TY - JOUR T1 - Dating Borneo’s Deltaic Deluge: Middle Miocene progradation of the Mahakam Delta JF - Palaios Y1 - In Press A1 - Nathan Marshall A1 - Vibor Novak A1 - Irfan Cibaj A1 - Wouter Krijgsman A1 - Willem Renema A1 - Jeremy Young A1 - Nicholas Fraser A1 - Alexander Limbong A1 - Morley, Robert J. ER - TY - JOUR T1 - Microbial carbonates in Miocene reefs in the Mahakam Delta in East Kalimantan, Indonesia JF - Sedimentary Geology Y1 - 0 A1 - Vedrana Pretković A1 - Juan C. Braga A1 - Vibor Novak A1 - Anja Rösler A1 - Willem Renema AB -

Coral patch reefs in the Miocene Mahakam Delta in East Kalimantan (Borneo, Indonesia) grew in shallow marine turbid waters. These patch reefs developed from delta front to deeper (prodelta) settings in areas with temporary reduced siliciclastic input. Langhian reef deposits are well exposed in limestone quarries in the Samarinda area and locally include microbial carbonates. Two different types of microbial carbonates have been found around Samarinda in two localities 2 km apart. These sections were logged in detail and 208 samples were collected. Meso and macrostructure of microbialites were identified at the outcrops. Thin sections from carbonate samples were examined under optical microscope and microfacies were classified using the Dunham (1962) and Insalaco (1998) terms. The carbonate content was analyzed using Total Inorganic Carbon analysis, with 12% carbon as a standard for carbon calibration. In the northern section, microbialites occur as low-relief domes, up to 2 m wide and 0.5 m high, with internal lamination, developed around large coral fragments at the transition from reef deposits to fine-grained siliciclastics.
The second type of microbialites has been found in the southern locality as decimeter-scale nodules ("megaoncoids") formed around nuclei of large coral fragments. Small nodules were bound together into bigger nodules. Microbial micrite with laminated to digitated fabrics intergrew with coralline algae to form the thick covers of these "megaoncoids", which laterally change into coral boundstones. In both sections microbialites are not components of the reef framework. They grew around large coral fragments on the flanks of the patch reefs. The microbialites that form low relief domes developed on nearly flat, stable seafloor seawards of the patch reef. The "megaoncoids" in the southern section formed as a result of downslope movement of coral fragments coated by microbialite/coralline algal crust. The steep slope at the flank of the patch reef favored falling and overturning of encrusted corals and continued growth of microbial crusts on other sides of nodules.

CY - Berlin, Germany ER - TY - CONF T1 - Microbial carbonates in Miocene reefs in the Mahakam Delta in East Kalimantan, Borneo, Indonesia T2 - SAGE2013 - Southeast Asian Gateway Evolution Y1 - 2013 A1 - Vedrana Pretković A1 - Juan C. Braga A1 - Vibor Novak A1 - Anja Rösler A1 - Willem Renema AB -

Microbial carbonates are deposits that form by the activity of bentic microbial communities. Microbialites usually form domical, columnar or conical structures and can have laminated, clotted, dendritic or homogenous macrofabric. They have a broad distribution and can grow in a variety of different environments such as hot springs, freshwater lakes, hypersaline lakes, reefs and other marine environments. This research focuses on microbialites associated to coral reefs. Coral patch reefs in the Miocene Mahakam Delta in East Kalimantan (Borneo, Indonesia) grew in shallow marine turbid waters. These patch reefs developed from delta front to deeper (prodelta) settings in areas with temporary reduced siliciclastic input. Langhian reef deposits are well exposed in limestone quarries in the Samarinda area and locally include microbial carbonates. Two different types of microbial carbonates have been found around Samarinda in two localities 2 km apart. These sections were logged in detail and 208 samples were collected. Meso and macrostructure of microbialites were identified at the outcrops. Thin sections from carbonate samples were examined under optical microscope and microfacies were classified using the Dunham (1962) and Embry and Klovan (1971) terms. The carbonate content was analyzed using Total Inorganic Carbon analysis, with 12% carbon as a standard for carbon calibration. In the northern section, microbialites occur as low-relief domes, up to 2 m wide and 0.5 m high, with internal lamination, developed around large coral fragments at the transition from reef deposits to fine-grained siliciclastics.
The second type of microbialites has been found in the southern locality as decimeter-scale nodules ("megaoncoids") formed around nuclei of large coral fragments. Small nodules were bound together into bigger nodules. Microbial micrite with laminated to digitated fabrics intergrew with coralline algae to form the thick covers of these "megaoncoids", which laterally change into coral boundstones. In both sections microbialites are not components of the reef framework. They grew around large coral fragments on the flanks of the patch reefs. The microbialites that form low relief domes developed on a nearly flat, stable seafloor seawards of the patch reef. The "megaoncoids" in the southern section formed as a result of downslope movement of coral fragments coated by microbialite/coralline algal crust. The steep slope at the flank of the patch reef favoured falling and overturning of encrusted corals and continued growth of microbial crusts on other sides of nodules.

JF - SAGE2013 - Southeast Asian Gateway Evolution CY - Berlin, Germany ER - TY - JOUR T1 - Distribution of larger foraminifera in mixed carbonate-siliciclastic systems JF - Journal of Asian Earth Sciences Y1 - 0 A1 - Vibor Novak A1 - Willem Renema ER - TY - JOUR T1 - Early Miocene larger foraminifera assemblage of the Taballar Limestone (East Kalimantan) JF - Journal of Foraminiferal Research Y1 - 0 A1 - Vibor Novak ER - TY - JOUR T1 - Larger foraminifera as environmental discriminators in Miocene mixed carbonate-siliciclastic systems JF - Palaios Y1 - In Press A1 - Vibor Novak A1 - Willem Renema ER - TY - JOUR T1 - Age of Neogene fossil localities in the Northern Kutei Basin JF - Palaios Y1 - Submitted A1 - Willem Renema A1 - Viola Warter A1 - Nathan Marshall A1 - Vibor Novak ER - TY - JOUR T1 - Coralline Algae from the Miocene Mahakam Delta (East Kalimantan, SE Asia) JF - Palaios Y1 - In Press A1 - Anja Rösler A1 - Vedrana Pretković A1 - Vibor Novak A1 - Willem Renema A1 - Juan C. Braga AB -

Miocene crustose coralline algae (CCA) from the South East Asia are poorly known, although the Miocene is the epoch of the onset of the biodiversity hotspot in the region and CCA are crucial to understand the evolutionary history of reef building. To fill this knowledge gap, CCA from Lower and Middle Miocene reefs and related carbonates in the Kutai Basin in East Kalimantan (Borneo, Indonesia) have been studied. The Kutai Basin was dominated by siliciclastic sediments of the Proto-Mahakam delta and only locally carbonate buildups occur laterally to or within the deltaic succession. CCA in the Kutai Basin occur in low-energy shallow-water platform carbonates and in association with coral reefs, encrusting the corals or bioclasts. Two main CCA assemblages have been recognized: 1) A shallow-water assemblage (S-assemblage), dominated by Neogoniolithon spp., thick crusts of Spongites spp., and Hydrolithon spp.; and 2) the D-assemblage, mainly consisting of thin crusts of Lithothamnion spp., Mesophyllum spp., and Sporolithon spp., which grew in darker waters. Light reduction in reefs in the Proto-Mahakam delta was due to increased water depth or higher turbidity by higher siliciclastic input. Assemblages with intermediate composition (I-assemblages) can also be found. Common CCA with large cells fusions and groups of heterocysts, typical features of modern reef CCA, in the S-assemblages in the Middle Miocene of East Kalimantan reflect the initiation of the reef-building CCA flora in the Indo-Pacific region. The occurrence of this kind of CCA confirms the biogeographic differentiation of a tropical reef flora.

ER - TY - JOUR T1 - A diverse patch reef from turbid habitats in the Middle Miocene (East Kalimantan, Indonesia) JF - Palaios Y1 - Submitted A1 - Nadiezhda Santodomingo A1 - Vibor Novak A1 - Vedrana Pretković A1 - Nathan Marshall A1 - Anja Rösler A1 - Emanuela Di Martino A1 - Elena LoGiudice A1 - Sonja Reich A1 - Juan Carlos Braga A1 - Willem Renema A1 - Kenneth G. Johnson ER - TY - JOUR T1 - Environmental reconstruction of a late Burdigalian (Miocene) patch reef in deltaic deposits (East Kalimantan, Indonesia) JF - Palaeogeography, Palaeoclimatology, Palaeoecology Y1 - 2013 DO - http://dx.doi.org/10.1016/j.palaeo.2013.01.009 A1 - Vibor Novak A1 - Nadiezhda Santodomingo A1 - Anja Rösler A1 - Emanuela Di Martino A1 - Juan Carlos Braga A1 - Paul D Taylor A1 - Kenneth G. Johnson A1 - Willem Renema SP - 110 EP - 122 AB -

Most studies of Cenozoic shallow-water, mixed carbonate-siliciclastic depositional systems have focused on their sedimentology. To date, however, comprehensive analyses of biotas and biofacies of Indo-West Pacific reefs that developed in mixed carbonate-siliciclastic systems are lacking. This study describes the palaeoenvironment and biodiversity of a late Burdigalian patch reef that developed in a mixed carbonate-siliciclastic depositional system. The studied exposure is located at the northeast margin of the Kutai Basin near Bontang (Indonesia), and is approximately 80 m wide and 25 m thick. Multi-taxon analysis of the most abundant fossil groups, including larger benthic foraminifera, corals, coralline algae, and bryozoans, aims to provide a model for environmental interpretation that will allow comparison with similar deposits of Indo-West Pacific region. Based on fossil content and lithology, five different facies types have been distinguished: foraminiferal packstone (FP), bioclastic packstone with foralgal communities (BP), thin-platy coral sheetstone (CS), platy-tabular coral platestone (CP), and shales (S). Among larger benthic foraminifera, smaller and more robust forms dominate in the FP and BP facies, while larger and flatter forms are the most abundant in the CS and CP facies. Thin-platy corals are dominant in the CS facies and gradually change into thicker platy-tabular forms in the CP facies. Assemblages and growth forms of coralline algae show no major differences between the facies types and are dominated by melobesioids and Sporolithon. The majority of bryozoan species are encrusting and were found only in the CS facies. Light-dependent organisms occurring in the reef indicate low light conditions typical for mesophotic reefs. The relatively small size of this reef complex and quite distinct vertical changes in the facies types, combined with the high siliciclastic content in most of the units, points to strong terrigenous input affecting water transparency as the main factor controlling the reef growth.

VL - 374 ER - TY - CONF T1 - Foraminiferal assemblages in Miocene carbonates of Indonesia T2 - Southeast Asian Gateway Evolution: SAGE2013 Y1 - 2013 A1 - Vibor Novak A1 - Willem Renema AB - Neogene carbonates in Indonesia are characterised by different depositional environments. We studied localities outcropping on Mangkalihat Peninsula, Kutai Basin, and Java, that were deposited in a time interval from Early (Te5) to Middle Miocene (Tf2). In order to reconstruct depositional environments and obtain biostratigraphic information, larger benthic foraminifera (LBF) assemblages were analysed from these three locations. The northernmost, and stratigraphically oldest, from the studied carbonates are exposed on Mangkalihat Peninsula. They were formed in shallow-water environment on carbonate platform. Stratigraphically important LBF indicate Early to Middle Miocene age (Te5-Tf1). Towards the south, in the Kutai Basin, isolated patch reefs occur within siliciclastic sediments, developed in mixed carbonate-siliciclastic depositional systems. In general, LBF assemblage is indicative of low-light conditions typical for mesophotic reefs. Based on LBF late Early to Middle Miocene age (Tf1-Tf2) can be suggested. The southernmost carbonate exposures are located on Central Java, in the Bulu Limestone member. The LBF assemblage composition indicate environmental conditions typical for continental shelf edge. Middle Miocene (Tf2) can be inferred for these limestones based on LBF. Here we present an overview of Indonesian Early to Middle Miocene LBF assemblages in a range of depositional environments. We will assess the interplay between stratigraphical and environmental control on LBF assemblages. JF - Southeast Asian Gateway Evolution: SAGE2013 CY - Museum fuer Naturkunde, Berlin ER - TY - CONF T1 - Larger benthic foraminifera – faunal pioneers in mixed carbonate-siliciclastic systems T2 - 2012 GSA Annual Meeting Y1 - 2012 A1 - Vibor Novak A1 - Nadiezhda Santodomingo A1 - Willem Renema AB - Larger benthic foraminifera are one of the most abundant and widespread organisms in shallow marine tropical environments. Their role as rapid colonizers of new substrates has been suggested, but little is still known to support this idea. To address this question, larger benthic foraminifera assemblages have been studied in the paleoenvironmental reconstruction of a Langhian (Middle Miocene) shallow-water patch reef, as part of a broader multitaxon fossil comunity analysis, including corals, coralline algae, and bryozoans. The studied outcrop (approx. 80 m wide and 25 m thick) is located at the northeast margin of the Kutai Basin near Bontang (Indonesia). The patch-reef was developed in mixed carbonate-siliciclastic depositional environment and despite the high terrigenous input affecting water transparency, this reef contains a diverse marine biota. Five different facies types were distinguished based on lithology and fossil content: foraminifera packstone, bioclastic packstone with foralgal communities, thin-platy coral sheetstone, platy-tabular coral platestone, and shales. Excluding the fossil barren shales facies, only larger benthic foraminifera occur in all four remaining facies types, showing the ability to rapidly adapt to changes in environment. In the current study, high siliciclastic input caused fluctuations in light levels, but also resulted in deposition of soft-bottom substrate. In newly developed conditions, the larger benthic foraminifera appear first and mark the initiation of reef growth. The persistence of LBF throughout the fossil reef succession indicates their high tolerance to terrigenous input and also highlight the role of foraminifera as primary colonizers, proving themselves as important faunal pioneers, particularly in mixed carbonate-siliciclastic systems. JF - 2012 GSA Annual Meeting CY - Charlotte, NC ER - TY - CONF T1 - Burdigalian turbid water patch reef environment revealed by larger benthic foraminifera T2 - The EGU General Assembly 2012 Y1 - 2012 A1 - Vibor Novak A1 - Willem Renema A1 - the Throughflow Project AB - Ancient isolated patch reefs outcropping from siliciclastic sediments are a trademark for the Miocene carbonate deposits occurring in East Kalimantan, Indonesia. They develop in transitional shelf sediments deposited between deltaic and deep marine deposits (Allen and Chambers, 1998). The Batu Putih Limestone (Wilson, 2005) and similar outcrops in adjacent areas have been characterized as shallow water carbonates influenced by high siliciclastic input, showing low relief patch reefs in turbid waters. Larger benthic foraminifera (LBF) are excellent markers for biochronology and paleoenvironmental reconstruction. This study aims to reveal age and paleoenvironment of a shallow water carbonate patch reef developed in mixed depositional system by using LBF and microfacies analysis. The studied section is located near Bontang, East Kalimantan, and is approximately 80 m long and 12 m high. It is placed within Miocene sediments in the central part of the Kutai Basin. Patch reef and capping sediments were logged through eight transects along section and divided into nine different lithological units from which samples were collected. Thin sections and isolated specimens of larger benthic foraminifera were analyzed and recognized to species level (where possible) providing age and environmental information. Microfacies analysis of thin sections included carbonate classification (textural scheme of Dunham, 1962) and assemblage composition of LBF, algae and corals relative abundance. Three environmentally indicative groups of LBF were separated based on test morphology, habitat or living relatives (Hallock and Glenn, 1986). Analysed foraminifera assemblage suggests Burdigalian age (Tf1). With use of microfacies analysis nine successive lithological units were grouped into five facies types. Paleoenvironmental reconstruction of LBF fossil assemblage indicate two cycles of possible deepening recorded in the section. Based on high muddy matrix ratio in analyzed thin-sections we still cannot conclude whether they were deeper water assemblage, or that they occurred in shallower water and influenced by turbid conditions as the result of terrigenous input. According to preliminary analysis and siliciclastic content in the sediments the later one should be more likely. Further work will include additional fossil groups analysis (corals, algae and bryozoans), detailed petrographical analysis and Strontium isotope stratigraphy. JF - The EGU General Assembly 2012 CY - Vienna ER - TY - JOUR T1 - Development of a turbid reef in the Middle Miocene (East Kalimantan, Indonesia) JF - Geological Society of America Abstracts with Programs Y1 - 2012 A1 - Nadiezhda Santodomingo A1 - Vibor Novak A1 - Nathan Marshall A1 - Emanuela Di Martino A1 - Nicholas Fraser A1 - Elena LoGiudice A1 - Vedrana Pretković A1 - Anja Rösler A1 - Willem Renema A1 - Kenneth G. Johnson SP - 623 KW - INDONESIA KW - marginal ecosystems KW - Miocene KW - palaeonvironmental reconstruction KW - patch reefs CY - Charlotte, North Carolina, USA VL - 77 UR - https://gsa.confex.com/gsa/2012AM/webprogram/Paper209284.html IS - 7 ER - TY - CONF T1 - Palaeoenvironmental reconstruction of a Miocene patch reef in East Kalimantan (Indonesia): a close-up on the bryozoan component T2 - IBA Larwood Meeting Y1 - 2012 A1 - Emanuela Di Martino A1 - Paul D. Taylor A1 - Vibor Novak A1 - Nadiezhda Santodomingo A1 - Anja Rösler A1 - Juan Carlos Braga A1 - Kenneth G. Johnson A1 - Willem Renema JF - IBA Larwood Meeting CY - Brno Czech Republic ER - TY - CONF T1 - Environmental reconstruction of a Langhian patch reef (East Kalimantan, Indonesia) T2 - Lyell Meeting 2012 Y1 - 2012 A1 - Vibor Novak A1 - Nadiezhda Santodomingo A1 - Anja Rösler A1 - Emanuela Di Martino A1 - Juan C. Braga A1 - Paul D Taylor A1 - Kenneth G. Johnson A1 - Willem Renema JF - Lyell Meeting 2012 ER - TY - CONF T1 - Bryozoans from a Langhian patch reef in East Kalimantan (Indonesia) T2 - Giornate di Paleontologia XII edizione – Catania, 24-26 Maggio 2012 Y1 - 2012 A1 - Emanuela Di Martino A1 - Paul D. Taylor A1 - Vibor Novak A1 - Nadiezhda Santodomingo A1 - Anja Rösler A1 - Juan Carlos Braga A1 - Kenneth G. Johnson A1 - Willem Renema JF - Giornate di Paleontologia XII edizione – Catania, 24-26 Maggio 2012 CY - Catania, Italy ER - TY - CONF T1 - Foraminifera assemblages of East Kalimantan through time and space T2 - 18th Phd-Day Biodiversiteit Y1 - 2011 A1 - Vibor Novak JF - 18th Phd-Day Biodiversiteit ER -