Chemical composition of a manganese nodule from the Blake Plateau, Atlantic Ocean

The area surveyed during project AMC-11-67 was the portion of the Blake Plateau between latitude 30°00'N and 33°00'N and between the 100 to 1000 fathom curves. The survey was conducted from 3 October until 18 October 1967. Survey operations included dredgings, camera and multi-sensor lowerings. A collection of manganese and phosphate concretions as well as coral and sediment samples were examined by the ESSA(NOAA) Atlantic Oceanographic Laboratories. Chemical analyses were conducted at the NASA Manned Spacecraft Center, Houston by Richard A. Laidley for X-Ray Fluorescence Analysis and H. Costello for Atomic Absorption Analysis. Later the whole collection of samples was transferred to the Smithsonian National Museum of Natural History were it is available for study (see, http://mineralsciences.si.edu/collections.htm).

(Page 290) Composition of a manganese deposit sample from the Todoroki Mine, Japan

The Todoroki Mine is situated about 25 kilometers to the south-east of Ginzan railway station in Siribesi Province, Hokkaido. The author analysed an interesting specimen of black manganese-ore which had a fractured surface which looked like that of a broken piece of wood. This new manganese mineral was studied in its form, physical properties and chemical composition. The author later named this mineral form as "todorokite".

(Table, page 95) Chemistry of bog manganese concretions and wad from the Columbia County, New York

Bog manganese was long ago reported from various places in Columbia county (1:54) and it seemed well to reexamine these occurrences. According to W. W. Mather in his report of the First District Survey, 1836-42, " in the counties of Columbia and Dutchess 50,000 tons of manganese could be procured without any great expense, if carefully prepared." He also stated that some of the bog manganese showed on analysis as high as 68.5 per cent manganese oxide and less than 5 per cent silica. At the direction of the State Geologist the writer has devoted most of the summer of 191 7 to this work. The results of this investigation, though not in any way confirming the quantitative results of Mr Mather, are herewith published as a matter of record and as an account of the manner of the occurrence and the genesis of postglacial bog manganese.

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.

(Table 1, page 1169) Chemical composition of land (fossil) manganese deposits rich in todorokite

Chemical, x-ray and other data are given for todorokite, (Mn, Mg, Ca, Ba, Na, K)2.Mn5O12.3H2O, from Charco Redondo, Cuba, Farragudo, Portugal, and Hüttenberg, Austria. Additional localities at Romanèche, France, Saipan Island, Bahia, Brazil and Sterling Hill, New Jersey, are noted. Delatorreite of Simon and Straczek (1958) is identical with todorokite.

(Table 2, page 1376) Chemical analyses of manganese nodules and crusts from the South-western Pacific

Phosphate deposits which apparently formed during the Miocene climatic optimum are widespread on the Chatham Rise and Camp bell Plateau, and on seamounts in the north Tasman Sea. They formed under oxidising conditions by the phosphatisation of older or contemporaneous foraminiferal oozes (Campbell Plateau and Chatham Rise) and coral limestones (Tasman Sea). The phosphorites of the rise and plateau were formed where current activity was sufficiently strong to prevent normal sedimentation, and now form lag deposits. After the Miocene, phosphorite formation ceased and was followed by manganese oxide deposition where conditions were highly oxidising on the eastern Campbell Plateau and north Tasman seamounts, and by glauconite formation in the much less oxidising environments of the western Campbell Plateau and the Chat ham Rise. The manganese deposits are not volcanogenic, as was formerly thought, but formed by slow precipitation from well oxygenated sea water.

(Table 2) Location, age of accompanied sediments, chemical and Sr isotopic compositions of manganese nodules in DSDP/ODP cores

Strontium isotopic compositions of acetic acid (HOAc) leachate fractions of eight manganese oxide deposits from the modern seafloor, and of twenty-one buried manganese nodules from Cretaceous to Recent sediments in DSDP/ODP cores were measured. ratios of HOAc leachates in all modern seafloor manganese oxides of various origins are identical with present seawater. The ratios of the HOAc leachates of buried nodules from DSDP/ODP cores are significantly lower than those of nodules from the modern seafloor and are mostly identical with coeval seawater values estimated from the age of associated sediments. It is suggested that the buried nodules in DSDP/ODP cores are not artifacts transported from the present seafloor during the drilling process, but are in situ fossil deposits from the past deep-sea floor during Cretaceous to Quaternary periods. The formation of deep-sea fossil nodules prior to the formation of Antarctic Bottom Water (AABW) indicates that the circulation of oxygenated deep seawaters have activately deposited manganese oxides since the Eocene Epoch, or earlier.

Chemical composition of manganese deposits (Birnessite) from Scotland

A manganese pan near Birness contains grains of an optically uniaxial negative mineral near (Na0.7Ca0.3)Mn7O14·2·8H2O, giving an X-ray powder pattern similar to that of synthetic materials described as 'manganous manganite' and delta-MnO2. Material giving a similar pattern has been described from a natural occurrence in Canada, but no mineral name was assigned; the name birnessite is now proposed. The mineral is probably formed by air-oxidation of manganous oxides under alkaline conditions.

Sand geochemistry on sediment core CRP-3 from the Ross Sea, Antarctica

A total of 167 samples distubuted throughout the CRP-3 drillhole from 5.77 to 787.68 mbsf and representing fine to coarse sandstones have been analysed by X-ray fluorescence spectrometry (XRF) Bulk sample geochemistry (major and trace elements) indicates a dominant provenance of detritus from the Ferrar Supergroup in the uppermost 200 mbsf of the core. A markedly increased contribution from the Beacon sandstones is recognized below 200 mbsf and down to 600 mbsf. In the lower part of CRP-3, down to 787.68 mbsf, geochemical evidence for influxes of Ferrar materials is again recorded. On the basis of preliminary magnetostratigraphic data reported for the lower 447 mbsf of the drillhole, we tentatively evaluated the main periodicities modulating the geochemical records. Our results identify a possible influence of the precession, obliquity and long-eccentricity astronomical components (21, 41, and 400 ky frequency bands) on the deposition mechanisms of the studied glaciomarine sediments.

Geochemical investigations of elements in sediment core CRP-1 from the Ross Sea, Antarctica

Geochemical data are presented for samples from strata, mainly of Miocene age, in the Cape Roberts-1 core (western McMurdo Sound, Antarctica) to assess the sediment provenance. Bulk (major and trace element) chemistry together with bulk mineralogy of fine-grained sandstones, siltstones, mudstones, and diamictites indicate that chemical alteration of source materials, fractionation due to sedimentary sorting, and diagenetic effects were not significant in the Cape Roberts sediment history. Relevant geochemical parameters are consistent with the Cape Roberts sediments being derived mainly from the crystalline basement and the Beacon Supergroup. On the basis of element distributions, an additional contribution from the Ferrar Dolerite and, mainly above about 60 m, influxes of detritus derived from basanitic to intermediate members of the McMurdo Volcanic Group are recognised.

Geochemistry of bulk samples and various minerals of sediment core CRP-1 from the Ross Sea, Antarctica

Thirty-nine medium and fine grained sandstones from between 19,26 and 147,23 mbsf in the Cape Roberts-l core (CRP-1) were analysed for 10 major and 16 trace elements. Using whole-lock compositions, 9 samples were selected for analyses of mineral and glass grains by energy dispersive electron microscope. Laser-Ablation Mass-Spectrometry was used to determine rare earth elements and 14 additional trace elements in glass shards, pyroxenes and feldspars in order to examine their contribution to the bulk rock chemistry. Geochemical data reveal the major contribution played by the Granite Harbour Intrusives to the whole rock composition, even if a significant input is supplied by McMurdo volcanics and Ferrar dolerite pyroxenes McMurdo volcanics were studied in detail; they appeal to derive from a variety of litologies, and a dominant role of wind transpoitation from exposures of volcanic rocks may be inferred from the contemporary occurrence of different compositions at all depths. Only at 116.55 mbsf was a thin layer of tephra found, linked to an explosive eruption McMurdo volcanic rocks exhibit larger abundances at depths above 62 mbsf, in correspondence with the onset of volcanic activity in the McMurdo Sound area. From 62 mbsf to the bottom of the core, McMurdo volcanics are less abundant and probably issued from some centres in the McMurdo Sound region. However, available data do not allow the exclusion of wind transport from some eruptive centres active in north Victoria Land at the beginning of the Miocene Epoch.