Earth Sciences Commons^™

Measuring The Rate Of Garnet Growth: Implications For Rb-Sr Garnet Chronology, Jessica Sousa

Boise State University Theses and Dissertations

Garnet growth rates have provided valuable information for understanding the rates of tectonometamorphic processes. In theory, during its growth, garnet records the decay of 87Rb within a rock matrix as steadily increasing ⁸⁷Sr/⁸⁶Sr from core to rim. By measuring the Sr isotopic zoning within garnet and matrix Rb/Sr and ⁸⁷Sr/⁸⁶Sr, the rate of garnet growth can be determined. To test this, we used ID-TIMS to measure Rb-Sr data for five samples from three major orogenic belts: central New England, southernmost Chile, and western Italian Alps. These new data introduce two major difficulties encountered using …