Sedimentation and Depositional Environment Based on Seismic and Drilling Core Analyses in Cimanuk Delta Indramayu, West Java

Core drilling had been carried out in three locations such as in Brondong Village (BH-01), Pasekan Village (BH-02), and Karangsong Village (BH-03). Those three cores are similar in lithology consist of clay. They are correlated based on fragment content, such as fine sand lenses, mollusk shells, rock and carbonate materials which discovered from different depths. Single side band of shallow seismic reflection recorded paleochannels in E sequence at the north and the west of investigated area. It’s predicted the north paleo channels were part of Lawas River or Tegar River, while the west paleo channels were part of Rambatan Lama River. Microfauna content of all those three cores indicated that from the depth of 0.00 meter down to 25,00 meters are Holocene/Recent, from 25,00 meters to the bottom are Pleistocene which were deposited in the bay to middle neritic environment. Key words: Core drilling, seismic interpretation, Cimanuk Delta Pemboran inti dilakukan di 3 (tiga) lokasi yaitu di Desa Brondong (BH-01), Desa Pasekan (BH- 02), dan Desa Karangsong (BH-03). Ke tiga inti bor itu mempunyai kesamaan litologi yaitu lempung. Korelasi dilakukan berdasarkan kandungan fragmen seperti lensa-lensa pasir halus, cangkang moluska, material batuan dan material karbonat yang terdapat pada kedalaman yang berbeda. Seismik pantul dangkal saluran tunggal merekam adanya alur purba pada runtunan E di bagian utara dan barat daerah penelitian. Diduga alur purba di bagian utara merupakan bagian dari tubuh Kali Lawas atau Kali Tegar, sedangkan di bagian barat sebagai bagian dari tubuh Kali Rambatan Lama. Kandungan mikrofaunanya menunjukkan ketiga bor inti mulai kedalaman 0,00 meter sampai 25,00 meter berumur Holosen/Resen, sedangkan dari 25,00 meter sampai batas bawah pemboran berumur Plistosen yang diendapkan pada lingkungan teluk hingga Neritik Tengah. Kata kunci: Bor inti, penafsiran seismik, Delta Cimanuk

Data Listing of the Bottom Materials Dredged and Cored from the Northern Philippine Sea (Part II. Studies on Basement Rocks)

Edited by Tsunemasa Shik

OCCURRENCE OF PHILLIPSITE MINERAL IN SUB- SEAFLOOR OF ROO RISE-INDIAN OCEAN : A TECTONIC EROSION SYNTHESIS

A single deep-sea core (MD982156) of 30.30 meters long which is obtained during the MD III-IMAGES IV Expedition from Roo Rise - Indian Ocean in 1998 was studied. Down to 30 meters of the core length, the sediment consists of abundance planktonic foraminiferas. Below 30 meters, it is mostly composed of phillipsite mineral-rich sediment that is associated with nannoplanktons.The Paleocene authigenic phillipsite minerals associated with nannoplanktons is separated from Late Miocene to Holocene planktonic foraminiferas rich-sediments by hiatus. This hiatus or non deposi- tional in Roo Rise suggest be triggered by long Cenozoic tectonic erosion

Stratigraphy of the Late Cretaceous-Paleogene deposits of the Western Cordillera Ecuador: Geodynamic implications.

International audienceTwo accreted oceanic terranes are classically recognized in the Cordillera Occidental of Central Ecuador, the Macuchi island arc to the West, and the Pallatanga oceanic terrane to the East. Detailed stratigraphic studies of the sedimentary cover of the "Pallatanga terrane" show that it actually comprises two terranes. During the late Campanian-early Maastrichtian, the eastern terrane received partially continent-derived turbidites, demonstrating that it was accreted to the Andean margin before mid Campanian times, i.e. 85-80 Ma ago. Meanwhile, the western terrane received fine-grained, pelagic siliceous black cherts indicating that it still belonged to the oceanic realm during mid Campanian-Maastrichtian times. Both series are unconformably overlain by a thick, coarsening upward siliciclastic series of Paleocene age, demonstrating that the western terrane accreted to the eastern one during the late Maastrichtian (≈ 69-65 Ma). The thick Paleocene clastic series recorded the uplift of the Eastern Cordillera, which was triggered by the latter accretion, and enhanced by the Late Paleocene accretion (≈ 58 Ma) of the Piñón oceanic terrane of southern coastal Ecuador

Popovia johnrolandi n.sp., a new smaller agglutinated foraminifera from northern Venezuela: a biostratigraphic example of the second law of thermodynamics

We describe a previously unrecognised species of Popovia, here named Popovia johnrolandi n.sp. from the Miocene of Eastern Falcon state in Venezuela. The internal complexity of this new species increased through the Serravalian from Zone N10 to N14. This apparent trend towards increasing internal complexity reflects increasing entropy through time, and is here interpreted as an evolutionary adaptation to life within an oxygen minimum zone

A Petrographic Analysis of the Microbial Thrombolite Buildup in the Oxfordian Smackover Formation, Little Cedar Creek Field, Alabama

The Jurassic (Oxfordian) Smackover Formation in Little Cedar Creek Field, Alabama is composed of microbial thrombolitic buildups. Core description, petrography, SEM, and isotopic analysis were used to identify the succession of organisms, microbial carbonate deposition, and diagenesis that contributed to formation of these thrombolitic buildups. The microbial thrombolite reef facies in this study accounts for 38.5% of the total Smackover Formation. This facies was deposited 0.5 to 6.75 miles from the paleo-coastline. Today it is located 10,225 to 11,750 feet in the subsurface and contains buildups 26 to 50 feet thick. Four microfacies were defined: A- Black Renalcis-like layers, B- Digitate, C- Chaotic and D- Brown laminated centimeter-scale cycles. In most of the buildup, distinct layers of microbially precipitated micrite forms in succession. Microfacies A (Black Renalcis-like Layer) is the relatively least porous and permeable, acting as a potential barrier to flow in contrast to the other more porous microfacies