Studi Kasus Karateristik Lumpur Sidoarjo 15 Tahun Setelah Kemunculan

Abstract

This research was conducted in an area of ±6 km2 which is located in the Sidoarjo Mud area, located in the south of Sidoarjo Regency, Porong, East Java. The Sidoarjo mudflow released a volume of ±60,000 m3 - ±80,000 m3 daily and still gushing to this day. By studying the mud content further, we can better understand the changes in the material characteristics of the Sidoarjo Mud for mitigation purposes and to calculate the economic potential of the mud material. The study began with sampling of surface mud at 32 points scattered around the area of the mudflow point. The samples were then prepared using a combination of dry sieving and wet sieving methods. After preparation, the samples were then processed using the Grain Size Analysis method to determine the proportion of mud grain size, the microscope observation method for the purposes of analyzing the content of foraminifera fosils and minerals with a mesh size of 120 – 250 mesh in the mud as an effort to identify the materials that make up the mud, and the XRD analysis method to determine mineralogy of the mud. The comparison results show a large percentage of the mud grain size below 62 microns. Observations of foraminifera fosils indicate the possible origin of the formation from the Sidoarjo Mud. XRD data analysis also showed some similarities with the comparison data, such as smectic clay minerals and monmorilonite which were the most dominant clay minerals, and minerals such as and Sulfur showed influence of marine and volcanic depositional environments.The location of the Sidoarjo Mud area is above the Watusokek Fault line which extends to the Arjuno-Welirang mountain complex.