Geochemical analysis of silica and travertine hydrothermal precipitates at the Cerro Machín volcanic system
The dacitic Cerro Machin Volcano, associated with bicarbonate waters, resides within the Tolima department of the Colombian Republic. At this system, two types of precipitates were identified through the study of three epithermal, and possibly low-sulphidation, localities. The locality of Puente Tie...
- Autores:
-
Horkley Jiménez, Nicholas
- Tipo de recurso:
- Trabajo de grado de pregrado
- Fecha de publicación:
- 2024
- Institución:
- Universidad de los Andes
- Repositorio:
- Séneca: repositorio Uniandes
- Idioma:
- eng
- OAI Identifier:
- oai:repositorio.uniandes.edu.co:1992/74445
- Acceso en línea:
- https://hdl.handle.net/1992/74445
- Palabra clave:
- Epithermal
Low sulphidation system
Sinter silica
Travertine
Arsenic
Cerro Machín
Geociencias
- Rights
- openAccess
- License
- Attribution-NonCommercial-NoDerivatives 4.0 International
| Summary: | The dacitic Cerro Machin Volcano, associated with bicarbonate waters, resides within the Tolima department of the Colombian Republic. At this system, two types of precipitates were identified through the study of three epithermal, and possibly low-sulphidation, localities. The locality of Puente Tierra consists predominantly of carbonate deposits with aragonite as the main mineral. In contrast, the locality of Aguas Calientes lacks significant carbonate deposits, but is dominated instead by amorphous silica. The third locality, Estalagmitas, can be characterized by a mix between the two other localities, because it is dominated by amorphous silica and carbonates in the form of calcite. To further understand the genesis of such deposits, the elemental composition of the hot springs has been analysed by inductively coupled mass spectrometry (ICP-MS). Complementary to this, the elemental composition of the hot spring deposits has been analysed by x-ray fluorescence (XRF). Initial results show that the physical parameters and elemental compositions of the hot springs can be used to understand the processes that form silica and travertine deposits. This study further shows that the carbonate deposits at Puente Tierra might also incorporate As through an arsenate replacement of the carbonate ion. Furthermore, by using the Giggenbach diagram, it was possible to estimate the reservoir temperature (160°C – 180°C) of the hydrothermal system at the CMV. This potentially implies cooling of the deep reservoir over a period of 42 years. Finally, the results from this research project could be useful to study the microbial biofilms observed growing on the sides of the precipitates. |
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