This research presents the results of initial geoarchaeological analysis of the Northern Australian site Madjebebe, formerly known as Malakunanja II. At 60ky, Madjebebe is among the oldest on the island, making research here an important part of understanding the larger history of indigenous Australian occupation. The project presented here compiles the results of geoarcaheological analysis of sediment samples excavated by Dr. Ben Marwick and his team as part of their 2012 field season. Our research question centers on assessing the site's environmental history, in order to gain further understanding of the long human occupation of the area. Sediment analyses are used to form a more complete picture of the environmental and anthropogenic processes that shaped this site and provide insight into the human systems and occupational history of the area. Organic content, pH, colour, electric conductivity, and magnetic susceptibility were measured in regular intervals along the sediment profile from the south by southwest portion of the site. Initial results suggest that, over time, the deposit became less acidic and had higher concentrations of organic matter, possibly as a result of or in accordance with human occupation. The most recent deposits were also the darkest coloured soils and had a higher level of magnetic susceptibility than their more ancient counterparts, further supporting the connections between the human occupation and impact on the ecology of Madjebebe. Our findings generally support previous claims that the environmental changes at Pleistocene-Holocene boundary may have affected the intensity of settlements in Northern Australia. The results of this study join the growing body of research on human-environment interactions and provide valuable information about how these interactions work to shape site formation and population in the earliest stages of Australian occupation.

The soil management practices characteristic of industrial agriculture often impede the longevity of soil production. Tillage, synthetic fertilizers, pesticides, and monocultures are often the primary culprits. In addition to the detriment to soil tilth, these practices also have adverse environmental effects. This study assesses the soils of the UW farm and associated non agricultural sires to determine changes in soil over time in response to organic agriculture. Using assessments of microbial activity, nutrient content, organic matter content, and plant health, practical differences between soils used and not used for urban agriculture are quantified.The conclusions of this study will help the UW farm with soil conservation practices.

Metals introduced to rivers bind to fine sediment and are transported to seabeds where a variety of complex sediment transport processes take over. Some of these metals can be hazardous to the marine biosphere, and it is therefore crucial to quantify the magnitude of these processes to understand where sediment containing toxic metals is accumulating. For this study, 25 surface sediment samples were collected from Tahsis Inlet, Nootka Sound, BC. An understudied region, Tahsis Inlet is a steep, narrow fjord with high tidal energy and is characterized by a sidewall river delta, a mid-inlet passage to another fjord, and two rivers at its head. Sediment samples were analyzed for grain size and concentration of a suite of 22 metals. Grain size distributions in Tahsis Inlet varied widely from very coarse (rocks, gravel, sand) around the sidewall delta to very fine (silt and clay) at both ends of the inlet. There were distinct patterns between different types of metals, where certain metals tended to co-vary along the sampling transect. Additionally, the toxic anthropogenic metals, arsenic and mercury, were detected at several of the Tahsis Inlet stations. The connection between metal concentrations and local logging and wood processing activities, physical transport via currents and landslide deposition, and biological processes will be described.

This study seeks to assess the health of part of the Bainbridge Basin area of Puget Sound using foraminifera as an indicator species. Foraminifera are microbiota that live in marine sediments around the world and are at the primary consumer level in the trophic chain. They produce shells of calcium carbonate (calcareous) or of cemented sediment grains (agglutinate), which are preserved in sediments. Foraminiferal species assemblages and shell conditions provide information about their environment. Puget Sound ecosystems contain high levels of both historic and modern pollutants that present health hazards to all life within the community, including human life. Bioaccumulation of pollutants begins with primary producers and magnifies as it ascends the trophic ladder to the quaternary consumers (humans). This study examined foraminifera samples collected in 1974, 1998, and 2009 from the Central Puget Sound. The study sites include Eagle Harbor and Rich Passage, areas both affected by industrial pollution. Designated a Superfund site in 1987, Eagle Harbor was the site of wood-treatment plant that leached harmful chemicals into the soil and groundwater. Samples were analyzed for foraminiferal assemblage composition, species richness and signs of test dissolution, which indicates low pH in the water. Sixteen species were identified from these samples. Species diversity in these assemblages was low, and 49% of calcareous individuals showed signs of test dissolution, indicating high levels of pollutants in the water. This study is part of the Puget Sound Foram Research Project, which seeks to assess pollution levels in Puget Sound. 

The interdisciplinary project titled the Amazon Tidal River and Mangroves Study is a National Science Foundation funded research project attempting to determine the future health of the coastal ecosystem of the lower Amazon River with the threat of sea level rise and a changing climate. The project is involved with building a comprehension of the present state and behavior of the river, particularly that of suspended sediment and river discharge. Five research cruises were completed at different times in the year that coincide with seasonal changes in river discharge. Each cruise collected profiles of suspended sediment concentrations (SSC) at locations along the tidal river, the lowermost region of the river that is affected by tides. For every location, instruments were deployed at three stations spanning the width of the channel. These instruments measured SSC, salinity, temperature, depth and velocity. For this project, data from the fourth cruise, which corresponded with high river flow, was organized and analyzed in order to evaluate the characteristics of the river. A strong tidal signature was detected in the locations closest to the mouth of the river, which diminished upstream. A large variation in SSC across the channel was observed upstream, while locations closer to the mouth displayed less variation across the channel and more diurnal variability. At every location in the tidal river, SSC profiles showed diurnally uniform concentrations at the surface while large diurnal SSC variability was observed near the bed. This result indicates that tidal forces are stronger near the bed than at the surface. Further research is necessary to analyze SSC behavior across seasons. This would entail organizing data obtained from the other four research cruises, using similar methods to develop spatial and temporal data of SSC, and comparing the SSC behavior from season to season.

Sediments in nature, which have magnetic carriers (mostly a mineral called magnetite), have a specific magnetic signature in which the direction of the prevailing magnetic field is aligned. The acquisition of this field vector depends on the position of earth’s magnetic pole when the sediment was deposited. Much like a compass, the magnetic carriers align themselves according to the earth’s magnetic pole at the time of deposition. The paleomagnetic signature is best preserved in fine-grained sediment where depositional energies are low. Analyzing such sediments in the Puget Lowland, will allow us to observe potential differences in the magnetic signature for sediments deposited during different time periods. Since the Earth’s pole is constantly “wandering”, sediments deposited during different time periods at the same location should have different magnetic signatures. Accounting for tectonic plate motion, which is significantly less compared to the rate at which the magnetic pole moves, the difference in the magnetic signatures over time can be studied. Using fine-grained glacial lacustrine sediments from Whidbey Island and Discovery Park, Washington, the application of this technique will be assessed. If sediments deposited during different time periods are found to have different magnetic signatures as hypothesized, a relationship between the field strength and the age of the sediment (as the position of the pole over times is known) can be established. For sediments where the age is known, the position of the magnetic pole during deposition can be located. Thus arises a potential for a new dating technique, and constraints on the age of important geologic events can be ascertained.