Department
Geosciences and Geological and Petroleum Engineering
Major
Geology/Geophysics
Research Advisor
Hogan, John P.
Advisor's Department
Geosciences and Geological and Petroleum Engineering
Funding Source
Missouri S& T Opportunities for Undergraduate Research Experiences (OURE) Program
Abstract
An Ovoid K-feldspar mantled by Na-feldspar is called rapakivi. Rapakivi may form either by (1) decompression during ascent of felsic magma through the crust to a shallow magma chamber or by (2) mixing of mafic- and felsic-magma within a magma chamber. We suggest that feldspar compositions may be used to distinguish between these two models. Rapakivi formed during decompression should have similar compositions. Conversely, if rapakivi have variable compositions this suggests variable interaction with compositionally unique magma at different times during crystallization. Cores and mantles of rapakivi feldspars from the Deer Isle Pluton, Maine were sampled using a 213 nm laser and analyzed using Inductively Coupled Plasma- Mass Spectrometry to determine differences (ppm) in trace element abundances, specifically barium. In a preliminary analysis of the data, it seemed that the barium content varied little in each of the facies. Yet, patterns across the pluton were recognizable.
Biography
Jason Kaiser is a senior at the Missouri University of Science & Technology majoring in geology. He is the son of Alan and Darcy Kaiser of DeSoto. He is the president of the geological sciences honor society at Missouri S& T, as well as a member of other local and national geological organizations. Jason was recently accepted to the master's program at the University of Massachusetts, Amherst, where he plans to study igneous petrology before pursuing a Ph.D. in volcanology.
Research Category
Natural Sciences
Presentation Type
Poster Presentation
Document Type
Poster
Location
Havener Center, Upper Atrium/Hallway
Presentation Date
9 Apr 2008, 1:00 pm - 3:00 pm
Using Laser Ablation ICP-MS to Constrain the Origin of the Rapakivi Texture of the Deer Isle Pluton, Maine
Havener Center, Upper Atrium/Hallway
An Ovoid K-feldspar mantled by Na-feldspar is called rapakivi. Rapakivi may form either by (1) decompression during ascent of felsic magma through the crust to a shallow magma chamber or by (2) mixing of mafic- and felsic-magma within a magma chamber. We suggest that feldspar compositions may be used to distinguish between these two models. Rapakivi formed during decompression should have similar compositions. Conversely, if rapakivi have variable compositions this suggests variable interaction with compositionally unique magma at different times during crystallization. Cores and mantles of rapakivi feldspars from the Deer Isle Pluton, Maine were sampled using a 213 nm laser and analyzed using Inductively Coupled Plasma- Mass Spectrometry to determine differences (ppm) in trace element abundances, specifically barium. In a preliminary analysis of the data, it seemed that the barium content varied little in each of the facies. Yet, patterns across the pluton were recognizable.
