Feathery and network-like filamentous textures as indicators for the re-crystallization of quartz from a metastable silica precursor at the Rusey Fault Zone, Cornwall, UK
Hydrothermal quartz crystals, which occur in the Rusey Fault Zone (Cornwall, UK), show feathery textures and network-like filamentous textures. Optical hot-cathodoluminescence (CL) analysis and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) investigations on quartz samples r...
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2016-11-01
|
| Series: | Solid Earth |
| Online Access: | http://www.solid-earth.net/7/1509/2016/se-7-1509-2016.pdf |
| Summary: | Hydrothermal quartz crystals, which occur in the Rusey Fault Zone (Cornwall,
UK), show feathery textures and network-like filamentous textures. Optical
hot-cathodoluminescence (CL) analysis and laser ablation inductively coupled
plasma mass spectrometry (LA-ICP-MS) investigations on quartz samples
revealed that positions exhibiting feathery textures (violet luminescence)
contain higher amounts of Al and Li than quartz positions without feathery
textures (blue luminescence), while concentrations of Al and Li are
significantly lower in feathery textures. Both Al and Li correlate negatively
with Si. Raman spectroscopy investigations revealed the presence of a weak
peak at 507–509 cm<sup>−1</sup> in quartz affected by feathery textures, which we
attribute to the presence of ≤ 5 % moganite, a microcrystalline
silica polymorph, intergrown with chalcedony. The combined occurrence of
feathery textures and network-like filamentous textures in quartz samples
from the Rusey Fault Zone points to the presence of a metastable silica
precursor (i.e., amorphous silica or silica gel) before or during the
crystallization. |
|---|---|
| ISSN: | 1869-9510 1869-9529 |