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MIOCENE PALYNOLOGY OF THE BARITO BASIN, SOUTH KALIMANTAN Lelono, Eko Budi; Setyaningsih, Christina Ani; Ningsih, L Nugraha
Scientific Contributions Oil and Gas Vol 37, No 1 (2014)
Publisher : PPPTMGB "LEMIGAS"

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29017/SCOG.37.1.623

Abstract

This study has succesfully disclosed the rich assemblage of palynomorph within the Miocene sediment ofthe Barito Basin, South Kalimantan. It is characterised by the the last occurrence of Florschuetzia trilobata(Middle/ Late Miocene boundary) and the fi rst occurrence of F. meridionalis (Early/ Middle Mioceneboundary). In addition, other Miocene markers appear to mark this age such as spores of Stenochlaeniditespapuanus (Late Miocene) and Scolocyamus magnus (Early/ Middle Miocene). Mean while, the regularoccurrence of brackish palynomorphs along the studied sections indicates marine infl uence during depositionincluding Zonocostites ramonae, Florschuetzia meridionalis (mangrove pollen), Florschuetzia levipoli andSpinizonocolpites echinatus (back-mangrove pollen). The depositional environment initially occurs in thefreshwater environment of delta plain during Early to Middle Miocene (lower well sections) as suggestedby domination of freshwater pollen in the absence of marine micro-fossils. It gradually shifts in to deepermarine setting in delta front to pro delta (with possible shallow marine environment) during Middle toLate Miocene (upper well sections) as indicated by the increase of brackish palynomorphs combined withmarine micro-fossils. This study identifi es peak of riparian pollen Myrtaceidites sp. which is potential forwell correlation. This pollen is common within the lower well sections suggesting the presence of riverdeposits. On the other hand, considerable appearance of freshwater palynomorphs may be an indication ofwell development of low land forests under wet climate condition.
Pollen Record Of Early/ Middle Miocene Boundary In The South Sumatra Basin Lelono, Eko Budi
Scientific Contributions Oil and Gas Vol 32, No 2 (2009)
Publisher : PPPTMGB "LEMIGAS"

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29017/SCOG.32.2.836

Abstract

Early to Middle Miocene sediment obtained from three wells drilled in South Sumatera area has been evaluated for its micropaleontological content including foraminifera, calcareous nannoplankton and palynomorph. The boundary of Early/ Middle Miocene is clearly represented by zone N8/ N9 boundary based on foraminiferal analysis and zone NN4/ NN5 boundary on the basis of calcareous nannoplankton analysis. The rich assemblage of foraminifera and calcareous nannoplankton indicates the occurrence of marine sediment within the well sections. In addition, environmental markers of benthonic foraminifera suggest the occurrence of inner to middle neritic along the studied sections. Palynological analysis however, proves the high occurrence of pollen and spore along the marine successions situated in Early/ Middle Miocene boundary which is the first time to yield a good quality of palynological record. The Early/ Middle Miocene boundary is marked by low sea level in global sea level curve as indicated by significant decrease of foraminifera and calcareous nannoplankton. In addition, palynological record reflects climatic changes over N8/ N9 sediment marking Early/ Middle Miocene boundary with the declines of pollen assemblage suggesting seasonal/ dry climate condition. N8 sediment shows high abundance and diversity of palynomorphs including those of wet climate markers. Palynological assemblage drops gradually approaching foram zone N9/ N8 boundary, whilst seasonal climate indicators increase. On the other hand, palynological record recovers its assemblage over N9 sediment.
The Migration Pathway Of Some Selected Australian Palynomorphs From Their Origin To Se Asia Lelono, Eko Budi
Scientific Contributions Oil and Gas Vol 35, No 2 (2012)
Publisher : PPPTMGB "LEMIGAS"

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29017/SCOG.35.2.777

Abstract

This paper proposes the alternative dispersal route of Australian elements of Dacrydium and Casuarina from their origin to Southeast Asia. It was previously thought that these Australian affi nities migrated to Sunda region following the collision of the Australian and the Asian plates at the Oligo-Miocene boundary (Morley, 1998 and 2000). The subsequent study by Lelono (2007) extended the record of these two taxa from the Oligo-Miocene boundary to the base Oligocene. This is unlikely, since at the time of basal Oligocene, when these pollen types fi rst appear, the Australian land mass would have been some 1000 kms south of the East Java area. Therefore, this fact led Lelono (2007) to propose the earlier arrival of the Gondwanan fragment to this area in Early Oligocene. However, recent records of Dacrydium have been reported from the Early Eocene of the Ninety East Ridge (55 Ma) and the Indian subcontinent (50 Ma) (Morley, 2009). This implies to the alternative dispersal route of this pollen. It is possible that Dacrydium dispersed into SE Asia prior to the Early Oligocene via the Ninety East Ridge and the Indian plate, and subsequently its distribution across the Sunda region and Indochina was limited by palaeoclimate, explaining why it is present in some areas of the Sunda region, but not others. Mean while, a model to explain the dispersal of Casuarina remains unresolved, since migration via India is unlikely as there is no pollen record from the Indian subcontinent. Therefore, long distance dispersal may be a possibility for this pollen.
The Dispersal Route Of The Australian Elements Of Dacrydium And Casuarina From Its Origin To Se Asia Lelono, Eko Budi
Scientific Contributions Oil and Gas Vol 32, No 3 (2009)
Publisher : PPPTMGB "LEMIGAS"

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29017/SCOG.32.3.846

Abstract

This paper proposes the alternative migration route of the Australian elements of Dacrydium and Casuarina from their origin to Southeast Asia. It was previously thought that these Australian affinities dispersed to Sunda region following the collision of the Australian and the Asian plates at the Oligo- cene boundary (Morley, 1998 and 2000).The subsequent study by Lelono (2007) extended the record of these two taxa from the Oligo-Miocene boundary to the base Oligocene. This is unlikely, since at the time of basal Oligocene, when these pollen types first appear, the Australian land mass would have been some 1000 kms south of the East Java area. Therefore, this fact led Lelono (2007) to propose the earlier arrival of the Gondwanan fragment to this area in Early Oligocene. However, recent records of Dacrydium have been reported from the Early Eocene of the Ninety East Ridge (55 Ma) and the Indian subcontinent (50 Ma) (Morley, 2009). This implies to the alternative dispersal route of this pollen. It is possible that Dacrydium dispersed into SE Asia prior to the Early Oligocene via the Ninety East Ridge and the Indian plate, and subsequently its distribution across the Sunda region and Indochina was limited by palaeoclimate, explaining why it is present in some areas of the Sunda region, but not others. Mean while, a model to explain the dispersal of Casuarina remains unresolved, since migration via India is unlikely as there is no pollen record from the Indian subcontinent. Therefore, long distance dispersal may be a possibility for this pollen.
Oligocene Palynological Zonation Scheme From East Java Sea Lelono, Eko Budi; Morley, Robert J
Scientific Contributions Oil and Gas Vol 34, No 2 (2011)
Publisher : PPPTMGB "LEMIGAS"

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29017/SCOG.34.2.797

Abstract

Systematic biostratigraphic analyses have been undertaken on the Oligocene clastic and carbonate Kujung Formation from the East Java Sea, North of Madura. The succession has been examined mainly using cutting samples in two wells, using a combination of foraminiferal, nannofossil and palynological analyses at regular spacing. Nannofossil analysis indicates that the Late Oligocene to basal Early Miocene succession is more or less complete, with zones NP24, NP25 and NN1 are all being well developed. In addition, the Early Oligocene is indentified by larger foraminifera indicating the Tc/ Td Letter Stage. Because the traditional palynological zonation of Morley (1978) does not work well in this area, the succession has been divided into broad assemblage zones, which appear to be controlled mainly by climate. These zones are OL-1, OL-2, OL-3, OL-4 and OL-5. Zone OL-1 is based essentially on the absence of seasonal climate and riparian elements, whilst zone OL-2 is characterized by the regular occurrence of seasonal climate elements, especially of Malvacipollis diversus. Zone OL-3 is indicated by common to abundant Dacrydium and Casuarina pollen, with a strong acme of dinoflagellate cysts dominated by Operculodinium spp. and Spiniferites spp., whereas zone OL-4 is marked by abundant Dacrydium and regular Casuarina pollen, but low representation of riparian elements. Finally, the youngest zone is OL-5 which is characterized by reduced Dacrydium and Casuarina pollen, and increased riparian elements. The above palynological zonation suggests climate change, which closely parallels the climate succession from West Java Sea (but with changes less pronounced). Therefore, this study provides a well dated Oligocene palynological zonation which can be applied across Java.
PALEOGENE PALYNOLOGY OF THE CENTRAL SUMATERA BASIN Lelono, Eko Budi; Setyaningsih, Christina Ani; Nugrahaningsih, L
Scientific Contributions Oil and Gas Vol 37, No 2 (2014)
Publisher : PPPTMGB "LEMIGAS"

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29017/SCOG.37.2.632

Abstract

Unlike rich pollen assemblage of other Paleogene sediments in western Indonesia (as seen in NanggulanFormation of Central Java, Tanjung Formation of South Kalimantan and Malawa Formation of SouthSulawesi), pollen assemblage of Paleogene sediments in the Central Sumatera Basin is considerablylow. Referring to the occurrence of Oligocene spore Cicatricosisporites dorogensis supported by pollenPalmaepollenites kutchensis and Meyeripollis naharkotensis, it is inferred that the studied sediment isassigned to Oligocene age. This is strengthened by the disappearance of many key Indian affi nities whicharrived in the Sundaland during Eocene. Palynologically, this study separates the Brown Shale from theUpper Red Bed. The Brown Shale is dominated by fresh water pollen without brackish element suggestingnon-marine environment. This sequence might have been formed in syn-rift setting. Surprisingly, lacustrineindicators of fresh water algae Botriococcus and Pediastrum (as found in the lacustrine sediment of TalangAkar Formation of Sunda-Asri Basin) are absent. Mean while, the Upper Red Bed is marked by signifi cantoccurrence of brackish palynomorphs suggesting the infl uence of marine environment during post-rift period.This condition proves the existence of the transgressive phase where sedimentation started in freshwaterenvironment during the Brown Shale deposition which gradually shifted into transition (shallow marine)environment during the Upper Red Bed sedimentation.
The Jurassic-Cretaceous Paleogeography Of The Sula Area, North Maluku Lelono, Eko Budi
Scientific Contributions Oil and Gas Vol 34, No 1 (2011)
Publisher : PPPTMGB "LEMIGAS"

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29017/SCOG.34.1.793

Abstract

The study of paleogeography and hydrocarbon potentiality of the Sula area, North Maluku has been conducted by the Lemigas Exploration team. This paper specifically presents a paleogeography of the Jurassic-Cretaceous age of the Sula area as a part of the result of this study. In this paper, paleogeography means palaeoenvironment which is defined based on biostratigraphy. Data used in this paper are mostly secondary data obtained from National Data Center which is combined with primary data collected during field work campaign. The subsurface data analysis allows subdivision of 7 depositional sequences throughout Jurassic-Cretaceous succession. In fact, each sequence mostly consists of transgressive and highstand system tracts. Lowstand system tract only occurs in the earliest sequence. Sequences 1 (Bobong Formation), 2, 3 and 4 (Buya Formation) are assigned to the Jurassic age, whilst sequences 5, 6 and 7 (Buya Formation) are attributed to the Cretaceous age. Generally, the depositional environment of most sequences is getting deeper toward the North. The shallowest environment takes place in non-marine setting, whereas the deepest environment occurs in outer neritic (100m-200m). It is most likely that Jurassic-Cretaceous depocenter was situated in the northern part of the study area. However, it is required additional data to confirm this interpretation.
Oligocene Climate Changes of Java Lelono, Eko Budi; Morley, Robert J
Scientific Contributions Oil and Gas Vol 34, No 3 (2011)
Publisher : PPPTMGB "LEMIGAS"

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29017/SCOG.34.3.803

Abstract

The study of palynology performed on the Oligocene marine sediment of the East Java Sea provides excellent recovery which allows the construction of palynological succession which applies regionally (Lelono et. al., 2011). In fact, this succession is characterized by assemblages that suggest climatic changes. These assemblages are divided into two major groups including mangrove and hinterland. The hinterland pollen group shows the most interesting succession, with elements on the one hand suggesting everwet climates (Dacrydium and Casuarina), and seasonal elements on the other (Gramineae, Schoutenia and Malvacipollis diversus). Mangrove pollen however suggests strong environmental control since mangrove pollen shows different abundance variations in the two wells. The age of the studied succession is independently defined using combined marine micro-fossils of foraminifer and nannoplankton which indicate Early to Late Oligocene. Although for most of the Oligocene in Southeast Asia, seasonal climate assemblages are the rule, this study interpretes the appearence of everwet climates. The Early Oligocene is characterized by common rain forest elements, suggesting an everwet rain forest climate at that time. The early part of the Late Oligocene, however, contains much reduced rain forest elements, and the presence of regular Gramineae pollen, suggesting a more seasonal climate, whereas for the latest Late Oligocene, rain forest (and peat swamp) elements return in abundance, suggesting a very wet rain forest climate. In fact, Java region experienced the wettest climate during Oligocene which probably reflected a wet climate fringe to the eastern margin of Sundaland prior to the collision of the Australian and Asian plates at the Oligo-Miocene boundary.
Oligocene Palynology Of On-Shore West Java Lelono, Eko Budi
Scientific Contributions Oil and Gas Vol 35, No 2 (2012)
Publisher : PPPTMGB "LEMIGAS"

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29017/SCOG.35.2.779

Abstract

Compared to its counterpart in the off-shore area (including Northwest Java and Northeast Java), the Oligocene sediment of on-shore West Java provides low pollen assemblages. In addition, superwet elements of Dacrydium and Casuarina commonly occurred in off-shore area are less represented in the on-shore area. However, it is believed that the study area still experienced wet climate condition as proved by common occurrence of rattan pollen Dicolpopollis spp. indicating a thick growth of swamp forest under moist climate. Unlike its counterpart in the off-shore North West Java, the studied sediment rarely yields lacustrine elements suggesting the disappearance of lake deposit. The Oligocene sediment of on-shore West Java is defi ned by the regular appearance of Oligocene marker of pollen Meyeripollis naharkotensis. The last occurrence of this pollen marks the top Oligocene age. In fact, the appearance of pollen M. Naharkotensis is obviously used to separate Oligocene age from Miocene age in the off-shore area. Moreover, marine micropaleontology analysis on foraminifers and calcareous nannoplankton confi rms this age. The studied sediment was deposited in the transition to shallow marine environment as indicated by rare occurrence of marine microfossils. The common brackish pollen of Zonocostites ramonae (Rizophora) and Spinizonocolpites echinatus (Nypa) indicates mangrove/ back-mangrove environment. Moreover, the domination of shallow water benthonic over the planktonic forms suggests shallow marine setting.
Australian Palinomorphs From The Buya Formation Of The Sula Island Lelono, Eko Budi
Scientific Contributions Oil and Gas Vol 35, No 3 (2012)
Publisher : PPPTMGB "LEMIGAS"

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29017/SCOG.35.3.784

Abstract

This research has proved the occurrence of pre-Tertiary palynomorphs within the Buya Formation of the Sula Island. Most palynomorphs have Australian affi nity and appear in most Mesozoic basins in Australia and in Papuan Basin of Papua New Guinea. The palynomorph assemblage mostly consists of spores as well as dinofl agellates. Three micro-fl ora zones can be defi ned referring to the existing index spores, including (from older to younger zone) Contignisporites cooksoniae zone, Murospora fl orida zone and Retitriletes watheroensis zone. Meanwhile, four dinofl agellate zones enable to be constructed such as (from older to younger zone) Caddasphaera halosa zone, Wanaea clathrata-Wanaea indotata zone, Dingodinium swanense zone and Criboperidinium perforans zone-younger zone. Both zonations suggest that the age of the Buya Formation is Middle to Late Jurrasic or Bathonian to Tithonian. From the palaeobiogeographic point of view, the similarity between palynomorphs from the Buya Formation of the Sula Island and those from the  Mesozoic sediment of Australia suggests land connection between both areas during Middle to Late Jurassic. It suggests that, during this age, the study area attached the Australian Continent which was situated far South from the equatorial. The study area appears in its recent position during Neogene.