Introduction
Methods
Sites and sampling
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Oya History Museum: a former extraction site, active from 1919 to 1986. During the World War II, it served as a hidden military warehouse and munition factory. It is now a museum showcasing the history of tuff quarrying in the region, but it is often used also as venue of music concerts, art exhibitions, theater performances, filmmaking, photo shoots, and even weddings. It has an impressive size, with an area of 20,000 m2 and a depth of 30 m (Oya Museum of Art 2021).
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Oya Park: a former quarry area including the Oya-ji temple, the Heiwa Kannon monument, the panoramic cliffs of Keikan Park, and a number of old extraction sites, now restructured, redeveloped, and open to visitors.
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Daidoji: an abandoned underground/semi-underground quarry, quite shallow and with numerous large openings to the surface.
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Ishi-no-Sato: an active underground quarry, 50 m deep.
Techniques
Results
Environmental survey
Microclimate
Water chemistry
Groundwater | Rainwater | |
---|---|---|
Na+ | 57.4 (14.2–120.9) | 0.8 |
Mg2+ | 0.4 (0.3–0.6) | 0.3 |
K+ | 1.8 (0.5–2.9) | bdl |
Ca2+ | 1.9 (0.8–3.6) | 1.9 |
NO3– | 1.8 (1.2–2.7) | 0.1 |
SO42– | 82.7 (8.0–186.7) | 2.4 |
Cl– | 5.1 (2.6–6.9) | 1.5 |
pH | 7.2 (7.0–8.0) | 5.5 |
Stone characterization
Petrography and geochemistry
Coarse-grained type | Fine-grained type | |
---|---|---|
Na2O | 2.13 | 2.31 |
MgO | 0.69 | 0.72 |
Al2O3 | 11.07 | 11.08 |
SiO2 | 69.48 | 70.85 |
K2O | 3.62 | 2.91 |
CaO | 1.28 | 1.55 |
TiO2 | 0.14 | 0.11 |
Fe2O3 | 1.75 | 1.60 |
LOI | 9.56 | 8.56 |
P | 96 | 86 |
S | 293 | 315 |
Cl | 97 | 115 |
Mn | 531 | 433 |
Zn | 86 | 105 |
Ga | 19 | 35 |
Rb | 118 | 108 |
Sr | 164 | 157 |
Y | 34 | 28 |
Zr | 156 | 156 |
Ba | 310 | 293 |
Ce | bdl | 188 |
Pb | 32 | bdl |