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"Penelitian ini merupakan langkah awal yang terbilang baru di Formasi Jatiluhur, Sungai Cibeet untuk menganalisis proses diagenesis, mengidentifikasi fitur diagenesis dan sejarahnya. Daerah penelitian tersusun oleh batuan silisiklastik berupa batupasir, batulanau, batulempung, terdapat pula batuan bersifat karbonatan. Sebanyak sepuluh sampel dilakukan analisis petrografi untuk menentukan karakterisasi tekstur dan mineralogi batuan. Selain analisis petrografi, analisis SEM dan XRD sebanyak masing-masing tiga sampel dapat digunakan untuk studi diagenesis. Beberapa proses diagenesis seperti kompaksi, sementasi, disolusi, dan penggantian mineral dapat memengaruhi keterbentukan batuan Formasi Jatiluhur. Proses kompaksi menghasilkan kontak antarbutir berupa point, long, concavo-convex, dan sutured serta semen yang ditemukan berupa semen kalsit dan mineral lempung seperti albit, ilit, kaolinit, dan smektit. Mineral kuarsa, mika, dan feldspar mengalami penggantian. Proses-proses diagenesis tersebut mengakibatkan perubahan porositas dari batuan. Tipe-tipe porositas didominasi oleh tipe intergranular dan intrapartikel dengan persentase antara 5-30%. Sejarah diagenesis pada daerah penelitian diawali oleh tahap eogenesis, mesogenesis, dan telogenesis. Dengan adanya pelaksanakan studi diagenesis, maka kualitas reservoar (misalnya) dapat ditentukan. Penelitian ini menunjukan bahwa proses diagenesis mengakibatkan adanya heterogenitas batuan Formasi Jatiluhur di sekitar aliran Sungai Cibeet.

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This research is a relatively new to conduct in the Jatiluhur Formation, especially Cibeet River that aimed to analyse the diagenesis process and identify diagenesis features and its history. The research area is composed of siliciclastic rocks in the form of sandstone, siltstone, and claystone but there are also carbonate rocks. A total of ten samples were subjected to petrographic analysis to determine the characterisation of rock textures and mineralogy. In addition to petrographic analysis, SEM and XRD analysis of three samples each are used for diagenesis studies. Several diagenesis processes such as compaction, cementation, dissolution, and mineral replacement affected the rock formation of the Jatiluhur Formation. The compaction process produced contact between grains in the form of point, long, concavo-convex, and sutured contacts as well as cement found in the form of calcite cement and clay minerals such as albite, illite, kaolinite, and smectite. Quartz, mica, and feldspar minerals underwent mineral replacement. These diagenesis processes resulted in changes in the rock porosity. The types of porosity are dominated by intergranular and intraparticle types with the percentage between 5-30%. The history of diagenesis in the research area began with the stages of eogenesis, mesogenesis, and telogenesis. With the implementation of a diagenesis study, the quality of the reservoir (for example) can be defined. This study shows that the diagenesis process resulted in the heterogeneity of the Jatiluhur Formation rocks around the Cibeet River streams."

"Sungai Cipamingkis termasuk ke dalam Formasi Jatiluhur yang memiliki umur Miosen Tengah-Miosen Akhir, serta memiliki litologi batuan sedimen campuran silisiklastik dan karbonat dengan kandungan foraminifera besar. Pemahaman mengenai distribusi dan karakteristik foraminifera besar pada batuan sedimen campuran silisiklastik dan karbonat dapat membantu menginterpretasikan lingkungan pengendapan dan sedimentasi pada suatu daerah. Pada studi ini, dilakukan metode stratigrafi terukur dan analisis petrografi dari menghasilkan empat fasies batuan sedimen karbonat yaitu Foraminiferal Packestone, Foraminiferal Rudstone, Foraminiferal Bivalvia Rudstone, dan Coral Foraminiferal Bindstone dan fasies batuan sedimen campuran silisiklastik dan karbonat, yaitu Foraminiferal Algae Sandy Allochem Limestone, Quartz Muddy Sandstone, Foraminiferal Algae Allochem Sandstone, Foraminiferal Bivalvia Sandy Allochem Limestone. Berdasarkan kandungannya, terdapat lima genus foraminifera besar, yaitu Heterostegina (Ht), Operculina (Op), Lepidocyclina (Le), Amphistegina (Amp), dan Cycloclypeus (Cy) yang menunjukan lingkungan laut dangkal dengan salinitas normal. Pengendapan pada daerah penelitian dibagi menjadi empat fase yang berhubungan dengan naik dan turunnya muka air laut, sehingga terjadinya pencampuran berupa punctuated mixing dan facies mixing. Lingkungan pengendapan daerah penelitian masuk ke dalam lingkungan laut zona foreslope hingga open shelf.

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The Cipamingkis River is included in the Jatiluhur Formation which has a Middle Miocene-Late Miocene age, and has a sedimentary rock lithology of mixed of siliciclastic and carbonate with large foraminifera content. An understanding of the distribution and the characteristics of large foraminifera in a mixed siliciclastic and carbonate sedimentary rocks can help interpreting the depositional and sedimentary environment of an area. In this study, measured stratigraphic methods and petrographic analysis were carried out to produce four carbonate sedimentary rock facies, namely Packestone Foraminiferal, Rudstone Foraminiferal, Bivalvia Rudstone Foraminiferal, and Bindstone Coral Foraminiferal and a mixed siliciclastic and carbonate sedimentary rock facies, namely Algae Sandy Quartz Foraminiferal, Foraminiferal Muddy Sandstone, Foraminiferal Algae Allochem Sandstone, Foraminiferal Bivalvia Sandy Allochem Limestone. Based on the content, there are five larger foraminifera genera, namely Heterostegina (Ht), Operculina (Op), Lepidocyclina (Le), Amphistegina (Amp), and Cycloclypeus (Cy) which show a shallow marine environment with normal salinity. Sedimentation in the study area is divided into four phases associated with the rising and the falling of sea levels, resulting in a mixing in the form of punctuated mixing and facies mixing. The depositional environment of the study area falls into the marine environment, from the foreslope zone to the open shelf."

"Batupasir Formasi Jatiluhur merupakan lapisan yang merupakan analogi singkapan yang baik dari salah satu lapangan migas di Cekungan Jawa Barat Utara. Aktivitas tektonik sejak Miosen Tengah telah menyebabkan lapisan ini pecah, terlipat, dan terpapar ke permukaan, yang menyebabkan lapisan ini mengalami proses diagenesis secara bertahap. Penelitian ini dilakukan untuk mengetahui tahapan dan proses diagenesis yang terjadi serta pengaruhnya terhadap porositas batuan. Data dalam penelitian ini berasal dari pengukuran potongan stratigrafi yang kemudian dimasukkan ke dalam laboratorium petrografi dan SEM. Hasil analisis petrografi menunjukkan bahwa batupasir Formasi Jatiluhur telah mengalami proses diagenesis berupa pemadatan, pelarutan, dan sementasi. Pemadatan meliputi penataan kembali butiran sedimen dan rekahan dalam sampel batuan. Sementasi terlihat pada analisis SEM yang menunjukkan bahwa semen pada batupasir adalah kalsit, ilit, smektit, dan pirit mineral autigenik. Pelarutan sampel batuan membentuk porositas sekunder, sehingga meningkatkan bilangan porositas. Porositas berkisar antara 1-20%. Variasi nilai porositas ini disebabkan oleh proses sementasi dan pelarutan yang intensif. Dari hasil integrasi analisis petrografi dan SEM, disimpulkan bahwa batupasir Formasi Jatiluhur telah mengalami regim mesogenesis diagenesis.

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The Jatiluhur Formation Sandstone is a layer which is an analogy of a good outcrop from one of the oil and gas fields in the North West Java Basin. Tectonic activity since the Middle Miocene has caused this layer to break, fold, and be exposed to the surface, which causes this layer to undergo a gradual diagenetic process. This research was conducted to determine the stages and processes of diagenesis that occur and their effect on rock porosity. The data in this study came from measurements of stratigraphic pieces which were then entered into the petrographic laboratory and SEM. The results of petrographic analysis show that the sandstones of the Jatiluhur Formation have undergone diagenetic processes in the form of compaction, dissolving, and cementation. Compaction includes the rearrangement of sediment grains and fractures in rock samples. Sementation can be seen in SEM analysis which shows that the cement in the sandstones is calcite, illite, smectite, and autigenic mineral pyrite. The dissolving of rock samples forms secondary porosity, thereby increasing the porosity number. The porosity ranges from 1-20%. This variation in the porosity value is caused by the intensive cementation and dissolving processes. From the results of the integration of petrographic and SEM analysis, it is concluded that the sandstones of the Jatiluhur Formation have undergone a mesogenesis diagenesis regime.

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"Formasi jatiluhur merupakan salah satu formasi yang terletak di utara cekungan Bogor dengan persebaran lateral yang cukup luas dan diperkirakan diendapkan pada Miosen tengah hingga Miosen akhir. Formasi Jatiluhur merupakan formasi yang disusun oleh litologi campuran sedimen klastik berupa batupasir, batulanau, batulempung dan batugamping. Daerah penelitian berada di sepanjang Sungai Cipamingkis yang terletak di Desa Sukamakmur, Kecamatan Jonggol - Bogor. Penelitian ini bertujuan untuk menentukan karakteristik litologi yang ada pada daerah penelitian yang nantinya akan digunakan dalam penentuan kelompok mikrofasies yang ada pada daerah penelitian. Terdapat tiga metodologi digunakan oleh penulis dalam penelitian ini yaitu pengukuran penampang stratigrafi, analisis petrografi dan analisis mikropaleontologi. Panjang lintasan yang didapatkan pada pengukuran penampang stratigrafi adalah sekitar 280 meter dengan total data sampel yang didapatkan adalah sebanyak 27 sampel. Dari 27 sampel yang didapatkan dipilih sebanyak 14 sampel untuk dilakukan analisis petrografi dan 5 sampel untuk dilakukan analisis mikropaleontologi. Secara umum ukuran butir penyusun batuan pada daerah penelitian didominasi oleh pasir halus hingga silt dan keseluruhan sampel memiliki kandungan karbonat dengan struktur bioturbasi yang cukup dominan. Dari hasil analisis sayatan tipis, dihasilkan tiga Standard Microfacies (SMF) pada daerah penelitian yaitu SMF-18, SMF-23, dan SMF-24. Ketiga mikrofasies tersebut, penulis namakan SMF-18 sebagai Fasies C, SMF-23 sebagai Fasies B, dan SMF-24 sebagai Fasies A. Berdasarkan semua data yang telah terkumpul, dihasilkan tiga event atau kejadian geologi yang terjadi pada daerah penelitian dengan lingkungan pengendapan berada pada brackish-clastic dominated, brackish-marine dominated dan platform interior restricted.

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Jatiluhur Formation is one of the unique formations found in the North of Bogor Basin which spread widely and deposited in the Middle Miocene to Upper Miocene. Jatiluhur Formation consists of mixed siliciclastics with carbonate such as sandstone, siltstone, claystone, and limestone. The research area is along the Cipamingkis River which is located in Sukamakmur Village, Jonggol District - Bogor. This study aims to determine the lithological characteristics present in the study area which will later be used in determining the microfacies groups present in the study area. There are three methodologies used by the authors in this study, namely stratigraphic cross-sectional measurements, petrographic analysis and micropaleontological analysis. The path length obtained from the stratigraphic cross-section measurement is about 280 meters with a total sample data obtained of 27 samples. Of the 27 samples obtained, 14 samples were selected for petrographic analysis and 5 samples for micropaleontological analysis. In general, the grain size of the rock constituents in the study area was dominated by fine sand to silt and all samples contained carbonate with a fairly dominant bioturbation structure. From the results of thin section analysis, three Standard Microfacies (SMF) were produced in the study area, namely SMF-18, SMF-23, and SMF-24. The authors call the three microfacies SMF-18 as Facies C, SMF-23 as Facies B, and SMF-24 as Facies A. Based on all the data that has been collected, three geological events have occurred in the study area with depositional environments on brackish-clastic dominated, brackish-marine dominated and restricted interior platforms."

"Penelitian ini dilakukan pada Formasi Jatiluhur, Kecamatan Jonggol, Kabupaten Bogor, Provinsi Jawa Barat. Tujuan dari penelitian ini untuk menentukan lingkungan pengendapan berdasarkan data fosil jejak, fasies batuan, dan data pengukuran penampang stratigrafi. Sebanyak tujuh spesies fosil jejak dan satu trackway pada daerah penelitian berupa Thalassinoides, Scolicia, Opiomorpha, Planolites, Circulichnis, Rhizocorallium, dan Taenidium yang kemudian akan menjadi 5 asosiasi fosil jejak yaitu, asosiasi fosil jejak Scolicia-Thalassinoides, asosiasi fosil jejak Thalassinoides-Circulichnis,asosiasi fosil jejak Rhizocorallium-Thalassinoides, asosiasi fosil jejak Planolites, dan asosiasi fosil jejak Taenidium. Hasil analisis tersebut dapat digunakan untuk menentukan kondisi paleokologi saat pengendapan terjadi terkait kandungan oksigen, energi, dan suplai makanan. Sebanyak sembilan fasies batuan pada daerah penelitian yaitu, fasies batuan perselingan batulempung dan batupasir (CS), fasies batupasir bioturbasi (BB), fasies batulempung (MC), fasies batulanau (MT), fasies batupasir laminasi (LS), fasies batupasir gampingan (AS), fasies batupasir endapan slump (SS), fasies batupasir hummocky (HS), dan fasies batupasir wave-ripple (WS). Hasil analisis tersebut dapat digunakan sebagai data pendukung untuk menentukan lingkungan pengendapan. Nilai indeks bioturbasi pada daerah penelitian menunjukkan nilai yang didominasi nilai yang hampir nol. Hal tersebut menunjukkan kecepatan sedimentasi yang rendah. Lingkungan pengendapan pada Formasi Jatiluhur bagian tengah khususnya di Sungai Cipamingkis berdasarkan fosil jejak, fasies batuan, dan nilai indeks bioturbasi dapat disimpulkan bahwa Formasi Jatiluhur bagian tengah memiliki lingkungan pengendapan berupa laut dalam sampai bagian slope-marine dengan kondisi oksigen yang rendah, suplai makanan yang sedikit, dan energi yang mengontrol semakin muda semakin meningkat.

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This research was conducted in the Jatiluhur Formation, Jonggol District, Bogor Regency, West Java Province. The purpose of this study was to determine the depositional environment based on trace fossil data, lithofacies, and stratigraphy logs data. A total of seven species of trace fossils and one trackway in the research area are Thalassinoides, Scolicia, Opiomorpha, Planolites, Circulichnis, Rhizocorallium, and Taenidium which will then become 5 trace fossil associations, such as, Scolicia-Thalassinoides association Thalassinoides-Circulichnis association, Rhizocorallium-Thalassinoides association, Planolites association, and Taenidium association. The results of this analysis can be used to determine paleoecological conditions when deposition occurred in terms of oxygen content, energy, and food supply. There are nine lithofacies in the study area, such as, alternating claystone and sandstone facies (CS), bioturbated sandstone facies (BB), massive claystone facies (MC), massive siltstone facies (MT), laminated sandstone facies (LS), allochemic sandstone (AS), slump sandstone facies (SS), hummocky sandstone facies (HS), and wave-ripple sandstone facies (WS). The results of this analysis can be used as supporting data to determine the depositional environment. The bioturbation index value in the study area shows a value dominated by a value that is almost zero. This indicates a low sedimentation rate. The depositional environment in the middle of Jatiluhur Formation, especially in Cipamingkis River based on trace fossils, lithofacies, and bioturbation index values can be concluded that the middle of Jatiluhur Formation has a depositional environment in the form of the deep sea to slope-marine parts with low oxygen conditions, less food supply, and energy that controls the younger it gets increased."

"Keberagaman litologi serta struktur sedimen yang terbentuk pada Formasi Jatiluhur dapat membantu menceritakan bagaimana kondisi dari lingkungan pengendapan pada saat proses pengendapan terjadi. Formasi Jatiluhur merupakan formasi yang terbentuk pada Miosen Tengah yang dibentuk oleh litologi berupa dominasi batulanau dan batupasir, disertai keberadaan batugamping pada beberapa tempat. Penelitian ini bertujuan untuk menentukan litofasies dan fasies sedimentasi yang terbentuk pada bagian bawah dari Formasi Jatiluhur, serta menentukan lingkungan pengendapan yang terbentuk pada bagian bawah dari Formasi Jatiluhur. Penelitian ini menggunakan data hasil pengukuran penampang stratigrafi, serta analisis sampel batuan berupa analisis petrografi dan analisis mikropaleontologi. Hasil analisis mikropaleontologi untuk data umur relatif tidak dapat ditentukan, namun menghasilkan informasi kedalam dan lingkungan pengendapan pada daerah penelitian yang berada pada middle shelf hingga outer shelf. Sedangkan analisis petrografi dilakukan untuk melihat kandungan batuan dan menentukan nama batuan dari lapisan batuan pada daerah penelitian. Klasifikasi litofasies didasari dari karakteristik litologi pada daerah penelitian dan sebanyak delapan belas (18) litofasies pada daerah penelitian yang dapat diidentifikasi. Setelah itu ditentukannya satuan asosiasi fasies berdasarkan analisis litofasies, mikropaleontologi dan petrografi dan ditemukan adanya sembilan (9) asosiasi fasies yang terbentuk pada daerah penelitian. Asosiasi-asosiasi fasies yang ditemukan berupa endapan sandy-offshore transition; endapan offshore; endapan offshore transition hingga offshore; endapan shoreface hingga offshore transition; endapan muddy-offshore transition; endapan inner fan hingga mid-fan; endapan offshore; endapan inner fan; dan endapan mid-fan. Hasil penelitian ini menunjukkan bahwa daerah penelitian terbentuk lingkungan pengendapan yang mencerminkan lingkungan pengendapan berupa laut dangkal yang ditandai oleh lingkungan shoreface hingga laut dalam yang ditandai oleh lingkungan mid-fan.

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The diversity of lithology and sedimentary structures that formed in the Jatiluhur Formation can help tell how the conditions of the depositional environment occurred during the deposition process. The Jatiluhur Formation is a formation formed in the Middle Miocene which is formed by lithology in the form of the dominance of siltstone and sandstone, accompanied by the presence of limestone in several places. This study aims to determine the lithofacies and sedimentation facies that form at the bottom of the Jatiluhur Formation, as well as determine the depositional environment that forms at the bottom of the Jatiluhur Formation. This study uses data from measurements of stratigraphic sections, as well as analysis of rock samples in the form of petrographic analysis and micropaleontological analysis. The results of the micropaleontological analysis for the relative age data cannot be determined, but it provides information on the depth and environment of deposition in the study area which is from the middle shelf to the outer shelf. Meanwhile, petrographic analysis is carried out to see the rock content and determine the rock name of the rock layers in the study area. The lithofacies classification is based on the lithological characteristics of the research area and as many as eighteen (18) identifiable lithofacies in the research area. After that, the facies association unit was determined based on lithofacies analysis, micropaleontology and petrography and it was found that there were nine (9) facies associations formed in the study area. The facies associations found were sandy-offshore transition deposits; offshore deposit; offshore transition to offshore deposits; shoreface to the offshore transition deposits; muddy-offshore transition deposits; inner fan to mid-fan deposits; offshore deposits; inner fan deposits; and mid-fan deposits. The results of this study indicate that the research area is formed a depositional environment which reflects the depositional environment in the form of shallow seas characterized by the shoreface to the deep sea which is characterized by the mid-fan environment."

"Penelitian terfokus pada Formasi Klapanunggal pada kala Miosen Tengah tersusun atas batugamping yang merupakan bagian dari Cekungan Jawa Barat dan Palung Bogor bagian Utara. Tujuan dari penelitian adalah menentukan karakteristik fasies, lingkungan pengendapan, dan sejarah diagenesis batugamping pada Formasi Klapanunggal, Jawa Barat. Metode penelitian yang dilakukan adalah pengumpulan data dan pengukuran penampang stratigrafi, analisis petrografi, X-ray Diffraction, dan Scanning Electron Microscope. Klasifikasi fasies yang didapatkan dari hasil deskripsi makroskopis dan analisis petrografi sebanyak enam (6) fasies, yaitu Skeletal Wackestone, Skeletal Packstone, Benthic Foram Grainstone, Skeletal Rudstone, Coral Rudstone, dan Bindstone. Kemudian, fasies-fasies tersebut diklasifikasikan menjadi asosiasi fasies berdasarkan makroskopis dan petrografi menghasilkan tiga (3) asosiasi fasies, yaitu Platform Interior (Open Marine), Platform Margin Reef, dan Slope. Selanjutnya, hasil analisis diagenesis dan paragenetik menghasilkan sejarah diagenesis batugamping pada Formasi Klapanunggal secara berurutan, yaitu tahapan eogenetik (marine phreatic dan meteoric phreatic), tahapan mesogenetik (burial), dan tahapan telogenetik (meteoric phreatic dan meteoric vadose). Kemudian, terdapat hubungan asosiasi fasies dengan diagenesis, yaitu fitur sementasi marine lebih intensif pada asosiasi fasies Platform Margin Reef dibandingkan dengan asosiasi fasies Slope dan Platform Interior (Open Marine). Selain itu, pengaruh kompaksi mekanik lebih kuat pada asosiasi fasies Platform Margin Reef dan Slope dibandingkan dengan asosiasi fasies Platform Interior (Open Marine).

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The research focused on the Klapanunggal Formation during the Middle Miocene which was composed of limestone which was part of the West Java Basin and the Northern part of the Bogor Trench. The purpose of this research is to determine facies characteristics, facies association, depositional environment and the history of limestone diagenesis in Klapanunggal Formation, West Java. Research method is data collection and measurement of stratigraphic sections, petrographic analysis, X-ray Diffraction, and Scanning Electron Microscope. The classification of facies obtained from the result of macroscopic description and petrographic analysis as many as six (6) facies, namely Skeletal Wackestone, Skeletal Packstone, Benthic Foram Grainstone, Skeletal Rudstone, Coral Rudstone, and Bindstone. Then, those facies classified into facies association based on macroscopic and petrographic analysis produces in three (3) facies association, namely Platform Interior – Open Marine, Platform Margin Reef, and Slope Furthermore, the results of diagenesis and paragenetic analysis produce a history of limestone diagenesis in the Klapanunggal Formation sequentially, namely the eogenetic stages (marine phreatic and meteoric phreatic), mesogenetic (burial) stages, and telogenetic stages (meteoric phreatic and meteoric vadose). Then, there is a relationship between facies associations with diagenesis, namely marine cementation features are more intensive in the Platform Margin Reef facies association than the Slope and Platform Interior (Open Marine) facies associations. In addition, the effect of mechanical compaction is stronger on the Platform Margin Reef and Slope facies association compared to the Platform Interior (Open Marine) facies association."

"Penelitian dilakukan pada Formasi Paciran yang berada di daerah Lamongan, Jawa Timur. Formasi Paciran ini tersusun atas batu gamping yang merupakan salah satu bahan baku dalam pembuatan semen. Tujuan dilakukannya penelitian ini yaitu menjelaskan mikrofasies, zona lingkungan pengendapan batugamping, tahapan, proses dan lingkungan diagenesis yang terjadi pada batugamping pada Formasi Paciran, Jawa Timur. Metode penelitian yang digunakan yaitu dengan pengamatan lapangan melalui pemetaan dan pembutan log stratigrafi (makroskopis) dan pengamatan laboratorium melalui analisis petrografi (mikroskopis). Dari hasil pengamatan secara makroskopis dan mikroskopis ditemukan sebanyak enam jenis fasies, yaitu Coral Framestone, Foraminifera Grainstone, Bivalvia Rudstone, Larger Foraminifera Rudstone, Larger Foraminifera Floatstone, dan Coral Floatstone. Fasies-fasies tersebut diendapkan pada lingkungan Platform Margin Reefs. Kemudian, untuk proses diagenesis yang berlangsung yaitu mikritisasi, sementasi, kompaksi, pelarutan, dan penggantian. Proses diagenesis ini terjadi dalam tiga tahapan diagenesis, yaitu eogenesis, mesogenesis, dan telogenesis . Kemudian, melalui proses dan tahapan tersebut menghasilkan fitur diagenesis yang dapat menentukan lingkungan diagenesis batugamping daerah penelitian yaitu zona marine phreatic, zona mixing, zona burial, zona meteoric phreatic dan zona meteoric vadose. Selain itu, berdasarkan fitur diagenesis batugamping di daerah penelitian, terdapat beberapa titik berpotensi sebagai akuifer, yaitu S1.5, S3.2, S5.1, S10, S12, S13, S16, S17, S20, S21, S22, dan S23.

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Research was carried out on the Paciran Formation in the Lamongan area, East Java. The Paciran Formation is composed of limestone which is one of the raw materials for making cement. The aim of this research is to explain the microfacies, environmental zones of limestone deposition, stages, processes and diagenetic environments that occur in limestone in the Paciran Formation, East Java. The research methods used are field observations through mapping and making stratigraphic logs (macroscopic) and laboratory observations through petrographic analysis (microscopic). From the results of macroscopic and microscopic observations, six types of facies were found, namely Coral Framestone, Foraminifera Grainstone, Bivalvia Rudstone, Larger Foraminifera Rudstone, Larger Foraminifera Floatstone, and Coral Floatstone. These facies are deposited in the Platform Margin Reefs environment. Then, the diagenesis processes that take place are micritization, cementation, compaction, dissolution and replacement. This diagenesis process occurs in three stages of diagenesis, namely eogenesis, mesogenesis, and telogenesis. Then, through these processes and stages, diagenetic features are produced that can determine the limestone diagenetic environment in the research area, namely the marine phreatic zone, mixing zone, burial zone, meteoric phreatic and meteoric vadose. In addition, based on the diagenesis features of limestone in the research area, there are several points that have the potential to be aquifers, namely S1.5, S3.2, S5.1, S10, S12, S13, S16, S17, S20, S21, S22, and S23."

"Daerah penelitian berada pada Formasi Klapanunggal, Kecamatan Klapanunggal, Kabupaten Bogor, Provinsi Jawa Barat. Formasi Klapanunggal berumur Miosen Tengah hingga Miosen Akhir yang merupakan bagian dari Cekungan Jawa Barat. Daerah penelitian memiliki jenis litologi berupa batugamping. Tujuan dari penelitian ini adalah untuk menganalisis dan melakukan rekonstruksi lingkungan purba daerah penelitian. Metode penelitian terdiri dari pengukuran penampang stratigrafi, analisis petrografi, dan analisis mikropaleontologi. Pada daerah penelitian, terdapat klasifikasi fasies yang terdiri dari fasies Coral Framestone, Skeletal Floatstone, Larger Foraminifera Floatstone, dan Skeletal Rudstone. Keempat fasies tersebut berasosiasi dengan Platform-margin Reef dengan lingkungan zona koral yang terdiri dari back reef, reef front, dan fore reef. Berdasarkan analisis yang dilakukan, daerah penelitian memiliki rentang umur dari N9 hingga N16 (Zonasi Blow) dan Tf 1 hingga Tf 3 (Letter Stage) berdasarkan biozona dari foraminifera Asterorotalia yabei. Hasil rekonstruksi daerah penelitian menunjukkan lingkungan purba dengan karakteristik energi tinggi, intensitas cahaya mesofotik hingga oligofotik, salinitas euhalin hingga sedikit mengarah ke hipersalin, temperatur 18°C hingga lebih dari 25°C yang mengindikasikan iklim subtropis hingga tropis, dan kedalaman laut sekitar 0 meter hingga 70 meter.

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The research area is located in Klapanunggal Formation, Klapanunggal District, Bogor Regency, West Java Province. Klapanunggal Formation is formed in Middle Miocene to Late Miocene which is part of the West Java Basin. The research area has type of lithology in the form of limestone. The purpose of this study is to analyse and reconstruct the paleoenvironment of the research area. The research method consisted of measuring section, petrographic analysis, and micropaleontological analysis. In the study area, there are facies classification consisting of Coral Framestone, Skeletal Floatstone, Larger Foraminifera Floatstone, and Skeletal Rudstone facies. The four facies are associated with the Platform-margin Reef with a coral zone environment consisting of the back reef, reef front, and fore reef. Based on the analysis conducted, the research area has an age range from N9 to N16 (Blow Zone) and Tf 1 to Tf 3 (Letter Stage) based on the biozone of the foraminifera Asterorotalia yabei. The results of the reconstruction of the study area show a paleoenvironment with high energy characteristics, mesophotic to oligophotic light intensity, euhaline salinity to slightly hypersaline, temperatures from 18°C ​​to more than 25°C indicating a subtropical to tropical climate, and sea depths of 0 to 70 meters."