Abstract
Measurements of susceptibility as a function of temperature are an important, standard method of quantifying a sample's magnetic mineralogy. These measurements are used to identify the Curie/Néel temperatures of constituent minerals and show evidence of thermally induced oxidation and formation of magnetic minerals. For these reasons, the High Temperature Susceptibility Bridge (HTSB) is a common instrument in paleomagnetism laboratories around the world. Here, we argue that HTSBs can be used to perform simple differential thermal analysis, a technique used to identify phase transitions and exo-/endothermic reactions by measuring deviations in temperature from a steady heating rate. Because HTSBs are designed to heat samples at a relatively constant rate, the standard susceptibility measurement can be used to obtain similar information, albeit crude, about the phase transitions taking place. For standard samples of vivianite, goethite, and maghemite, we compare the heating curves of the sample and a blank run, to identify DTA-analogous information. In the case of goethite and vivianite, the reactions identified do not have a corresponding expression in susceptibility, demonstrating that this approach expands the utility of this common piece of equipment. We estimate the minimum enthalpy of reactions detectable and their mass dependence. Additionally, we show that this approach is successful in detecting the dehydration of vivianite in a mixed mineralogy natural sample.
| Original language | English (US) |
|---|---|
| Article number | e2021JB023789 |
| Journal | Journal of Geophysical Research: Solid Earth |
| Volume | 127 |
| Issue number | 7 |
| DOIs | |
| State | Published - Jul 2022 |
Bibliographical note
Funding Information:This is Institute for Rock Magnetism (IRM) publication #2109. Part of this work was performed at the IRM at the University of Minnesota. The IRM is a US National Multi‐user Facility supported through the Instrumentation and Facilities program of the National Science Foundation, Earth Sciences Division, and by funding from the University of Minnesota. The authors express gratitude to Brian Spindler and Andreas Stein for use of and help with the DSC, to Mark Shapley at LacCore for the natural vivianite samples, to Peat Solheid and Mike Jackson for their insight into the HTSBs, and Bruce Moskowitz, Erwin Appel, and Liao Chang for feedback and comments that improved original versions of the manuscript. And finally, this research was made possible by the Subir Banerjee fellowship and the V. R. Murthy/Janice Noruk fellowship for women through the Department of Earth & Environmental Sciences at the University of Minnesota. The University of Minnesota is built on the ancestral lands of the Wahpekute band that was ceded to the United States by the Treaty of Traverse des Sioux in July of 1851, in an agreement that was not paid in full and whose underlying aim was the dissolution of the Dakota culture. The University has also benefited from Chippewa and Dakota (Medewakanton, Wahpekuta, Wahpeton, and Sisseton Bands) land ceded by treaty and given to the University of Minnesota via the Morrill Act.
Funding Information:
This is Institute for Rock Magnetism (IRM) publication #2109. Part of this work was performed at the IRM at the University of Minnesota. The IRM is a US National Multi-user Facility supported through the Instrumentation and Facilities program of the National Science Foundation, Earth Sciences Division, and by funding from the University of Minnesota. The authors express gratitude to Brian Spindler and Andreas Stein for use of and help with the DSC, to Mark Shapley at LacCore for the natural vivianite samples, to Peat Solheid and Mike Jackson for their insight into the HTSBs, and Bruce Moskowitz, Erwin Appel, and Liao Chang for feedback and comments that improved original versions of the manuscript. And finally, this research was made possible by the Subir Banerjee fellowship and the V. R. Murthy/Janice Noruk fellowship for women through the Department of Earth & Environmental Sciences at the University of Minnesota. The University of Minnesota is built on the ancestral lands of the Wahpekute band that was ceded to the United States by the Treaty of Traverse des Sioux in July of 1851, in an agreement that was not paid in full and whose underlying aim was the dissolution of the Dakota culture. The University has also benefited from Chippewa and Dakota (Medewakanton, Wahpekuta, Wahpeton, and Sisseton Bands) land ceded by treaty and given to the University of Minnesota via the Morrill Act.
Publisher Copyright:
© 2022 The Authors.
Keywords
- differential thermal analysis
- high temperature susceptibility bridge
- magnetic minerals
Continental Scientific Drilling Facility tags
- HERD