Saved in:
| Main Author: | |
|---|---|
| Format: | Artículo científico |
| Language: | en |
| Published: |
Universidad Nacional Autónoma de México
2006
|
| Subjects: | |
| Online Access: | https://www.redalyc.org/articulo.oa?id=56845205 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
Table of Contents:
- Cooling rate effects on the magnetization of volcanic rocks: Some implications for paleointensity determination Juan Morales Avto Goguitchaichvili Jaime Urrutia-Fucugauchi Ciencias de la Tierra Cooling rate paleointensity volcanic rocks rock magnetism Effects of variation of cooling rate in the acquisition of thermoremanent magnetization (TRM) are analyzed on a suite ofvolcanic rocks. We use a three-step cooling rate experimental procedure applied at three distinct temperatures of TRM acquisition.Sixteen selected, thermally stable samples from Late Quaternary lava flows were given a pTRM (300°C) at a slow cooling rate.The acquired intensities were measured at room temperature. A second pTRM was applied to the same specimens using a fastcooling rate, and the acquired intensities were measured at room temperature. Finally a third pTRM was induced as in the firststep, using a slow cooling rate. The procedure was repeated to create pTRMs at higher temperatures of 450° and 550°C.Corresponding percent variations between magnetization intensities acquired at slow-fast and at slow-slow cooling rates werecalculated to investigate the influence of cooling rate on TRM intensity acquisition, and on TRM acquisition capacity. Weobserve values as high as 300 % in the former case (300 °C). Intensity of the ancient geomagnetic field obtained from volcanicrocks could be overestimated by at least 15% due to a variation in cooling rate normally employed in the laboratory, as comparedto slower rates found in nature. 2006 artículo científico 0016-7169 https://www.redalyc.org/articulo.oa?id=56845205 en http://www.redalyc.org/revista.oa?id=568 Geofísica Internacional application/pdf Universidad Nacional Autónoma de México Geofísica Internacional (México) Num.2 Vol.45