Shallow Marine Areas Research Articles

Marbled Murrelets prefer stratified waters close to freshwater inputs in Haida Gwaii, British Columbia, Canada

Abstract The Marbled Murrelet (Brachyramphus marmoratus) is a small seabird that is currently listed as threatened in Canada. Understanding this species’ marine habitat preferences plays a vital role in our ability to focus conservation planning. We used the longest-running at-sea survey dataset available in British Columbia to examine hotspot persistence and habitat use at Laskeek Bay, Haida Gwaii, BC. The Laskeek Bay Conservation Society has been conducting spring and summer surveys along fixed transect routes in open and shoreline waters from 1997 to 2018. Along with analyzing this long-term dataset, we conducted surveys to measure oceanographic variables (2018–2019) and tested whether Marbled Murrelets in the same area used prey and oceanographic information to select marine habitat in conjunction with physical habitat features. Our hotspot persistence map, defined as areas that repeatedly had counts above a 75% threshold relative to other areas during a given survey, showed that murrelets consistently preferred shoreline transects. Murrelets also preferred shallow marine areas closer to streams, above higher proportions of sandy substrate and closer proximity to abundant nesting habitat. Modeling weather and time variables contributed little additional predictive power. Nonetheless, models that included physical environmental, oceanographic, and prey variables outperformed those with only physical environmental variables. Stratified water was the oceanographic variable most strongly related to higher counts. Our study suggests that stratified waters could work with stream systems to create productive zones for foraging murrelets, and highlights the importance of murrelets having access to marine areas with the preferred physical features.

Les faunes coralliennes de l’Oligocène de Malte : biodiversité et paléoenvironnement

The study of the coral biodiversity of the Upper Oligocene sedimentary series (Lower Coralline Limestone, Chattian) of Malta permitted the identification of 25 scleractinian genera represented by 41 species. Three new species are proposed: Miophoranaxxarensis n. sp., Nerthastraeamaltensis n. sp. and Gyrosmiliamaltensis n. sp. Observations made in various Oligocene sites in Malta, especially around Naxxar and Tal Bajjada, allow to establish a suite of coral associations which may vary spatially and vertically. The identified scleractinian associations can be represented by different types of coral assemblages and bioconstructions: isolated colonies, coral beds of varying density but of large spatial extent, more cohesive coral banks (coral carpets) or patch reefs forming morphologies with gentle lateral slopes. The colonial morphologies are closely linked to these different types of bioconstructions. These coral constructions have been established and developed in shallow marine areas. The coral biodiversity of the Oligocene of Malta fits well in the evolution of the Cenozoic reef phenomenon whose development reached its peak in the Oligocene with great coral richness in the Chattian in the Mediterranean area.

Bryozoan‐rich stromatolites (bryostromatolites) from the Silurian of Gotland and their relation to climate‐related perturbations of the global carbon cycle

ABSTRACTBryozoan–stromatolite associations (bryostromatolites) formed conspicuous reef structures throughout the Sheinwoodian (Wenlock) to Ludfordian (Ludlow) stratigraphy on Gotland but have not been described so far. They are mainly composed of encrusting bryozoans forming a complex intergrowth with porostromate and spongiostromate microbes and are different from the abundant stromatoporoid–coral–algal reefs with respect to their composition. In the bryostromatolite different growth stages can be identified. The observed succession can be taken as evidence for cyclic environmental changes during reef formation. Stenohaline reef‐dwelling organisms, such as echinoderms, sponges, corals and trilobites, indicate fully marine salinities. Ten localities exposing bryostromatolites were discovered. Individual bryostromatolites are small with few decimetres up to one metre in size, and occur solely in shallow marine areas. Common features of these reefs on Gotland are cauliflower‐like growth, a high bryozoan diversity, a high abundance of phosphatic fossils and components such as bryozoan pearls and inarticulate phosphatic brachiopods, enhanced bioerosion, Palaeomicrocodium crusts, vadose silt and gypsum pseudomorphs. The high abundance of Palaeomicrocodium, as well as the alternation with other crust‐forming contributors, suggest that it could have been formed directly at the palaeo‐sea surface, probably in times of minor but high‐frequency sea‐level fluctuations. Vadose silt and pseudomorphs after gypsum in reef cavities indicate subaerial exposure shortly after reef growth. The high amount of phosphatic components indicates a high nutrient input, probably by dust. All bryostromatolites were formed in times of strongly elevated δ13C values. The unusual combination of sedimentological and palaeoecological features, as well as their occurrence exclusively during strong positive δ13C excursions, are evidence that the bryostromatolite development responded to climatic/oceanographic changes, which may have played an important role in reef control.

Constraints of applying strontium isotope stratigraphy in coastal and shallow marine environments: insights from Lower Cretaceous carbonates deposited in an active tectonic setting (N Iberian Basin, Spain)

The Lower Cretaceous Leza Formation is an essentially carbonate unit deposited at the northernmost active margin of the Cameros Basin (N Spain) under an extensional tectonic regime. This unit is composed of freshwater, marine-influenced, marginal-marine and hypersaline marine carbonate facies, interbedded with variable amounts of alluvial deposits, mainly derived from the erosion of the Jurassic substrate. 87Sr/86Sr, δ18O and δ13C analyses were obtained from carbonate facies of the Eastern and Western sectors of the basin. δ18O values follow the expected trend in both sectors: they are more negative (down to − 7.9‰) in freshwater carbonates and more positive (up to + 2.8‰) in marginal-marine to hypersaline facies. However, independently of the seawater or freshwater influence, in the Western Sector the 87Sr/86Sr values (0.707373–0.707801) are significantly lower and closer to the published Lower Cretaceous seawater 87Sr/86Sr ratios, than those of the Eastern Sector (0.707988–0.709033), where the overall marine influence was relatively high and the alluvial input low. These data strongly suggest that 87Sr/86Sr ratios were mainly controlled by those of the riverine freshwater arriving to the coastal and marine areas after the weathering and erosion of the Jurassic carbonates or siliciclastic rocks, in the Western and Eastern sectors, respectively. Thus, data indicate that, in coastal and shallow marine carbonates, the influence of the riverine water on the 87Sr/86Sr ratios should be systematically evaluated. This is particularly necessary in active tectonic settings, where the uplifted areas are significantly prone to weathering and erosion and where alluvial fan systems commonly developed, eventually discharging into coastal and shallow marine areas.

Gaziköy-Mürefte (Marmara Denizi) arasında yer alan sığ denizel bölgenin sismik yansıma verileri ışığında tektonik anlamı, KB Anadolu

Within the scope of this paper, seismic reflection and bathymetry studies were carried out in the shallow marine area forming the westernmost part of the Tekirdag Basin using the R/V Selen Research Vessel within the MTA Marine Research Department. In the study area, ~ 500 km length bathymetry data and ~191 km shallow seismic profiles ( 41 lines) were collected. By means of the data, tectonic structures and deformation textures of the North Anatolian Fault System (NAFS) in the marine area of Gazikoy were examined. As a result of the processing and interpretation of the seismic sections, compression structures occurring due to the SW rotation of the NAFS in the study area, the morphology of the Ganos depression that formed as a result of faulting and also three different stratigraphic units were distinguished. These units are separated from each other by distinct unconformity surfaces and each unit presents different deformation structures. One of the most significant results obtained from the seismic data is that the unconformity surface that separates the current sediments of the seafloor from the older units is represented by the overlapping structures indicate sea level changes. It has been assessed that this situation occurred as a result of the erosional process developed during sea level fall.

Feeding ecology of pipefish species inhabiting Mediterranean seagrasses

Pipefish are a vulnerable and diverse group of ichthyofauna tightly associated to seagrass meadows, key habitats in shallow marine areas. Despite of their charismatic role, main ecological features, habitat and diet of this group remain largely unknown. This study focuses on assessing pipefish habitat and feeding preferences including different hosting seagrasses such as Posidonia oceanica and Cymodocea nodosa from the Balearic Islands, western Mediterranean. Four species (Syngnathus typhle, S. abaster, Nerophis ophidion and N. maculatus) were found associated to different seagrasses. S. typhle and N. maculatus were more frequent in P. oceanica meadows, while S. abaster and N. ophidion in C. nodosa. Individuals of all species captured in P. oceanica were larger than those living in C. nodosa, suggesting a size-dependent habitat preference. Feeding preferences, however, were driven by prey availability and fish features, e.g head/snout morphology. For the first time in the western Mediterranean, a thorough description of the diet and potential preys of this group was carried out. Epifaunal assemblages (potential prey) were dominated in both habitats by harpacticoid copepods and gammarid amphipods, and they were also the primary preys according to stomach contents of all species. These results can contribute to future pipefish conservation and management actions, such as targeting crucial habitat identification and designing culture and reintroduction protocols.

Migration routes and habitat use of a highly adaptable salmonid (sea trout, Salmo trutta) in a complex marine area

BackgroundUnderstanding fish movements and migrations are paramount for management and conservation efforts. By applying Hidden Markov Models (HMMs) on records from electronic tags, migration routes of tagged fish can be reconstructed and new insights to the movement ecology of a species can be gained. We demonstrate the usability of HMMs on a widespread, iteroparous salmonid (sea trout, Salmo trutta) in a complex marine area with highly variable temperatures and salinities within small geographic distances. Understanding how the highly adaptable sea trout cope with these complex conditions could shed new light on factors driving the movement ecology of salmonids. Migration tracks of fish migrating at sea are reconstructed by applying an HMM on temperature and depth records from eight wild post-spawned sea trout from four Danish rivers.ResultsThe fish migrated at sea for 47–142 days. Estimated positions of all fish were close to the coast (< 100 km) throughout the marine period, but migrations along coastlines up to 580 km away from the natal river occurred. Seven of eight individuals resided in or actively migrated into stratified or shallow marine areas that heat up fast during spring, while all eight individuals resided in deeper and more heterogeneous areas that heat up slow during summer. All fish entered the Skagerrak (located between Denmark and Norway) at some stage during summer. Migrations were directed into less saline areas during the first 15 days at sea for all individuals. Mean linear progression of the fish was 16 km day−1 (range 0–58 km day−1).ConclusionsThe results corroborate the expectation that sea trout are more coastally orientated than other salmonids, but also suggest that longer migrations occur in the seas surrounding Denmark compared to elsewhere. This could be a consequence of the fish seeking out habitats with optimal conditions (e.g. salinity, temperature, predation and foraging options) for growth in different parts of the year. The coinciding movement from shallow or stratified marine areas that heat up fast during spring to deeper, more well-mixed areas that heat up slow during summer suggested that some habitat selection had occurred. These results shed new light on factors influencing marine migrations in salmonids and demonstrate how HMMs can expand our knowledge on behaviour and movement ecology of marine fishes.

Geotechnical characteristics of a selected shallow marine area considered for quay wall construction

Quay wall defense systems are useful marine structures for berthing of vessels and other marine operations. Before quay-walls are constructed in shallow marine areas, there is need for adequate subsurface investigation to ensure proper design and construction of quay-walls that will be able to satisfactorily support the facilities they are intended for. This research work focuses on subsurface investigation involving the geotechnical characterization of soil in a selected shallow marine area in the Niger Delta area of Nigeria. Percussion rigs were used for both the on-land and over-the-water borings. A total of seven (7) on-land and six (6) over-the-water borings, all to a depth of 40 m each below existing ground level and sea bed respectively, were carried out. Field and laboratory tests were performed in order to effectively characterize the soils. Stratigraphy of on-land borings showed soft fibrous organic peaty clay layer, underlain below by silty sands and clays. Beneath this layer to the end of boring is well-graded sands and gravels. The borings over-water had a very soft to soft clay layer underlain by silty-sand, being underlain by poorly-graded sands and well-graded sands to the limits of the borings. Deep foundation systems employing reinforced concrete piles to depths (coinciding with the sandy horizon) were recommended for the on-land piles, reinforced hollow cylindrical steel piles for piers and piles for offshore landing jetties, and concrete sheet piles for shore protection works. This will form the ballasts for mooring of cargo vessels for conveying oil and gas final products.

Underwater noise level predictions of ammunition explosions in the shallow area of Lithuanian Baltic Sea

Among the noisiest man-made activities in the seas, emitting very high acoustic energy are the underwater explosions of various objects and ship shock trials. Sound energy emitted by high explosives can be predicted or measured at sea. Sometimes, it can be convenient to apply empirical formulas and scaling laws to approximate the energy of underwater explosions. In addition, at some instances the determination of the spectral properties of the explosions is useful, i.e. when possible animal exposure to impulsive noise has to be evaluated. This paper presents an example of an application of freely available scaling laws and equations for prediction of noise levels of underwater explosions of historical ordnance in the shallow sea environments.Main findings of the study: An available scaling laws applied to model underwater explosion properties; spatial extent of explosion mapped; arising issues of modelling of underwater explosions in the shallow marine areas discussed.

Age and life style affect macroalgae colonization by amphipods in shallow marine environments

Dispersal and colonization processes are complex and affected by several factors in the marine realm. Understanding how and where individuals go can be challenging, particularly for marine invertebrates that do not have a sessile phase. We selected the amphipod-macroalga system to investigate if life stage and life style can influence colonization patterns from algal patches placed at different distances and having variable amounts of available substrate for colonization. Amphipods are key organisms connecting the benthonic and pelagic environments through food chains and our results bring important contributions for conservation and management of these systems in shallow marine areas. We ran field and laboratory experiments to compare the colonization of Sargassum fronds between adult and juvenile amphipods, as well as tube-dwelling and free-living species. We found three times more juveniles than adults colonizing the experimental patches, and both tube-dwelling and free-living juveniles occupied experimental patches across all distances in the field. In the laboratory, we observed the tube-dwelling Cymadusa filosa remaining in more proximal patches than the free-living Hyale niger. Juveniles occupied similarly small and large algal surface area patches both in the field and in the laboratory, while adults occupied primarily large algal surface area patches in the field. We did not observe differences regarding life style in the colonization of small or large algal surface area patches by juveniles in the field or in the laboratory. Our findings support the idea that juvenile amphipods may have higher dispersal potential by colonizing more distant areas and/or patches with variable amounts of available substrate when compared to adults. Amphipods life style may influence colonization distance during initial dispersal movements of juveniles due to the fact that tube-dweller juveniles stay closer to the site where they were released.

The current status of the macrozoobenthos around the Atlantic walrus haul-outs in the Pechora Sea (SE Barents Sea)

Although benthic fauna in the Pechora Sea (SE Barents Sea) is generally well-studied, information on the bottom communities in the shallows near islands and the mainland is still sparse. Shallow marine areas in the Pechora Sea serve as important feeding grounds for numerous benthophagous fish, waterfowl and marine mammals, including the Atlantic walrus (Odobenus rosmarus rosmarus). To study the patterns of macrozoobenthic distribution in the shallows and evaluate the ecological state of the zoobenthic populations close to walrus haul-outs, sampling was performed in 2014 and 2016 around an archipelago in the Pechora Sea. In 2014, the average biomass, the Shannon's Diversity Index and the predominance of filter feeders in benthic communities were, in general, similar to the respective characteristics in neighboring deeper areas studied in the 1990s. In 2016, significant differences in species number and in biomass were recorded compared to 2014. An increase was observed in Atlantic boreo-Arctic species. Analysis of the trophic structure showed a slight decrease in the proportion of filter feeders and a significant increase in the proportion of subsurface deposit feeders. However, the Shannon's Diversity and Ecological Stress Indices indicated that the macrozoobenthos in the study area was in a state of equilibrium. Changes in the zoobenthos may result from several factors, such as an increase in water temperature, sediment re-deposition under wind-induced waves and the plowing of bottom sediments by walruses during their foraging.

Cyclic carbonate–siliciclastic sedimentation in a shallow marine to coastal environment (latest Kimmeridgian–early Tithonian, Galve sub-basin, Spain)

The sedimentological analysis of the uppermost Kimmeridgian to lower Tithonian Villar del Arzobispo Formation (Galve sub-basin, NE Spain) has allowed characterizing different carbonate, mixed and siliciclastic facies deposited in coastal to shallow marine areas. Its age calibration has been specified on the basis of new biostratigraphic and chemostratigraphic data. Four successive sequences (30–80 m thick) characterized by the relative dominance of carbonate and siliciclastic facies reflect a sedimentary change from reciprocal to mixed carbonate–siliciclastic sedimentation. Sequences 1 and 2 are reciprocal sedimentation cycles from carbonate-dominated (muddy coastal plain-carbonate lagoon) to siliciclastic coasts (muddy coastal plain-wave dominated delta). Sequence S3 is also reciprocal, from a mixed carbonate–siliciclastic coastal plain-lagoon at the lower part to a wave-dominated delta on top. A mixed carbonate–siliciclastic coastal plain-lagoon characterizes the entire sequence 4. Climate and tectonics controlled carbonate deposition and siliciclastic supply. Reciprocal sedimentation in sequences 1–3 was controlled by orbitally-driven climate changes (from arid to humid conditions) on the age range of long-term eccentricity cycles. A greater imprint of extensional synsedimentary tectonics at the upper part of sequence 3 and during sequence 4 is thought to be the main factor producing the gradual opening of the sub-basin to the wave influence and a more continuous siliciclastic supply, then controlling the change from reciprocal to mixed sedimentation and obliterating the possible imprint of orbitally-induced climatic changes.

Evolution and migration of shale facies and their control on shale gas: A case study from the Wufeng-Longmaxi Formations in the Sichuan Basin and its surroundings

The Fuling gas field, the largest commercial discovery of shale gas in China, has been producing from the organic-rich shale in the Upper Ordovician Wufeng Formation and Lower Silurian Longmaxi Formation in the Sichuan Basin, China. A refined shale gas E&amp;P and sweet spots identification require studies to be carried out not only at the sedimentary facies scale but also at the petrographic scale. This paper focuses on the characteristics of organic-rich shales. Based on data from outcrops, drilling cores, X-ray diffraction, thin sections, and scanning electric microscope, a systematic analysis of wells and well-correlation sections indicates that shales in the study area underwent two progressive and regressive cycles. In addition, differences in lithofacies and their organic or inorganic components are significant either in the vertical or in the horizontal direction, which generally controls the material basis of shale gas. The early-stage siliceous shale distributes in the east, whereas the late-stage carbonate-bearing shale extends to the west. In the southeastern Sichuan Basin, the siliceous composition decreases, whereas the clay minerals increase upward. In the central Sichuan uplift, there is a higher carbonate content. And with our new lithofacies maps, distribution of the sweet spots was identified. The northeastern Sichuan Basin has the siliceous shale in the Wufeng Formation and the silicon-bearing shale in the Longmaxi Formation, making it a play area with the greatest gas potential. The southern Sichuan Basin occurs as a favorable lithofacies area with the stacked siliceous shale in the Wufeng Formation and the calcareous shale in the Longmaxi Formation. The relatively favorable lithofacies area covers the regions extending from the periphery of southern Sichuan Basin toward the central Sichuan uplift and the northern Guizhou uplift, featuring stacked carbonate-bearing shale and clay mineral-bearing shale in the Longmaxi Formation. The shallow-marine areas close to the uplifts are dominated by mudstone and silty mudstone, thereby possessing poor material basis.

Simplistic underwater ambient noise modelling for shallow coastal areas: Lithuanian area of the Baltic Sea

It is known that underwater sea soundscapes are produced by natural noise sources that occur on the water surface and subsurface water layers. Wind, water splashes, sprays, and breaking waves produce a bubble layer, which in turn produces downward directed sound radiation. There are several additional sources that contribute to underwater noise levels, mainly from commercial shipping, and various anthropogenic sources both out at sea and in coastal areas. Recent research projects have investigated the effects of shipping traffic on the ambient soundscape in the Baltic Sea, stressing the need for long term ambient soundscape monitoring using underwater noise measurements and modelling. Freely available underwater noise models allow for the evaluation of ambient noise levels produced on water surfaces as well, as the creation of soundscape maps. In this manuscript, a simplistic underwater noise model is presented, developed for evaluating and mapping the soundscape in shallow marine areas, and for investigating the noise levels in different seasons.

Progress in the Study of Coastal Storm Deposits

Numerous studies have been carried out to identify storm deposits and decipher storm-induced sedimentary processes in coastal and shallow-marine areas. This study aims to provide an in-depth review on the study of coastal storm deposits from the following five aspects. 1) The formation of storm deposits is a function of hydrodynamic and sedimentary processes under the constraints of local geological and ecological factors. Many questions remain to demonstrate the genetic links between storm-related processes and a variety of resulting deposits such as overwash deposits, underwater deposits and hummocky cross-stratification (HCS). Future research into the formation of storm deposits should combine flume experiments, field observations and numerical simulations, and make full use of sediment source tracing methods. 2) Recently there has been rapid growth in the number of studies utilizing sediment provenance analysis to investigate the source of storm deposits. The development of source tracing techniques, such as mineral composition, magnetic susceptibility, microfossil and geochemical property, has allowed for better understanding of the depositional processes and environmental changes associated with coastal storms. 3) The role of extreme storms in the sedimentation of low-lying coastal wetlands with diverse ecosystem services has also drawn a great deal of attention. Many investigations have attempted to quantify widespread land loss, vertical marsh sediment accumulation and wetland elevation change induced by major hurricanes. 4) Paleostorm reconstructions based on storm sedimentary proxies have shown many advantages over the instrumental records and historic documents as they allow for the reconstruction of storm activities on millennial or longer time scales. Storm deposits having been used to establish proxies mainly include beach ridges and shelly cheniers, coral reefs, estuary-deltaic storm sequences and overwash deposits. Particularly over the past few decades, the proxies developed from overwash deposits have successfully retrieved many records of storm activities during the mid to late Holocene worldwide. 5) Distinguishing sediments deposited by storms and tsunamis is one of the most difficult issues among the many aspects of storm deposit studies. Comparative studies have investigated numerous diagnostic evidences including hydrodynamic condition, landward extent, grain property, texture and grading, thickness, microfossil assemblage and landscape conformity. Perhaps integrating physical, biological and geochemical evidences will, in the future, allow unambiguous identification of tsunami deposits and storm deposits.

Diversity and tectonics: predictions from neutral theory

AbstractNumerical simulations of neutral metacommunities are used here to predict the effects of growth and shrinkage of metacommunities, as well as their separation and merging caused by continental collision and rifting and their secondary eustatic effects. Although growth and shrinkage of metacommunities predictably change diversity, separating and merging metacommunities have counterintuitive effects. Separating and merging metacommunities change diversity within the individual areas, especially so for smaller areas, but they cause no change in total diversity of the system, contrary to previous predictions. The response times of metacommunities are likely to be geologically undetectable except for enormously large systems. These models can be used to predict the plate-tectonic effects on the diversity of terrestrial, coastal-marine, deep-marine, and oceanic-island systems. Of these, global and regional coastal-marine systems are the most acutely sensitive to the changes in area and fragmentation caused by plate tectonics. Oceanic-island systems also experience global and regional changes in diversity during supercontinent breakup and assembly, with the global effects driven by the changing length of volcanic arcs, and the regional effects also driven by secondary eustatic changes in shallow-marine area. Although individual terrestrial provinces or continents may experience substantial changes in diversity from rifting and collision, global terrestrial diversity should be unchanged except for the relatively modest contributions caused by the secondary eustatic effects on land area. These changes in diversity may be reinforced or counteracted by the changing latitudinal position of metacommunities.

Method for the simplistic modelling of the acoustic footprint of the vessels in the shallow marine area

The definitions of the 11th descriptor of the EU Marine Strategy Framework Directive (MSFD) “Underwater noise and other forms of energy” outlines the standards for the continuous noise evaluation and monitoring in the European seas. Long lasting fluctuations of the continuous underwater noise at the shallow marine areas in the low frequency bands (<1?kHz) are mostly associated with the shipping noise, where these fluctuations are sensitive to changes in the spatial distribution of human activities, or changes of environmental and climatic variables. Underwater noise modelling is usually considered as a supplement to noise measurements, where models increases the utility of the measurement results. Noise mapping is considered as a form of spatial modelling, providing a convenient and accessible way to visualise models. Therefore, underwater noise models and maps can be used in management and evaluation of environmental state. There are number of freely available widely used noise source and sound propagation models. Still the simplistic logarithmic rules purposed for the sound propagation loss computations do not account for the number of factors in the marine environment, i.e. sediment type, water depth or frequency. On the other hand the sophisticated physical models purposed for the description of the footprint of noise sources such as ships are complex and their programing requires very specific knowledge. In this paper the details of the method purposed for modelling of the ship noise footprint in shallow seas is presented. Proposed method allows to compute:•depth dependent ship sound transmission losses in 1?Hz frequency bands;•sound propagation losses during different seasons (summer/winter);•acoustic footprint accounting for vessel noise directivity.

Geochemical Characteristics of Sedimentary Manganese Deposit of Binkılıç, Trache Basin, Turkey

The Binkilic manganese deposit, occurring in the Congeria and Fish Series of the Oligocene in Thrace Basin, is associated with relatively rapid marine transgressions and regressions across older basement rock and is called as shallow-marine basin-margin deposit. The geochemical characteristics of the deposit were examined by means of major oxide, trace and rare elements (REE) contents and the origin of mineralization was discussed. The deposit contains lower Mn / Fe ratios than those of hydrothermal and sedimentary exhalative deposits. The concentrations of Ba, Co, Sr, Cu, Zn and Ni are closely related to the increase of manganese content and indicate the element’s nature in various manganese minerals. According to trace element spider diagram normalized to shale composite NA, the ore is clearly enriched in Sr, Ni while distinctly depleted in Rb. The chemical analysis results indicated that total REE contents of the samples are relatively low and the ratio of ΣLREE/ΣHREE shows a primary enrichment for LREE that has occurred during the Mn oxidation process. The increase in total LREE is mainly associated with the amount of terrigenous material that was transported in the depositional environment. The chondrite-normalized REE patterns are remarkably similar, yielding HREE-depleted curves with a small negative Ce and middle positive Eu anomalies and reflect their same origin of ore source. The Ce values and Ce/Ce* ratios show that the Binkilic deposit is mainly associated with the marine basin and the ore is formed in both anoxic and oxic conditions. The major oxide, trace element and REE assessments indicated that the Binkilic Mn deposit occurred as a diagenetic type of Mn deposit with terrigenous material addition, but some manganese oxides are related to the upwelling of reducing waters containing abundant organic matter and dissolved Mn to the shallow-marine areas.

Late Cenozoic palaeogeography of Sulawesi, Indonesia

Sulawesi has a remarkable biodiversity, an unusually rich endemic fauna, and is the largest island in Wallacea, just west of the Wallace Line. Alfred Russel Wallace himself suggested it could perhaps be the most remarkable island on the globe because of its peculiar fauna. It was home to extinct fossil fauna such as dwarf proboscideans, records significant Pleistocene faunal turnover, and evidence of early human occupation suggests an important role in hominid migration through the Sunda-Sahul region. Information on Neogene palaeogeography is essential for understanding biogeographic patterns, biodiversity and faunal changes. New palaeogeographic maps reflecting recent work on Sulawesi's complex geology and changes in tectonic interpretations are presented for intervals from the Early Miocene to Pleistocene, at 20, 15, 10, 8, 6, 5, 4, 3, 2, and 1Ma. Additional maps illustrate the effects of glacially-driven sea level change in the last 1Myr. They are based on a field-based investigation of sedimentary rocks in Sulawesi, accompanied by palaeontological, petrological and heavy mineral studies and U-Pb dating of detrital zircons, to date and determine depositional environments. The new results have been supplemented by re-evaluation of previous studies, including reports from oil company wells and seismic lines. Igneous rocks provided ages, indications of surface environment of eruptions, and location of magmatic activity. For most of the Neogene from the Early Miocene Sulawesi was a shallow marine area with a number of small islands, surrounded by relatively deep marine areas. Deep inter-arm bays began to form in the Late Miocene and the islands became larger. The most significant palaeogeographic change began in the Pliocene with an increase in the area and elevation of land accompanied by major subsidence of the inter-arm bays. The separate islands gradually coalesced in the Pleistocene to form the distinctive K-shaped island known today.

Ancient animal migration: a case study of eyeless, dimorphic Devonian trilobites from Poland

AbstractWe report evidence of one of the oldest known animal migratory episodes in the form of queues of the eyeless trilobite Trimerocephalus chopini Kin &amp; Błażejowski, from the Late Devonian (Famennian) of central Poland. In addition, there is evidence for two morphs in this population, one with nine segments and the other with ten. We infer that these queues represent mass migratory chains coordinated by chemotaxis, comparable to those observed in modern crustaceans such as spiny lobsters, and further suggest that the two forms, which occur in an approximately 1:1 ratio, may be dimorphs. These ancient arthropods may have migrated periodically to shallow marine areas for mass mating and spawning. The sudden death of the trilobites in the queues may have been caused by excess carbon dioxide and hydrogen sulphide introduced into the bottom water by distal storm disturbance of anoxic sediments. This study demonstrates the potential for further research on the evolution and ecology of aggregative behaviour in marine arthropods.