Swamp Deposits Research Articles

AN UPDATE TO THE GEOLOGY OF SEBUKU ISLAND, SOUTH KALIMANTAN, INDONESIA: CONSTRAINTS FROM PETROLOGICAL STUDIES

Sebuku Island is located at the southeastern tip of Kalimantan Island and has geological similarities with the Bobaris-Meratus complex in distribution pattern and stratigraphic sequence. The pattern of straightness of geological structures between the two, both folds and faults, is generally directed from northeast-southwest to northwest-southeast. The previous geological research on Sebuku Island focused on the distribution of ultramafic rocks, which are speculated to contain iron, particularly from laterite soils. This research aims to determine the rock units in the study area to update the geological map of Sebuku Island, especially in the Sei Pinang and Halaban areas. The research method consists of fieldwork, laboratory analyses, and data analyses. The geological fieldwork collected 34 samples from detailed mapping on outcrops, trenching, and drilling. Geological structure observations were carried out on fresh outcrops and measured 57 structural geological elements from 6 locations. Petrographic analysis of 34 samples was carried out with the aim of determining rock type and mineralogical composition. Stereographic analysis of geological structure measurement data was used to define the general direction and type of geological structures in the investigated outcrops. The geological map is constructed on the basic topographic map in the scale 1:50,000 using Map-Info Pro v17.0.5. Based on petrographic observations and detailed field observations, especially in North Damar, from surface outcrops and drill core observations from Madang, the following results are revealed. In the geology of North Damar, in particular, and Sebuku Island, in general, the lithology can be described as an ultramafic rock unit (lherzolite, harzburgite, and dunite), pyroclastic rock unit (crystallo-lithoclastic tuff and crystalloclastic tuff), limestone unit, dike rock unit (microgabbro and diorite), sandstone unit, and alluvial deposit. Almost 60% of Sebuku Island outcrops belong to the ultramafic rock units, which are tectonically covered by crystalline lithic tuff and crystalline tuff and volcaniclastic rock units with interbedded limestone, unconformably covered by sandstone units, alluvial deposits, and swamp deposits. Microgabbro and diorite were observed from the drill core and were not exposed to the surface. Hydrothermal mineralization is indicated by quartz veins cross-cutting the pyroclastic rock group observed in drill cores. This research shows a more detailed geological description of the study area compared to previous research and regional geological map.

Late Quaternary history of the Gumants catchment, Papua New Guinea

The Gumants River, rising on the eastern flank of the Mount Hagen stratovolcano, forms part of the headwater catchment of the Wahgi River in the central highlands of Papua New Guinea. The late Quaternary history of the catchment was shaped by a massive debris avalanche with an estimated volume >15 km3 that most likely occurred 400 ± 100 ka. The Upper Gumants River, which occupies about one-quarter of the 420 km2 catchment and underlain almost entirely by volcanic deposits including the avalanche, lahars and widespread airfall tephras that ceased falling ca 200 ka, once flowed directly to the Wahgi River through the Guga subcatchment rather than through the rest of the Gumants Basin. The Kuk Swamp part of the Guga catchment, intensively investigated for evidence of agriculture stretching back 10 ka, was added to the UNESCO World Heritage List in 2008. Nearly 40% of the 79 km2 of the Kugimi Basin is underlain by at least 30 m of swamp deposits with all but the uppermost few metres of the varied swamp and alluvial deposits beyond the range of radiocarbon dating. The Muga Basin forms nearly half of the Gumants catchment with about 50 km2 of swamp deposits and colluvial/alluvial sediments, which have been accumulating rapidly in the last few hundred years but are still underlain at a depth of a few metres by ancient sediments and, by inference, debris avalanche deposits that extend downvalley beyond the junction of the Gumants River with the Wahgi River. While there has been speculation for decades that the Wahgi River once flowed westward, it is now clear that the Gumants River has always flowed eastward, and it seems very likely that that is also true of the Wahgi River.

Lower Campanian palynoflora from the Araçatuba Formation (Bauru Group), Southeastern Brazil

This paper presents the first record of a rich palynoflora within the Bauru Group (Cretaceous of southeastern Brazil). The Bauru Group is rich in animal fossils, but has been virtually barren in palynomorphs. There are only two previous palynological works from the Bauru Group: (1) that of the São Carlos Formation, whose outcrop is located outside the formal boundary of the Bauru Basin, and (2) the extremely poor and poorly preserved palynoflora from a coprolite of the Marília Formation. The material studied here, from the Araçatuba Formation, is the only one palyniferous sample from a groundwater well drilled in the central-west region of the state of São Paulo. The Araçatuba Formation, constituted by swamp deposits, rests directly on the basalts of the Serra Geral Group. The Araçatuba palynoflora contains index palynomorphs – Cretacaeiporites polygonalis, C. scabratus and Hexaporotricolpites emelianovi – signifying an early Campanian age. Moreover, the absence of Santonian indices and of older ages, confirms attribution to the lower Campanian. In paleoclimatic terms, the assemblage suggests aridity, given the abundance of ephedroid pollen grains and the low frequency of pteridophytic spores. The occurrence of spores of water ferns confirms the paludal setting. The aqueous environment is also suggested by the occurrence of zooclasts derived from crustacean eggs. However, the virtual absence of phytoplankton may indicate the ephemeral nature of the water body.

Characteristics and Genesis of Laterite Bauxite in Sompak District and Surrounding Areas, Landak Regency, West Kalimantan

West Kalimantan has very large bauxite resources, reaching 2.07 billion tons, equivalent to 57.32% of the total bauxite resources in Indonesia with bauxite reserves of 0.84 billion tons or equivalent to 66.77% of the total national mineral reserves. The researched area covers Sompak District and surrounding areas, Landak Regency, West Kalimantan. This research aims to determine geological conditions, laterization, and characteristics of laterite bauxite in the studied area. Methods used in this research are geological mapping, lateritic mapping, and petrographic and geochemical analyses. The lithology of the researched area is composed of granodiorite, porphyry quartz diorite, granite, porphyry andesite, porphyry basalt, alluvial, and swamp deposits. Laterite profiles in the researched area generally consist of topsoil, latosol, bauxite, and clay zone. The laterite bauxite derived from granodiorite is classified as a medium grade, laterite bauxite from porphyry quartz diorite is classified as high-grade bauxite, laterite bauxite from andesite porphyry is classified as low-medium grade bauxite, and laterite bauxite from porphyry basalt in the studied area is classified as high grade bauxite. Laterite bauxites in the researched area were formed from weathered parent rocks which were intermediate - alkaline igneous rock.

Land Suitability Evaluation of Soils of Bayelsa State for Oil Palm Production

Selected soils of Bayelsa State were evaluated for oil palm production using FAO land suitability classification. Eight pedons were sunk on each the three geomorphic features found in Bayelsa State. A total of twenty-four pedon were investigated and soil samples were taken to the laboratory for routine analysis. The average of the results from each geomorphic unit was calculated. Results of the physicochemical properties of soil showed that soils of Mangrove Swamp Deposits (MSD) and Sombreiro Warri Deposit (SWD) were characterized by sandy texture while the texture of soils of Recent and Sub-recent Alluvial Deposits (RSA) were loamy sand. Soil pH ranged from strongly (3.9) to moderately (6.2) acidic. Organic matter reduces down the profile. Effective cation exchangeable capacity (E.C.E.C.) ranged from 3.34-7.28cmol/kg while base Saturation ranged from 33 – 48.6%. From the land suitability results, rainfall and temperature were highly suitable while relative humidity was moderately suitable for oil palm production. The texture was marginally suitable in RSA while it was not suitable in MSD and SWD. For soil fertility characteristics, the major limitation affecting oil palm production was the C.E.C. which placed these soils in suitability class N1 (Not Suitable). Organic matter was another serious constrain to oil palm cultivation in RSA.

Current and Potential Soil Suitability for Cassava for Sustainable Production in Varying Soils of Bayelsa State Nigeria

Mangrove swamp deposit, Sombreiro Warri deltaic deposit, and Recent and sub-recent alluvial deposit soils of Bayelsa State were characterized and evaluated for arable crop cassava production. Results showed that there were variations in the soil physicochemical properties. Soils underlain by Mangrove swamp deposit being better than others since it had greater content of organic matter, total nitrogen, Ca and total exchangeable bases. It also recorded higher pH making it less acidic for crop production. The results of the current (actual) suitability map of the soils showed a wide range of moderate to marginal suitability scores for cassava production except in in soils of Otuoke (11.4 to 24.28%) indicating temporary nonsuitable (N1) for cassava production. However, the potential suitability map of the study area revealed that the soils were moderately suitable for cassava. The study also revealed that fertility is a major constraint to the production of cassava and managerial strategies capable of boosting fertility status should be employed for cassava production in this region.

Utilization of Remote Sensing Images for Compiling The Characteristics Map of Indramayu Beach, West Java

The beach has an important role in the development and economy of a region. Therefore, it is important to understand the condition and characteristics of the coast so that it can be managed and developed wisely. One way to understand the condition of the beach is through making a map of the characteristics of the beach. A coastal characteristic map is a graphical representation of the conditions and characteristics of the geology, geography, and hydrology of a coast. Making a coastal characteristic map with remote sensing requires several steps, namely: 1). satellite data collection: Pre-processing satellite data; 2). classification of satellite data; 3). satellite data analysis; and finally 4). making a coastal characteristic map. The area that is the fabric material is the beach of Indramayu Regency, West Java. Based on the analysis and interpretation of 2015 Landsat 8 (LDCM) image data, 2020 Sentinel 2 Image data, BATNAS, and DEMNAS data, it is known that the characteristics of the Indramayu beach are that it has geo-quaternary building materials which include: (a) coastal bunds, ( b) swamp deposits, (c) shallow marine deposits, (d) sand deposits, (e) flood plains, (f) river deposits, and (g) floodplain deposits. The morphology includes: (a) beach sand plains, (b) concave coastal swamps, (c) old beach bunds, (d) young beach bunds, (e) alluvial plains, (f) flood plains, and (g) fan plains delta. Finally, it has a distribution of surface sediments on the seabed which includes: (a) sand, (b) silt, gravelly sand, (d) slightly gravelly silt, (e) slightly gravelly sandy mud, and (f) gravelly mud.

Textural characteristics, mode of transportation and depositional environment of the Stormberg Group in the Eastern Cape, South Africa: evidence from grain size and lithofacies analyses

Abstract The Stormberg Group comprises the Molteno, Elliot and Clarens formations and is one of four stratigraphical groups that make up the Karoo Supergroup in South Africa. The group is the highest unit in the Karoo Basin, representing the final phase of preserved sedimentation. The major problem with the Stromberg Group is that the mode of transport, hydrodynamic energy conditions and depositional environment are still poorly understood. For the present paper, grain size and lithofacies studies on selected sandstones from the Molteno, Elliot and Clarens formations were performed so as to elucidate their textural characteristics, depositional processes, sedimentation mechanisms and hydrodynamic energy conditions and to discriminate different depositional environments. The statistical parameters of grain size distribution (mean grain size, standard deviation, skewness and kurtosis) show that the sandstones are predominantly unimodal, fine grained, moderately well sorted, mesokurtic and near symmetrical. The bivariate diagrams of the aforementioned statistical parameters demonstrate that river and aeolian dune had the greatest impact on the depositional environments. Likewise, the C-M pattern (Passega diagram) shows that the sandstones were mostly deposited through tractive current process. Furthermore, the C-M diagram reveals the prevalence of rolling, suspension and graded suspension modes of sediment transportation. Seventeen sedimentary lithofacies were identified and grouped into seven lithofacies associations. These lithofacies associations indicate braided channel, overbank and swamp deposits for the Molteno Formation, alluvial fan/floodplain and playa deposits for the Elliot Formation and aeolian deposits for the Clarens Formation.

Sedimentary facies of a tide-dominated estuary and deltaic complex in a tropical setting: The middle Miocene Oficina Formation of the Orinoco Oil Belt, Venezuela

Although the middle Miocene Oficina Formation of the Orinoco Oil Belt represents most of Venezuela's hydrocarbon resource, a comprehensive and detailed sedimentary facies model for the whole belt has never been put forward. Based on the analysis of cores and well logs, nine sedimentary facies (FA-I), forming five facies assemblages (FA1-5), have been characterized. Both sedimentologic and ichnologic datasets have been integrated in this study. The Oficina Formation records the typical succession of fluvial incision during relative sea-level fall, fluvial deposition during lowstand, transition from fluvial to estuary valleys during the subsequent transgression and deltaic progradation during highstand. FA1 consists of fluvial-braided channel (FB), floodplain (FG2), and swamp (FH1) deposits, as well as paleosols (FG3). This facies assemblage occurs in the lower member, representing the infill of lowstand fluvial valleys. FA2 consists of meandering estuary-channel deposits (FA, FC, FD, FE, and FI). This facies assemblage occurs in the middle member, representing the infill of tide-dominated estuary valleys during the early stages of the Langhian transgression. FA3 consists of tidal-flat and tidal-creek (FC, FD, FE, FF, and FG2), and swamp (FH1 and FH2) deposits, together with paleosols (FG3). This facies assemblage is present in the middle member, revealing backstepping and retrogradation within the estuary system during a continuing transgression. FA4 consists of outer-estuary sandbar (FC, FD, and FG1); swamp (FH2) deposits and paleosols are present at the margins of the estuary (FG3). This facies assemblage occurs in the uppermost part of the middle members, representing a late stage of the Langhian transgression, culminating in a maximum flooding surface. FA5 consists of deltaic distributary channel (FC and FD), floodplain and interdistributary-bay (FG2), and swamp (FH1) deposits. This facies assemblage occurs in the upper member, recording sedimentation in the delta plain of a tide-dominated delta during a highstand. Freshwater conditions in the fluvial system, as well as in the inner portions of the estuary and the delta plain are further supported by the presence of the Scoyenia Ichnofacies, whereas brackish-water segments of the estuary are characterized by the Skolithos and depauperate Cruziana Ichnofacies. The substrate-controlled Teredolites, and Glossifungites Ichnofacies occur in connection to erosional exhumation during ravinement. The absence of fully marine ichnofaunas is consistent with the embayed nature of the Orinoco Oil Belt. The tropical and humid character of the Oficina depositional systems is manifested in the development of widespread wetlands in marginal-marine settings, with formation of swamps and embayed areas, typically displaying evidence of waterlogged paleosols with pervasive root trace fossils. The abundance of crustacean burrows, such as Ophiomorpha and Thalassinoides, is also typical of low-latitude marginal- and shallow-marine settings. Although tidal forces tend to be weaker in lower latitudes because Coriolis effects are stronger there, both the estuary and delta systems are regarded as tide-dominated, most likely reflecting the embayed nature of the shoreline.

Organic geochemical characterization of Early-Mid-Holocene swamp deposits near the Neolithic settlement in Yenikapı-Istanbul: Assessment of environmental variability and anthropogenic impacts

During the archaeological excavations in the Byzantine Theodosian harbor (Istanbul) a Holocene dark gray to black clay sequence was uncovered. This clay unit was deposited under anoxic conditions in a small swamp. Both wooden artifacts from the Neolithic period, but also dispersed organic matter were perfectly preserved within this sequence. The aim of this study was the assessment of environmental changes and anthropogenic impacts with the help of organic geochemical and isotopic characterization of organic matter in this clay unit. The age model, based on 14C data, showed that the clay was deposited during a period about from 11,100 to 7500 cal. years BP. Hydrogen Index values lower than 100 mgHC/gTOC, n-alkane distributions with maxima at nC29 or at nC31, a predominance of long-chain n-alkanes (C25–C33) and δ13Corg values around −24‰ to −27‰ suggest a predominantly terrestrial origin of organic matter from C3 plants. Obvious excursions of bulk δ13Corg and compound-specific δ13C and δD values of nC27, nC29, nC31, and nC33 are interpreted as indicators of changes in environmental and climatic conditions. Several shifts toward colder and warmer climatic conditions were identified and dated. Furthermore, two sudden changes in the hydrological regime were dated to 9000–8820 cal. years BP and to 8150–8050 cal. years BP toward wetter and drier conditions, respectively. Specific molecular organic geochemical indicators such as faecal sterols or a strong enrichment of δ15N caused by human impact could not be detected. Therefore, the swamp should not have been intensively affected by Neolithic people and/or respective indicators of their influence have been diluted due to the high sedimentation rate.

REVIEW OF THE LAND SUBSIDENCE HAZARD IN PEKALONGAN DELTA, CENTRAL JAVA: INSIGHTS FROM THE SUBSURFACE

Land subsidence is a global threat to coastal areas worldwide, including the North Java coastal area. Of many areas experiencing land subsidence in North Java, the rate of land subsidence in Pekalongan has matched the high subsidence rates usually found in big cities. The rate of land subsidence in Pekalongan far exceeds the sea-level rise, resulting in a looming threat of land loss. The devastating impacts of land subsidence are the manifestation of its subsurface movement. Therefore, it is essential to understand the subsurface to elucidate the mechanism of land subsidence. Previous studies on land subsidence in Pekalongan are mainly related to subsidence rate monitoring and have not elaborated on the subsurface condition. This paper reviews the Pekalongan subsurface geology based on available literature to provide insight into the land subsidence problem. The results revealed that the land subsidence occurs in the recent alluvial plain of Pekalongan, consisting of a 30-70 m thick compressible deposit. Possible mechanisms of land subsidence arise from natural compaction, over-exploitation of confined groundwater, and increased built areas. As the seismicity of the study area is low, tectonic influence on land subsidence is considered negligible. It is expected that the offshore, nearshore, and swamp deposits are still naturally compacting. As the surface water supply is minimal, over-exploitation of groundwater resources from the deltaic and Damar Formation aquifers occurs. In the end, future research direction is proposed to reduce the impacts of the subsidence hazard.

Geochemistry of the upper estuarine sediments of the Santos estuary: provenance and anthropogenic pollution

Major and trace element geochemistry of the upper estuarine sediments of the Santos estuary has been used to characterize sediment geochemistry, classification, distribution, and possible sources of industrial pollution. The vertical sediment cores were collected on the margin of the Cubatão, Perequê, Mogi, Piaçaguera and Jurubatuba rivers, the main effluents of the Santos estuarine system. Samples of selected basement rocks (n=12), industrial waste (n=2) and one weathering profile (organic soil, residual soil and saprolite rock) were also analyzed. The sedimentary deposits showed interbedding of medium, fine, and very fine sands in the upper portion of the estuary and subordinate silt-clay units derived from lower energy in swamp/mangroves deposits in the lower estuary. Marked geochemical differences occurred among these fluvial sediments. The calculated indices of chemical weathering, such as Chemical Index of Alteration (CIA) and A-CN-K ternary diagram indicate that the estuarine sediments display a wide range of weathering effects, from unweathered derived of Proterozoic gneiss and granitic rocks to intensely weathered site in the swamp deposits of the Piaçaguera River. Phosphogypsum waste stored in the catchment area of the Mogi River showed high concentrations of S, La, Ce, Ca, Sr, Nd, Nb, U, Ba, P, Y and F when compared with the regional rocks, soils and fluvial sediments samples analyzed in the study area, which make it a potential source of environmental contamination. The UCC-normalized patterns, geoaccumulation indexes (Igeo), robust linear regression (RA) and principal component analysis (PCA) were used to identify geochemical anomalies and discuss their probable sources. The principal component scores exhibited strong spatial association with anthropogenic sources. The principal component loading allowed to separate heavy metal elements (Cr, Cu, Ni, Pb and Zn) from the elements related to phosphogypsum waste (e.g., Ce, La, Nd and F). The geochemical anomalies of Ce, La, Nd and F in the fluvial sediments of the Mogi downstream River may be related to phosphogypsum waste in the catchment area, whereas the Cr, Cu and Ni anomalies may be related to fossil fuel, chemical industries and industrial waste deposits which occur near the Pereque and Cubatão rivers.

Understanding reservoir heterogeneity using variography and data analysis: an example from coastal swamp deposits, Niger Delta Basin (Nigeria)

Abstract For efficient reservoir management and long-term field development strategies, most geologists and asset managers pay special attention to reservoir chance of success. To minimise this uncertainty, a good understanding of reservoir presence and adequacy is required for better ranking of infill opportunities and optimal well placement. This can be quite challenging due to insufficient data and complexities that are typically associated with areas with compounded tectonostratigraphic framework. For the present paper, data analysis and variography were used firstly to examine possible geological factors that determine directions in which reservoirs show minimum heterogeneity for both discrete and continuous properties; secondly, to determine the maximum range and degree of variability of key reservoir petro-physical properties from the variogram, and thirdly, to highlight possible geological controls on reservoir distribution trends as well as areas with optimal reservoir quality. Discrete properties evaluated were lithology and genetic units, while continuous properties examined were porosity and net-to-gross (NtG). From the variogram analysis, the sandy lithology shows minimum heterogeneity in east-west (E–W) and north-south (N–S) directions, for Upper Shoreface Sands (USF) and Fluvial/Tidal Channel Sands (FCX/TCS), respectively. Porosity and NtG both show the least heterogeneity in the E–W axis for reservoirs belonging to both Upper Shoreface and Fluvial Channel environments with porosity showing a slightly higher range than NtG. The vertical ranges for both continuous properties did not show a clear trend. The Sequential Indicator Simulation (SIS) and Object modelling algorithm were used for modelling the discrete properties, while Sequential Gaussian Simulation (SGS) was used for modelling of the continuous properties. Results from this exercise show that depositional environment, sediment provenance, topographical slope, sub-regional structural trends, shoreline orientation and longshore currents, could have significant impacts on reservoir spatial distribution and property trends. This understanding could be applied in reservoir prediction and for generating stochastic estimates of petrophysical properties for nearby exploration assets of similar depositional environments.

Quaternary volcanostratigraphy setting in Rawa Danau Caldera, Banten Province

The volcano complex in the Rawa Danau of Banten Province or called the Dano Volcano has an association with the eruption of the Krakatoa volcano, observed from the direction of the ridge lineament. The Dano volcanic eruptions occurred during the Holocene period, causing the accumulation of volcanic material deposits into the northern part of Banten Province. This research area is covering five mountains which are Mount Parakasak, Mount Marikangen, Mount Tukung-Gede, and Mount Karang (sorted from the oldest to the youngest). Field mapping method we use in accordance with previous research and literature studies, as well as the results of the analysis in the form of the senses and geomorphology, stratigraphy, geological structure, and petrography to conclude volcanic facies in the Rawa Danau and surrounding areas. The results of the study showed that there were 4 volcanic facies around the Dano Volcano area. The central facies comprise of dome of Mount Parakasak with steep morphology while the proximal facies with andesitic lava. The structural geology feature formed from sheeting joints in the Southwest-Northeast direction with azimuth of N15° E/44° and tectonic fractures with Northwest-Southeast direction with azimuth N135° E/70° with steep morphology. The medial facies is tuffs and tuff breccias with gentle slope morphology, and the distal facies only have mud deposit, clay lithology with flat morphology. Rawa Danau in this study is located in the distal zone which consists of swamp deposits resulting from the destruction of the surrounding volcanic material.

Origins and occurrences of Ti-nanominerals in a superhigh-organic-sulfur coal

Two Ti-nanomineral types seldom seen in a superhigh-organic-sulfur coal (Ganhe coal) are identified through the integrated techniques of high-resolution transmission electron microscopy (HR-TEM), energy-dispersive X-ray spectrometer (EDS), and fast Fourier transformation (FFT). The first Ti-nanomineral type is that of irregular-shaped Ti-nanominerals (Rutile, Ti4O7, and Ti6O11) associated with minor proportions of Cr and V. This is unusual, because Ti4O7 and Ti6O11, which are referred to as Ti magnéli phases (very high temperature products), are rarely found in coal. In addition, other integrated evidence of acid volcanic-ash components in Ganhe coal are also confirmed, including sanidine associated with Tl, flocculated texture illite, La-monazite associated with minor proportions of V, and rare-earth elements (REEs) distribution patterns (Eu negative anomalies). It is thus implied that the origin of the irregular-shaped Ti-nanominerals is the transformation of rutile to Ti4O7 and Ti6O11 under the influence of acid magma followed by transportation and deposition in the Ganhe peat swamp. The second type is that of spherical Ti-nanominerals that exist individually within the organic matrix; they have minimum areas of 3.79–56.10 nm2 and contain large proportions of Cr and V. It is considered that owing to the euxinic, anoxic, and reducing marine deposition environment, Ti, Cr, and V could easily have been originally precipitated or adsorbed by the organic macromolecular structure within the peat and low-rank coal. With elevation of the coal rank, they could then have been expelled by dehydration, decarboxylation, and demetallation via closed nano-size pores (nano pores) prior to finally entering mineralization under natural hydrothermal conditions. Although this result is promising, the hydrothermal formation of nano TiO2 particles requires further demonstration using an artificial coalification experiment.

Fish, amphibian and reptilian assemblage from the middle Miocene locality Gračanica—Bugojno palaeolake, Bosnia and Herzegovina

This paper presents the first fossil fish, amphibian and reptilian fauna from Bosnia and Herzegovina Dinarides. The fauna of ectothermic vertebrates of the Bugojno palaeolake, dated to 15.2–14.0 Ma, composes of killifishes (Cyprinodontiformes indet.), a barb (Barbini indet. (aff. Barbus), a crocodile newt (Chelotriton sp.), a painted frog (Latonia sp.) and a crocodile (Alligatoroidea indet. [?Diplocynodon]). The crocodile remains are confined to the lower part of the section corresponding to the swamp deposit (unit 1). The remaining fauna, which includes fishes and amphibians, come from the upper lacustrine unit 2. A possible Barbus (Barbini indet. (aff. Barbus)) could represent one of the oldest fossil records of the genus found in Europe, which composes of skeletal elements and pharyngeal teeth. The crocodile newt (Chelotriton sp.) represents the first record of this group from the area. For the first time, fossil tadpoles of the genus Latonia are described in this paper, which, moreover, are the first record of tadpole for both the family Discoglossidae and clade of discoglossoid frogs. The crocodile remains, identified as Alligatoroidea indet., should belong to the genus Diplocynodon, which will be tested later on a better preserved material. The fossils, coming from the lacustrine interval, are referred to the deeper water facies. Taphonomic observations of the fossil remains suggest relatively short phase of decay of the animal bodies and their (probably quick) sedimentation in the deeper parts of the lake, with poor oxygen content.

Multiproxy studies of lake sediments during mid-Holocene in Zhengzhou region of the Henan Province, central China, and the implications for reconstructing the paleoenvironments

The Holocene environmental evolution of the Zhengzhou region that is a major birthplace of Chinese civilization is of great interest to a wide community. In this study, we conducted a systematic investigation on grain size, total organic carbon (TOC), geochemistry, pollen and magnetic minerals of core PT sediments from the Zhengzhou region of the Henan Province in central China. Five units of sedimentary facies are identified as alluvial deposit, lacustrine deposit, swamp deposit, lacustrine deposit and alluvial deposit from bottom to top. Magnetic measurements indicate that magnetite and hematite dominate the magnetic mineral assemblages. The lacustrine and swamp deposits (1380-640 cm) were AMS 14C dated to 5580-2670 yr BP and the chronology is further corroborated by the pedostratigraphic correlation to the adjacent cores in Zhengzhou region. Palynologically speaking, the period from 5580 to 5210 yr BP was characterized by lowest pollen percentages of Artemisia, Chenopodiaceae, Gramineae and Cyperaceae, higher values in clay contents, Sr contents and Fe/Mn ratios and also contents of magnetic mineral. The period from 5210 to 4760 yr BP was typified by rapid increases in Typha, Myriophyllum, Artemisia and Cyperaceae pollen percentages, gradual increases in ARM/SIRM and ARM/χ values, drastic drops in χ, ARM and SIRM values, with rather high values in clay contents, Sr contents and Fe/Mn ratios. The period between 4670 and 2670 yr BP was featured by gradual decreases in Gramineae, Artemisia, Typha and Myriophyllum pollen percentages, and increasing trends of χ, ARM and SIRM values, and decreasing trends of ARM/χ and ARM/SIRM values. Tracing the environmental changes since the mid-Holocene in the Zhengzhou region can provide an environmental reference for studying the human societal development in this birthplace of Chinese civilization.

The tectono-sedimentary evolution of a major seismogenic zone with low slip rate activity: A geochronological and sedimentological investigation of the Dobrá Voda Depression (Western Carpathians)

Seismically active fault zones receive a great deal of attention due to their potential for quantification of seismic hazards. Zones with low slip rates pose a challenge, however, since their poor topographic expression is related to difficulties in the quantification of fault movement. This study focuses on the Dobrá Voda Depression, an area with the highest level of seismic activity in the Western Carpathians. The Quaternary tectono-sedimentary evolution of the small intramontane basin was investigated with the use of facies analysis of cores, dated with the use of cosmogenic nuclide depth profiles (10Be, 26Al and 36Cl), together with 26Al/10Be burial dating and radiocarbon dating. A set of archived boreholes and geoelectric survey data was used for the correlation of results with those from new boreholes across the depression. Four facies associations were distinguished: (FA1) Colluvial deposits that comprise subaerial debris flows and mudflows; (FA2) Fluvial deposits with high sediment supply: accommodation ratio, composed mostly of sandy-gravelly channel fill facies; (FA3) Fluvial deposits with low sediment supply: accommodation ratio, consisting mostly of floodplain muds, overbank heterolithic facies and minor sandy-gravelly channel fills; and (FA4) Swamp deposits, which are mostly made up of peat. Geochronological results suggest that the studied part of FA3 was deposited before 1.0 Ma due to a rise in the base level following a major incision event. Overbank-dominated deposits of FA3 covered an incision surface, resulted in a difference of ca. 65 m of elevation of these strata, which represents the minimal thickness of FA3. The second phase of incision was related to reactivation of Miocene normal faults resulting in further topographic differentiation. The initiation of fault activity is recorded by the deposition of colluvial FA1 before ca. 250 ka. FA2 accumulated between ca. 160 and 100 ka, mostly at the toes of slopes bounding the fault scarps on the basin margins. The last documented phase of evolution represents an increase of accommodation, which was connected to the deposition of Holocene peat in swamps as well as floodplain muds of FA4 above FA2. The observed settings imply that variation between incision and accumulation in a scale of hundreds of thousands of years is characteristic for low relief tectonically active zones. The presented research demonstrates the significance of sedimentological analysis for reconstruction of tectonic evolution in areas with low slip rate activity.

Facies analysis and depositional environment of the Campano – Maastrichtian coal-bearing Mamu Formation in the Anambra Basin, Nigeria

Detailed sedimentological logging was carried out within the exposed rock sections of the late Campanian to early Maastrichtian successions of the coal-bearing Mamu Formation, southeastern province of Nigeria. Lithofacies analytical approach was employed in describing the outcropping rock units. The focus was to understand the distribution of these facies and their depositional environments. Eleven lithofacies recognized were found occurring within fining/thinning upward successions typical of retrogradational stacking patterns formed during transgressive episodes and coarsening/thickening succession typical of progradational stacking patterns formed during regressive episodes. These lithofacies were further classified into five facies associations, namely: lagoonal or swamp deposits (FA1); barrier island deposits (FA2); shoreface deposits (FA3); offshore-transition zone deposits (FA4) and; open shelf deposits (FA5). FA1 is dominantly coal and carbonaceous shale deposited in a swamp or lagoonal setting. FA2 is dominantly parallel laminated and cross-bedded fine to medium grained sandstones formed by wave and longshore currents within barrier island complexes. FA3 is dominantly bioturbated sandstone, planar and rippled laminated sandstones, and planar and trough cross-bedded sandstones facies deposited in a shoreface environment, by migrating dunes formed under unidirectional flows above fair-weather wave base. FA4 is mainly wave ripple laminated, hummocky and swaley cross-bedded sandstones deposited by waning oscillatory and combined flows within a storm wave-dominated shelf region, below fair-weather wave base. FA5 is fissile shales and mudstones deposited in an open shelf setting below fair-weather and storm wave base. This study indicates that outcropping units represent lithofacies, which record depositional elements of high frequency transgressive and regressive events in a coastal swamp through shelfal depositional environment. In addition, the coal seams and carbonaceous shale facies (source/seal rocks), and the sandstones, siltstone and heterolithic facies (reservoir rocks) indicate the possible presence of key elements of petroleum system in the Mamu Formation of the Anambra Basin.

Establishing a chronological framework for a late Quaternary seasonal swamp in the Australian ‘Top End’

Abstract Swamps in the seasonal tropics have good potential for the reconstruction of late Quaternary monsoonal dynamics. Their successful use, however, has often been compromised by chronological limitations introduced by a variety of depositional and post-depositional processes actively modifying the swamp deposits. We here present and discuss the results of a multiple dating approach at Table Top Swamp (TTS) in northern Australia (the ‘Top End’). Single-grain luminescence dating of quartz was successfully used to provide chronology in the lowermost core where insufficient organic material prevents the application of radiocarbon dating. In the uppermost, fine-grained and peaty section of the core, two different organic fractions (pollen concentrate and humins) were dated with AMS radiocarbon yielding significantly different chronologies. While this could point to the incorporation of younger pollen into the profile along seasonal dry cracks, older humins may also move up in the profile due to vertical mixing. Additional, spatially highly resolved measurements of the bulk OSL signal (Ln and Ln/Tn) combined with data on down-core variation in K, Th, and U concentration, grain size and moisture content were used to (i) guide the development of an age-depth relationship (i.e. age model) for the entire core based on three different data input scenarios, and (ii) test the applicability of novel luminescence screening techniques in seasonal swamp settings. Results suggest only minor differences among the applied models and scenarios, providing an overall reliable representation of the depositional history in the swamp. Even though all resulting age-depth models have relatively large uncertainties in the lower part of the core, there are significant changes in sedimentation rate over time, providing a chronological basis for a more detailed palaeoenvironmental analysis at TTS. The approach used may also be useful in developing age models in other complex environments, and has shown the importance of understanding carbon pathways as well as controls on luminescence signals when developing age models.