Disentangling sediment source from sediment transport is a fundamental marine geologic challenge critical to the interpretation of any sedimentary record. The Eirik Ridge, a sediment drift south of Greenland, receives terrigenous sediment primarily from subglacial erosion of south Greenland’s Precambrian bedrock and Paleogene volcanics that outcrop in east Greenland and...
Stratigraphy and chronology are essential to sedimentological study of Earth system histories. And, stratigraphy and chronology are often challenging and interesting problems themselves. The Quaternary (2.588 Ma - present) experienced paleoenvironmental and paleo-geomagnetic variability well outside the range of the recent instrumental record, providing the opportunity to place recent observations...
This research presents a u-channel based study of the natural remanent magnetization (NRM), the laboratory magnetization, Anhysteretic Remanent Magnetization (ARM), and magnetic susceptibility (k), from the upper 100 m of International Ocean Discovery Program (IODP) Expedition 383 Site U1543 in the eastern South Pacific sector of the Southern Ocean. Alternating...
Sedimentary records from the North Atlantic, instrumental in the development of modern paleo-geomagnetic concepts, show a highly variable field even during times of constant polarity. Yet, our understanding of how the magnetization is acquired in the sediments is poorly understood. Primary magnetizations preserved in deep-sea sediments are known to be...
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Joseph S. Stoner
Sedimentary records from the North Atlantic, instrumental in the
Around 74 ka, a supervolcano, Toba Caldera in Sumatra, Indonesia erupted, producing the Youngest Toba Tuff and its associated caldera. After this catastrophic eruption, a lake filled the caldera, sedimentation within the lake occurred, and the process known as resurgence began. Today, the resurgent dome, Samosir Island, is uplifted 700...
The deglacial behavior of the sub-Arctic North Pacific is poorly constrained, with many published records suffering from limited age control due to extensive post- depositional biogenic carbonate dissolution. Potential alternative dating methods could include the correlation of stable-isotopic and/or paleomagnetic secular variation records to an independently-dated regional template, however no...
This dissertation presents results from three studies that address major scientific questions in glacial geology and paleoclimatology for the late Pleistocene and Holocene using relatively new geochemical and statistical techniques. Each of the studies attempts to answer a longstanding question in the respective field using geochemical or statistical methods that...
Sediment cores were retrieved from a landslide-dammed lake, recording events back to the 5th century AD in a forested, mountainous catchment. These cores provide an opportunity to compare the impacts of known recent perturbations, including floods and timber harvesting with those of the early period of the core, flood, fire,...
The production of carbon and export to deep ocean sediments is linked to carbon partitioning between the ocean and atmosphere and is a key driver of climate change over the glacial-interglacial transition. Yet conflicting reconstructions create barriers to understanding changes to the carbon system over this important climate transition. Production...
Recruitment of larvae from the plankton is an important determinant of
community structure in marine systems. In populations of many marine species,
recruitment determines the basic demographic parameters of immigration, emigration,
and reproduction. Moreover, the effect of recruitment as an "ecological subsidy" can
determine the strength of interactions among species...