E-ISSN : 2541-5794 P-ISSN : 2503-216X Journal of Geoscience, Engineering, Environment, and Technology Vol 02 No 02 2017 110 Winantris et al./ JGEET Vol 02 No 02/2017 Paleoenvironment of Tanjung Formation Barito Basin- Central Kalimantan Based on palynological data Winantris 1, *, Helman Hamdani 1 , Ellin Harlia 1 1 Padjadjaran University Abstract The research area is located in the Muara Teweh, North Barito, Central Kalimantan. The cocking coal deposits are well known as they were produced from this area. Upper part of Tanjung Formation is target coal production. The study objectives are to analyze paleoenvironment and to determine the relative age of coal deposits based on palynological data. Preparing palinological analysis used standard procedure by hydrofluoric acid method.Palynomorphs data grouped into six types of ecology, and the sequence is as follows ; fresh water and lowland (41,75 %), brackish water swamp (30,10%), Peat and freshwater swamp (17,96%), marine element (7,77 %), back mangrove (1,46%) and upland element (0,97). Palmae pollen is very dominant, especially from freshwater and peat swamp that grow around coastal area i.e. Dicolcopollis, Proxapertites cursus, Proxapertites operculatus, Longapertites and Palmaepollenites kutchensis. Although marine fossil found, but the frequency less than one percent, that was the evidence of influence sea water to swamp area. The palynomorphs indicate the coal sedimented at upper delta plain. Fossil index of relative age consist of Proxapertites cursus, Proxapertites operculatus, Magnastriatites howardi Verrucatosporites usmensis, Retistephanocolpites , and Ixonantes type which refer to Late Eocene. Key world: Paleoenvironment, pollen, Tanjung Formation, Central Kalimantan. 1. Introduction Tertiary Barito basin spread through Central Kalimantan until South Kalimantan. The northern basin bordered by West Kutai Basin, and in the west by Schwaner High, to the east by Meratus High, in the south of the Java Sea. The basin covering an area of some 75,000 km2, sediment thickness varies from about 2000 to 5000 meters. Basin formation started at the Late Cretaceous after the collision micro- continent between Paternoster and SW Borneo microcontinent (Satyana and Idris, 2006). The complete cycle sedimentation of sedimentary rock is found in this basin from Eocene to Miocene by regression and transgression series. Tanjung Formation rocks is an oldest sedimentary rock in this basin which was deposited unconformity above Pre- Tertiary basement rock. Sediment deposition process takes place in an environment fluvio-deltaic, delta front until neritic zone. The Tanjung Formation occurred since Late Paleocene until Late Eocene (Satyana and Silitonga, 1994). Coal was a sedimentary rock that filled the earliest Tanjung Formation, so that coal is the oldest sedimentary rocks that formed in the Barito basin. Tanjung Formation generates cooking coal that estimated formed in the Late Eocene (Belkin dan Tewalt, 2007; Friederich, et al, 2009; Nas dan Hindartan, 2010). Construction of Tanjung Formation started since Paleocene until Late Eocene (Satyana and Silitonga, 1994). The area spread from Central Kalimantan until South Kalimantan, so very possibly to occupy various environment. Research focus on coal Tanjung Formation of Muara Teweh, Central Kalimantan. This objective of study to determine the age and depositional environment condition during the sedimentation of Tanjung Formation which was exposed in the study area. The Tanjung coal formation are outcropping in the Northern part of Barito Basin. The coordinates of coal sample is 1 o 3'39,74'' S and 114 o 38'37,26'' E within 50 km to the southwest of Muara Teweh district and about 250 km to the northeast from Palangkaraya City, situated is established between 1 o 3'39,74'' S and 114 o 38'37,26''E (Fig 1). 2. Stratigraphy Bariro Basin Stratigraphy Barito Basin in research area arranged into five Formation and an alluvium sediments (fig 2), as follows: Tanjung Formation is the oldest rock sediment. The lower part of Tanjung Formation consists of alternating among glauconitic sandstones, shale, siltstone and conglomerate of various materials, some of which are calcareous. Conglomerate's components consist of quartz, feldspar, granite, schist, gabbro and basalt. * Corresponding author : win.oncos@gmail.com Tel.:+81-80-929-1466; fax: +81-72-867-1658 Received: 2 May, 2017. Revised : 28 May 2017, Accepted: 30 May, 2017, Published: 1 June 2017 DOI: 10.24273/jgeet.2017.2.2.305 mailto:win.oncos@gmail.com Winantris et al./ JGEET Vol 02 No 02/2017 111 Fig. 1. Location of coal sample (right) and coal outcrop (left) Fig. 2. Stratigraphy of research location (Modified from Supriatna et.al,1981) 112 Winantris et al./ JGEET Vol 02 No 02/2017 The upper part consists of alternating quartz sandstone, siltstone, limestone, and coal. The relative age of Tanjung Formation is Late Eocene, it lays unconformity on the basement Mesozoic rocks, a thickness of sediment about 1,300 meters and the depositional environment is the swamp. Berai Formation composed of gray and white limestone, fine to medium grained, partly recrystallized, contains a large foraminifera and coral, partially layered, it lays conformity on the Tanjung Formation, relative age about Middle Oligocene to Late Oligocene, deposited in Shallow marine environment, the thickness reach 1.250 meters, it occupies a steep karst hills. Karamuan Formation composed of consists of gray mudstone, partly calcareous and fossilized; quartz sandstones; gray siltstone; light-gray tuffaceous siltstone, there is fossil insert in the limestone, carbonaceous siltstone, shally siltstone overlie the Tanjung Formation conformably, and estimated interfingering with Berai Formation, deposited in shallow marine to outer self. Montalat Formation characterized by white quartz sandstones, cross bedding structures, partly calcareous, deposited overlie the Formasi Tanjung conformably in a marine environment, interfingering with Berai Formation, Oligocene, the sediment about 1.400 meters thick. Warukin Formation, the character of the sandstone includes beds that are medium grained, well sorted. Contain carbonaceous mudstone, carbonaceous siltstone. Party conglomeration sandstone, semi-solid, cross and parallel laminations. This formation overlies the Berai Formation, the depositional environment of the Warukin Formation is coastal at Middle Miocene, estimated to be 500 meters in thickness. Alluvial deposit Consist of gravel, pebbles, sand, mud and plant debris. 3. Material and Methods Sample have been prepared by the standard method using hydrofluoric acid digestion continued by oxidation. The function of each chemical material is; concentrated hydrofluoric acid to remove silica, potassium hydroxide to remove humic acid, hydrogen chloride to remove carbonate, zinc chloride with specific gravity 2.2 to separate palynomorphs from others material. Acetolysis is a process to remove cellulose. Before making slides, palynomorphs colored by safranin. Examination of palynomorphs was using transmission light microscope in different magnification of 100x, 400x, and 1000x. Based on the environment of palynomorphs origin then grouped based on their environmental, in this case grouped into six i.e: marine, back mangrove, brackish water swamp, freshwater swamp, freshwater and upland element. Marine palynomorphs which observed only dinocyst and linning test foraminifera, both of them were found in the sample. Back mangrove element referred to pollen and spore that produced by vegetation which grows behind mangrove environment. Freshwater swamps elements are pollens and spores that came from around streams or lake which influenced by rain and seasonal flooding so causes water levels to fluctuate swampy condition. Freshwater elements are pollen, spore, and algae which came from the freshwater environment around lowland area. The upland element is pollens and spore which produced by vegetation came from mountain vegetation. Type of vegetation environmen have been publish by Haseldonxk (1974). 4.Result and discussion 4.1.Paleoenvirnment Acquired 206-grain palynomorphs that comprising 7.84% of the marine environment, which consists of Dinoflagellate cyst and linning test foraminifera. Brackish water swamp 19.61%, consisting of pollen/spore derived from the fact brackish environment is derived from mangrove and back mangrove. Peat and Freshwater swamp 30.39%, those are pollen and spore which produced by plants from peat swamps, freshwater swamps, and riparian. Freshwater and lowland 41.18%, consist of pollen which produced by lowland and freshwater plants. Upland pollen 0.98%, the result of wind- transported pollen (Fig 3).Overall palmae pollen is the highest pollen that consisting of Proxapertites cursus, Proxapertites operculatus, Palmapollenites kuthensis, Longapertites and Dicolcopollis. The plants grow in the coastal areas, especially in the brackish marshes that position area is behind the mangrove until around the river. This fact supported by Acrostichum aureum spores were found at the site as indicator brackish area.The collision of India and Asia plate in the middle Eocene to propagate plants from India to Southeast. Asia region. At that time both the northern region of the Indian plate and the Sunda region experiencing always wet climate, which is reflected in the equatorial climate and common events coal formation in both areas (Morley1998, 2003). Pollens are considered developing in the Sunda Region follow the collision and found at the study area are Palmapollenites kutchaensis, Retistephonocolpites , Magnastritatites grandiosus / Magnastriatites howardii, Ixonanthes type / Spiniulotriporites spinous, Lakiapollis ovatus.Even marine fossils obtained very few, its presence indicates that the sediment deposition occured in the transitional basin. Dinoflagellate cyst and inner test foraminifera are marine fossils that transported by tidal current through a channel and a connection between the deposition area and the sea. Based on palynomorphs composition which dominated by pollen and spore from swamp environment that refers to the delta environment, particularly delta plain. Winantris et al./ JGEET Vol 02 No 02/2017 113 Fig.3. Palynomorphs group in quantity and percentage Fig. 4. Cicatricosisporites eocenicus (1), Palmapollenites kutchensis (2), Proxapertites cursus (3) Dicolcopollis (4) Inner test foraminifers (5), Podocarpidites (6) 114 Winantris et al./ JGEET Vol 02 No 02/2017 Table 1. Ecological group of Palynomorphs No Ecological group Palynomorphs 1 Marine element Marine dynocyst Foraminifera test linning 2 Back mangrove Acrostichum aureum 3 Brackis water swamp Proxapertites operculatus Proxapertites cursus Dicolcopollis 4 Fresh water swamp Blumeodendron Lakiapollis ovatus Lanagiapollis emerginatus Longapertites Palmapollenites kutchaensis Polygalacidites sp Sapotaceoidaepollenites sp Verrucatosporites usmensis 5 Fresh water Anacolosidites lutoides Bombacaeae Cycadopites Gothanipollis Gymnospermae Ixonantes type Lycopodium cernuum Lycopodium phlegmaria Magnastriatites howardi Margocolporites vanwijhei Matonia sp Monoporites annulatus Osmundacidites Palmae undet Polygonum Protecidites Verrucatosporites spp Retistephanocolpites wiliamsi Laevigatosporites Freshwater Algae 6 Upland element Cedripites Podocarpidites Winantris et al./ JGEET Vol 02 No 02/2017 115 Table 2. Age relative based on pollen and spore marker 4.2. Relative age Some importance fossils have been obtained which can be used to determine relative age Tanjung Formation particularly in the research area as follow: Proxapertites cursus, Proxapertites operculatus, Palmapollenites kuthensis (Iguanurinae), Verrucatosporites usmensis, Magnastritatites grandiosus/Magnastriatites howardii, Retistephanocolpites . Both Proxapertites operculatus and Proxapertites cursus, those fossils existed in the Kalimantan until the Late Eocene, although the first appearance was not explicitly described (Morley, 1991). Magnastritatites howardi recorded appeared in the border of Late Eocene - Early Oligocene (Morley.1998), the appearances of Verrucatoporites usmensis approaching the middle-late Eocene border. Palmapollenites khutcensis existed since Eocene until Oligocene, and Retistephanocolpites wiliamsi appeared in the Middle Eocene and disappeared in the Late Oligocene. Based on those taxa the establishment process of coal in the study area during Late Eocene (Fig 4). 5. Conclusions The results showed that the Tanjung coal formation in the Barito Basin was formed at Late- Eocene. This is different from previous research that said Tanjung Formation in the Muara Teweh the age relative was early Eocene. The dominance of pollen which derived from swamp habitat indicates that the process of coal sedimentation occurred in the swamp environment with marine influence. Acknowledgements We are grateful to Rector of Padjadjaran University who have suport this research through Academic leadership programme (ALG). References Anonim, 2016. Swamp, bog, and wetland. National Geographic Society Belkin, H.E, and Tewalt, S.J, 2007. Geochemistry of Selected Coal Samples from Sumatra, Kalimantan, Sulawesi, and Papua, Indonesia. USGS. Science for changing the world. 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Nas, Ch and Hindartan, 2010. Kalimantan Coal and Mineral Resources. Proceeding MGEI-IAGI,29- 30 March 2010, Balikpapan, Kalimantan Indonesia 116 Winantris et al./ JGEET Vol 02 No 02/2017 Satyana, A.H., Idris, R., 2006. Chronology and Intensity of Barito Uplifts, Southeast Kalimantan: A Geochemical Constraint and Windows of Opportunity: Abstract 2006. Satyana, A.H., Silitonga, P.D., 1994. Tectonic reversal in East Barito Basin, South Kalimantan: Consideration of the types of inversion structures and petroleum system significance. Proc. Indones. Pet. Assoc. Twenty-third Annu. Conv. Oct. 1994 57 74. Witts, D., Hall, R. Morley, R.J. and BouDagher- Fadel, M. K. 2011. Stratigraphy and sediment provenance, Barito Basin, Southeast Kalimantan. Proceedings Indonesian Petroleum Association, 35th Annual Convention, IPA11-G-054 1-18. Witts, D., Hall, R; Nichlos,G and Morley, R.J. 2012. A new depositional and provenance model for the Tanjung Formation Barito Basin,SE Kalimantan Indonesia. Journal of Asian Earth Sciences 56 (2012) 77 104. 1. Introduction 2. Stratigraphy Bariro Basin 3. Material and Methods 4.Result and discussion 4.1.Paleoenvirnment 4.2. Relative age 5. Conclusions Acknowledgements References