From mixing models using bromide concentrations in injected and produced water, injected water in Block 29 T2k2 formation defines a long plume, which could reflect transport along depositional narrow sand bar-like deposits within the fluvial sediment. In the T2k1 formation in Block 29, three flow paths appear to occur, two trending south to north and one from east to west. In Block 29, J1b formation, and Block 67, J1b formation, water spreads in all directions from injection wells. In block 60, production from wells from multiple formations made using natural tracers ineffective.

Several key natural background fluorescence peaks produced from dissolved organic substances (e.g. ë286 and ë618 nm) varied linearly in block 29, Triassic T2k2 formation. Block 29, Triassic T2k1 formation appeared to have, based on fluorescence, two possible kinds of formation waters, one defined by fluorescence peaks ë290 and ë324 and another also by peaks ë571 and ë621. Block 60 produces water from multiple formations, and fluorescence data could not clearly define end members because mixing included waters from multiple formations.

Two component-mixing models based on major fluorescence peaks defined contour maps different from those produced from bromide. Perhaps BTEX in the formation waters degraded to produce relative fluorescence intensity that reflects degradation and organic acids, rather than organics in the formation water itself. Or perhaps the injected water solubilizes organics from the oil in the formation, thereby masking diagnostic fluorescence peaks. Multiple fluorescence peaks also overlap and complicate the analysis from a quantitative standpoint.

Correlation Matrix statistical analysis, Principal Component Analysis (PCA), Discriminant Analysis (DA) and Cluster Analysis (CA) can, however distinguish among wells from background fluorescence peaks. Well H0538 and H0214 in block 29 Triassic T2k2, well H0218, H0225 and H0208 in block 29 Triassic T2k1, well H0510 and H0702 in block 29 Triassic J1b, Well H8031 and H8021 in block 67 Jurassic J1b have different dominant fluorescent peak combinations than other wells in those blocks. Discriminate analysis shows fluorescence of water from the J3q formation differs from the J1b, T2k1 and T2k2 formations.

Statistical analysis of solute concentrations does not show the same results as BFA peaks did. The major solutes mainly show which major elements dominate in the area and wells. Much sulfate exists in the injected water, which can combine with Ca and may block the pores in the formation by precipitation of calcium sulfate.

Characterizing waters from different formations would be useful to determine the extent to which formations actually are isolated or not from each other. At least using natural tracers, such as bromide, avoids complications of introducing radioactive substances or other anthropogenic tracers into otherwise natural systems, although it appears that BFA is not a reliable tracer method for this application.

The study site was a 30 m stretch of stream that underwent stream restoration through installation of a cross-vane and engineered rock riffle over a natural pool-riffle-pool sequence. Pre-restoration, mini-piezometers and temperature profile rods were spatially located around the riffle. Fourteen mini-piezometers were installed at a 15 cm depth into the streambed and coupled with temperature profile rods that recorded temperature in the water column as well as at 5 cm intervals to a depth of 30 cm into the streambed. Sampling of pore water occurred during baseflow conditions as well as during and after Tropical Storm Irene. Principal component analysis was used to understand the controls on both spatial and temporal stream and pore water chemistry. Through the use of a MATLAB program that utilizes a one-dimensional heat transport model, vertical exchange rates in the streambed were calculated using the measured temperature fluctuations in the streambed during baseflow conditions. Similar to pre-restoration, 19 mini-piezometers and 10 temperature profile rods recorded pore water geochemistry and vertical exchange rates around the installed cross-vane and engineered rock riffle during baseflow conditions one year after restoration.

Pre-restoration, the majority of spatial variability in pore water geochemistry (62%) is driven by differential mixing of surface and ground water across the hyporheic zone. The second largest driver of pore water geochemistry (17%) was temporal dilution and re-enrichment of infiltrating surface water during Tropical Storm Irene. Hyporheic sites minimally affected by upwelling groundwater showed temporal fluctuations in pore water geochemistry across the reach influenced by both changes in infiltrating stream chemistry as well as hyporheic residence time and flowpath length. The streambed zone influenced by groundwater discharge increased in size during Tropical Storm Irene, indicating that the area of localized groundwater inputs grows in response to storm events.

After restoration, hyporheic exchange rates increased by an order of magnitude immediately adjacent to the cross-vane and engineered rock riffle, when compared to exchange rates around the riffle in pre-restoration conditions. Away from the restoration structure, exchange rates are similar between pre- and post- restoration. A Rhodamine WT injection suggested 100% of streambed pore water immediately adjacent to the structure originated from the stream, while the rest of the study site received roughly 20 percent stream water. Evidence of nitrate production and uptake were seen across the pre-restoration riffle, but the post-restoration cross-vane and rock riffle showed evidence of only nitrate uptake. Therefore, although restoration produces hot spots of hyporheic exchange, the high exchange rates reduce hyporheic flow path residence time such that nitrate production cannot change nitrate concentrations in the streambed. While zones of groundwater inputs are present pre- and post- restoration, the zone of groundwater upwelling increased post-restoration, suggesting cross-vane installation may have disturbed subsurface hydraulic conductivity.

I synoptically collected 26 water samples in 2010 on the lake and 88 water samples on north-western sub-watersheds, and analyzed them for field parameters (e.g. pH, SC, DO, TDS, etc.), nutrients, and major and minor solutes which are useful to fingerprint solute sources and geochemical reactions controlling them.

Graphical methods such as bivariate plots and Piper Diagrams show the waters broadly change throughout the basin from calcium-magnesium-bicarbonate hydrochemical facies type water to mixed sodium-sulfate-chloride type waters. No halite sources occur in the basin so the addition of sodium, chloride and potentially sulfate in the major solute mix logically should be related to land use and potential contamination from it.

Principle component analysis (PCA) of stream and lake water chemical compositions produced three principal components that explained 71% loading of the cumulative variance in the water quality. These three principal components reflect three major types water chemistry related to land use patterns. Agriculture land use is associated with greater concentrations of nutrients; urban areas are associated with high concentration of sodium, chloride, sulfate, fluoride and potassium, and western low hills and northern study areas largely show a calcium-magnesium-bicarbonate water type. Hierarchical cluster analysis produced results similar to that of the PCA analysis, clustering into agriculture, urban area, rural area and forestry areas, lake water and water at tributaries mouths. Broadly speaking, future remediation to reduce nutrient loadings to the lake or industrial contamination could now be focused on specific land use practices, readily identifiable using GIS.

Active volcanism in southeastern Papua New Guinea occurs on the Papuan Peninsula (Mt. Lamington, Mt. Victory and Waiwa), in the Woodlark Rift (Dobu Island, SE Goodenough Island, and Western Fergusson Island), and in the Woodlark Basin . In the Woodlark Basin, seafloor spreading is active and decompression melting of the upper mantle is producing basaltic magmatism. However, the cause of Pliocene and younger volcanism in the Woodlark Rift is controversial. Two hypotheses for the tectonic setting have been proposed to explain Pliocene and younger volcanism in the Woodlark Rift: 1) southward subduction of Solomon Sea lithosphere beneath eastern PNG at the Trobriand Tough and 2) decompression melting of mantle, previously modified by subduction , as the lithosphere undergoes extension associated with the opening of the Woodlark Basin.

A comparison of 40Ar/39Ar ages with high field strength element (HFSE) concentrations in primary magmas indicates that HFSE concentrations correlate with age in the Woodlark rift. These data support the hypothesis that Pliocene to active volcanism in the Woodlark Rise and D'Entrecasteaux Islands results from decompression melting of a relict mantle wedge. The subduction zone geochemical signatures (negative HFSE anomalies) in Woodlark Rift lavas younger than 4 m.y. are a relict from older subduction beneath eastern Papua, likely in the middle Miocene . As the lithosphere is extended ahead of the tip of the westward propagating seafloor spreading center in the Woodlark Basin, the composition of volcanism is inherited from prior arc magmatism (via flux melting) and through time evolves toward magmatism associated with a rifting (via decompression melting).