The Jeongok-ri Paleolithic Historic Site located along Hantan River is a place where traces of the oldest residential neighborhood in the country are left. It is a very important historic site for those studying the culture of the Paleolithic Period of the country and East Asia. Paleolithic archaeologists the world over also regard it as a very important historic site for their study. An 800,000㎡-wide basalt area southwest of Jeongok-ri was designated and protected as National Historic Site No. 268. The Gyeonggi-Do Office opened the Jeongok Prehistoric Museum in April 2011 for the preservation and positive use of the prehistoric site.
Acheulean Hand Axe
Acheulean refers to stone tools representing the early Paleolithic Period first found in St. Acheul, France. The tools are said to have emerged in present-day Konso-Gardula, Ethiopia 1.4 million years ago, and then disappeared 100,000 years ago. Acheulean hand axes are oval or triangular-shaped, and both sides of their blade are evenly trimmed. Their sides look similar to two palms held together. Many of them dating back to the early period are coarsely trimmed, but they gradually took on more refined shapes.
Many hand axes found in Jeongok-ri appear to be similar to early Acheulean-type ones. There are oval-shaped hand axes made of quartz with trimmed facades.
Soil quality formation
Hantangang River originates in the northeast part of the Chugaryeong Fault Zone, which longitudinally divides the soil quality of the Korean Peninsula into two, passes through Jeongok-ri, and flows into Imjingang River or passes through Munsan and flows into Hangang River. The Imjin and the Han flow into the West Sea. Jeongok-ri is about 50km from the West Sea. Mountains in Pocheon to the east of Jeongok-ri and in areas to the east of Pocheon are higher than those to their west.
The stream flowed down the valleys formed long ago in the Gyeonggi Gneiss Zone during the Precambrian Era. Basalt formed on the bottom of the valleys during the Quaternary Period of the Cenozoic Era, extending to Munsan along the river.
With small and large lava zones and perpendicular basalt cliffs along Hantangang River, the Jeongok-ri Historic Site area displays very unique natural scenery that you cannot find elsewhere in the country. The unique topographical structure was formed by the flow of lava from the crater in the present-day Orisan Mountain in Pyeonggang and the 680m-high hill near Geombulrang Station during the Quaternary Period of the Cenozoic Era. The lava from the eruption filled the former Hantangang River and flowed to the Munsan area passing through the Jeongok area.
The liquidity of lava at the time was very high that it can flow to very far away, almost around 90km. Recently, a joint team of Korean/Japanese natural scientists found that there are two types of basalt (i.e., Jeongok Basalt and Chatan Basalt) along Hantangang River and Imjingang River, and that they were formed by the lava spewed 500,000 years and 170,000 years ago, respectively.
Hantangang River flowing over the lava field has remaining alluvial sediments like pebbles, sand, and silt. By and by, Hantangang River eroded the lava field, and fine grains of loess taken by winds came to cover river sediments. The stone tools left by people of the Paleolithic Period in Jeongok-ri are found in the clay layer, which appears to have been formed by winds.
Alluvial sediments 4m-8m thick are left on the lava field in Jeongok-ri. In some areas, thick sand layers are left as sediment of the river flow. There are also purely clay layers where basalt accounts for the bulk of the area.
The clay layer on the upper part of a sedimentary layer comes to 4m ~ 6m in some areas. Aeolian layers (i.e., layers of loess and loess-turned soil) are heaped alternately. There are traces of vertical cracks along the surface of old soil. A typical sediment structure can be found in the E55S20-Ⅳpit, which was excavated in 2000 and whose reproduced copy is displayed at the museum in Jeongok-ri.
Recently, surveyors found Aira-Tn ash from Japan 30cm below the land surface and Ktz ash from 100,000 years ago 1 meter away from it in the E55S20-IV pit. The discovery of the volcanic ash from two different sources in a sedimentary layer shows that the layer 1 meter below the land surface is more than 100,000 years old. A 70cm-deep sedimentary layer appears to have been formed in about 70,000 years. Based on the foregoing, the stone tools found 3.5m below ground are thought to be 350,000 years old.
It is thought that, as a result of measuring it with two different absolute dating methods, the basalt layer forming the bottom of the Jeongok-ri Historic Site is about 500,000 years old. Many OSL layers between the 95,000-year-old Ktz layer and the bottom layer appear to be 100,000 ~ 200,000 years old; thus bolstering the reliability of the dating of the groups of unearthed stone tools. Stone tools unearthed from Jeongok-ri are very old ones, but Jeongok-ri-related dating has problems to be solved.
It is assumed that, during the Prehistoric Period, locals obtained food from plants and fruits growing in the field and mountains, gathered clams and caught fish in Hantangang River, and hunted animals. They must have built shelters for winter and moved from one place to another to get food.
Stone tools like the hand axes unearthed from the Jeongok-ri Historic Site are those made by Paleolithic people for use in their day-to-day living. Hundreds of stone tools were found in a few sites. It is assumed that the places were sites of production of stone tools used to hunt animals and gather fruit. Thus, Jeongok-ri was a precious living foundation of the Paleolithic people.
Curator｜Jonghun Kim, Hyunchul Sim
Photograph｜Jeongok Prehistory Museum's Archive
Project Support｜Taeyong Kim, Seoyeon Choi, Youngdae Kim, Hakseong Lee, Sohyun Park, Hyungmo Seong, Hogyun Kim, Kyungmin Kim(PR & Marketing Team, Gyeonggi Cultural Foundation)