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The Dispersal Route Of The Australian Elements Of Dacrydium And Casuarina From Its Origin To Se Asia Eko Budi Lelono
Scientific Contributions Oil and Gas Vol 32 No 3 (2009)
Publisher : Testing Center for Oil and Gas 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.
Gondwanan Palynomorphs From The Paleogene Sediments Of East Java The Evidence Of Earlier Arrival Eko Budi Lelono
Scientific Contributions Oil and Gas Vol 30 No 2 (2007)
Publisher : Testing Center for Oil and Gas LEMIGAS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29017/SCOG.30.2.864

Abstract

The palynological investigation of the Paleogene sediments is based on cutting samples collected from the exploration wells which are drilled in East Java area. The occurrence of pollen Meyeripollis naharkotensis and spore Cicatricosisporites dorogensis in the upper well sections suggests the pollen zone of Meyeripollis naharkotensis which is equivalent to Oligocene age. Meanwhile, the occurrence of pollen Proxapertites operculatus and spore Cicatricosisporites eocenicus below Meyeripollis naharkotensis zone indicates the appearance of Proxapertites operculatus zone within the lower sections which is equivalent to Eocene. In addition, foraminiferal and nannoplankton analyses confirm the Oligocene-Eocene age by identifying the occurrence of letter stage of Te4-Tb and nanno zone of NP20-P25. The appearance of the Gondwanan/Australian elements including Dacrydium and Casuarina with common and regular occurrences throughout the studied sections are controversial as these pollen were firstly recorded in the younger sediments (Early Miocene) of other areas such as Northwest Java sea, South Sumatra and Natuna sea following the collision of the Australian plate and the Sundaland in the latest Oligocene. Furthermore, the absence of these palynomorphs within the Paleogene sediments of Central Java and South Sulawesi strengthens the above assumption. Therefore, in regard to East Java, the appearance of Dacrydium and Casuarina may indicate earlier arrival of the Gondwanan/ Australian fragment in this area compared to that in other areas of Indonesia.
Palynology Of The Lower Kalicapung Formation Tlogosari, Central Java Eko Budi Lelono
Scientific Contributions Oil and Gas Vol 25 No 2 (2002)
Publisher : Testing Center for Oil and Gas LEMIGAS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29017/SCOG.25.2.878

Abstract

The palynological investigation focuses on the transition sediment of the Lower Kalipucang Formation which overlies the non-marine lava of the Gabon Formation. Both formations are firmly separated by the unconformity which is indicated by the occurrence of basal conglomerate. The Lower Kalipucang Formation outcrops in a small village called Tlogosari, Central Java. Lithologically, it is characterised by the occurrence of basal conglomerate with the intercalation of thin lignites. This lithology is overlain by 2 meter thick of claystone containing lignite strings and some igneous fragments. The intercalation of thin sandstones, conglomerate and lignites are found within claystone lithology. Four samples from the Lower Kalipucang Formation were selected for laboratory processing. Only two samples collected from the upper part of this formation yield rich palynomorphs. The palynomorph assemblage shows the occurrence of brackish and fresh water floras. Based on the appearance of pollen Florschuetzia meridionalis and F. trilobata, it is predicted that the age of the Lower Kalipucang Formation is Middle Miocene. The high abundance of mangrove taxa (especially in sample number LKP-4) such as Avicenia type, Zonocostites ramonae and Camptostemon indicates a well development of mangrove environment. This assumption is supported by well preservation of large mollusc with excellent ornamentation. This ornamentation must have developed in the environment with low energy such as mangrove.
The Use of Palynology in Sequence Stratigrafy Analysis a Case Study, The Eocene Nanggulan Formation Eko Budi Lelono
Scientific Contributions Oil and Gas Vol 23 No 3 (2000)
Publisher : Testing Center for Oil and Gas LEMIGAS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29017/SCOG.23.3.882

Abstract

This paper is a part of palynological investigationon The Eocene Nanggulan Formation, Yogjakarta Central Java. The Nanggulan Formation containing rich palynomorph assemblage provider excellent data to support sequence stratigraphy analysis. The palynomorph assemblage changes (especially between mangrove and freshwater palynomorphs) may reflect sea level changes whitch can be used to interpret system tracts, which are the internal building blocks of sequences.
PALYNOLOGICAL INVESTIGATION OF THE OLIGOCENE SEDIMENT IN EAST JAVA SEA Eko Budi Lelono
Scientific Contributions Oil and Gas Vol 30 No 1 (2007)
Publisher : Testing Center for Oil and Gas LEMIGAS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29017/SCOG.30.1.970

Abstract

The palynological study of the Oligocene sediments is based on cutting samples collected from the exploration wells which are drilled in East Java Sea. The occurrence of pollen Meyeripollis naharkotensis along the well sections suggests the pollen zone of Meyeripollis naharkotensis which is equivalent to Oligocene age. This is supported by the regular occurrence of the Oligocene marker of the trilete spore of Cicatricosisporites dorogensis along the studied well sections. In addition, foraminiferal and nannoplankton analyses confirm the Oligocene age by identifying the occurrence of letter stage of Tc- Te4 and nanno zone of NP21-NP25. On the other hand, most palynomorphs marking Eocene age disappear from the studied wells as they are stratigraphically older than the studied sediments. Unlike the Oligocene sediment of West Java and Central Sumatra which was formed in the freshwater swamp or lake under dry climate condition, the studied sediment was deposited in the transition to shallow marine environment as indicated by the moderate diversity of marine dinoflagellates coupled with the frequent occurrence of limestone along the sections. Furthermore, the regular appearance of back-mangrove pollen of Spinizonocolpites echinatus throughout the well sections supports the indication of marine influence. The appearance of the Australian immigrants including Dacrydium (common occurrence) and Casuarina (regular occurrence) may indicate earlier arrival of the Australian continent in this area compared to that in other areas of Indonesia.