Ground Penetrating Radar Surveying and Sediment Coring Analysis of a Post-glacial Lake, Eastern Newfoundland

Ground Penetrating Radar Surveying and Sediment Coring Analysis of a Post-glacial Lake, Eastern Newfoundland
Author: Jianguang Chen
Publisher:
Total Pages:
Release: 2018
Genre:
ISBN:

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Ground penetrating radar (GPR) is a relatively newly developed high-frequency electromagnetic technique that has been widely used in the shallow subsurface investigation for the last few decades. Recently, a GPR survey of a small organic-rich post-glacial lake (Grassy Pond) in Eastern Newfoundland shows significant continuous laminations within the lake sediments in the GPR profiles. Since there have been very few GPR stratigraphy studies of lacustrine sediments, the main focus of this project is on the correlation between the sediment stratigraphy and the GPR sub-bottom profiles. Secondary interests are: to estimate the carbon content of a typical small inland lake to help assess how such bodies have contributed to the carbon budget since the last glaciation; and to investigate chemical variability within the sediments. The work in this project includes GPR surveying, sediment coring, and sediment physical, geochemical and chronostratigraphic data acquisition, calibration and correlation. First of all, 50 and 100 MHz GPR surveys were completed on Grassy Pond when the lake surface was frozen in the winter. Bathymetric and depth-to-bedrock maps were created from the GPR profiles. Based on these two maps, a sediment distribution map was also created and this was used to choose sediment coring locations. Four sediment cores were collected by using a rod-driven piston corer, and additional GPR profiles were collected over these core locations. The cores were then scanned by a Multi-Sensor Core Logger (MSCL) to determine the physical properties. After that, the cores were sub-sampled and geochemically analyzed by ICP-OES. Selected sediment samples were also analyzed for C and N contents and isotopes, and radiocarbon dated. Lastly, the linkage was made between the geophysical and geochemical data, and a simple GPR forward model was created based on the sediment physical properties to enhance the data interpretation and correlation. The results show that the lake sediments of Grassy Pond are highly-organic and water-rich. Forward models of EM wave reflections show that the laminated GPR reflections within the sediments are caused by variations in water content. The geochemical analysis shows that the water content is anti-correlated to the lithic elemental concentrations. Since the lithic inputs can reflect past climate changes, we suggest that paleoclimatic changes may ultimately be responsible for the laminations seen in the GPR profiles. The carbon budge of Grassy Pond is calculated based on the sediment volume and average carbon content of the sediments, and it is estimated as 29 kg/m2, which is significantly higher than forest soils. Besides these major results, one of our basal sediment samples is dated back to 8.6 radiocarbon years ago, which corresponds to the end of last glaciation in the same region of Newfoundland. The sediments of Grassy Pond are found to be highly enriched in arsenic (As) and molybdenum (Mo), likely associated with the erosion of iron oxide minerals in the surrounding land, as Grassy Pond overlies the alteration zone of a gold prospect. In the deepest sediment core, many elements show a concentration peak near 6.3k years ago when the regional climate started to become drier, and erosion rates increased.

Gravity Surveying, Potential-field Modeling, and Structural Mapping and Analysis of the Howley Basin, Western Newfoundland

Gravity Surveying, Potential-field Modeling, and Structural Mapping and Analysis of the Howley Basin, Western Newfoundland
Author: Linden Ernst
Publisher:
Total Pages:
Release: 2018
Genre:
ISBN:

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The northeast trending Cabot Fault transects western Newfoundland. Early Carboniferous, possibly late Devonian, activation and continued strike-slip movement throughout the late Paleozoic has led to the deposition of non-marine, fluvial and lacustrine facies, in an isolated sedimentary basin in western Newfoundland, the Deer Lake Basin. The Howley Basin is the northeast depocenter within the Deer Lake Basin. It is separated from the Humber Basin depocenter to the west by a northeast trending, elongated ridge of inverted older Carboniferous sedimentary units. Active oil seeps, bitumen in shallow drill core, organic rich lacustrine shales and mudstones, porous sandstones, and a large negative gravity signal over the Howley Basin make it an attractive hydrocarbon exploration target. Poor exposure, limited shallow drilling along the margins, and a lack of high-resolution geophysics leaves much of the Howley Basin's internal stratigraphy and structure unknown. Integration of potential-field geophysics and detailed structural mapping and analysis is used to asses the Howley Basin's structure and hydrocarbon potential. A large lake overlies most of the Howley Basin. Full coverage of gravity surveying required acquisition of gravity stations over the lake. A Ground Penetrating Radar was used in conjunction with the gravity survey to determine the bathymetry of the lake and was used to remove the anomalous mass of the water column in the complete Bouguer gravity anomaly. Gravity data collected in this study was combined with reprocessed pre-existing gravity datasets. A high-resolution aeromagnetic survey and the gravity data was used to model the Howley Basin. Interpretations show that the basin forms an asymmetric half-graben deepening to the east, reaching a depth of 4.3 km, well into the predicted oil window. Structural mapping of the Howley Basin revealed that the basin has been affected by episodes of transtension and transpression throughout the Carboniferous and likely continuing into the Permian. Hydrocarbon maturation is predicted to have peaked in the late Pennsylvanian to early Permian. Late-stage transpressional inversion of the Howley Basin is interpreted to have been focused on its margins, potentially creating large wavelength structural traps in the center of the basin.

Spring Meeting

Spring Meeting
Author: American Geophysical Union. Meeting
Publisher:
Total Pages: 420
Release: 2002
Genre: Geophysics
ISBN:

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Limnogeology: Progress, Challenges and Opportunities

Limnogeology: Progress, Challenges and Opportunities
Author: Michael R. Rosen
Publisher: Springer Nature
Total Pages: 592
Release: 2021-04-24
Genre: Science
ISBN: 3030665763

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This book honors the career of Professor Elizabeth Gierlowski-Kordesch who was a pioneer and leader in the field of limnogeology since the 1980s. Her work was instrumental in guiding students and professionals in the field until her untimely death in 2016. This collection of chapters was written by her colleagues and students and recognize the important role that Professor Gierlowski-Kordesch had in advancing the field of limnogeology. The chapters show the breadth of her reach as these have been contributed from virtually every continent. This book will be a primary reference for scientists, professionals and graduate students who are interested in the latest advances in limnogeologic processes and basin descriptions in North and South America, Europe, Africa, and China. *Free supplementary material available online for chapters 3,11,12 and 13. Access by searching for the book on link.springer.com

Ground Penetrating Radar Theory and Applications

Ground Penetrating Radar Theory and Applications
Author: Harry M. Jol
Publisher: Elsevier
Total Pages: 545
Release: 2008-12-08
Genre: Science
ISBN: 0080951848

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Ground-penetrating radar (GPR) is a rapidly developing field that has seen tremendous progress over the past 15 years. The development of GPR spans aspects of geophysical science, technology, and a wide range of scientific and engineering applications. It is the breadth of applications that has made GPR such a valuable tool in the geophysical consulting and geotechnical engineering industries, has lead to its rapid development, and inspired new areas of research in academia. The topic of GPR has gone from not even being mentioned in geophysical texts ten years ago to being the focus of hundreds of research papers and special issues of journals dedicated to the topic. The explosion of primary literature devoted to GPR technology, theory and applications, has lead to a strong demand for an up-to-date synthesis and overview of this rapidly developing field. Because there are specifics in the utilization of GPR for different applications, a review of the current state of development of the applications along with the fundamental theory is required. This book will provide sufficient detail to allow both practitioners and newcomers to the area of GPR to use it as a handbook and primary research reference. *Review of GPR theory and applications by leaders in the field*Up-to-date information and references*Effective handbook and primary research reference for both experienced practitioners and newcomers

Long-term Environmental Change in Arctic and Antarctic Lakes

Long-term Environmental Change in Arctic and Antarctic Lakes
Author: Reinhard Pienitz
Publisher: Springer Science & Business Media
Total Pages: 579
Release: 2005-05-03
Genre: Science
ISBN: 1402021259

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Concerns about the effects of global climate change have focused attention on the vulnerability of circumpolar regions. This book offers a synthesis of the spectrum of techniques available for generating long-term environmental records from circumpolar lakes.

CRREL Bibliography

CRREL Bibliography
Author:
Publisher:
Total Pages: 656
Release: 1998
Genre: Cold regions
ISBN:

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