Geology Commons^™

Migmatite Formation, Geochronometer Petrogeneisis, And Rare Earth Element Mineralization In The Adirondack Mountains, Ny, Kaitlyn Suarez

Doctoral Dissertations

The Adirondack Mountains in upstate New York contain exposures of complex partially melted rocks, in addition to iron oxide-apatite (IOA) deposits with variable rare earth element (REE) concentrations. Previous workers have suggested that melting occurred during the ca. 1150 Ma Shawinigan and the ca. 1050 Ma Ottawan orogenies. However, there are challenges in determining the timing of melting and the number of partial melt events. Further, tectonic models must be developed to describe the petrogenesis of IOA and REE mineralization. Migmatites are present along Rt. 4/22 near Whitehall, NY. In chapter two, all layers of a single migmatitic rock were …

Heat Flow In The Southern Margin Of Salar De Atacama: Deep Groundwater Temperature Distributions And The Implications For Subsurface Flow And Land Surface Energy Budgets, Graham Thomas

Masters Theses

Salar de Atacama (SdA) located in Northern Chile is home to one of the planet’s largest salar systems and lithium resources. Managing groundwater resources in salars is not obvious due to the lack of scientific understanding on the connectivity between the freshwater and brine systems. Using heat as a tracer in SdA provides a cost-effective method to further investigate groundwater flow in salars. This study employs 372 temperature-depth profiles from 90 boreholes between 2013-18 to understand the distinct thermal zones and flow between them in SdA. Three thermal zones exist within the southern margin of SdA’s thermal regime, at higher …

Architecture Of Extraction: Imagining New Modes Of Inhabitation And Reclamation In The Mining Lifecyle, Erica Dewitt

Masters Theses

Mining is the primary method through which modern society obtains the minerals needed to fuel the global economy, provide for modern energy requirements, and support the built environment. Presently, mining accounts for nearly 1% of the global ice-free land surface, with a dramatic increase anticipated in the coming decades. Mining permanently changes and often destroys the pre-existing topography, hydrology, and ecology of the ground, and efforts to reclaim mining landscapes—with the aim of encouraging reforestation and soil replenishment—are often unsuccessful, rendering the land of abandoned mines both unusable and uninhabitable.

This thesis addresses the current state of mining in the …

Modeling Spatial Distributions Of Tidal Marsh Blue Carbon Using Morphometric Parameters From Lidar, Bonnie Turek

Masters Theses

Tidal marshes serve as important “blue carbon” ecosystems that accrete large amounts of carbon with limited area. While much attention has been paid to the spatial variability of sedimentation within salt marshes, less work has been done to characterize spatial variability in marsh carbon density. Driven by tidal inundation, surface topography, and sediment supply, soil properties in marshes vary spatially with several parameters, including marsh platform elevation and proximity to the marsh edge and tidal creek network. We used lidar to extract these morphometric parameters from tidal marshes to map soil organic carbon (SOC) at the meter scale. Fixed volume …

Geomorphology Of Tidal Wetlands: Impacts Of Extreme And Annual Flood Events To Salt Marsh And Mangrove Systems, Frances R. Griswold

Doctoral Dissertations

Tidal wetlands are vital for buffering coastal settings from the threats of accelerated sea level rise and storms. Understanding the factors that are most influential for the maintenance and recovery of tidal wetlands after extreme events compounded by future accelerated sea level rise is of the utmost importance, yet this knowledge is not well established. Two tidal wetland schemas investigated in this dissertation are mangrove systems in Vieques, Puerto Rico (including robust lagoonal-mangrove forest systems and fringing mangrove forests), and salt marshes in New England. While the climatic forcings, vegetation type, and locations are vastly different for these two tidal …

Size, Timing, And Landscape Impacts Of Glacial Lake Outburst Floods In The Channeled Scabland Of Eastern Washington, Usa, Karin E. Lehnigk

Doctoral Dissertations

Extreme floods have dramatically altered landscapes on Earth and Mars through bedrock erosion, sediment deposition, and canyon formation. The Channeled Scabland of the Columbia Plateau in eastern Washington, USA, is perhaps the most striking example of such a landscape, where outburst floods from an ice-dammed glacial Lake Missoula eroded immense canyons and transported large volumes of sediment during the late Pleistocene. Despite advances in numerical modeling and geochemical exposure dating methods, it has remained a challenge to untangle the complex interactions between floodwater, bedrock, and glacial ice to link the size of a flood with its impact on the landscape. …

Antarctic Ice Sheet Stability During Warm Periods: Integrating Numerical Modeling With Geologic Data, Anna Ruth W. Halberstadt

Doctoral Dissertations

Sea level rise is one of the major social and environmental challenges that threatens modern civilization, yet the response of polar ice sheets to future warming is deeply uncertain. Mass loss from the Antarctic Ice Sheet is projected to dominate global sea level rise in the near future, but how much, and when, remains a key unknown. The challenges associated with projecting Antarctica’s future sea level contribution are derived from a knowledge gap of physical ice sheet processes in a world warmer than today, and a lack of understanding of climatic thresholds that drive potentially irreversible retreat. Future and even …

Improving The Hydrological Analysis Of Groundwater Flow Paths By Integrating Geochemical And Physical Characteristics Of A Highly Fractured Aquifer System To Create Sustainable Use Of Groundwater In A Climate With Projected Drying Trends., Marsha K. Allen

Doctoral Dissertations

Improving the hydrological analysis of groundwater flow paths by integrating geochemical and physical characteristics of a highly fractured aquifer system to create sustainable use of groundwater in a climate with projected drying trends. Precipitation over Caribbean islands has decreased steadily since the 1950's, which has led to severe drought conditions. The most recent Pan-Caribbean Drought occurred from 2013 to 2016. Climate models predict that drying trends are expected to continue and become more severe over time as precipitation decreases and temperatures rise. In addition, evaporation rates on these islands are expected to increase by ~15-17%, contributing to the drought. Though …

Fundamental Controls On The Water Cycle In Arid Environments: A Mechanistic Framework For Spatiotemporal Connectivity Between Hydroclimate And Groundwaters In The Dry Andes, Brendan J. Moran

Doctoral Dissertations

There remain many persistent uncertainties regarding fundamental aspects of natural water cycles in arid mountainous regions, the Dry Andes of South America represents one of the most extreme examples of these environments on the Planet. Deep water tables (>100 meters), long groundwater transit times and distances (>100 years, 10-100 kilometers), limited and infrequent rainfall, remote and difficult to access terrain, and complex salar/evaporite hydrogeology common in these environments make reliable monitoring of these hydrological systems particularly difficult. As a result, major gaps remain in our understanding of critical aspects of the water cycle such as recharge and evaporation …

Sedimentary Processes Influencing Divergent Wetland Evolution In The Hudson River Estuary, Kelly Mckeon

Masters Theses

Consistent shoreline development and urbanization have historically resulted in the loss of wetlands. However, some construction activities have inadvertently resulted in the emergence of new tidal wetlands, with prominent examples of such anthropogenic wetlands found within the Hudson River Estuary. Here, we utilize two of these human-induced tidal wetlands to explore the sedimentary and hydrologic conditions driving wetland development from a restoration perspective. Tivoli North Bay is an emergent freshwater tidal marsh, while Tivoli South Bay is an intertidal mudflat with vegetation restricted to the seasonal growth of aquatic vegetation during summer months. Using a combination of sediment traps, cores, …

Testing The Impact Of A Freshwater Wetland Restoration On Water Table Elevation And Soil Moisture Using A Parametric Groundwater Modeling Approach, Erika T. Ito

Masters Theses

Wetlands are now recognized for the many social, environmental, ecological, and economic benefits they provide. They improve water quality, support biodiversity, abate floods and storms, and provide local recreational areas. Historically, many wetlands have been drained or altered for residential, commercial, or agricultural use. Effective wetland restoration projects reestablish ecosystem services and mitigate legacy effects of land use change to create self-sustaining systems. However, a persisting lack of scientifically-vetted methodological and evaluation guidelines in the field of restoration ecology has caused many restoration efforts to fail to restore natural wetland hydrologic conditions. By definition, wetlands must be saturated, permanently or …

Benjamin Smith Lyman: Geologist At The Intersection Of Hokkaido, Japan, And The United States, Benjamin Ashby

Masters Theses

Benjamin Smith Lyman was a geologist from Northampton, Massachusetts, who was contracted by the Japanese government in 1872 to carry out coal surveys on the island of Hokkaidō 北海道. What started out as a standard geological survey, quickly evolved into a lifelong interest in Japan for Lyman. The large collection of letters, books, photographs, and other documents housed under the Benjamin Smith Lyman Collection at the University of Massachusetts Amherst, serve as a primary source on both early relations between the Japanese and the West and the beginnings of the large network of academic writings which today can be classified …

Coastal Groundwater Catchments Of The Gulf Of Alaska, Aeon Russo

Masters Theses

High latitude mountain environments are experiencing disproportionately adverse effects in a currently changing climate. The Gulf of Alaska (GoA) region is an exemplar of this. Dramatic shifts are occurring in the region’s freshwater reservoirs as glaciers retreat more with each passing year. Research in the region places much focus on observing and predicting climate driven shifts in glacier mass balance, surface discharge, and associated nutrient fluxes to the ocean. On the other hand, coastal groundwater discharge (CGD) is given very little attention. Global and near-global estimates of CGD indicate variable results spanning an order of magnitude. Focusing on regionally specific …

The Earth, William Clement

Sustainability Education Resources

The Earth is a 4-credit introduction to the Geosciences. This course is required for several majors in the College of Natural Science at the University of Massachusetts Amherst. These majors include Earth Systems, Environmental Science, and Geology. The course also fulfills a 4-credit Physical Science (PS) General Education requirement and may be an elective science course in a number of other majors. Our goal in Geology 101 is to provide a basic knowledge of how the Earth works, the role of the geologist in contemporary society, and the application of geologic knowledge in solving real world problems. These are broad …

Petrogenesis Of The 91-Mile Peridotite In The Grand Canyon: Ophiolite Or Deep-Arc Fragment?, S. J. Seaman, M. L. Williams, K. E. Karlstrom, P. C. Low

Geosciences Department Faculty Publication Series

Recognition of fundamental tectonic boundaries has been extremely difficult in the (>1000-km-wide) Pro-tero-zoic accretionary orogen of south-western North America, where the main rock types are similar over large areas, and where the region has experienced multiple postaccretionary deformation events. Discrete ultramafic bodies are present in a number of areas that may mark important boundaries, especially if they can be shown to represent tectonic fragments of ophiolite complexes. However, most ultramafic bodies are small and intensely altered, precluding petrogenetic analysis. The 91-Mile peridotite in the Grand Canyon is the largest and best preserved ultramafic body known in the southwest United …

Crustal Evolution Of The New England Appalachians: The Rise And Fall Of A Long-Lived Orogenic Plateau, Ian Hillenbrand

Masters Theses

The rise and demise of mountain belts, caused by growth, modification, or removal of the continental lithosphere are fundamental processes that influence almost all Earth systems. Understanding the nature, timing, and significance of active processes in the creation and evolution of modern mountain belts is challenged by a lack of middle crustal and lower crustal exposures. Analogues can be found in ancient orogens, whose deeply eroded roots offer a window into deeper processes, yet this record is complicated by overprinting events and complex deformational histories. Research presented herein constrains the tectonic history of multistage Appalachian Orogen, type locality of the …

Magnetite Mineralization Of The Hammondville Pluton: Poly-Phase Kiruna Type Iocg Magnetite-Apatite Deposits In The Lyon Mountain Granite, Phillip Geer

Masters Theses

Recent mapping of the Eagle Lake Quadrangle, NY, coupled with whole-rock geochemistry and microscopy has offered insight into the petrogenesis of the magnetite-apatite deposits of the Hammondville mining district in the eastern Adirondack Mountains. This study provides insight into the magmatic history of the ca. 1060-1050 Ma Lyon Mountain Granite (Hammondville Pluton) which is intimately related to, and hosts the deposits in this area. Magnetite seams are commonly surrounded by well layered magnetite gneiss, which typically parallel the seams, although in some outcrops appear to be slightly truncated by them. Mineralization is generally concordant with the weak layering found throughout …

Implications And Significance Of Partial Melting On The Tectonic History Of The Eastern Adirondack Mountains, Claire Rose Pless

Doctoral Dissertations

The eastern Adirondack Mountains contain abundant exposures of high-grade metamorphic rocks. These exposures are interpreted to be a window into the mid/deep crust of an ancient, large, hot, long-duration orogen, allowing the Adirondack Mountains to be used as an analogue to the deep processes of modern orogens. Currently interpreted thermo-tectonic events in the eastern Adirondack Mountains include the ca. 1245-1220 Ma Elzevirian orogeny, the ca. 1190-1150 Ma Shawinigan orogeny, emplacement of the ca. 1150 Ma AMCG igneous suite, the ca. 1090-1050 Ma Ottawan orogeny, and a ca. 1050-1020 Ma extensional collapse phase. This dissertation focuses on six migmatite domains within …

3-D Shear Wave Velocity Structures Of The Crust And Upper Mantle Beneath Cascadia And New Zealand From Full-Wave Ambient Noise Tomography, Sampath Rathnayaka Mudiyanselage

Doctoral Dissertations

The (de)hydration process and the amount of hydrated sediment carried by the downgoing oceanic plate play a key role in the subduction dynamics. The deformation and (de)hydration of the downgoing tectonic plates, as well as the seismic, tsunami, volcanic hazards, in Cascadia and the New Zealand regions are not fully understood, partly due to a lack of combined studies of onshore and offshore data. In order to address these questions, we developed a 3-D high-resolution shear wave velocity model beneath Cascadia, the North and the South Islands of New Zealand, extending from offshore to onshore, with the use of full-wave …

Plio-Pleistocene Paleoceonography Of The Ross Sea, Antarctica Based On Foraminifera From Iodp Sites U1523, U1522, And U1521, Julia Seidenstein

Masters Theses

The West Antarctic Ice Sheet (WAIS) is currently thinning and retreating because shifting oceanic currents are transporting warmer waters to the ice margin, which could lead to a collapse of the ice sheet and global sea level rise. International Ocean Discovery Program (IODP) Expedition 374 sailed to the Ross Sea in 2018 to study the history of the WAIS over the last 20 million years. Previous geologic drilling projects into Ross Sea sediments that record the history of the WAIS (DSDP Leg 28, RISP, MSSTS, Cape Roberts Drilling Project, ANDRILL), as well as modeling studies, show considerable variability of ice-sheet …

Seeing Through The Ottawan Overprint, Adirondack Mtns., Ny: Integrating Microstructural Analysis, Geothermobarometry, And In-Situ Monazite Petrochronology, Justin Mistikawy

Masters Theses

Integrating field observation with petrochronology is critical for understanding the tectonometamorphic evolution of the North American Grenville Province. Despite methodological advances in geothermobarometry and geochronology, incorporating these data into larger models of the Adirondack Mountains remains particularly challenging due to the presence of multiple generations of deformation, primarily related to the ca. 1190 – 1140 Ma Shawinigan and ca. 1090 – 1020 Ma Ottawan Orogenies (McLelland et al.,2013). The Rock and Bear Ponds area is a dome of tight-to-isoclinally folded metapelites in structural contact with orthogneiss. Fold generations are orthogonal and partitioned such that the northern area is dominated by …

Threshold Processes And Stream Temperature Distribution In A Small New England Headwater Stream Catchment., Mitchell Isaacson

Masters Theses

Rising air temperature and decreasing stream flow trends are predicted to result in corresponding increases in stream temperatures. As a result, the future of ectothermic stream fishes, which rely on seasonal and spatial distributions of stream temperature for growth and survival, could be in jeopardy. Fortunately, contradicting stream temperature trends in forested headwater catchments suggest that non-climatic variables, such as baseflow indices and catchment geologic structure, may have an important confounding influence on the future of stream temperature. Most significantly, the annual stability of groundwater temperature has long been recognized as an important buffer between air and stream temperature. The …

Petrogenesis Of Basaltic Lavas In Iceland And The Springerville Volcanic Field, U.S.A.: The Influence Of Tectonic Setting, Depth Of Melting And Volatiles, Marissa Mnich

Doctoral Dissertations

Icelandic basalts were long thought to be low in water (e.g. Gunnarsson et al., 1998), but more recent studies suggest that hotspots, like the Iceland mantle plume, may be a source of hydrous basaltic melts (Nichols et al., 2002). To explore a possible link between location, volatile concentration and resulting petrogenetic implications, samples were collected from eleven volcanic centers throughout Iceland. Water concentrations were measured in melt inclusions and phenocrysts using Fourier transform infrared (FTIR) spectroscopy. Results for a subset of samples indicate variable water in melt inclusions ranging from approximately 50 ppm to over 3000 ppm. Samples from southwestern …

Numerical Modeling Of Deformation Within Restraining Bends And The Implications For The Seismic Hazard Of The San Gorgonio Pass Region, Southern California, Jennifer Hatch

Doctoral Dissertations

Assessment of seismic hazards in southern California may be improved with more accurate characterization of active geometry, stress state, and slip rates along the active San Andreas fault strands within the San Gorgonio Pass region. For example, on-going debate centers on the activity and geometry of the Mill Creek and Mission Creek strands. Calculated misfits of model slip rates to geologic slip rates for six alternative active fault configuration models through the San Gorgonio Pass reveal two best-fitting models, both of which fit many but not all available geologic slip rates. Disagreement between the model and geologic slip rates indicate …

In-Situ Zircon And Monazite Geochronology From Compositionally Distinct Layers In A Single Migmatitic Paragneiss Sample Located In The Eastern Adirondack Mountains, Ny, Kaitlyn Suarez

Masters Theses

Migmatites are a common rock type in the Adirondack Mountains, NY. We analyzed a single sample of biotite-garnet-sillimanite paragneiss with foliation parallel leucosome along Route 22 south of Whitehall, NY in order to determine the timing of melting using both in-situ monazite and zircon U/Pb geochronology from the restite and leucosome layers of the same rock. Monazite was analyzed via in-situ EMPA on the Ultrachron microprobe at the University of Massachusetts. Zircon was analyzed via LA-ICP-MS (in-situ and mounted mineral separates) at the LaserChron Center. Monazite analyses from the restite yielded six compositionally distinct populations with dates of 1178 ± …

Legacy Sediment Controls On Post-Glacial Beaches Of Massachusetts, Alycia Ditroia

Masters Theses

Here we examine seasonal grain-size trends on 18 beaches in the Northeastern US and dispersed along the post-glacial coast of Massachusetts (USA) in order to explore the mechanisms influencing median grain size and slope. Over 800 grain size samples were collected along 200 summer and winter cross-shore beach elevation surveys. Obtained grain size and beach slope data are compared to coastal morphology, sediment source, wave height, and tidal magnitude in order to ascertain controls on beach characteristics. In general, median grain size increases with intertidal beach slope in the study region. However, grain sizes along post-glaciated beaches in the study …

Introduction To Oceanography – Honors (Geol 103h), Isla Casteneda

Sustainability Education Resources

A general education course designed to acquaint you with the fascinating features of the nearly 71% of our home planet covered by water. These are broad themes that reflect the spirit and value of the general education curriculum that is a part of your UMass experience. As citizens of our small world, we would argue that everyone should take a course like this! With jet service to almost anywhere in the world, financial markets electronically and politically linked for “real time” transactions 24-7, and global populations striving to live as well as we do here in the U.S., it's important …

Accessible Science: The Natural History Of The Connecticut River Valley, Fred Venne

Science and Engineering Saturday Seminars

Many students take an Earth science or geology course to fulfill a requirement, knowing little to nothing about the field. Like all sciences, geology can appear to have ready answers unconnected to other areas of human endeavor, such as art, religion or philosophy. An interdisciplinary approach to teaching can ameliorate this perception for students who are intimidated by the subject and deepen understanding for those who are already excited about geology. We will examine two strategies designed to support the nature of science while scaffolding student learning in geology: research based digital resources use and museum of natural history visits. …

Evaluation Of The Erodibility Of Soft Clays And The Influence Of Biopolymers, Pamela Judge

Doctoral Dissertations

Erosion of silts and clays is less well understood than erosion of sands. Further, current and anticipated climate change impacts along coastlines compel consideration of new approaches to coastal protection measures; seawalls and breakwaters designs now include natural and nature-based measures. The first research topic consists of the Adaptive Gradients Framework which was a theoretically-informed facilitation tool. The framework was intended to aid a collaborative and interdisciplinary decision-making process to encourage inclusion of natural and nature-based measures in coastal protection planning and design. This research is the culmination of a series of workshops and fieldtrips executed by the Sustainable Adaptive …

Modeling Deformation Behavior And Strength Characteristics Of Sand-Silt Mixtures: A Micromechanical Approach, Mehrashk Meidani

Doctoral Dissertations

This dissertation is comprised of six chapters. In the first chapter the motivation of this research, which was modeling the deformation behavior and strength characteristics of soils under internal erosion, is briefly explained. In the second chapter a micromechanis-based stress-strain model developed for prediction of sand-silt mixtures behavior is presented. The components of the micromechanics-based model are described and undrained behavior of six different types of sand-silt mixtures is predicted for several samples with different fines contents. The need for a more comprehensive compression model for sand-silt mixtures is identified at the end of this chapter. This desired compression model …