Behind its natural beauty, the Dieng Geopark Area holds a long history of geological evolution, spanning two periods: the Tertiary and Quaternary Eras. Beginning with the Tertiary Era, particularly during the early to middle Miocene, the Rambatan Formation was formed, consisting of a combination of shale, marl, and limestone sandstone. Additionally, the Sigugur Member of the Rambatan Formation can be found in this area, a limestone layer containing large foraminifera fossils, indicating the diversity of marine life during that time. Transitioning to the late Miocene and early Pliocene, the Volcanic Rock was formed in the form of the Halang Formation, composed of tuffaceous sandstone, conglomerate, marl, and claystone. Moving into the Pliocene Era brings us to the Kalibiuk Formation, formed by layers of marl, claystone, and thin intercalated tuff sandstone. Additionally, there is the Diorite Intrusion Rock, adding geological diversity during this period.



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The emergence of the Breccia Member of the Ligung Formation with layers of andesite breccia, hornblende andesite lava, and tuff, accompanied by the appearance of the Clay Member of the Ligung Formation rich in layers of tuffaceous claystone, cross-bedded sandstone, and conglomerate. Additionally, remnants of plants and young coal were found, indicating deposition on land. This uniqueness and diversity mark the transition between the Pliocene and Pleistocene Eras. Moving on to the Quaternary Era, specifically the Pleistocene Epoch, the journey of rocks continues with the formation of the Jembangan Volcanic Rock, featuring andesite lava from volcaniclastic rocks. Stepping into the Holocene Epoch, we encounter Surface Deposits and Sedimentary Rocks of Lake Deposits and Alluvium consisting of sand, lake, mud, and clay covering the surface. Additionally, the Alluvial Fan, a result of volcanic eruptions, becomes a characteristic feature of this period. Not stopping there, the presence of Andesite Volcanic Rock consisting of andesite lava, andesite-quartz, and volcaniclastic rocks further adds to the diversity of rock formations in the Dieng Geopark Area. The late Holocene, marking the end of the Quaternary Era, is characterized by the presence of the Sindoro Volcanic Rock. This rock consists of hypersthene-augite and olivine-augite andesite lava, as well as flow breccia, pyroclastic breccia, and lahar. The presence of the Sindoro Volcanic Rock serves as both a complement and a conclusion to the geological journey of the Dieng Geopark Area.