A B ST RA K Data kelimpahan foraminifera dan karakteristik sedimen inti laut dalam digunakan sebagai proksi untuk merekonstruksi iklim, lingkungan, dan oseanografi di masa lalu. Penelitian ini menggunakan sebuah sampel sedimen inti laut dalam (ST-13) sepanjang 173 cm dari Selat Sumba, Nusa Tenggara Timur. Sampel sedimen tersebut diambil dengan menggunakan Kapal Riset Baruna Jaya VII pada saat Ekspedisi Widya Nusantara (E-WIN) tahun 2016. Sebanyak 22 subsampel sedimen diambil secara vertikal pada setiap interval delapan cm untuk analisa kelimpahan foraminifera, karakteristik fisik sedimen dan kandungan unsur kimianya. Tujuan dari penelitian ini adalah untuk mengetahui hubungan antara unsur biogenik (kelimpahan foraminifera) terhadap unsur anorganik (karakteristik fisik sedimen dan kandungan unsur kimia) melalui pengujian korelasi Pearson pada piranti lunak XLSTAT. Hasil analisis menunjukkan bahwa nilai korelasi yang tinggi antara kelimpahan foraminifera dengan nilai rata-rata, kemencengan, persentase pasir, Ca, dan Sr (-0,64, 0,72, 0,66, 0,71, dan 0,75). Sedangkan nilai korelasi yang lemah terjadi antara kelimpahan foraminifera terhadap pemilahan, kurtosis, Fe, Ti, dan K (-0,13, 0,43,-0,18,-0,43, dan-0,42). Nilai korelasi tersebut menunjukkan bahwa kelimpahan foraminifera mempengaruhi ukuran butir rata-rata, pergeseran distribusi kearah lebih kasar, persentase pasir, dan juga Ca dan Sr sebagai unsur dari cangkang foraminifera tersebut.

Foraminifera distribution is one of the proxies used to reconstruct climatic conditions and paleoceanography. Specific species or groups of foraminifera can be associated with certain oceanographic parameters. As one of the entrances of Indonesia Through Flow (ITF), North Papua Waters has the role of channeling water masses from the Pacific Ocean to the Indonesian Waters. It is also influenced by global thermohaline circulation and ENSO. In this study, observations were made of changes in the distribution of foraminifera to reconstruct paleoclimate and paleoceanographic conditions in the North Papua Waters and their relation to global climate conditions. The analysis was performed on 246 cm core sediments with eight cm foraminifera observation intervals at sample depths 246-126 cm and four cm at sample depths of 126-0 cm. Pulleniatina spp., Neogloboquadrina spp., and Globorotalia spp., are used for radiocarbon dating. Planktonic abundant species of foraminifera are Pulleniatina obliqueloculata, Neogloboquadrina dutertrei, Globorotalia menardii, Globigerinoides ruber, Globigerinoides trilobus, and the benthonic are Melonis pompilideus, Pullenia bulloides, Oolina sp., Planulina bradyii, Oridorsalis umbonatus, Cibicides subhaidingerii, Eggrela bradyii, Planulina wuelestroffi, and Quinqueloculina spp.,. Division according to cluster analysis can show the difference between Holocene and Pleistocene, which is then more detailed divided into 17 clusters. Based on biozonation there are some events that can be observed: climate variability since Late Pleistocene, record Pleistocene-Holocene boundary based on the significant variability of foraminifera distribution, and records some of the global climate events such as Last Glacial Maximum (~19-17 kyr), Younger Dryas (~11-9 kyr), and 8,2K event.

The presence of calcareous nannofossils in samples of the Post-Gondwana sequences (Kolbano and Viqueque sequence) gives guidance about the relative age of the study area located in the Outer Banda Arc, namely Timor, Rote, and Sawu Island. The study was carried out on six traverses, Timor Island traverse (Baun and Camplong), Rote Island traverse (Termanu and Central Rote), and Sawu Island traverses (West Sawu and East Sawu). There is 29 outcrop sample prepared using the smear slide method and observed using a polarizing microscope with 1000x magnification. The results of the study showed the presence of Cretaceous, Paleogene, and Neogen-Quarternary calcareous nannofossil. There are 82 species from 14 families identified in the post-Gondwana sequence. The results showed that the assemblage of calcareous nannofossil in Cretaceous characterized by the presence of Watznaueria fasciata, Watznaueria cynthae, Cyclagelosphaera brezae, Orastrum campanensis, and Micula concava. The assemblage of Paleogene calcareous nannofossil characterized by the presence of Coccolithus staurion, Chiasmolithus solitus, Discoaster minimus, Tawelus (?) magnicrassus, Chiasmolithus bidens, Prinsius africanus, Cyclicargolithus luminus, Spenolithus elongatus, Reticulofenestra umbilica, Cruciplacolithus vanheckae, and Helicospharea seminulum, and the assemblage of Neogene calcareous nannofossil characterized by the presence of Reticulofenestra pseudoumbilica, Discoaster quinqueramus, Helicosphaera princei, and Discoaster pansus. Quarternary calcareous nannofossil characterized by the presence of Ponthospaera indooceanica.

No abstract

Formasi Ofu berumur Neogen-Kuarter tersingkap baik di bagian tengah Pulau Timor. Kumpulan nannofosil gampingan Formasi Ofu berumur Neogen terdiri tujuh famili dan 25 spesies. Nannofosil gampingan berumur Neogen didominasi genus Discoaster, Dictyococcites, dan Reticulofenestra sedangkan umur Kuarter didominasi oleh genus Gephyrocapsa. Nannofosil gampingan Neogen terdiri dari dua zonasi, dan satu zona Kuarter. Permulaan Miosen, Burdigalian-Tortonian (zona NN 4-NN 10) ditandai pemunculan awal Reticulofenestra pseudoumbilica hingga pemunculan awal Discoaster quinqueramus. Zona NN11 yang berumur Tortonian-Messinian ditandai pemunculan awal hingga pemunculan akhir Discoaster quinqueramus. Kuarter (Zona NN20)  ditandai pemunculan awal Ponthospaera indooceanica.