Crystal fractionation and the sorting and transport of phenocrysts in magmatic bodies are fundamental processes driving the evolution and diversity of igneous rocks. The chemical diversity of igneous rocks has long been known and studied, but an understanding of the physical processes that drive such chemical evolution is also necessary. Episodic emplacement and filling regimes of intrusive magmatic bodies, analogous to episodic volcanic eruptive events, can leave a record of the magmatic system dynamics in the final distribution of an attendant phenocryst population. Phenocryst distribution profiles of multiply injected systems are here investigated, and features common to certain filling dynamics are established by coupling theories of particle settling in viscous flows with those of conductive cooling and solidification front advancement. Fourteen vertical and one horizontal sample profiles of the Ferrar Dolerites sill complex in the McMurdo Dry Valleys, Antarctica are analyzed in this work. Twelve of those sample profiles are from the Basement Sill, and were mostly gathered in the area of and near Bull Pass. The chemical and phenocryst profiles of all these sections are examined and reveal information about the emplacement dynamics of that system, particularly with respect to episodic filling and expansion via radial lobes. Experiments performed in the laboratory to create a physical analog model of a phenocryst-laden magmatic system also reveal information about the dynamics of emplacement of such magmatic bodies and the features that may exist in the record of phenocryst distribution.
|Advisor:||Marsh, Bruce D.|
|School:||The Johns Hopkins University|
|School Location:||United States -- Maryland|
|Source:||DAI-B 71/05, Dissertation Abstracts International|
|Keywords:||Antarctica, Basement Sill, Emplacement, McMurdo Dry Valleys, Phenocrysts, Slurries|
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