Water release and homogenization by dynamic recrystallization of quartz
<p>To evaluate changes in water distribution generated by dynamic recrystallization of quartz, we performed infrared (IR) spectroscopy mapping of quartz in deformed granite from the Wariyama uplift zone in NE Japan. We analyzed three granite samples with different degrees of deformation: almos...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2023-04-01
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| Series: | Solid Earth |
| Online Access: | https://se.copernicus.org/articles/14/409/2023/se-14-409-2023.pdf |
| _version_ | 1797844293492146176 |
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| author | J. Fukuda T. Okudaira Y. Ohtomo |
| author_facet | J. Fukuda T. Okudaira Y. Ohtomo |
| author_sort | J. Fukuda |
| collection | DOAJ |
| description | <p>To evaluate changes in water distribution generated by
dynamic recrystallization of quartz, we performed infrared (IR) spectroscopy
mapping of quartz in deformed granite from the Wariyama uplift zone in NE
Japan. We analyzed three granite samples with different degrees of
deformation: almost undeformed, weakly deformed, and strongly deformed.
Dynamically recrystallized quartz grains with a grain size of
<span class="inline-formula">∼10</span> <span class="inline-formula">µ</span>m are found in these three samples, but the
percentages of recrystallized grains and the recrystallization processes are
different. Quartz in the almost-undeformed sample shows wavy grain
boundaries, with a few bulged quartz grains. In the weakly deformed sample,
bulging of quartz, which consumed adjacent host quartz grains, forms regions
of a few hundred micrometers. In the strongly deformed sample, almost all
quartz grains are recrystallized by subgrain rotation. IR spectra of quartz
in the three samples commonly show a broad water band owing to H<span class="inline-formula"><sub>2</sub></span>O
fluid at 2800–3750 cm<span class="inline-formula"><sup>−1</sup></span>, with no structural OH bands. Water contents in
host quartz grains in the almost-undeformed sample are in the range of
40–1750 wt ppm, with a mean of <span class="inline-formula">500±280</span> wt ppm H<span class="inline-formula"><sub>2</sub></span>O. On the
other hand, water contents in regions of recrystallized grains, regardless
of the recrystallization processes involved, are in the range of 100–510 wt ppm, with a mean of <span class="inline-formula">220±70</span> wt ppm; these values are low and
homogeneous compared with the contents in host quartz grains. These low water
contents in recrystallized regions also contrast with those of up to 1540 wt ppm in adjacent host grains in the weakly deformed sample. Water
contents in regions of subgrains are intermediate between those in host and
recrystallized grains. These results for water distribution in quartz imply
that water was released by dynamic recrystallization.</p> |
| first_indexed | 2024-04-09T17:19:57Z |
| format | Article |
| id | doaj.art-e0cecf9602b043ca897dc26fd74613f2 |
| institution | Directory Open Access Journal |
| issn | 1869-9510 1869-9529 |
| language | English |
| last_indexed | 2024-04-09T17:19:57Z |
| publishDate | 2023-04-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Solid Earth |
| spelling | doaj.art-e0cecf9602b043ca897dc26fd74613f22023-04-19T05:22:11ZengCopernicus PublicationsSolid Earth1869-95101869-95292023-04-011440942410.5194/se-14-409-2023Water release and homogenization by dynamic recrystallization of quartzJ. Fukuda0T. Okudaira1Y. Ohtomo2Department of Geosciences, Osaka Metropolitan University, Osaka, 558-8585, JapanDepartment of Geosciences, Osaka Metropolitan University, Osaka, 558-8585, JapanDepartment of Education, Art and Science, Yamagata University, Yamagata, 990-8560, Japan<p>To evaluate changes in water distribution generated by dynamic recrystallization of quartz, we performed infrared (IR) spectroscopy mapping of quartz in deformed granite from the Wariyama uplift zone in NE Japan. We analyzed three granite samples with different degrees of deformation: almost undeformed, weakly deformed, and strongly deformed. Dynamically recrystallized quartz grains with a grain size of <span class="inline-formula">∼10</span> <span class="inline-formula">µ</span>m are found in these three samples, but the percentages of recrystallized grains and the recrystallization processes are different. Quartz in the almost-undeformed sample shows wavy grain boundaries, with a few bulged quartz grains. In the weakly deformed sample, bulging of quartz, which consumed adjacent host quartz grains, forms regions of a few hundred micrometers. In the strongly deformed sample, almost all quartz grains are recrystallized by subgrain rotation. IR spectra of quartz in the three samples commonly show a broad water band owing to H<span class="inline-formula"><sub>2</sub></span>O fluid at 2800–3750 cm<span class="inline-formula"><sup>−1</sup></span>, with no structural OH bands. Water contents in host quartz grains in the almost-undeformed sample are in the range of 40–1750 wt ppm, with a mean of <span class="inline-formula">500±280</span> wt ppm H<span class="inline-formula"><sub>2</sub></span>O. On the other hand, water contents in regions of recrystallized grains, regardless of the recrystallization processes involved, are in the range of 100–510 wt ppm, with a mean of <span class="inline-formula">220±70</span> wt ppm; these values are low and homogeneous compared with the contents in host quartz grains. These low water contents in recrystallized regions also contrast with those of up to 1540 wt ppm in adjacent host grains in the weakly deformed sample. Water contents in regions of subgrains are intermediate between those in host and recrystallized grains. These results for water distribution in quartz imply that water was released by dynamic recrystallization.</p>https://se.copernicus.org/articles/14/409/2023/se-14-409-2023.pdf |
| spellingShingle | J. Fukuda T. Okudaira Y. Ohtomo Water release and homogenization by dynamic recrystallization of quartz Solid Earth |
| title | Water release and homogenization by dynamic recrystallization of quartz |
| title_full | Water release and homogenization by dynamic recrystallization of quartz |
| title_fullStr | Water release and homogenization by dynamic recrystallization of quartz |
| title_full_unstemmed | Water release and homogenization by dynamic recrystallization of quartz |
| title_short | Water release and homogenization by dynamic recrystallization of quartz |
| title_sort | water release and homogenization by dynamic recrystallization of quartz |
| url | https://se.copernicus.org/articles/14/409/2023/se-14-409-2023.pdf |
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