. The enrichment of manganese, and consequent depletion of iron and a series of trace elements, in the manganiferous crusts from Sta. 6243 is attributed to the diagenetic remobilisation of manganese within the sediment column and the resultant enrichment of this element in the encrustations from this station. Molybdenum, and possibly nickel, appear to show similar migration characteristics. Submarine vulcanism does not appear to play any significant role in controlling nodule composition within the area.

Description: The cores and dredges described in this report were taken on the HILO Expedition in March-April 1962 by Scripps Institution of Oceanography from, the R/V Stranger. A total of 21 cores and dredges were recovered and are available at Scripps for sampling and study.

Description: The cores described in this report were taken during the R/V Robert Conrad Cruise 01 from 4 until 20 December 1962 by the Lamont Geological Observatory, Columbia University. A total of 10 cores were recovered and are available at Lamont-Doherty Earth Observatory for sampling and study.

Description: The cores and dredges described in this report were taken during the Vema 17 Expedition from December 1960 until October 1961 by the Lamont Geological Observatory, Columbia University from the R/V Vema. An approximate total of 210 cores, dredges and camera stations were recovered and are available at Lamont-Doherty Earth Observatory for sampling and study.

Description: Photography has become an integral part of submarine geological and biological investigations of the ocean bottom. The underwater cameras used to make these photographs were designed by Harold Edgerton. The pictures were taken from 1960 to 1962, from ships of the Woods Hole Oceanographic Institution. They show that life occurs even in the deepest trenches, and that sedimentary and biological processes in deep water do not differ in kind from those in shallow water.

Description: The sulfide deposit at Site 471 occurs between overlying pelagic sediment and underlying basalt. The deposit is vertically zoned and consists, from top to bottom, of the following mineral assemblages: (1) pyrite, chalcopyrite, and Zn-sulfide in chert and calcite gangue (~ 35 cm thick); (2) a 5-cm-thick metalliferous sediment layer and (3) a 4-cm-thick chert layer. The calcite gangue appears at a later stage than chert gangue in the sequence of deposition, also filling in voids and fractures. The manganese content of calcite is particularly high and varies systematically, reaching a maximum at the top of the massive sulfide portion of the deposit.

Description: Elevated regions in the central parts of ocean basins are excellent for study of accumulation of eolian material. The mass-accumulation rates of this sediment component appear to reflect changes in the influx of volcanic materials through the Early Cretaceous to Recent history of Deep Sea Drilling Project Site 463, on the Mid-Pacific Mountains. Four distinct episodes of eolian accumulation occurred during the Cretaceous: two periods of moderate accumulation, averaging about 0.2 to 0.3 g/cm**2/10**3 yr, 67 to 70.5 m.y. ago and 91 to 108 m.y. ago; a period of low accumulation, approximately 0.03 g/cm**2/10**3 yr, 70.5 to 90 m.y. ago; and a period of high accumulation, about 0.9 g/cm**2/10**3 yr, 109 to 117 m.y. ago (bottom of the hole). Much of the Cenozoic section is missing from Site 463. Upper Miocene to Recent sediments record an upward increase in accumulation rates, from less than 0.01 to about 0.044 g/cm**2/10**3 yr. The late Pliocene-Pleistocene peak may reflect the change to glacial-wind regimes, as well as an increase in volcanic source materials.

Description: Reports on ATLANTIS Cruises 280 and 281 to the New England Seamount Chain are combined here. . A continuous bathymetric survey was run on both cruises, with profiles across several seamounts. A series of dredge and camera stations were made. They are dicussed in this report. Also included are photographs representative of each camera lowering and photographs of dredged material.

Description: Neogene palynofloras of southern California have been all too infrequently studied. Previous investigations of Pacific Coast sediments have been largely restricted to Pacific Northwest locales. Some important studies include those by Gray (1964), Wolfe, Hopkins, and Leopold (1966), Wolfe and Leopold (1967), Hopkins (1968), Piel (1969, 1977), Ballog, Sparks, and Waloweek (1972), and Musich (1973). The only published study of southern California materials is that of Heusser (1978) on Holocene sediments of the Santa Barbara basin. Most of these studies are concerned with the microflora from a particular formation; thus they have limited stratigraphic value and in most cases involve nonmarine to marginal marine rocks where no planktonic zonation was available. Musich's (1973) study was the first attempt at tying pollen assemblages to a planktonic zonation over an extended stratigraphic interval (Miocene to Pleistocene).Its location in the southern California Borderland and the sedimentary sections sampled make Leg 63 extremely valuable in deciphering the palynologic history of the Pacific Coast Neogene. Site 467 was chosen for our initial detailed study, because the relatively slow sedimentation rate provides an almost complete Neogene sequence of mainly terrigenous sediments and reliable planktonic age control is available.The goals of this study were to: (1) establish a reference section of Neogene palynomorph assemblages; (2) develop biostratigraphic criteria for use in correlation with other localities; (3) correlate the palynologic assemblages with the planktonic zonations; and (4) study the paleoenvironmental history in the southern California Neogene.

Description: From 1950 through 1900 studies on the glacial geology of northern Greenland have been made in cooperation with the U.S. Air Force Cambridge Research Laboratories. As a result of these studies four distinct phases of the latest glaciation have been recognized. The last glaciation extended over most of the land and removed traces of previous anes. Retreat of the ice mass began some time previous to 6000 years ago. This was followed by a rtse in sea level which deposited clay-silt succeeded by karne gravels around stagnant ice lobes in the large valleys. Marine terraces, up to 129 meters above present sea level, developed as readjustment occurred in the land free of ice. About 3700 years ago an advance of glaciers down major fjords took place followed by retreat to approximately the present position of the ice. Till in Peary Land, north of Frederick E. Hyde Fjord, contains only locally derived matertals indicating that the central Greenland ice cap did not cover the area.

Description: During the 33th voyage of the R/V "Vityaz" in the Indian Ocean iron-manganese nodules were collected at several stations. Both nodules and associated sediments were analysed by spectral analysis over 30 chemical elements. Radioactivity measurements were also performed on these samples.

Description: Chemical analyses are presented for two Cretaceous clays from Noil Tobee, Timor. Mineralogical examination has shown that they consist principally of quartz, feldspar, illite and chlorite, together with minor amounts of montmorillonite. Both chemically and mineralogically the clays are very similar to the recent argillaceous deep-sea sediments of the Pacific and Indian Oceans, which confirms Molengraaff's theory (1921) that they are of deep-sea origin. Further confirmation of this theory is provided by comparison of the composition of micromanganese nodules, separated from one of these clays, with that of manganese nodules from the Pacific Ocean.

Description: The cores and dredges described at this site were taken on the SAFARI II cruise from 21 July until 1 September 1981 by the MusÈum National d'Histoire Naturelle from the R/V Marion Dufresne. A total of 65 cores, dredges and camera stations were recovered and are available at MNHN for sampling and study.

Description: Various manganese nodules donated to the Scripps Institution of Oceanography from the Hakurei Maru Cruise GH77-1, January-March, 1977, in the Central Pacific Basin have been analysed for their lithium content by J. Korkish from the Institute of Analytical Chemistry, Analysis of Nuclear Raw Materials Division, University of Vienna, Austria. The author has used a Perkin-Elmer atomic-absorption spectrometer 303 after speration by dissolution in hydrochloric acid.

Description: The cores and dredges described in this report were taken on the RISEPAC Expedition from October 1961 until February 1962 by the Scripps Institution of Oceanography from the R/V Spencer F. Baird. A total of 164 cores and dredges were recovered and are available at Scripps for sampling and study.

Description: The vast extent of pelagic deposits, covering about 70 per cent of the ocean floor, thus about half of the earth, makes them of obvious importance to all Earth Science. All the pelagic (eupelagic) sediments, whether largely of plankton remains or fine inorganic particles, have certain distinctive characteristics to reflect their environment of accumulation. The great segregation of manganese in pelagic sediments presents many problems. It is hypothesized that in the formation of present day nodules a relatively slow accumulation in order to permit deposition of more of the manganese as large nodules, rather than as the disseminated micronodules that are in larger proportion in the Tertiary.

Description: The cores and dredges described in this report were taken on the KH-69-2 Expedition in April-June, 1969 by the Ocean Research Institute, University of Tokyo from the Hakuho Maru. A total of 12 cores and dredges sites have been recovered.

Description: New information on possible resource value of sea floor manganese nodule deposits in the eastern north Pacific has been obtained by a study of records and collections of the 1972 Sea Scope Expedition. Nodule abundance (percent of sea floor covered) varies greatly, according to photographs from eight stations and data from other sources. All estimates considered reliable are plotted on a map of the region. Similar maps show the average content of Ni, Cu, Mn and Co at 89 stations from which three or more nodules were analyzed. Variations in nodule metal content at each station are shown graphically in an appendix, where data on nodule sizes are also given. Results of new analyses of 420 nodules from 93 stations for mn, fe, ni, cu, CO, and zn are listed in another appendix. Relatively high Ni + Cu content is restricted chiefly to four groups of stations in the equatorial region, where group averages are 1.86, 1.99, 2.47, and 2.55 weight-percent. Prepared for United States Department of the Interior, Bureau of Mines. Grant no. GO284008-02-MAS. - NTIS PB82-142571.

Description: Basal metalliferous sediments from sites 77B, 80 and 81 of the Deep Sea Drilling Project represent mixtures of pelagic clay, biogenic ooze, and a metalliferous component of hydrothermal origin. The metalliferous end-member of the sediments displays a strong inverse relationship (r = -0.88) between Mg and Mn. Mg is most likely tied up in an X-ray amorphous Mg-silicate ("sepiolite"), whereas Mn occurs almost exclusively in an oxide phase. Precipitation of the Mg-rich phase is favored by high flow rates and limited mixing of the hydrothermal end-member (source of silica) with seawater (source of Mg). Under those conditions much of the hydrothermal Mn(2+), with its slow oxidation kinetics, may escape to the free water column. In contrast, in highly-diluted hydrothermal fluids, which provide a source solution for Mn-rich sediments, dissolved silica is diluted below saturation with respect to "sepiolite". The separation of the Mn and Mg phases may be further compounded by hydraulic fractionation.

Description: Lake George, New York, is the site of a new discovery of iron-manganese nodules. These nodules occur at a water depth between 21 and 36 m along a stretch of lake extending for about 5 mi north and south of the Narrows, a constricted island-dotted area which separates the north and south Lake George basins. Nodules occur on or within the uppermost 5 cm of a varved glacial clay. Some areas are solidly floored with a carpet of nodules in areas where active currents keep the nodules exposed. The nodules form around nuclei which consist of clay and less commonly of spore capsules, detrital particles, or bark. By their shape we recognize three types of nodules: spherical, discoidal, and lumps. On X-ray examination all nodules show small goethite peaks; in one nodule the manganese mineral birnessite was identified. Manganese and part of the iron appears to be in X-ray amorphous ferromanganese compounds. The Lake George nodules are enriched in iron with respect to marine nodules but are lower in manganese. They have a higher trace element concentration than nodules from other known freshwater lake occurrences, but a lower concentration than marine nodules.

Description: The nodules from the Briançon area in the French Alps show two types of cauliflower shaped botryoidal growth. One could be diagenetic and the other purely chemical. They could also be in-situ stromatolite like in their origin but this needs to be confirmed.

Description: We report here chemical analyses of sulfide and other minerals occurring in the massive sulfide deposit cored at Site 471. Details of the mineralogy and inferred paragenesis of the deposit will be reported elsewhere. The sulfide deposit at Site 471 occurs between overlying pelagic sediment and underlying basalt. The deposit is vertically zoned and consists, from top to bottom, of the following mineral assemblages: (1) pyrite, chalcopyrite, and Zn-sulfide in chert and calcite gangue (about 35 cm thick); (2) a 5-cm-thick metalliferous sediment layer described in detail by Leinen (this volume); and (3) a 4-cm-thick chert layer. The overlying sediment is a calcareous silty claystone that contains middle Miocene coccoliths (Bukry, this volume). The underlying basalt has been extensively chloritized and veined with calcite. In places feldspars are albitized, and calcite occurs as pseudomorphs after olivine. Relict textures suggest that the basalt grades into diabase and gabbro with increasing depth. Neither stock work nor disseminated sulfides was observed in the altered rocks.

Description: The investigation of the sediments at the bottom of a lake provides a record of past geologic and climatic events that have influenced the lake and its associated drainage basin. The most recent sediments of a lake are indicators of man's impact on the surrounding watershed and emphasize the complex nature of interaction between chemical, biological, and physical processes that affect the distribution of sediments and their associated minerals and chemical species. The conclusions of this report are based on samples and measurements obtained during an extensive research cruise conducted in Lake Michigan by the Canada Survey Ship Limnos in August, 1975. Grab samples were collected at the intersections of a 12-by-12-km Universal Transverse Mercator (UTM) grid over most of the lake bottom; a more detailed 7-by-7-km UTM grid was used in Green Bay and in the northeastern corner of the lake. Systematic chemical analysis was performed on the sediment samples over 23 elements. In Green Bay, elevated levels of a number of chemical elements in the sediments - notably arsenic, barium, manganese, and iron - suggest that a local geochemical process or source is important. One possible explanation is that ferromanganese nodules or concretions were observed in surface sediments from a number of locations in Green Bay and extreme northwestern Lake Michigan.