Traces of Mesozoic Volcanic Activity Discovered in Jido-eup Seondo

Discovery of Phreatomagmatic Activity as Evidence of Intense Volcanic Activity

A large phreatomagmatic eruption was discovered on Seondo Island, Jido-eup, Sinan-gun. (Photo by Sinan-gun)

[Asia Economy Honam Reporting Headquarters Reporter Kim Ki-woon] Sinan-gun, Jeollanam-do (Governor Park Woo-ryang) announced on the 12th that large accretionary lapilli were discovered in the Mesozoic strata exposed on the north side of Seondo, Jido-eup.

Accretionary lapilli are nearly spherical rocks shaped like baseballs formed during volcanic eruptions. They are created underwater when volcanic ash containing a lot of moisture becomes sticky and clumps together. Their usual size is known to be within 10 mm.

This discovery was made on a large scale near Beomdeoksan Mountain north of Seondo, Jido-eup, Sinan-gun, and large accretionary lapilli over 100 mm were also found.

This suggests that there were large underwater volcanic eruptions in the past at the location of Sinan-gun. It is a rare phenomenon domestically for accretionary lapilli, generally known to be within 10 mm in size, to appear in such large and large-scale forms.

Seondo, where the accretionary lapilli were found, consists of tuff and volcanic rock from the Mesozoic Cretaceous period, and most of the islands belonging to Sinan-gun are also composed of volcanic rock (volcanic and igneous rock) formed by solidified lava from Mesozoic volcanic eruptions and tuff formed by clumped volcanic ash.

The discovery of these accretionary lapilli was made during a preliminary field inspection for an on-site survey. It is expected to have high value not only for research on the past geological era of Sinan-gun but also as a tourism element linked to various coastal sedimentary landforms and coastal erosion landforms that Sinan-gun possesses, as well as the ‘Korean Tidal Flats’ nominated as a World Natural Heritage site.

Seondo, Jido-eup, is an island belonging to the Sinan tidal flats, which are part of the ‘Korean Tidal Flats’ nominated as a World Natural Heritage site. It underwent an on-site inspection by the International Union for Conservation of Nature (IUCN) on October 5 last year.

A Sinan-gun World Heritage official stated, “The Sinan tidal flats can be called a representative ‘mature archipelago-type island tidal flat’ that well demonstrates the formation of the thickest intertidal mud deposits in the world and the sedimentary evolution process during the Holocene period due to sea level rise.” He added, “We are considering ways to utilize the accretionary lapilli discovered this time and unique landforms like the discovery site in connection with the ‘Korean Tidal Flats’ as tourism resources such as geological attractions and educational programs like outdoor field learning sites.”

The final decision on the inscription of the ‘Korean Tidal Flats’ as a UNESCO World Natural Heritage site will be made at the ‘44th World Heritage Committee’ meeting to be held in July.

This content was produced with the assistance of AI translation services.