Show simple item record

dc.contributor.authorMcGregor, Heath Andrew
dc.date.accessioned2014-03-04T18:28:56Z
dc.date.available2014-03-04T18:28:56Z
dc.date.issued2010-05
dc.identifier.othermcgregor_heath_a_201005_ms
dc.identifier.urihttp://purl.galileo.usg.edu/uga_etd/mcgregor_heath_a_201005_ms
dc.identifier.urihttp://hdl.handle.net/10724/26418
dc.description.abstractAlkaline lamprophyre rocks crop out as sills and sub parallel dikes near the Spanish Peaks, CO. Lamprophyre dikes and sills north, south, and west of Spanish Peaks are moderately mafic (~7 wt.% MgO), basic (~49 wt.% SiO2 ), and range from relatively sodic (Na2O>K2O) to relatively potassic (K2O>Na2O). Previous geochronologic and isotopic research on rocks investigated in this study, indicate that sodic and potassic magmatism originated at approximately the same time and from isotopically similar mantle sources. Rock types include minettes and sannaites, which have phlogopite or amphibole ± clinopyroxene ± olivine phenocrysts and groundmass potassium feldspars. Rare diopside grains in potassic rocks have greenish, Fe- and Al-rich cores found worldwide in other potassium-rich, mafic igneous rocks. Major and trace element abundance data from this study indicate that the two magma series formed independently from distinct sources.
dc.languageeng
dc.publisheruga
dc.rightspublic
dc.subjectSpanish Peaks
dc.subjectalkaline lamprophyre
dc.subjectsodic rocks
dc.subjectpotassic rocks
dc.subjectmajor element abundances
dc.subjecttrace element abundances
dc.subjectminettes
dc.subjectsannaites
dc.subjectRio Grande Rift
dc.subjectmantle metasomatism
dc.subjectphlogopite
dc.subjectamphibole
dc.titlePetrogenetic realtionships between relatively potassic and relatively sodic alkaline rocks from the Spanish Peaks area near Walsenburg, Colorado
dc.typeThesis
dc.description.degreeMS
dc.description.departmentGeology
dc.description.majorGeology
dc.description.advisorMichael Roden
dc.description.committeeMichael Roden
dc.description.committeeAlberto Patino-Douce
dc.description.committeeDouglas Crowe


Files in this item

FilesSizeFormatView

There are no files associated with this item.

This item appears in the following Collection(s)

Show simple item record