Delamination has been invoked to explain Pliocene (3.5 Ma) magmatic activity in the central and southern Sierra Nevada Range (SNR). However, the extent and timing of proposed delamination is unknown. By examining volcanic rocks of a similar age in the northern SNR the extent of delamination can be further characterized. Alternatively, Pliocene magmatism in the northern SNR could be a result of subduction, making the area part of an ancestral Cascade Range. The Mendocino Triple Junction was located just south of Lake Tahoe at the time of eruption of Pliocene magmatism in the northern part of the range. Although the geochemical and isotopic compositions of the samples from the northern SNR are closely related to Cascade magmatism the differences include: higher K2O and lower MgO and CaO at a given value of SiO 2, a restricted range of SiO2, and two distinct magmatic events at 4 and 11 Ma.
|Advisor:||Glazner, Allen F.|
|Commitee:||Barnes, Jason B., Coleman, Drew S.|
|School:||The University of North Carolina at Chapel Hill|
|School Location:||United States -- North Carolina|
|Source:||MAI 50/02M, Masters Abstracts International|
|Keywords:||Delamination, Pliocene magmatism, Sierra Nevada Range|
Copyright in each Dissertation and Thesis is retained by the author. All Rights Reserved
The supplemental file or files you are about to download were provided to ProQuest by the author as part of a
dissertation or thesis. The supplemental files are provided "AS IS" without warranty. ProQuest is not responsible for the
content, format or impact on the supplemental file(s) on our system. in some cases, the file type may be unknown or
may be a .exe file. We recommend caution as you open such files.
Copyright of the original materials contained in the supplemental file is retained by the author and your access to the
supplemental files is subject to the ProQuest Terms and Conditions of use.
Depending on the size of the file(s) you are downloading, the system may take some time to download them. Please be