Batubara merupakan salah satu komoditas terbesar yang digunakan untuk menghasilkan energi listrik di Indonesia. Mengingat batubara merupakan sumber energi yang tidak terbarukan, maka perlu dilakukan eksplorasi untuk mencari sumber potensi batubara baru. Eksplorasi yang dilakukan berada di daerah Jangga, Kabupaten Batang Hari, Provinsi Jambi. Kegiatan ini merupakan kegiatan eksplorasi tahap pendahuluan yang dilakukan bersama Pusat Sumber Daya Mineral, Batubara, dan Panas Bumi. Kegiatan eksplorasi yang dilakukan terdiri dari dua kegiatan, yaitu pemetaan geologi permukaan dan pengeboran inti. Setelah itu, dilakukan pengolahan data untuk merekonstruksi bentuk model 3D lapisan batubara dan menghitung estimasi potensi batubara. Pada kegiatan pemetaan geologi permukaan didapati kondisi geologi daerah penelitian yang terdiri dari dua satuan batuan, yaitu satuan batuan batupasir dan satuan batulempung, serta didapati tiga singkapan batubara permukaan. Kegiatan pengeboran dilakukan pada empat titik koordinat yaitu MK-01, MK-02, MK-03, dan MK-04. Pemodelan lapisan dan estimasi potensi batubara dilakukan dengan menggunakan perangkat lunak MineScape 5.7. Hasil data pengeboran menunjukkan bahwa terdapat 8 lapisan batubara yang dapat dimodelkan dengan data pendukung berupa data singkapan batubara. Estimasi potensi batubara pada penelitian ini mengacu pada SNI 5015:2019 yang terbagi menjadi kelompok target eksplorasi dan kelompok inventori batubara. Hasil perhitungan estimasi diketahui bahwa total target eksplorasi minimum adalah 1.158.822,74 ton dan maksimum 4.208.379,08 ton, sementara total estimasi potensi batubara pada kelompok inventori tereka sebesar 12.916.775,7 dan inventori tertunjuk sebesar 9.296.304,45 ton.

Proxapertites have become one of the most significant indicators of ancient rock in Indonesia. Walat Formation is one of the oldest rocks exposed in Sukabumi, West Java, Indonesia. These Proxapertites have not been described in detail about their characteristics in previous studies, especially on Walat Formation. Therefore, knowing the characteristics of Proxapertites becomes interesting, especially in Walat Formation, which can be a reference for the characteristics of the late Eocene Proxapertites (37.8 - 33.9 million) in Indonesia. Acetolysis method was carried out for the preparation of pollen and spores; description and determination were carried out to see the characteristics of Proxapertites that present in Walat Formation. Result, there are three types of Proxapertites. Proxapertites operculatus have sizes 23 – 86 µ with average 40.5 (P) and 51.1 (E) µ, index PE 0,43 - 1, Peroblate – Subspheroidal – Oblate Spheroidal, Fine-Reticulate ornamentation, and Asymmetric Monosulcate aperture. Proxapertites cursus have sizes 23 – 86 µ with average 39.8 (P) and 49.8 (E) µ, index PE 0.51 - 1, Oblate – Subspheroidal – Oblate Spheroidal, Reticulate ornamentation, and Asymmetric Monosulcate aperture. Whereas Proxapertites psilatus have sizes 29 – 75 µ with average 42.3 (P) and 52.5 (E) µ, index PE 0.58 - 1, Oblate – Subspheroidal – Oblate Spheroidal, Psilate ornamentation, and Asymmetric Monosulcate aperture. These three Proxapertites can be distinguished by their type of ornamentation. Meanwhile, other aspects have similar characteristics and are affected by the appearance of individual pollen on the slide during preparation.

IClimate is the prevailing weather condition of an area throughout the year. Climate affects the vegetation in a region. The research aimed to study the climate and humidity change during the Holocene in Bandung Paleo-Lake based on palynomorph analysis. The twenty-four samples were taken using hand drill in 172.5 - 52.5 cm depth, continued with preparation and determination. In this study, descriptive analysis and comparison between pollen, spores and their sediments to show the climate and humidity change in Bandung Paleo-Lake. The results show that the samples which were taken on peat deposits showing four times climate changes in five zones, which characterized by montane forest pollens, i.e. Podocarpaceae and Pinaceae, lowland forest pollen i.e. Commelinaceae, Moraceae, spores from the Family Polypodiaceae, Pteridaceae and Dennstaedtiaceae, and Gramineae at the study area.Keywords: Climate, palaeo, analysis, palinology, Bandung Lake.

AbstrakAlga merupakan mikroorganisme fotosintesis yang tidak memiliki tubuh sejati dengan distribusi lingkungan yang sangat luas dan memiliki banyak fungsi, salah satunya sebagai indikator perubahan lingkungan. Wilayah Cekungan Bandung telah dilakukan penelitian dari beberapa aspek. Akan tetapi, penelitian terutama dari aspek alga yang memperlihatkan perubahan lingkungan belum dilakukan pada daerah tersebut. Penelitian ini dilakukan untuk melihat bagaimana perubahan lingkungan dari endapan sag pond bekas Danau Bandung pada wilayah Cekungan Bandung menggunakan keberagaman alga dan ukuran butir sedimen. Metode asam dilakukan untuk memisahkan alga dari endapan, serta deskripsi batuan dilakukan untuk melihat ukuran butir endapan pada lokasi penelitian. Analisis data dan pemodelan dilakukan dengan mengelompokkan alga sesuai dengan kondisi habitatnya yang terbagi menjadi kelompok Pinnularia, Euglena, Acrinastrum dan Dinobryon. Hasil penelitian menunjukkan bahwa lokasi penelitian mengalami empat kali perubahan lingkungan yang dibagi kedalam zona-zona dan subzona. Setiap zona tersebut diawali dengan kondisi air tercemar yang ditandai oleh peningkatan kelompok Euglena dan ukuran butir halus dari sedimen. Sedangkan pada bagian akhir, perairan memperlihatkan kondisi air normal yang ditunjukkan dengan peningkatan kelompok Pinnularia dan ukuran butir sedimen yang menjadi lebih kasar.AbstractAlgae is known as a photosynthetic microorganism that don’t have a true body with very broad distributions of the environment. Algae have a lot of functions, one of which is an indicator of environmental change. The Bandung Basin area has been researched from several aspects. However, research especially from the algae aspect that shows environmental changes, has not been carried out in this area. This research was conducted to see how the environmental changes of Lake Bandung sag pond deposits in the Bandung Basin by using algae diversity and grain size deposits. The acetolysis method is carried out to see algae content in the sediment, and rock description is carried out to see the grain size of the sediment in the study area. Furthermore, data analysis and modeling were conducted by grouping algae according to environmental conditions which are divided into Pinnularia group, Euglena group, and other groups. The result showed that the study area occurred four times in environmental changes which were divided into zones and subzones. Each zone initially had polluted water conditions characterized by an increase in Euglena groups and the fine grain size of sediment. While in the end, the waters showed normal water conditions characterized by an increase in Pinnularia group and the grain size of the sediment became coarser.

Rajamandala Formation is a limestone reef formation that is exposed in the Rajamandala – Sukabumi area, West Java. Different from those in the Rajamandala area, this formation which is located in the Sukabumi area is still rarely analyzed, especially from its large foraminifera. This study aims to assess the content, age, and depositional environment of reef limestone from the Rajamandala Formation based on large foraminifera. Research method was carried out in several stages. Sampling was done by spot sampling as many as 6 samples. Then, thin section observations was carried out using Olympus CX-22 binocular microscope. Finally, age and environmental analysis were carried out using basic biostratigraphic methods and cluster analysis based on the fossil content of large foraminifera. Result, the limestone reefs of Rajamandala Formation in Sukabumi area have varied material content. These rock ages were found to be in the Late Oligocene range (Chattian). This rock depositional environment is in shallow marine environment which is divided into 3 main clusters. The first cluster is dominated by Austrotrilina and Borelis which shows the Backreef shelf environment. The second cluster is dominated by Heterostegina and Cycloclypeus which shows the Forereef shelf environment. Finally, the third cluster is dominated by all large foraminifera representing the Reef environment. When compared with previous studies, the limestone of Rajamandala Formation in Sukabumi and Rajamandala areas has the same age and depositional environment.