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Gumunso (Korean: 구문소; Hanja: 求門沼) is a swamp in Dongjeom-dong, Taebaek, Gangwon Province, South Korea which features a river that pierces through a mountain, the only one of its kind in Korea. It is also known for its geological value, as its stratigraphic continuity is well-preserved.[1] It names the surrounding village and neighborhood (dong).[2]
With an area of 685,109 m2, the "Ordovician Deposits and Topography of Stream Erosion of Gumunso" is a part of Gangwon Paleozoic National Geopark[3] and is the 417th Natural Monument of South Korea.[4] In Gumunso, the Jigunsan and Makgol Formation (with the former unconformably overlying the latter) from the Lower Paleozoic Ordovician period (~440 to 500 million years ago) can be found.[5] The two streams Cheolamcheon (철암천) and Hwangjicheon (황지천) meet in Gumunso, and could be considered the start of the Nakdong River.[6]
Name
[edit]The name Gumunso is a Hanja version of the name Gumuso (구무소; 구무沼; lit. hole swamp), where "구무" is a Middle Korean term for "hole". A purely native-Korean name is Tturunae (뚜루내, compare 뚫다). Historical documents such as the geological survey included in the Veritable Records of Sejong (세종실록지리지; 世宗實錄地理志) and Daedongyeojido records the name as Cheoncheon (천천; 穿川).[5] The cave itself is called "자개문" (子開門).[1]
Formation and history
[edit]Formation
[edit]During the Ordovician era, the Taebaek region was originally underseas, with organisms like coral depositing limestone that would form today's Gumunso.[7] Some time after, the sea became isolated, and became extreme salty as it dried up. Because of this, rectangular imprints left by salt crystals are present on the rocks. Additionally, around Gumunso, sedimentary rocks can be found which were deposited during the Paleozoic Era, approximately 520 to 460 million years ago.[8] Geological structures like trilobite fossils and stromatolites can be seen. Further upstream is the Jigunsan Formation, which contains abundant fossils.[9] In 2000, calathid fossils was discovered in the Gumunso-adjacent Makgol Formation, the first to be found in the Korean peninsula.[10]
From 30000 to 70000 years ago, Hwangjicheon used to have an extremely sharp rightward bend where today's Gumunso would be, eroding the limestone. The stream formed an Ω-shaped (or horseshoe-shaped) meander and deposited well-rounded gravel with interbedded sand. Dating shows that this sedimentary layer lasted for the aforementioned years.[11] From 30000 to 10000 years ago, 40000 years of erosion has opened a small channel in through the limestone in Gumunso, reducing the flow to the meander. This was reflected by smaller pebbles being present in the deposits of that time.[12] Around 30000 years ago, the hole was fully formed, and the weakened meander disappeared completely, becoming a swamp.[13] Today, this abandoned channel consists of farmlands[14] and is called 사군다리.[6]
Modern
[edit]Sinjŭng Tongguk yŏji sŭngnam, a 1530 geography book, notes: "The Hwangjicheon is located 110 ri west of Samcheok-bu. Its waters flow south for about 30 ri, piercing through a small mountain and continuing southward—called Cheoncheon".[6] During the Japanese colonial period, the Japanese dug a tunnel next to Gumunso in 1937, aiming to build a road to transport coal and workers.[8] On 2000 April 28, the "Ordovician Deposits and Topography of Stream Erosion of Gumunso" was designated as the 417th Natural Monument of South Korea.[1] In September 1998, the Taebaek city reduced the number of neighborhoods from 16 to 8, and merged Dongjeom-dong and a part of Jangseong-dong (장성동) together. The resulting dong was named Gumunso-dong.[2]
Folklore
[edit]There is a lot of folkloric myths surrounding Gumunso. One creation myth correctly identifies 사군다리 as an abandoned channel: the story involves a large tree that has been uprooted in a flood, explaining how it crashed into the mountain and created the tunnel.[6] Another legend involves the legendary king Yu the Great accidentally creating the tunnel with his sword while learning water control. One tells the story of the White Dragon blasting the tunnel while battling the Blue Dragon for the control over the Nakdong river. Historical prophetic work Jeonggamnok claims that going through the stone tunnel will during midnight will bring one to a paradise free from hunger.[9]
The Dragon King is also featured in a lot of folklore.[15]
See also
[edit]References
[edit]- ^ a b c "태백 구문소 오르도비스기 지층과 제4기 하식지형". Doopedia (in Korean). Retrieved 2025-04-13.
- ^ a b "행정구역". 태백시청 (in Korean). Retrieved 2025-04-11.
- ^ "구문소 전기고생대 지층 및 하식지형". National Geoparks of Korea. Search up "구문소" to access the source.
- ^ "태백 구문소 오르도비스기 지층과 제4기 하식지형 (太白 求門沼 오르도비스紀 地層과 第四紀 河蝕地形)". Korea Heritage Service.
- ^ a b 이, 의한, "태백 구문소 전기고생대 지층 및 하식지형 (太白 求門沼 前期古生代 地層 및 河蝕地形)", 한국민족문화대백과사전 [Encyclopedia of Korean Culture] (in Korean), Academy of Korean Studies, retrieved 2025-04-10
- ^ a b c d 한국지명유래집 중부편 지명 (in Korean). 국토지리정보원. December 2008. ISBN 9791170090687 – via Naver Encyclopedia.
- ^ Myeong 2006, p. 51.
- ^ a b 우, 경식 (2022-06-25). "[지구는 살아있다] 강원도 태백 구문소에는 고생대 기후의 흔적이 남아있다". www.dongascience.com (in Korean). Retrieved 2025-04-13.
- ^ a b Myeong 2006, p. 52.
- ^ Lee, Dong Jin (June 2000). "구문소지역 태백층군 상부에서 산출된 오르도비스기 CALATHID화석" [Occurrence of calathids from the Makkol Formation (Middle Ordovician), Taebaek, Korea]. 고생물학회지. 16 (1): 37–43. (Free access is provided at the journal's website)
- ^ Shin, Cheong & Choi 2016, p. 55.
- ^ Shin, Cheong & Choi 2016, p. 55-56.
- ^ Shin, Cheong & Choi 2016, p. 56.
- ^ "네이버 지도". map.naver.com (in Korean). Retrieved 2025-04-13.
- ^ 이은식 (2011-06-27). 지명이 품은 한국사 3 : 서울·강원도 편 (in Korean). 타오름. ISBN 978-89-94125-14-5.
Journal citations
[edit]- Myeong, Nam-Jae (2006). "구문소의 진실". 하천과문화 (River and Culture). 2 (2). 한국하천협회 (Korean River Association): 50–58. ISSN 1738-7213 – via KoreaScience.
- Shin, Seungwon; Cheong, Daekyo; Choi, Jeong-Heon (2016). "태백 구문소 구하도 퇴적단면의 연대측정을 통한 하도(황지천)의 유로 변화 연구". Journal of the Geological Society of Korea (in Korean). 52 (1): 51–56. doi:10.14770/jgsk.2016.52.1.51.