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Frank T. Manheim

Publications and source records attributed to Frank T. Manheim.

At least 19 recordsLinked to original sources
USGS2013

Cobalt-rich ferromanganese crusts from the Central Pacific

Ferromanganese crusts coat most hard substrates on seamounts, ridges, and plateaus in the centralPacific basin. Crusts from less than 2500 m water depth are rich in Mn, Co, Ni, Pb, and Pt. Samples we collected from the EEl of the Hawaiian, Johnston, Palmyra, and Marshall Islands are discussed. Necker Ridge in the Hawaiian EEl has the greatest average crust thickness of 4 em. The dominant mineral in all crusts is o-Mn02' Substrate rocks are dominantly volcanic breccia. Slumping and turbidity currents on the flanks of the submarine edifices partly control crust thicknesses by burial and dissolution or erosion. Regional variations in crust chemistry and mineralogy can be related to various oceanographic and geologic conditions. Of the areas examined in Some detail, the EEl of Johnston, Palmyra, and the Marshall Islands hold the greatest economic potential.

Conference Paper↗
USGS2011

Referees and the publications crisis

Routine refereeing by peers of manuscripts submitted to scholarly journals is a logical and effective device that can obviate ‘crankiness, irrelevance and gross incompetence’ [ Ziman , 1970 a ] on the one hand and minimize editorial arbitrariness on the other. As reviewed by Zuckerman and Merton [1971], the device has historical roots that extend back to the beginning of the first scholarly journals, such as Transactions of the Royal Society, and Journal des Scavans . The growth of science since World War II and the pressure of burgeoning manuscript submission appear to have been important factors in making automatic peer review nearly universal in American and British Commonwealth natural science journals and in international journals influenced by Anglo‐North Americans. A 1962 survey cited by Zuckerman and Merton [1971] found that 71% of 156 physical and biological science journals in 13 countries made use of referees.

Eos, Earth and Space Science News↗
USGS2006

Ground water beneath coastal bays of the Delmarva Peninsula: Ages and nutrients

To complement a large-scale geophysical investigation of occurrence and discharge of fresh water beneath Delaware, Maryland, and Virginia (Delmarva) coastal bays, we measured (1) salinity and nutrient concentrations in ground water samples from several offshore coring sites and (2) a suite of chemical and isotopic parameters, including age tracers, in ground water samples from a Delaware site. Samples were collected in a variety of Holocene and Plio-Pleistocene sediments in nearshore and offshore areas of the bays. Ground waters that were significantly fresher than overlying waters were found in plumes up to at least 15 m thick extending to more than 500 m offshore in some areas. Steep salinity and nutrient gradients occur within a few meters of the sediment surface in most locations studied. The zone of transition from deeper fresher waters to shallower brackish waters is generally thin near shore, but thickens and becomes more gradual offshore. Ground water ages at the Delaware site were mostly < 50 yr in both fresh waters and brackish waters up to 22 m below the bay bottom. Water chemistry and age data indicate that fresh water plumes beneath the estuary are active extensions of the surficial aquifer carrying nitrate from recharge areas on land, whereas brackish ground water surrounding the fresh water plumes is recharged beneath the estuary and contains ammonium and phosphate released by diagenesis of shallow estuarine sediments. Denitrification affects some of the fresh water nitrate before it mixes with brackish ground water or discharges to surface water.

Delaware, Maryland, Virginia↗
USGS2006

Hydrogeologic setting and ground water flow beneath a section of Indian River Bay, Delaware

The small bays along the Atlantic coast of the Delmarva Peninsula (Delaware, Maryland, and Virginia) are a valuable natural resource, and an asset for commerce and recreation. These coastal bays also are vulnerable to eutrophication from the input of excess nutrients derived from agriculture and other human activities in the watersheds. Ground water discharge may be an appreciable source of fresh water and a transport pathway for nutrients entering the bays. This paper presents results from an investigation of the physical properties of the surficial aquifer and the processes associated with ground water flow beneath Indian River Bay, Delaware. A key aspect of the project was the deployment of a new technology, streaming horizontal resistivity, to map the subsurface distribution of fresh and saline ground water beneath the bay. The resistivity profiles showed complex patterns of ground water flow, modes of mixing, and submarine ground water discharge. Cores, gamma and electromagnetic-induction logs, and in situ ground water samples collected during a coring operation in Indian River Bay verified the interpretation of the resistivity profiles. The shore-parallel resistivity lines show subsurface zones of fresh ground water alternating with zones dominated by the flow of salt water from the estuary down into the aquifer. Advective flow produces plumes of fresh ground water 400 to 600 m wide and 20 m thick that may extend more than 1 km beneath the estuary. Zones of dispersive mixing between fresh and saline ground water develop on the upper, lower, and lateral boundaries of the the plume. the plumes generally underlie small incised valleys that can be traced landward to stream draining the upland. The incised valleys are filled with 1 to 2 m of silt and peat that act as a semiconfining layer to restrict the downward flow of salt water from the estuary. Active circulation of both the fresh and saline ground water masses beneath the bay is inferred from the geophysical results and supported by geochemical data.

Delaware↗
USGS2006

Studying ground water under Delmarva coastal bays using electrical resistivity

Fresh ground water is widely distributed in subsurface sediments below the coastal bays of the Delmarva Peninsula (Delaware, Maryland, and Virginia). These conditions were revealed by nearly 300 km of streamer resistivity surveys, utilizing a towed multichannel cable system. Zones of high resistivity displayed by inversion modeling were confirmed by vibradrilling investigations to correspond to fresh ground water occurrences. Fresh water lenses extended from a few hundred meters up to 2 km from shore. Along the western margins of coastal bays in areas associated with fine-grained surficial sediments, high-resistivity layers were widespread and were especially pronounced near tidal creeks. Fresh ground water layers were less common along the eastern barrier-bar margins of the bays, where sediments were typically sandy. Mid-bay areas in Chincoteague Bay, Maryland, did not show evidence of fresh water. Indian River Bay, Delaware, showed complex subsurface salinity relationships, including an area with possible hypersaline brines. The new streamer resistivity system paired with vibradrilling in these investigations provides a powerful approach to recovering information required for extension of hydrologic modeling of shallow coastal aquifer systems into offshore areas.

Delaware, Maryland, Virginia↗
USGS2004

The legacy of contaminated sediments in Boston Harbor

Scientists at the U.S. Geological Survey (USGS) have assembled a significant body of data that is now in a usable form. The USGS adopted an interdisciplinary approach to begin the pioneering effort at data rescue. This work involved collaboration with the Environmental Protection Agency (EPA), the U.S. Army Corps of Engineers (USACE), the Massachusetts Water Resources Authority (MWRA), Massachusetts Coastal Zone Management, and the National Oceanic and Atmospheric Administration (NOAA). More than 100,000 sediment chemistry analyses from over 1,500 samples were gleaned from 500 references, compiled, and scientifically edited by the USGS and other workers for use in studies of the distribution and fate of contaminants.

Massachusetts↗
USGS2003

Suspended matter in surface waters of the northern Gulf of Mexico

Analyses of about 200 surface water samples collected during late fall 1966 show that concentrations of suspended matter greater than 1 mg/liter were restricted to within a few kilometers off Florida, but extended more than 100 km off Louisiana and Texas. Suspensates from areas farther than 100 km from shore contained mainly combustible organic matter, part of which was attributable to living plankton. Organic aggregates encompassing appreciable amounts of inorganic detritus were particularly noteworthy in transitional areas. Zooplankton metabolism and fecal pellet production appears to be a geologically significant mechanism for depositing fine suspended matter and may contribute to the zonation of bottom sediments. The mineral composition of surface suspensates ranges from a low magnesian calcite‐aragonite suite off Florida to montmorillonite‐kaolinite combinations from Alabama to Texas. The mineral composition of the suspensates resembles that of the bottom sediments in each area.

Northern Gulf of Mexico↗
USGS1999

Cobalt-rich ferromanganese crusts in the Pacific

Co-rich Fe-Mn crusts occur throughout the Pacific on seamounts, ridges, and plateaus where currents have kept the rocks swept clean of sediments at least intermittently for millions of years. Crusts precipitate out of cold ambient sea water onto hard-rock substrates forming pavements up to 250 mm thick. Crusts are important as a potential resource for Co, Ni, Pt, Mn, Tl, Te, and other metals, as well as for the paleoclimate signals stored in their stratigraphic layers. Crusts form at water depths of about 400 to 4000 m, with the thickest and most Co-rich crusts occurring at depths of about 800 to 2500 m, which may vary on a regional scale. Gravity processes, sediment cover, submerged and emergent reefs, and currents control the distribution and thickness of crusts on seamounts. Crusts occur on a variety of substrate rocks that generally decrease in the order, breccia, basalt, phosphorite, limestone, hyaloclastite, and mudstone. Because of this wide variety of substrate types, crusts are difficult to distinguish from the substrate using remotely sensed data, such as geophysical measurements, but are generally weaker and lighter-weight than the substrate. Crusts can be distinguished from the substrates, however, by their much higher gamma radiation levels. The mean dry bulk density of crusts is 1.3 g/cm3, the mean porosity is 60%, and the mean surface area is extremely high, 300 m2/g. Crusts generally grow at rates of 1 to 10 mm/Ma. Crust surfaces are botryoidal, which may be modified to a variety of forms by current erosion. In cross-section, crusts are generally layered, with individual layers displaying massive, botryoidal, laminated, columnar, or mottled textures. Characteristic layering is persistent regionally in the Pacific. Crusts are composed of ferruginous vernadite (δ-MnO2) and X-ray amorphous Fe oxyhydroxide, with moderate amounts of carbonate fluorapatite (CFA) in thick crusts and minor amounts of quartz and feldspar in most crusts. Elements most commonly associated with the vernadite phase include Mn, Co, Ni, Cd, and Mo, whereas those most commonly associated with Fe oxyhydroxide are Fe and As. Detrital phases are represented by Si, Al, K, Ti, Cr, Mg, Fe, and Na; the CFA phase by Ca, P, Sr, Y, and CO2; and a residual biogenic phase by Ba, Sr, Ce, Cu, V, Ca, and Mg. Crusts contain Co contents up to about 2.3%, Ni to 1%, and Pt to 3 ppm, with mean Fe/Mn ratios of 0.6 to 1.3. Fe/Mn decreases, whereas Co, Ni, Ti, and Pt increase in central Pacific crusts and Fe/Mn, Si, and Al increase in continental margin crusts and in crusts with proximity to west Pacific volcanic arcs. Vernadite and CFA-related elements decrease, whereas Fe, Cu, and detrital-related elements increase with increasing water depth of crust occurrence. Cobalt, Ce, Tl, and maybe also Ti, Pb, and Pt are strongly concentrated in crusts over other metals because of oxidation reactions. Total rare earth elements (REEs) commonly vary between 0.1% and 0.3% and are derived from sea water along with other hydrogenetic elements, Co, Mn, Ni, etc. Platinum, Rh, Ir, and some Ru in crusts are also derived from sea water, whereas Pd and the remainder of the Ru derive from detrital minerals. The older parts of thick crusts were phosphatized during at least two global phosphogenic events during the Tertiary, which mobilized and redistributed elements in those parts of the crusts. 240Silicon, Fe, Al, Th, Ti, Co, Mn, Pb, and U are commonly depleted, whereas Ni, Cu, Zn, Y, REEs, Sr, and Pt are commonly enriched in phosphatized layers compared to younger nonphosphatized layers. The dominant controls on the concentration of elements in crusts include the concentration of metals in sea water and their ratios, colloid surface charge, types of complexing agents, surface area, and growth rates. Crusts act as closed systems with regard to the isotopic ratios of Be, Nd, Pb, Hf, Os, and U-series, which in part have been used to date crusts and in part used as isotopic tracers of paleoceanographic and paleoclimatic conditions. Those tracers are especially useful in delineating temporal changes in deep-ocean circulation. Research and development on the technology of mining crusts are only in their infancy. Detailed maps of crust deposits and a better understanding of small-scale seamount topography are required to design the most appropriate mining equipment.

Book chapter↗
USGS1997

Environmental geochemistry and sediment quality in Lake Pontchartrain: database development and review

This paper reports on preliminary results of a project to develop a comprehensive data base of chemical and environmental information on sediments from Lake Pontchartrain, Louisiana, and surrounding water bodies. The goal is to evaluate all data for reliability and comparability, and to make it widely accessible and useful to all users. Methods for processing heterogeneous, historical data follow previous methods employed in the Boston Harbor and Massachusetts Bay area. Data from 11 different data sets, encompassing about 900 total samples, have been entered to date. Questionable or anomalous data were noted in a minority of cases. Problems tend to follow distinct patterns and are relatively easy to identify. Hence, comparability of data has not proven to be the major obstacle to synthesis efforts that was anticipated in earlier years (NRC, 1989). Quality-controlled data sets show that the bulk of sediment samples in the more central parts of Lake Pontchartrain have values within normal background for heavy metals like Cu, Pb, and Zn. The same or lower concentrations were found in the vicinity of the Bonnet Carre Spillway, representing influx from the Mississippi River. Mean concentrations for Cu, Pb, and Zn were 17, 21, and 74 µg/g (total dissolution analyses), respectively. However, values as high as 267 µg/g Pb and comparable increases for other metal and organic contaminants are found in sediments within 2 km of the coastal strip of New Orleans. Additional sampling in such areas and in other inland coastal waterways is needed, since such levels are above the threshold for potential toxic effects on benthic organisms, according to effects-based screening criteria. The most contaminated sites, Bayou Trepagnier and Bayou Bonfouca, involve industrial areas where waste discharge has now been controlled or remediated, but where sediments may retain large concentrations of contaminants, e.g. tenths of a percent of Pb, Cr, and Zn or more for Bayou Trepagnier.

Louisiana↗
USGS1996

Contaminants in the Gulf of Maine-What's here and should we worry?

The Gulf of Maine is a dynamic environment that has highly variable bottom type and localized depositional and transport processes. It is used and impacted by the people around it who hope to use the marine system for many purposes such as fishing, recreation, housing, sewage and dumped disposal, shipping, recreation, and preservation. In order to identify "pollution", which is defined as detrimental effects in the ecosystem that are attributable to human activity, the spatial and temporal distribution of contaminants in Gulf of Maine sediments are established using data that have been compiled into a Contaminated-Sediment Database for the Gulf of Maine. The potential for high contaminant levels in the sediments to induce toxic effects in the Gulf ecosystem is then assessed. In the Gulf of Maine, we have large urban centers that adversely affect the marine ecosystem well offshore through a variety of human activities. We are also in the fortunate position of still having many relatively pristine marine areas. It is unlikely that we will reach an endpoint of "zero toxic effects" in the ecosystem; however, much of the information needed to move closer to the shared goal of managing a sustainable ecosystem in the Gulf of Maine is currently available. Future success will rely on continued efforts to 1) identify rate-limiting physical and biological processes, 2) provide appropriate data synthesis and 3) involve the public.

Maine, Massachusetts, New Hampshire↗