Graduate Thesis Or Dissertation
 

Data.zip

Public Deposited
No preview available

Download the file

https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/41687n65w

Descriptions

Attribute NameValues
Creator
Abstract
  • Solid phases that form under the influence of changing environmental conditions often record such changes in their chemical composition. Quantification of these compositional variations is invaluable in reconstructing paleoenvironmental changes. Laser ablation, employed as a solid sample introduction system, offers fine spatial resolution (50 - 250 [mu]m) for spectroscopic analysis of solid samples. When used in conjunction with an inductively coupled plasma-mass spectrometer (ICP-MS), the analysis is capable of high sensitivity, low detection limits, and low background. Here we present protocols for using infrared LA ICP-MS for the analysis of ferromanganese oxyhydroxide crusts for the purpose of elucidating records of environmental changes contained within these matrices. The dependence of data quality on proper matrix-matching of standards and normalization of instrumental response is addressed, and examples of environmental inferences from our observations are presented. LA ICP-MS analysis was applied to a study of ferromanganese crusts. Ferromanganese oxyhydroxide phases have been the subject of a number of paleoceanographic studies because they function as recorders of surrounding seawater conditions over periods of millions of years. Changes in interelemental relationships within the layered ferromanganese oxyhydroxide matrix can help elucidate changes in environmental conditions such as the degree of oxia, relative water depth, and hydrothermal or diagenetic influence. Submersible cruises have recovered a large number of ferromanganese crusts and nodules from the Mendocino Ridge. The Mendocino Ridge has a complex geological history. This major topographic feature, extending 3000 km westward from the California coast, was once at sea level, but has been subsiding for the past 5.5 to 8 million years. This work presents background information about the Mendocino Ridge, reviews paleoceanographic literature related to manganese nodules and crusts, presents hypotheses about geochemical records present in Mendocino Ridge manganese nodules and crusts, examines a number of geochemical proxies and their relevance to Mendocino Ridge manganese deposits, and discusses the results of these investigations.
Rights Statement

Relationships

Parents:

Items

Thumbnail Title Date Uploaded Visibility Actions
file details Data.zip 2017-10-25 Public Download