5:15 PM - 7:15 PM
[O05-P06] Observation of Takahata-ishi stone at the old Takahata station
★Invited Papers
Keywords:Takahata-ishi, old Takahata Station, tuff stone material,, Observation of lithology
1. Introduction
The old Takahata Station, now known as the old Takahata Station Park, is located in Takahata Town, Yamagata Prefecture. The station’s main building (Fig. 1) and platform were recognized as national tangible cultural properties in 2016.
Constructed in 1934, the exterior walls of the Takahata Station building and surrounding structures are made of Takahata-ishi, a tuff stone quarried from the lower part of the Akayu Formation. According to information displayed at the Takahata Town Local History Museum, the stone used for the old Takahata Station was sourced from the upper part of the Uriwari Quarry, which is now the Uriwari Rock Garden Park.
Tamiya (2024) analyzes the distribution of tuffs in the Ou Mountains from a cultural geological perspective, particularly focusing on the landscape. The Late Miocene tuffs consist of thick pyroclastic flow deposits formed by the explosive eruptive activity of caldera volcanoes, creating a unique landscape that attracts tourists to the region.
Takahata-ishi, which was mined until 2010, is a Late Miocene tuff. Although many remnants of quarries exist in Takahata Town, it has been a long time since mining ceased, making it difficult to observe the rock facies on-site due to weathering and other factors. In the past, additional stones, such as Innai-ishi, Tateoka-ishi, Nakagawa-ishi, Yamadera-ishi, and Akiu-ishi were extracted from the tuffs found in the Ou Mountains. However, few quarry remnants are suitable for observation.
By contrast, the exterior walls of the old Takahata Station are in excellent condition for lithological observation. Observing the lithology of remaining building stone materials is considered an effective method, particularly if the quarrying site has been documented. For instance, the upper part of the Uriwari Quarry can be seen in the old Takahata Station, built in 1934, whereas the lower part is visible at the Yamadera Basho Memorial Museum in Yamagata City, constructed in 1989. This enables observation of Takahata-ishi in the layered order in which it was quarried at the time of construction.
2. Observation of Takabatake-ishi
The Akayu Formation spans approximately 10 km from Nanyo City to Takahata Town. The lower part mainly consists of massive, unstratified tuff breccia, which contains xenoliths. The upper part is composed of fine-grained tuff and mudstone with well-developed laminae. The lower part of the formation has been utilized as stone material (Applied Geological Society of Yamagata, 2016).
The Takahata-ishi exterior wall of the old Takahata Station (Fig. 2) exhibits the following lithology: a fine ochre-colored volcanic ash matrix that contains numerous fibrous pumice stones, ranging from several millimeters to several centimeters. Common exotic xenoliths include medium-grained hornblende-biotite granodiorite, black altered andesite, mudstone, and siliceous mudstone, with sizes ranging from several centimeters to 10 cm. The granodiorite is believed to originate from the Cretaceous granites in the basement, the altered andesite from the Inakotoge Formation, and the mudstone from the Osawa Formation. In addition, a coeval xenolith (autolith) made of tuff breccia, approximately 30 cm in diameter, was observed in the Uriwari Rock Garden.
References
Tamiya R. (2024) Cultural geology viewpoint of tuff distributed in the Ou Mountains, especially the landscape. Abstracts, the Annual Meeting of the Geological Society of Japan (2024, Yamagata), T3 O-18.
Applied Geological Society of Yamagata (2016) Explanatory text of 1:100,000 geological map of Yamagata Prefecture. Yamagata University Press, 61p.
The old Takahata Station, now known as the old Takahata Station Park, is located in Takahata Town, Yamagata Prefecture. The station’s main building (Fig. 1) and platform were recognized as national tangible cultural properties in 2016.
Constructed in 1934, the exterior walls of the Takahata Station building and surrounding structures are made of Takahata-ishi, a tuff stone quarried from the lower part of the Akayu Formation. According to information displayed at the Takahata Town Local History Museum, the stone used for the old Takahata Station was sourced from the upper part of the Uriwari Quarry, which is now the Uriwari Rock Garden Park.
Tamiya (2024) analyzes the distribution of tuffs in the Ou Mountains from a cultural geological perspective, particularly focusing on the landscape. The Late Miocene tuffs consist of thick pyroclastic flow deposits formed by the explosive eruptive activity of caldera volcanoes, creating a unique landscape that attracts tourists to the region.
Takahata-ishi, which was mined until 2010, is a Late Miocene tuff. Although many remnants of quarries exist in Takahata Town, it has been a long time since mining ceased, making it difficult to observe the rock facies on-site due to weathering and other factors. In the past, additional stones, such as Innai-ishi, Tateoka-ishi, Nakagawa-ishi, Yamadera-ishi, and Akiu-ishi were extracted from the tuffs found in the Ou Mountains. However, few quarry remnants are suitable for observation.
By contrast, the exterior walls of the old Takahata Station are in excellent condition for lithological observation. Observing the lithology of remaining building stone materials is considered an effective method, particularly if the quarrying site has been documented. For instance, the upper part of the Uriwari Quarry can be seen in the old Takahata Station, built in 1934, whereas the lower part is visible at the Yamadera Basho Memorial Museum in Yamagata City, constructed in 1989. This enables observation of Takahata-ishi in the layered order in which it was quarried at the time of construction.
2. Observation of Takabatake-ishi
The Akayu Formation spans approximately 10 km from Nanyo City to Takahata Town. The lower part mainly consists of massive, unstratified tuff breccia, which contains xenoliths. The upper part is composed of fine-grained tuff and mudstone with well-developed laminae. The lower part of the formation has been utilized as stone material (Applied Geological Society of Yamagata, 2016).
The Takahata-ishi exterior wall of the old Takahata Station (Fig. 2) exhibits the following lithology: a fine ochre-colored volcanic ash matrix that contains numerous fibrous pumice stones, ranging from several millimeters to several centimeters. Common exotic xenoliths include medium-grained hornblende-biotite granodiorite, black altered andesite, mudstone, and siliceous mudstone, with sizes ranging from several centimeters to 10 cm. The granodiorite is believed to originate from the Cretaceous granites in the basement, the altered andesite from the Inakotoge Formation, and the mudstone from the Osawa Formation. In addition, a coeval xenolith (autolith) made of tuff breccia, approximately 30 cm in diameter, was observed in the Uriwari Rock Garden.
References
Tamiya R. (2024) Cultural geology viewpoint of tuff distributed in the Ou Mountains, especially the landscape. Abstracts, the Annual Meeting of the Geological Society of Japan (2024, Yamagata), T3 O-18.
Applied Geological Society of Yamagata (2016) Explanatory text of 1:100,000 geological map of Yamagata Prefecture. Yamagata University Press, 61p.