Savage River Research Articles

In situ measurements of labile Cu, Cd and Mn in river waters using DGT

The technique of diffusive gradients in thin-films (DGT) has been trialed in two river systems for in situ trace metal speciation measurements. This paper presents results for cadmium, copper and manganese concentrations in fresh and estuarine waters and demonstrates for the first time the effectiveness of using DGT to measure labile metal concentrations in such waters. This work has shown that even with very simple deployment systems the technique is sensitive and reproducible. The precision of in situ DGT measurements was typically 11% or better when the precision of subsequent analysis was good. The in-built metal pre-concentration procedure of DGT allowed Cd to be measured at concentrations below the detection limit of a direct determination by GF-AAS. The theoretically predicted linear increase in mass with time was obtained in river deployments of up to 72 h, confirming steady state river conditions and indicating no adverse effects due to biofouling over this period. Concentrations of DGT-labile Cu and Cd were equal to dissolved (0.45 μm) metal concentrations for the Ring and Stitt Rivers indicating the absence of tightly bound organic complexes or colloidal species. DGT-labile Cu and Cd were approximately 50% of the dissolved metal in the Que River and DGT-labile Cu was approximately 30% of dissolved Cu in the Savage River. A concentration–depth profile of labile manganese was obtained in a stratified estuary by deployment of a string of DGT devices at 0.3-m intervals across the redoxcline. Results revealed a large spike (maximum concentration=1.4 mg/l) of DGT-labile Mn at the base of the redoxcline and demonstrate the utility of DGT to determine vertical changes in metal speciation across redox boundaries in stratified estuarine systems. It is in such dynamic systems as this that the in situ capabilities of DGT are likely to be most useful. DGT records multiple metal species as they exist in situ, overcoming the considerable problems of contamination often associated with sample collection and handling.

Use of man-made impoundment in mitigating acid mine drainage in the North Branch Potomac River

The US Department of the Army, Baltimore District Corps of Engineers, oversees a long-term monitoring study to assess and evaluate effects of the Jennings-Randolph reservoir on biota in the North Branch Potomac River. The reservoir was intended, in part, to mitigate effects of acid mine drainage originating in upstream and headwater areas. The present study assessed recovery of benthos and fish in this system, six years after completion of the reservoir. Higher pH and lower iron and sulfate concentrations were observed upstream of the reservoir compared to preimpoundment conditions, suggesting better overall water quality in the upper North Branch. Water quality improved slightly directly downstream of the reservoir. However, the reservoir itself was poorly colonized by macrophytes and benthic organisms, and plankton composition suggested either metal toxicity and/or nutrient limitation. One large tributary to the North Branch and the reservoir (Stony River) was shown to have high (and possibly toxic) levels of manganese, iron, zinc, and aluminum due to subsurface coal mine drainage. Macroinvertebrate diversity and number of taxa were higher in sites downstream of the reservoir in the present study. Compared with previous years, the present study suggested relatively rapid recovery in the lower North Branch due to colonization from two major unimpacted tributaries in this system: Savage River and South Branch Potomac. Abundance of certain mayfly species across sites provided the most clear evidence of longitudinal gradients in water quality parameters and geomorphology. Fish data were consistent with macroinvertebrate results, but site-to-site variation in species composition was greater. Data collected between 1982 and 1987 suggested that certain fish species have unsuccessfully attempted to colonize sites directly downstream of the reservoir despite the more neutral pH water there. Our results show that recovery of biota in the North Branch Potomac was attributed to decreased acid inputs from mining operations and dilution from the Savage River, which contributed better water quality. Continued improvement of North Branch Potomac biota may not be expected unless additional mitigation attempts, either within the reservoir or upstream, are undertaken.

Nesting Ecology and Microhabitat of the Eastern Phoebe in the Central Appalachians

-In 1984, a study of the eastern phoebe (Sayornis phoebe) was conducted on the Appalachian Plateau in western Maryland, principally in the Savage River State Forest. Fledging success and mortality patterns were used as indicators of differences in quality of nest-site microhabitats. A total of 229 fledglings resulted from 84 nesting attempts, an average of 2.73 fledglings per attempt. Fledging success was 61.4%, with early nests generally more successful than late nests. Fledging success was similar among nesting structures, with adherent nests having higher success than statant nests, except on rock outcrops. However, late-adherent nests on rock outcrops did have higher fledging success than late-statant nests. The success of new-active and old-active nests was the same. Losses attributed to predators amounted to 70.1% of all losses. Losses attributed to small predators (55.6%) were significantly higher than that from large predators (14.6%). Other losses were attributed to nests falling (13.9%), human disturbance (5.6%), hatching failure (4.2%), adult death/desertion (3.5%) and inclement weather (2.8%). Losses ascribed to small predators increased from early to late nesting attempts on all nesting structures, but less so for adherent nests on rock outcrops. The principal nest predator was probably the eastern chipmunk (Tamias striatus). Stepwise discriminant function analysis was used to distinguish between microhabitats of high-success (>60%) and low-success (?60%) phoebe nests. Evergreen canopy cover (%), height to nest rim and distance to nearest understory tree were greater at high-success nests; while angle of recess in which the nest was built was smaller. Microhabitat variables with no differences among nesting structures, and therefore probably important in overall nestsite selection, included height of rock outcrop or other structure at the nest location, height to nest rim, width of shelf used for support of nest, length of overhanging structure above nest, height to underhanging structure below nest, height of understory trees and percent evergreen canopy cover. Variables associated with access to the nest tended to affect success more than others.

A further large magnesite deposit along the Savage River in northwestern Tasmania

A further large magnesite deposit along the Savage River in northwestern Tasmania

Post-Fire Regeneration of Rainforest and Mixed Forest in Western Tasmania

An area of rain forest burnt in the Zeehan fire of 1981 is regenerating toward pure rain forest. This fire was small and patchy and therefore many trees survived to provide a seed source for a major germination of rain forest species after the fire. However, several seral stages are expected to precede the climax vegetation. In contrast, an area of mixed forest burnt in the Savage River fire of 1982 has undergone a major change in species composition because of the proximity of a sclerophyll seed source. The Eucalyptus nitida overstorey is likely to be maintained, but sclerophyllous species will probably increase in dominance in the understorey at the expense of the pre-fire rain forest dominance. Given a long, fire-free interval, this forest may undergo succession to the climax rain forest, but this is unlikely due to large amounts of fuel, the drying effect of the forest edge, and the nearby road which allows access for human-caused fires.

The magnesite deposit at Main Creek, Savage River, Tasmania

The magnesites at Main Creek, a tributary of Savage River in northwestern Tasmania are associated with dolomite and talc-chlorite schist in a mildly metamorphosed belt running northeastward across the area. The nearly vertically dipping lens of magnesite is over 218 m thick, and although the extension to the south and north is very uncertain, reserves most likely exceed 40 million metric tons. As a result, mining is being considered. A further deposit of about equal size is found to the north at Arthur River. The carbonate mineralogy is well characterized by the use of a very sensitive backscattered electron detector which easily distinguishes magnesite and dolomite and also demonstrates the zoning of Mg and Fe in both the magnesite and dolomite. Apart from the thin bands of schist and dolomite, the magnesite ore contains about 5 to 10 percent quartz and 5 to 10 percent dolomite. In the upper dolomite horizons especially, replacement of dolomite by magnesite is evident. Mg metasomatism by dilute MgCl 2 solutions is considered more likely than a sedimentary origin. The amount of FeCO 3 in the magnesite falls steadily from about 3 percent at the surface to less than 1 percent FeCO 3 at 305 m. Experimental studies of Johannes (1970) suggest that a MgCl 2 solution with small amounts of FeCl 2 would be expected to form more Fe-rich magnesite at higher (cooler) horizons and more Mg-rich magnesite at depth. It is also suggested that the Savage River magnesites, which were once dolomites, may be contemporaneous with the Savage River dolomites which lie to the west, outside the Arthur lineament, and which are considered to be early Cambrian in age.

An introduction to the geology and metallic ore deposits of Tasmania

The major operating metallic ore deposits of Tasmania are (a) volcanic-hosted massive-sulfide deposits at Que River, Rosebery and Hercules (Fe-Zn-Pb-Cu type), Mt. Lyell (Fe-Cu type), and Savage River (Fe oxide type); (b) tin-tungsten deposits in veins at Aberfoyle, Lutwych, Storys Creek, and Mt. Oakleigh; (c) tin deposits of carbonate-replacement type at Renison and Cleveland; and (d) scheelite-skarn deposits at King Island and Kara. The massive sulfide deposits are Cambrian and occur in calc-alkaline volcanics, the magnetite deposits at Savage River are Proterozoic and occur in basaltic volcanics, and the tin and tungsten deposits are related to Devonian granitoids of various types.Tasmania has in the past been also a producer of osmiridium, nickel sulfide ore (in Cambrian mafic-ultramafic rocks), and gold (in early Paleozoic mudstone-graywacke successions).

Clay shale and discontinuous rock mass studies: Attewell, PB Taylor, RK, Durham Univ. Report, 20 July, 1973, 22OP. AD-770004

Abstract : ;Contents: Slope profiles in the Kimmeridge clay, Yorkshire, England; Field and laboratory investigations and anaylses pertaining to Chatfield damsite, Littleton, Colorado; Field and laboratory investigations and analyses pertaining to Bloomington and Savage River (W. Virginia/Maryland) damsites with reference also to Curwensville damsite; Mineralogical and geochemical study of Cucaracha clay shale samples taken during a field investigation in the Panama Canal Zone.

A DESIGN OF AN EARTH MOVEMENT SURVEY SYSTEM AT SAVAGE RIVER

The Savage River mine in North West Tasmania requires frequent surveys to measure the movement of up to 200 points upon the faces of the pit.

Municipal Watersheds in the Northeast

In Connecticut, about two-thirds of the watersheds for municipal supply are owned by water companies. Of these, the New Haven Water Co. has the largest area, 21,000 acres; the Bridgeport Hydraulic Co. has about 17,000 acres. As to lands owned by cities and towns for water supply and reservoir sites, Hartford ranks first with about 20,000 acres; New Britain and Waterbury each have approximately 5,000 acres. Delaware's sole entry in this table is the 280-acre reservoir property of the Wilmington Water Dept. In Maine, five of six areas range from 75 to 250 acres; Portland, the largest area, has approximately 1,600 acres. In Maryland, over one-third of the municipal area is made up of the forested reservoir properties owned by Baltimore, about 18,000 acres. The Savage River State Forest makes up another third ; it provides domestic and industrial water for Luke, Piedmont, and Westernport. Frederick has a watershed of 8,000 acres and Frostburg and Cumberland have forests of about 1,500 acres each. In Massachusetts, the largest watershed forest, slightly more than 12,000 acres, is at Springfield. The Metropolitan District Commission of Boston owns 9,000 acres; and North Adams, Westfield, and Worcester have 6,0007,000 acres each. New Hampshire's largest area is Manchester, with 5,200 acres, followed by Gorham, with 4,700 acres. New Jersey's 48,000 acres in watershed forests was made up largely by New-

Geology of the Savage River, Maryland, dam and reservoir site

The history of the Savage River dam site investigations is described as an example of the applicability of geology to engineering work even in places where the geology is very simple. The earth dam will rest on a series of well-consolidated beds of sandstone, sandy shale, and limestone of Paleozoic age. The beds are unfaulted and dip downstream at low angles. The water table is at or close to the surface throughout the reservoir area. Exposures are good; the zone of weathering is shallow.The factors that influenced the choice of site are presented in detail. The presence of a large alluvial cone along one bank of the stream narrowed the choice of available sites. Toward the close of the drilling campaign small caves were discovered in the limestone in which the spillway will be cut and which will form part of one abutment. The discovery caused the inclusion of an extensive grouting program in the design.Considerable quantities of shale will be removed from the spillway excavation. Largely as a result of geologic evidence, it was decided that this shale would prove sufficiently durable for use in the dam embankment. The decision led to important changes in design and will result in savings many times as great as the cost of the geologic investigations.