scholarly journals LARGE FORAMINIFERA FROM LIMESTONE IN THE RAJAMANDALA FORMATION, SUKABUMI, WEST JAVA

2020 ◽  
Vol 5 (2) ◽  
pp. 51-55
Author(s):  
Rizki Satria Rachman ◽  
Winan tris
Keyword(s):  
Depositional Environment ◽  
Late Oligocene ◽  
West Java ◽  
Reef Environment ◽  
Shallow Marine ◽  
The Third ◽  
Reef Limestone ◽  
Binocular Microscope ◽  
Large Foraminifera ◽  
And Cluster Analysis

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.

Litofasies dan Diagenesis Batugamping Formasi Rajamandala di Lintasan Cikamuning

2020 ◽  
Vol 8 (1) ◽  
pp. 5077
Author(s):  
Wahyu Budhi Khorniawan
Keyword(s):  
Depositional Environment ◽  
Carbonate Platform ◽  
Petrographic Analysis ◽  
Late Oligocene ◽  
Burial Diagenesis ◽  
West Java ◽  
North West ◽  
Collection Data ◽  
Platform System

Abstract. Limestone of Rajamandala Formation is one of formation that located in North West Java basin with Late Oligocene age based on  Martodjojo, 1984. Rajamandala Formation is well exposed in Padalarang area extends to Sukabumi area of West Java. Due to its vast expanse and sufficient variety of rocks in the carbonate platform system, it can be a good model for studying Tertiary reef systems in Indonesia. The method used in this research is the outcrop collection data in the field and petrographic analysis which aims to find out the facies, diagenesis, and age of the Rajamandala Formation especially on the Cikamuning track. The results of the study there are 10 litofasies foraminiferal grainstone, skeletal- coralclast grainstone, skeletal-intraclast rudstone (breccia), platy coral boundstone, foraminiferal packstone, skeletal - coralclast grainstone, large benthic foram grainstone, coral boundstone, compositional grainstone, and compositional breccia grainstone. These facies are covering at least 4 diagenesis environment : marine phreatic, meteoric phreatic, burial diagenesis and meteoric vadose, deposited in Late Oligocene based on paleontology analysis where depositional environment is shallow marine.Key words: Cikamuning, Diagenesis, Facies, Rajamandala Formation Abstrak. Batugamping Formasi Rajamandala merupakan salah satu formasi yang berada di cekungan Jawa Barat Utara yang mempunyai umur Oligosen Akhir berdasarkan Martodjojo, 1984. Formasi Rajamandala ini tersingkap dengan baik di daerah Padalarang dan melampar sampai dengan daerah Sukabumi Jawa Barat. Dikarenakan pelamparannya yang sangat luas dan variasi batuan yang cukup lengkap dalam sistem platform karbonat sehingga dapat dijadikan model yang baik untuk mempelajari sistem terumbu Tersier di Indonesia. Metode yang digunakan dalam penelitian ini adalah pengambilan data singkapan di lapangan serta analisis petrografi yang bertujuan untuk mengetahui fasies, diagenesis, serta umur dari Formasi Rajamandala khusunya pada lintasan Cikamuning. Hasil dari penelitian terdapat 10  litofasies: foraminiferal grainstone, skeletal- coralclast grainstone, skeletal-intraclast rudstone (breccia), platy coral boundstone, foraminiferal packstone, skeletal - coralclast grainstone, large benthic foram grainstone, coral boundstone, compositional grainstone, dan compositional breccia grainstone. Batuan karbonat pada lintasan penelitian telah mengalami setidaknya 4 lingkungan diagenesis, yaitu marine phreatic, meteoric phreatic, burial diagenesis, dan meteoric vadose. Umur batuan pada lokasi penelitian adalah Oligosen Akhir berdasarkan analisis foraminifera besar, dengan lingkungan pengendapan adalah laut dangkal.Kata Kunci : Cikamuning, Diagenesis, Fasies, Formasi Rajamandala

Wing Folding in Lepidoptera

1964 ◽  
Vol 96 (1-2) ◽  
pp. 148-149 ◽  
Author(s):  
Janet Sharplin
Keyword(s):  
Posterior Margin ◽  
Anterior Margin ◽  
Effective Length ◽  
Wing Base ◽  
The Third ◽  
Binocular Microscope ◽  
Axillary Sclerites ◽  
Median Plate ◽  
Micrometer Eyepiece ◽  
Wing Folding

The wing folding mechanism was investigated after a detailed study of the wing base morphology had been made (Sharplin, Canad. Ent. 95: 1024; 1121). Living moths were observed with a binocular microscope equipped with a micrometer eyepiece.The first and second axillary sclerites do not move anteroposteriorly; only the distal half of the wing base is involved in wing folding. The folding muscle originates on the pleural ridge and inserts on the third axillary sclerite. The movement of the third axillary is communicated to the bases of the anterior veins through the median plates. The radial plate rotates around the ventral second axillary sclerite which lies underneath the radial bridge at point p, (Fig. 1). Bending cuticle allows the radial bridge to buckle when the wing is folded. The first median plate ( Ml ) rotates about its articulation ( f ) with the dorsal second axillary sclerite. The distal median plate (M2) passes underneath the second cubitus and is fused to the radius. This connection to the radius restricts the backward movement of the second median plate so that point e instead of following the wider arc eg of a circle with its centre at f, must follow the arc cegd drawn about pivot p. The median plates are bent upwards during wing folding and their effective length is shortened so that they can follow the shallow arc epg. When point e is in position g the posterior margin of the median plates is straight, although the anterior margin remains arched causing the median plates to be buckled, (Fig. 2).

scholarly journals Age and Depositional Environment of Walat Formation Based on Palynological Analysis in Sukabumi Regency, West Java, Indonesia

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Rizki Satria Rachman ◽  
Winantris ◽  
Budi Muljana
Keyword(s):  
Data Analysis ◽  
Chemical Treatment ◽  
Depositional Environment ◽  
Treatment Method ◽  
Late Eocene ◽  
West Java ◽  
Palynological Analysis ◽  
First Occurrence ◽  
Pollen And Spores

AbstractWalat Formation is equivalent to Bayah Formation. This formation is the beginning of Bogor basin deposition. In this case, age and environment of this formation have been analyzed by previous researchers, but the results of age and environment interpretations have different ranges, especially from its palynological aspect which until now Walat Formation is rarely analyzed using this aspect. This research was conducted to identify the age and depositional environment of Walat Formation in Sukabumi region by using pollen and spores to confirm different interpretations of previous studies. Measure section was carried out in sampling and chemical treatment method was carried out to see palynomorph content in the rock. Furthermore, data analysis was carried out with range of interval zones and pollen grouping based on their environment.The results show that Walat Formation has Late Eocene age based on the interval zone between first occurrence of Verrucatosporites usmensis and Meyeripollis naharkotensis, and the last occurence of Proxapertites operculatus, Proxapertites cursus, and Cicatricosisporites eocenicus. Walat Formation has fluvial depositional environment characterized by the dominance of Proxapertites operculatus and Proxapertites cursus. The results of this study confirm that the Walat Formation has an Eocene age and a fluvial depositional environment from a palinological aspect.

scholarly journals Vestige of The Ancient Estuarine of Cisaar Valley, Sumedang as One of the Pleistocene Fossil Bearing Site in West Jawa

2019 ◽  
Vol 8 (2) ◽  
pp. 65-80
Author(s):  
Unggul Prasetyo Wibowo ◽  
Anton Ferdianto ◽  
Nurul Laili ◽  
Dida Yurnaldi ◽  
Ruli Setiawan
Keyword(s):  
Depositional Environment ◽  
Sedimentary Rocks ◽  
Estuarine Environment ◽  
Shallow Marine ◽  
East Part ◽  
The Past ◽  
Braided Channel ◽  
Freshwater Mollusk ◽  
Past Data

Cisaar Valley is located on the east part of Sumedang Regency, West Jawa Province. It’s close to the boundary of Sumedang-Majalengka Regency. In this location the sandy and clay dominated sedimentary rocks are well exposed along the outcrops in the Cisaar Valley. These sedimentary rocks is inferred from Pliocene-Pleistocene deposits from Kaliwangu and Citalang Formation. Foraminifera microfossil that commonly used for interpretation of depositional environment is rarely found, whereas freshwater mollusk and vertebrate fossils often found in the sediment rocks of this area.  This condition raises a question, what is the environment of this valley in the past? Data obtained from measured stratigraphic sections along Cisaar river and its tributary rivers in Cibengkung and Cirendang hamlets, Jembarwangi village. There are at least three depositional paleoenvironments which from old to young are: shallow marine, estuarine and fluviatil braided channel depositional paleoenvironment.  Characteristics of the lower, middle and upper of the estuarine environment were found in this Cisaar Valley as the evidences of the oceanic regression processes was happened in the past in this area. 

scholarly journals Reticulate Nummulites (N. fabianii Linage) and Age of the Pellatispira-Beds of the Drazinda Formation, Sulaiman Range, Pakistan

2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Ozcan E
Keyword(s):  
Mediterranean Region ◽  
Late Eocene ◽  
Test Surface ◽  
Time Interval ◽  
Late Oligocene ◽  
Shallow Marine ◽  
Western Tethys ◽  
Two Samples ◽  
Evolutionary Scheme ◽  
Weak Surface

The Eocene shallow marine Pellatispira-beds in the upper part of the Drazinda Formation represent the latest phase of Cenozoic Tethyan marine deposition in the Sulaiman Range, West Pakistan. The unit consists of stratigraphically important taxa as Heterostegina,Silvestriella, Pellatispira, a new Baculogypsina (possibly ancestral to modern Baculogypsina) and reticulate Nummulites implying a latest middle to late Eocene (late Bartonian-Priabonian) age. A more precise age of the unit requires the biometric study of reticulate Nummulites, the evolutionary scheme of which is better known from the peri-Mediterranean region in the Tethys. This group, which was subdivided into a series of successive chrono-species based on the biometry of inner cross-diameter of proloculus and changes in the types of granulation/reticulation on the test surface in the late Eocene-late Oligocene interval, appears to have a significant biostratigraphic potential for a high-resolution biostratigraphy in the peri-Mediterranean region (Western Tethys). The reticulate Nummulites in two samples from Rakhi Nala and Zinda Pir, ZP22 and RNB10, were studied and compared with those from the peri-Mediterranean region. The isolated specimens have a weak surface granulation externally, a distinct small umbonal granule (pile) and typical reticulation. The samples ZP22 and RNB10 from Zinda Pir and and Rakhi Nala sections have an average inner cross diameter of proloculus of 152.0 and 153.0 μm respectively. The reticulate Nummulites in both samples are assigned to N. hormoensis, a chrono-species characteristic for the shallow benthic zone (SBZ 18), referable to latest Bartonian-early Priabonian time interval. Since Heterostegina in peri-Mediterranean region and in Pakistan belongs to different lineages, a correlation of N. hormoensis in the studied samples with the wellestablished evolutionary scheme of Heterostegina reticulata and H.armenica lineages from the Western Tethys was not possible.

Detailed Lithofacies and Architectural Facies Analyses on Mixed Carbonate-Siliciclastic Clastic Shoreline Depositional Environment of the Cibulakan Formation in Cipamingkis River, Jonggol, Bogor, West Java

2021 ◽  
Author(s):  
E. Edwin
Keyword(s):  
Spatial Variation ◽  
Depositional Environment ◽  
Field Observations ◽  
West Java ◽  
Thin Sections ◽  
Fragment Type ◽  
Interesting Study ◽  
Facies Modelling ◽  
Depositional Setting ◽  
Mixed Carbonate

Cibulakan Formation as one of the prolific hydrocarbon-bearing intervals has become an interesting study object for many researchers. The continuous outcrop of the Cibulakan Formation in the Cipamingkis River comprises claystone, sandstone, and subordinate limestone of grainstone, packstone, and wackestone facies. The outcrop should be able to give a clearer vertical and spatial variation of sandstone and limestone geometry compared to the conventional core alone. Field observations followed by measuring the section is conducted to distinguish lithofacies and to create a stratigraphic profile from the chosen interval. Samples and thin sections from sandstone and limestone lithofacies are observed further to determine fragment type variation, matrix, cement, texture, and porosity types qualitatively. Fourteen (14) lithofacies have been recognized from the observation, i.e., Slumped Sandstone (A1), Claystone (A2), Slightly-bioturbated Sandstone (B1), Cross-laminated Sandstone (B2), Parallel-laminated Siltstone (B3), Calcareous Claystone (B4), Moderately-bioturbated Sandstone (C1), Hummocky Cross-stratified Sandstone (C2), Skeletal – Coral clast Wackestone (C3), Skeletal-clast Packstone (C4), Coralline Foraminiferal Boundstone (C5), Low-angle Planar Cross-bedded Sandstone (D1), Intensely-bioturbated Sandstone (D2), and Trough Cross-bedded Sandstone (D3). There are four architectural facies in the research interval and each of them is composed of different and specific lithofacies. An ideal parasequence is composed of all Architectural Facies namely : (A) Offshore-Transition (B) Lower Shoreface (C) Upper Shoreface with the whole thickness range between 15 to 25 m and the parasequence shows thickening upward succession. The detailed information about the lithofacies and architectural facies hopefully will provide a better understanding of the facies modelling of the mixed carbonate-siliciclastic depositional setting, new insights for parasequence recognition in clastic shoreline depositional environment and become a reference for other areas lacking in core data and/or outcrop analogue.

scholarly journals Climate change at the Triassic/Jurassic boundary: palynological evidence from the Furkaska section (Tatra Mountains, Slovakia)

2009 ◽  
Vol 60 (2) ◽  
pp. 139-149 ◽  
Author(s):  
Katrin Ruckwied ◽  
Annette Götz
Keyword(s):  
Climate Change ◽  
Volcanic Activity ◽  
Depositional Environment ◽  
Sudden Increase ◽  
Tatra Mountains ◽  
Shallow Marine ◽  
Early Mesozoic ◽  
Central Atlantic Magmatic Province ◽  
Tatra Mts ◽  
Central Atlantic

Climate change at the Triassic/Jurassic boundary: palynological evidence from the Furkaska section (Tatra Mountains, Slovakia)The palynology of the Triassic/Jurassic boundary interval of the Furkaska section (Tatra Mts, Slovakia) was studied with respect to a major climatic change during that period. The palynofacies is dominated by terrestrial particles, indicating a shallow marine depositional environment. The palynomorphs are fairly well-preserved and the assemblage shows characteristic changes within the Triassic/Jurassic boundary interval: the lower part of the section is characterized by high abundance ofRicciisporites tuberculatus.The sudden increase in abundance of trilete spores, the decrease in the abundance ofOvalipollisspp., the last appearance ofAlisporites minimusandCorollinaspp., and the first appearance ofConcavisporites rhaetoliassicus, Cyatidites australis, Callialasporites dampieri, Pinuspollenites minimus, Platysaccusspp. andZebrasporites fimbriatusare striking features for a subdivision of two palynomorph assemblages. The detected spore shift is interpreted to display a sudden increase in humidity most probably caused by the volcanic activity of the Central Atlantic Magmatic Province (CAMP) associated with the onset of rifting of Pangaea during early Mesozoic times.

Shallow marine Lower and Middle Miocene deposits at the southern margin of the North Sea Basin (northern Belgium): dinoflagellate cyst biostratigraphy and depositional history

2000 ◽  
Vol 137 (4) ◽  
pp. 381-394 ◽  
Author(s):  
S. LOUWYE ◽  
J. DE CONINCK ◽  
J. VERNIERS
Keyword(s):  
North Sea ◽  
Depositional Environment ◽  
Middle Miocene ◽  
Depositional History ◽  
Shallow Marine ◽  
Dinoflagellate Cyst ◽  
Southern North Sea ◽  
The North ◽  
Southern Margin ◽  
The North Sea

Detailed dinoflagellate cyst analysis of the Lower–Middle Miocene Berchem Formation at the southernmost margin of the North Sea Basin (northern Belgium) allowed a precise biostratigraphical positioning and a reconstruction of the depositional history. The two lower members of the formation (Edegem Sands and decalcified Kiel Sands) are biostratigraphically regarded as one unit since no significant break within the dinocyst assemblages is observed. The base of this late (or latest) Aquitanian–Burdigalian unit coincides with sequence boundary Aq3/Bur1 as defined by Hardenbol and others, in work published in 1998. A hiatus at the Lower–Middle Miocene transition separates the upper member (the Antwerpen Sands) from the underlying member. The greater part of the Antwerpen Sands were deposited in a Langhian (latest Burdigalian?)–middle Serravallian interval. The base of this unit coincides with sequence boundary Bur5/Lan1. Biostratigraphical correlation points to a diachronous post-depositional decalcification within the formation since parts of the decalcified Kiel Sands can be correlated with parts of the calcareous fossil-bearing section, up to now interpreted as Antwerpen Sands. The dinoflagellate cyst assemblages are dominated by species with a inner neritic preference, although higher numbers of oceanic taxa in the upper part of the formation indicate incursions of oceanic watermasses into the confined depositional environment of the southern North Sea Basin.

Development of the New Hebrides archipelago

1975 ◽  
Vol 272 (918) ◽  
pp. 277-285 ◽  
Keyword(s):  
Late Miocene ◽  
Middle Miocene ◽  
First Episode ◽  
Late Oligocene ◽  
Calc Alkaline ◽  
Land Area ◽  
Early Pliocene ◽  
The Third ◽  
New Hebrides ◽  
Volcanic Islands

The general geology of the New Hebrides is summarized in terms of three volcanic and two main sedimentary episodes. Calc-alkaline volcanics ol the first episode occur on the western islands and accumulated mainly on the submarine slopes below small reef-fringed volcanic islands in Late Oligocene to Middle Miocene times. During the Late Miocene and Early Pliocene wholly submarine tholeiitic or high-Al volcanics accumulated in the eastern and southern part of the New Hebrides while calcareous sediments were forming in the western islands. During the third volcanic phase, of Pliocene to Recent age, regional uplift has led to most of the volcanics being subaerial while extensive flights of limestone terraces occur round the older islands. In consequence the land area of the New Hebrides has increased rapidly during Quaternary times. The landforms produced are briefly described.

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