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The Kope Formation is a rock unit that extends over southwest Ohio and adjacent areas of Kentucky and Indiana, USA. It is characterized by meter-scale cycles of mudstones and limestones where thick mudstone is sandwiched between thin limestone layers. Kope Formation mudstones are less durable than the mudstones in the area. They cause abundant slope failures in areas of their outcrops. This study evaluates chemical, mineralogical and textural properties of Kope mudstones to determine why it is less durable. The Two-cycle slake durability index (ID 2 ) was measured on thirty mudstones belonging to three consecutive cycles of the Kope Formation. Chemical composition and mineralogy of Kope mudstones do not show significant relationship with the ID 2 . Instead, a relationship to fabric was found. Kope mudstones with two main fabric types were observed in the field; laminated mudstones and non-laminated mudstones. Detailed micro-fabric analysis on Kope mudstones was done using the scanning electron microscope. Laminated mudstones with turbostratic fabric showed higher ID 2 and lower moisture content than the non-laminated mudstones with matrix fabric. The difference in the ID 2 of laminated mudstones and non-laminated mudstones is statistically significant. Both mudstone types exist in many cycles of the Kope Formation. Thus, core samples should be selected from both types for preliminary tests in geotechnical practice, to obtain more accurate estimations of the geotechnical properties of the Kope mudstones. The results and data interpretations of this study can be correlated with the mudstones and shale in different areas of the world. Specifically, a great attention should be paid to the macro and micro textural properties of any rock type regardless of their classification.

This study provides a physicochemical assessment of manganese deposits on brass and lead components from two fully operational drinking water distributions systems. One of the systems was maintained with chlorine; the other, with secondary chloramine disinfection. Synchrotron-based in-situ micro X-ray adsorption near edge structure was used to assess the mineralogy. In-situ micro X-ray fluorescence mapping was used to demonstrate the spatial relationships between manganese and potentially toxic adsorbed metal ions. The Mn deposits ranged in thickness from 0.01 to 400 μm. They were composed primarily of Mn oxides/oxhydroxides, birnessite (Mn(3+) and Mn(4+)) and hollandite (Mn(2+) and Mn(4+)), and a Mn silicate, braunite (Mn(2+) and Mn(4+)), in varying proportions. Iron, chromium, and strontium, in addition to the alloying elements lead and copper, were co-located within manganese deposits. With the exception of iron, all are related to specific health issues and are of concern to the U.S. Environmental Protection Agency (U.S. EPA). The specific properties of Mn deposits, i.e., adsorption of metals ions, oxidation of metal ions and resuspension are discussed with respect to their influence on drinking water quality.

Results of multiple sulfur isotope analyses from five Archean paleosols show the widespread presence of mass-independently fractionated sulfur in the regolith developed on the pre-2.5 Ga Earth. Analysis of sulfur from a small set of diamictite samples gave similar results. All values of Δ 33 S are negative, indicating that the Archean surface environments preferentially retained atmospheric S from the SO 4 2 − pathway, which carried a negative Δ 33 S signal, whereas a portion of the S from the S 8 pathway, with a positive Δ 33 S, was transferred to the oceans. The soil SO 4 2 − was then converted to sulfide by bacterial sulfate reduction with terrestrial organic matter in the weathering horizon acting as a reductant. Some S from the S 8 pathway also included, which resulted in a net soil Δ 33 S anomaly from atmospheric S in the range − 0.3 to − 0.6‰, similar to values for pyrites from floodplain sediments. Excess S 8 -derived S was carried to the oceans, resulting in the negative/positive dichotomy between terrestrial and marine systems. Pyrite that formed in paleosols and pyrite grains that formed in flood-plain deposits, both carrying the terrestrial Δ 33 S signal, were then recycled into detrital pyrite grains now found in sandstones and conglomerates deposited before the rise of atmospheric oxygen. Therefore the Earth's early regolith constituted a reservoir of S with negative Δ 33 S values that could be important for balancing the predominantly positive Δ 33 S signature found in marine sediments.

Two Permian/Triassic boundary sections in central Japan provide a rare window into environmental conditions within the Panthalassic Ocean, which encompassed more than half the Earth's surface at 252 Ma. Integration of petrographic, geochemical, and time series data provides new insights regarding the fluxes of major and trace components to the sediment as well as environmental conditions in both the deep and intermediate water masses at each study site. The Ubara section was located in a high-productivity peri-equatorial location, whereas the Gujo-Hachiman section was located in a moderate-productivity location at some distance from the paleoequator. An upward transition from gray organic-poor cherts to black siliceous mudstones at both sites occurred in conjunction with increased primary productivity, intensified euxinia within the oxygen-minimum zone (OMZ), and decimation of the radiolarian zooplankton community. Euxinia in the OMZ of the equatorial Panthalassic Ocean developed episodically for a ~ 200–250 kyr interval during the Late Permian, followed by an abrupt intensification and lateral expansion of the OMZ around the Permian–Triassic boundary. Throughout the study interval, bottom waters at both sites remained mostly suboxic, a finding that counters hypotheses of development of a “superanoxic” Permo-Triassic deep ocean as a consequence of stagnation of oceanic overturning circulation.

Physiochemical data were obtained for five iron tubercles from a single drinking water distribution system (DS). Texturally, there were two groups based on internal morphology: one with a core of soft brownish material marbled with veins of a hard black material, the other has a core consisting mostly of the hard, black material. Three iron mineral phases occur, α-FeOOH, γ-FeOOH, or Fe 3 O 4 . All three coexist in each tubercle but in widely varying proportions. These iron pipe tubercles exhibit a greater diversity within a single DS than previously thought. Because the chemical conditions for the formation of each material is different, water quality parameters may not be the main control of tubercle formation and growth.

The Permian–Triassic boundary at Nhi Tao, Cao Bang Province, Vietnam was sampled in a 7.5-m-thick outcrop section at high resolution (∼ 5 cm intervals) for chemostratigraphic and magnetic susceptibility analysis. The section consists entirely of slightly argillaceous limestone representing shallow-marine facies of the Jinxi Platform, one of several large carbonate platforms within the Nanpanjiang Basin, located on the southern margin of the South China Craton. Upper Permian strata (Beds 1–7) are mainly dark-gray, cherty fossiliferous wackestones and packstones containing a diverse open-marine fauna, whereas uppermost Permian and Lower Triassic strata (Beds 9 and higher) are medium-gray calcimicrobial framestones containing rare macrofossils. These facies are separated by a 12-cm-thick oolitic–pisolitic grainstone (Bed 8) that coincides with the disappearance of most Late Permian faunal elements as well as with the first appearance of various geochemical anomalies that continue into the Lower Triassic part of the section. This “Late Permian event horizon” is characterized by (1) an abrupt decline in total organic carbon to near-zero values, (2) the onset of a sustained decline in carbonate δ13C, and (3) the first of eight concentration peaks in pyrite sulfur. Significantly, each sulfide peak is associated with lower pyrite δ34S values as well as with the onset of a negative carbonate δ13C excursion (or the acceleration of an excursion already in progress). These chemostratigraphic relationships are consistent with multiple episodes of upwelling of sulfidic, 34S- and 13C-depleted deep-ocean waters onto the Jinxi Platform. The first upwelling event was the most intense and caused a drastic reduction in primary productivity and the demise of the Late Permian fauna; subsequent episodes were less intense but may have contributed to a delay in recovery of Early Triassic marine ecosystems. A ten-fold increase in magnetic susceptibility in Bed 9 may record the influx of fine detrital particles following destruction of terrestrial ecosystems and massive soil erosion. The terrestrial signal of the end-Permian catastrophe thus follows the marine signal with a 12-cm lag, which may reflect the time-of-transit of soil-derived particles across the Nanpanjiang Basin, suggesting that the marine and terrestrial crises in the Nhi Tao region occurred more-or-less synchronously. These observations suggest a model in which renewal of global-ocean overturn followed a prolonged interval of deep-ocean stagnation during the Late Permian, with upwelling intensity modulated by short-term (∼ 20 kyr) climate cyclicity.

The Southern California Continental Borderland (SCCB) is part of the broad San Andreas transform-fault plate boundary that consists of a series of fault-bounded, petroleum-generating basins. The SCCB has high heat flow and geothermal gradients produced by thinned continental crust and Neogene volcanism. Barite deposits in the SCCB occur along faults. Barite samples from two sea-cliff sites and four offshore sites in the SCCB were analyzed for mineralogy, chemical (54 elements) and isotopic (S, Sr) compositions, and petrography. Barite from Palos Verdes (PV) Peninsula sea-cliff outcrops is hosted by the Miocene Monterey Formation and underlying basalt; carbonate rocks from those outcrops were analyzed for C, O, and Sr isotopes and the basalt for S isotopes. Cold-seep barite from Monterey Bay, California was analyzed for comparison. SCCB offshore samples occur at water depths from about 500 to 1800 m. Those barites vary significantly in texture and occurrence, from friable, highly porous actively growing seafloor mounds to dense, brecciated, vein barite. This latter type of barite contrasts with cold-seep barite in being much more coarse grained, forms thick veins in places, and completely replaced rock clasts in breccia. The barite samples range from 94 to 99 wt% BaSO4, with low trace-element contents, except for high Sr, Zr, Br, U, and Hg concentrations compared to their crustal abundances. δ34S for SCCB offshore barites range from 21.6‰ to 67.4‰, and for PV barite from 62‰ to 70‰. Pyrite from PV sea-cliff basalt and sedimentary rocks that host the barites averages 7.8‰ and 2.2‰, respectively. Two offshore barite samples have δ34S values (21.6‰, 22.1‰) close to that of modern seawater sulfate, whereas all other samples are enriched to strongly enriched in 34S. 87Sr/86Sr ratios for the barites vary over a narrow range of 0.70830–0.70856 and are much lower than that of modern seawater and also lower than the middle Miocene seawater ratio, the time of deposition of the host rocks for the PV samples. This indicates that the mineralizing fluids were not unaltered seawater. We develop a model in which the barites precipitated both below the sediment–water interface and at the seafloor from low-temperature fluids that circulated along faults. The isotopic, chemical, and textural data indicate that the barites formed by several processes. Mesozoic and Cenozoic basement rocks (crystalline and overlying sedimentary rocks), Quaternary basin fill, turbidite fans, and seawater provided various elements for the barites in different environments. The fluids had a deep-seated source and were hydrothermal in the deeper parts of the system for all the barite types, including the seafloor cold-seep deposit, based on Sr isotopes and regional geothermal gradients. These deep-seated fluids mixed with other fluids as they ascended, including seawater at and near the seafloor. The high δ34S values may have resulted from extreme Rayleigh fractionation during bacterially mediated (semi)closed-system sulfate reduction, probably driven by the flux of methane- and hydrocarbon-bearing fluids through basement rocks and basin sediments. Early diagenetic dolomite and pyrite in the host Monterey Formation in the PV Headland also formed in a zone of sulfate reduction, but within sediment buried only centimeters to a few meters and with a predominantly seawater source for the sulfur. Dolomite occurring with vein barite in the PV Headland formed at temperatures in the range of 40–90 °C. The cold-seep barites have δ34S values near that of modern seawater, although still somewhat fractionated. The barites that precipitated below the sediment–water interface have higher δ34S values, suggesting that the fluids were relatively reduced with molar dissolved barium in excess of dissolved sulfate. Those samples were exposed at the seafloor by uplift along faults and are composed predominantly of massive, brecciated, and vein barite.

Geochemical and petrographic data from the Konkola North deposit of the Zambian Copperbelt permits construction of a basement topography-driven fluid mixing model for mineralization. In this drill-core based study, the basement topography is inferred from the topography at the top of the footwall. Petrographic evidence suggests mineralization was a relatively late event and we have therefore assumed that present day basin floor topography is roughly similar to that at the time of mineralization. The basement topography appears to have controlled cross-strata migration of mineralizing fluids and to have induced fluid mixing that resulted in Cu mineralization, as well as in deposition of barite and other non-ore minerals. For the portion of the basin sampled, the footwall, and by inference the basement, shows considerable relief, with the deepest part of the basin on the southeastern end of the line of cores sampled. Following the line of cores to the Northwest, the footwall rises sharply to a local high and then drops into a local low before rising on the basin flank. Geochemical and petrographic data suggest that an oxidizing fluid enriched in Cu, Ba, K, and possibly Co migrated laterally within the footwall from the deep basin toward the basin flank. As the footwall and basement rose, the footwall fluid was forced upward into the Ore Shale horizons. Another fluid, likely a reducing one carrying H2S, traveled at a higher stratigraphic level and may have sunk into the Ore Shale horizons where the basin floor fell. Mixing between the two fluids in the vicinity of the lowest Ore Shale horizon resulted in sulphide mineralization. The fluid mixing also appears to be demarcated by barite immediately above or below the sulphide mineralization. The barite is generally below the base of the Ore Shale where falling basement topography permitted the upper fluid to sink and above where rising topography may have driven the footwall fluid upward to meet the upper fluid. Barite is rare above the basement highs, suggesting that the upper fluid may have been largely forced higher than the Ore Shale. Mineralization is strong above basement highs, but is dominated by more oxidized phases, not by sulphides common deeper in the basin. Both mineralization and barite are scarce between the local basement high and the high flank, suggesting that the footwall fluid, forced upward on the high, did not fully descend into the local low. In general, mineralization is stronger where basement topography is rising or high and weaker in the basement lows. It is likely that more than one episode of fluid flow has affected the basin and that the model presented is simplistic, but it may still provide useful insight into the possible relationship between basement topography and mineralization for this deposit and possibly others in the Copperbelt.

The black shale submember of core shales of Pennsylvanian Kansas-type cyclothems is highly enriched in redox-sensitive trace elements (TEs) relative to the overlying gray shale submember as well as to many other modern and ancient organic-rich deposits. Controls on trace-element behavior in the black shale can be inferred from trace-element enrichment factors (EFs, relative to gray shale) and the relationship of TEs to total organic carbon (TOC). Most TEs conformed to one of two patterns: (1) Mo, U, V, Zn, and Pb exhibited moderate EFs and strong covariation with TOC in samples having 10 wt.% TOC; and (2) Cu, Ni, Cr, and Co exhibited low EFs and moderate to strong covariation with TOC in all samples. These patterns are inferred to represent different responses to benthic redox conditions. The first pattern is characteristic of TEs of ‘‘strong euxinic affinity’’, i.e., those taken up in solid solution by Fe-sulfide or involved in other reactions catalyzed by free H2S, and resident mainly in authigenic phases, whereas the second pattern is characteristic of TEs of ‘‘weak euxinic affinity’’, i.e., those not strongly influenced by the presence of free H2S and resident mainly in the organic carbon or detrital fractions of the sediment. These inferences allowed development of a multiproxy technique for assessing redox facies in black shale samples: euxinic conditions were considered to have existed if at least two of four ‘‘redox-indicator’’ trace elements (Mo, U, V, Zn) showed euxinic levels of enrichment, and nonsulfidic anoxic conditions were inferred otherwise. The validity of the procedure is indicated by (1) agreement among all four ‘‘redox indicators’’ for a large majority of samples (69% of 185); (2) among samples yielding a mixed redox signal, a systematic sequence of TE enrichment (V !Zn !Mo !U); and (3) for TEs of ‘‘weak euxinic affinity’’, reduced variance among samples representing each redox facies. Sequential enrichment may be a response to differential redox thresholds for accumulation (e.g., V) or postdepositional remobilization of trace elements (e.g., U) and may provide a basis for finer assessment of redox conditions in low-oxygen paleoenvironments than permitted by simple classification schemes. The multiproxy procedure for redox-facies analysis developed in this study is likely to be more reliable than widely used single-proxy indicators based on trace elements (e.g., Mo, authigenic U, or V/(V+Ni)) or C–S–Fe systematics (e.g., S/TOC or DOP). D 2004 Elsevier B.V. All rights reserved.

Water chemical data from the Botucatu Sandstone aquifer in the Sao Paulo State part of the Parana Basin, Brazil, was evaluated using geochemical methods and two statistical analyses: cluster analysis and factor analysis. The results were used to develop a conceptual geochemical model, in which three geochemical regions were identified, and their chemical behavior was modeled. The characteristic chemicals, changing from the recharge area to the center of the basin, are: SiO2—(HCO3− and Ca2+)—(Na+, CO32−, and SO42−). The distribution of the chemicals is interpreted as controlled by different water–rock interaction processes in the different regions. In the recharge area, dissolution of alkali–feldspar minerals in the sandstone is the main reaction observed; in the mid-section of the basin, calcite dissolution results in high calcium and bicarbonate concentration; in the center of the basin, leakage from underlying layers becomes the governing factor.

The Pinar del Rio district of western Cuba contains several examples of stratiform Pb–Zn mineralization underlain by stockwork Cu mineralization. Similar deposits in Canada and Australia have been variously interpreted as products of seafloor hydrothermal systems or of much later hydrothermal activity associated with peak metamorphism during deep burial. The Cuban deposits are Jurassic in age and are less overprinted by later tectonic events than other deposits of this type, so they offer a useful opportunity to resolve these controversies. Vitrinite reflectance and illite and chlorite crystallinity were studied from cores and mine exposures from several localities in western Cuba. Dispersed vitrinite in host shales shows a sharp increase in thermal maturity over three distinct stages from host-rock to stratiform mineralization to stock-work mineralization. Based on vitrinite data from modern hydrothermal systems, the paleotemperatures are 175, 250, and 300 °C. The clay mineral results also show a step-wise increase in the crystallinity of illite and chlorite. In addition, there is an increasing dominance of chlorite over illite. When compared to burial diagenetic trends, chlorite crystallinity in the Cuban samples matches values expected from R r , whereas illite tends to yield lower-than-expected crystallinities. The clay results indicate that chlorite is an ore-stage mineral that equilibrated at the same temperature/pressure conditions as the vitrinite, whereas the illite is largely detrital and only incompletely recrystallized in the relatively short times available. These results are best explained as reflecting relatively low amounts of heating of shales in the country rock by burial diagenesis, progressing to intermediate heating by exhalative seafloor hydrothermal fluids in the stratiform portion of the deposits, and finally to still higher temperatures in the sub-seafloor stockwork portion.

The available literature includes conflicting descriptions of the anatomy and function of the oblique retinacular ligament. We have studied this ligament in the index finger to better define its presence, configuration, points of attachment, length, and relationship to the proximal interphalangeal joint axis. Twenty fresh frozen index fingers were dissected. Five additional specimens were decalcified, mounted, sectioned transversely at 1 mm intervals and studied under the microscope. An oblique retinacular ligament was identified on the radial side of the index finger in 95% and on the ulnar side in 90% of the specimens. The radial oblique retinacular ligament was usually longer and more developed than the ulnar oblique retinacular ligament. Proximally, the ligament arose from the middle third of the proximal phalanx and the A-2 pulley whereas, distally, it inserted into the lateral extensor band with a fan-shaped expansion centered 4 to 6 mm distal to the proximal interphalangeal joint line. In 70% of the specimens, the oblique retinacular ligament was supplemented by a contribution from the proximal cruciform pulley (C-1). Histologic cross sections also confirmed the presence of the oblique retinacular ligament but not the supplemental contribution arising from the C-1 pulley. The relationship of the oblique retinacular ligament to the proximal interphalangeal joint axis is dependent on the proximal interphalangeal joint position; the ligament lies palmar to the proximal interphalangeal joint axis only when the proximal interphalangeal joint is flexed.

Unlike other marine-sedimentary manganese ore deposits, which are largely composed of manganese oxides, the primary ore at Molango (Hidalgo State, Mexico) is exclusively manganese carbonate (rhodochrosite, Mn-calcite, kutnahorite). Stable isotope studies of the carbonates from Molango provide critical new information relevant to the controversy over syngenetic and diagenetic models of stratiform manganese deposit formation. Negative δ 13 C values for carbonates from mineralized zones at Molango are strongly correlated with manganese content both on a whole rock scale and by mineral species. Whole rock δ 13 C data fall into three groups: high-grade ore = −16.4 to −11.5%.; manganese-rich, sub-ore-grade = −5.2 to 0%.; and unmineralized carbonates = 0 to +2.5%. (PDB). δ 18 O data show considerable overlap in values among the three groups: +4.8 to −2.8, −5.4 to −0.3%., and −7.4 to +6.2 (PDB), respectively. Isotopic data for individual co-existing minerals suggest a similar separation of δ 13 C values: δ 13 C values from calcite range from −1.1 to +0.7%. (PDB), whereas values from rhodochrosite are very negative, −12.9 to −5.5%., and values from kutnahorite or Mn-calcite are intermediate between calcite and rhodochrosite. 13 C data are interpreted to indicate that calcite ( i.e . unmineralized carbonate) formed from a normal marine carbon reservoir. However, 13 C data for the manganese-bearing carbonates suggest a mixed seawater and organic source of carbon. The presence of only trace amounts of pyrite suggests sulfate reduction may have played a minor part in oxidizing organic matter. It is possible that manganese reduction was the predominant reaction that oxidized organic matter and that it released organic-derived CO 2 to produce negative δ 13 C values and manganese carbonate mineralization.

The activities of acid and alkaline phosphatases were significantly increased in subcellular fractions isolated from the aorta of deoxycorticosterone-acetate induced hypertensive rats as compared to normotensive Sprague-Dawley rats. Calcium uptake by the microsomal vesicles of deoxycorticosterone-acetate induced hypertensive rats was slightly reduced as compared to normotensive Sprague-Dawley rats, particularly in the presence of 10 μ m free CaCl 2 . Total tissue Ca 2+ content in the aortae was significantly increased in deoxycorticosterone-acetate induced hypertensive rats as compared to normotensive Sprague-Dawley rats. These results suggest that increased activities of phosphatases in the vascular smooth muscle may be representative of biochemical alterations occurring in the deoxycorticosterone-acetate-hypertensive rats.

The general hypothesis as to the mode of action of chemotherapeutic agents, which has been formulated by Fildes, Woods, McIlwain, and others (2), offers a rational and useful guide to the design of new drugs. Thus, bacteriostasis is pictured as caused by the blocking of reactions essential to growth by an inhibiting substance which has a structure similar to that of one of the normal enzymes or metabolites essential to the growth of the organism.