Structure Control of Iron Ore Education on Sebuku Island

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INTRODUCTION
The existence of Ore in the Mining Authority area is essential to know with certainty its potential. It will later aim to support national steel projects that are used to meet national and international steel needs Thamsi, Jafar, et al., 2021). Mineralization in Sebuku Island is formed by the lateralization process, which is closely related to weathering, oxidation, and leaching processes under normal pressure and temperature conditions. The state of rock that is destroyed by tectonic processes plays an active role in the rapid weathering process because it facilitates the infiltration of surface water so that the leaching process runs perfectly in the enrichment zone (supergene enrichment zone) (H. Bakri et al., 2021;. This process of iron mineralization has prompted further research. (Pambudi, 2013). Kalimantan is one of the areas that have a wide distribution of Ore. Especially in South Kalimantan; iron ore deposits are pretty abundant in the southern part, where the southeastern part of South Kalimantan is generally composed of ultramafic igneous rocks; iron ore deposits have interesting, unique characteristics ranging from their formation related to weathering processes to elemental associations. -altered elements of the original rock. (Rustandi, 1995). This study aims to determine the characteristics of iron ore and the distribution pattern of laterite iron ore deposits (S. Bakri et al., 2022).

METHODS
Based on the data obtained from drilling data analysis and analysis of Fe element assay data and its associations, the distribution pattern will be known, which will be done manually and will be correlated with X-Ray results, then compared with titration or manual analysis and the data obtained will be processed using ArcGIS.
The quantitative analysis used in this study is evidentiary by combining several data, including literature review, field data, drilling data, and grade analysis data. They were studied and analyzed comprehensively to determine Fe content data's characteristics and distribution patterns. The stages in Copyright © 2022, Journal of Geology & Exploration, Page: 9 this research include a Literature study conducted before and during the study. At this stage, the collection of sources of information related to the characteristics of iron ore and its distribution pattern is carried out.
In this stage, the data obtained is then processed to determine the spread laterally and vertically. After getting the value of Fe content from each drill point using Niton X-Ray, proceed with making the distribution of drill points at the research site using ArcGIS software. Then compare the value of Fe content from one drill point to another to determine iron ore characteristics. In the data processing process using Arcgis, it is necessary first to know what parameters need to be considered: drill point data consisting of easting, northing, elevation, depth, and lithology.

RESULTS AND DISCUSSION Core Drilling Data Analysis (Drill Log)
The drilling results obtained samples in cores, then got five types of lateralization zone division at PT. SILO is based on the characteristics of each zone which include: 1. Brownish Soil The brownish soil or overburden (OB) zone is generally shown in the appearance of the core with a blackish brown to reddish brown color because it consists of soil resulting from weathering, decaying leaves, iron oxide, and is commonly known as humic acid. Red soil indicates the presence of ultramafic rocks, although this is not always true.

Gravel
This gravel zone is a red-brown weathered soil with nickel and more iron elements. There are small rock fragments due to the weathering process of the parent rock. Gravel-sized materials are generally dark brown to black, large gravel to boulders (Wentworth scale), well rounded to moderately angled, weak to solid magnetism, and inflexible hardness; the dominant mineral of each gravel material is generally limonite, hematite, and goethite, thick zone it is an average of 3 meters.

Yellowish soil
The yellowish soil zone has a yellowish-brown color, visible texture, fine-grained, slightly plastic to very plastic, elastic, weak magnetism, completely weathered, and soft hardness; the dominant mineral composition in this zone is limonite. In this zone, sometimes found black manganese oxide. In general, tiny organic remains such as plant roots are located, and this zone is thin in steep areas.

Green soil
The greenish soil zone is yellow-green, delicate to coarse-grained, slightly plastic, inelastic, weak magnetism, moderate weathering, fresh or discolored rock is still present, and the original rock texture is still visible, the minerals forming the bedrock can still be seen. This zone is a transition from yellowish soil to Bedrock.

Bedrock
The bedrock zone is characterized by blackish gray and greenish gray. It consists of ultramafic igneous rock (peridotite) and serpentinite which are still compact. There are fractures filled with silica veins. Drilling sometimes does not reach the bedrock layer due to several factors, namely frequent landslides on the rock walls, and the drill bit cannot penetrate the rock, so the drilling is stopped; the drill tool used is a manual drill.