Burial Period Research Articles

Effects of Sedimentation on the Photobiology of Mesophotic Rhodoliths From the Southwestern Atlantic Ocean

ABSTRACTMesophotic rhodolith beds are free‐living nongeniculate coralline algae (NGCA) bioconstructions with slow growth rates and massive associated diversity, distributed worldwide along continental shelves. They are subjected to deleterious impacts of sedimentation from natural and anthropogenic sources, which can bury the thalli, causing photosynthetic reduction and impaired gas exchange, among other effects. There have been only a few studies exploring the consequences of smothering and burial, which limit our knowledge of these type of impact. In this study, we evaluated the photosynthetic response and recovery of NGCA under different sedimentation conditions in the laboratory. Experiments were performed considering different loads of natural sediment (medium sand) during continuous burial periods. The Potential (Fv/Fm) and Effective Quantum Yield (ΔF/Fm′) of photosystem II (PSII) and the relative Electron Transport Rate (rETR) were determined using pulse‐amplitude modulated fluorometry as indicators of PSII integrity and photosynthetic activity. PSII functionality (Fv/Fm) was impaired over time under the highest sediment load tested (burial under 100 g of sediment per thallus). However, only 2 days was necessary to recover at least half of the photosynthetic capacity observed in the control samples. This recovery pattern was also supported by ΔF/Fm′ and rETR. Our results illuminated the limits of the resilient behaviour of NGCA to sediment smothering and burial, where long burial periods (2 months) associated with heavy sediment load could cause heavy damage to the photosynthetic apparatus, which can lead to death. However, these organisms could recover after sediment removal. These results provide important information for setting up management strategies to assess the smothering and burial impacts of sediments on rhodoliths.

Study on the internal alteration mechanism of marble jade artifacts from Sanxingdui ritual Pit no. 3, Sichuan

Study on the internal alteration mechanism of marble jade artifacts from Sanxingdui ritual Pit no. 3, Sichuan

Cassava Peel - Cowpea Hull Blended Agro-Waste Fillers: Effect on Mechanical, Morphological and Degradation Properties of Polypropylene

Abstract: This study is aimed at harnessing the effect of cassava peel and cowpea hull blended agro-waste on the mechanical, morphological and degradation properties of polypropylene and recycled polypropylene. Fine powders of mesh size of 75µm cassava peel and cowpea hull were homogeneously mixed at the ratio of 50:50 to form the hybrid filler. The virgin pellets of PP and recycled polypropylene (rPP) were filled with varying weight percentages (5, 10, 15, 20) of the blended filler and the composites produced via injection moulding technique. The mechanical properties; tensile strength, percentage elongation at break, hardness, compressive strength, and shear modulus were studied according to American Society for Testing and Materials (ASTM) standards. The morphological properties were studied with a Scanning Electron Microscope at 10,000 magnifications. The degradation study was achieved by soil burial method for one hundred and eighty (180) days period. The results of the mechanical properties showed increased tensile strength, hardness, compressive strength and shear modulus while the percentage elongation at break decreased as the filler load increases. The micrographs showed that the virgin PP has better adhesion and interfacial bonding with the filler than the rPP. Biodegradation test revealed a reduction in the mass of the composites after one hundred and eighty (180) days burial period indicating that the composite is degradable. From the findings, the cassava peel-cowpea hull blended filler can be used in materials where stiffness and strength is required. Hence, it is suggested that agro-wastes such as cassava peel and cowpea hulls could be used as fillers in production of degradable plastics as they are readily available, cheap and easy to use.

Microstructure characterization and corrosion resistance in soil of Mg-2Zn-xCe-yCu alloy for light agricultural machinery

Microstructure characterization and corrosion resistance in soil of Mg-2Zn-xCe-yCu alloy for light agricultural machinery

Fungal biomass and ectomycorrhizal community assessment of phosphorus responsive Pinus taeda plantations.

Ectomycorrhizal fungi and non-ectomycorrhizal fungi are responsive to changes in environmental and nutrient availabilities. Although many species of ectomycorrhizas are known to enhance the uptake of phosphorus and other nutrients for Pinus taeda, it is not understood how to optimize these communities to have tangible effects on plantation silviculture and P use efficiency. The first step of this process is the identification of native fungi present in the system that are associated with P. taeda and influence P uptake efficiency. We used sand-filled mesh bags baited with finely ground apatite to sample ectomycorrhizal and non-ectomycorrhizal fungi associated with the rhizosphere of P-responsive P. taeda under several field conditions. Mesh bags were assessed for biomass accumulation over three years using a single three-month burial period pre-harvest and three six-month burial periods post-planting. Amplicon sequencing assessed ectomycorrhizal and non-ectomycorrhizal communities between phosphorus treatments, sites, mesh bags, and the rhizosphere of actively growing P. taeda in the field. We found biomass accumulation within the mesh bags was inversely related to increasing phosphorus fertilization (carryover) rates from pre-harvest to post-planting. Up to 25% increases in total biomass within the bags were observed for bags baited with P. Taxonomic richness was highest in Alfisol soils treated with phosphorus from the previous rotation and lowest in the Spodosol regardless of phosphorus treatment.

Using luminescence dating to constrain lake sediment records: A new age model for the 1.38 Ma lake Malawi drill core, Eastern Africa

Using luminescence dating to constrain lake sediment records: A new age model for the 1.38 Ma lake Malawi drill core, Eastern Africa

Utility of in situ ion‐exchange membranes to assess nutrient availability, productivity, and fertilizer response of coastal Douglas‐fir of the Pacific Northwest

AbstractDouglas‐fir [Pseudotsuga menziesii (Mirb.) Franco] is the predominant forest plantation species in the Pacific Northwest (PNW), with site productivity and fertilizer response influenced by climate and soil variations. This study investigates the utility of in situ 12‐week supply measurements of nitrogen (N), calcium (Ca), and phosphorus (P) to ion‐exchange resins (specifically Plant Root Simulator [PRS] probes) to estimate carbon (C):N ratios, soil nutrient contents (0–1 m), foliar nutrient concentrations, Douglas‐fir productivity (site index and basal area mean annual increment), and fertilizer volume response. PRS nutrient supply rates were correlated with N, Ca, and P soil nutrient contents (0–1 m), C:N ratios, and foliar nutrient concentrations. Low PRS NO3 supply rates (<25 mg N·m−2·burial period−1) were correlated with lower Douglas‐fir productivity and greater fertilizer volume response. PRS NO3 supply rates performed as well as total soil N contents and foliar N concentrations at estimating volume growth response to fertilizer. Twelve weeks after fertilization, PRS NO3, NH4, and Ca supply rates were significantly elevated compared to the unfertilized treatment. This research found that PRS probes were an effective in situ tool and are recommended for understanding N, Ca, and P nutrient availabilities, site productivity, and fertilizer response in Douglas‐fir plantations and for developing fertilizer prescriptions.

Soil Biodegradation Resistance of Cotton Fiber Doped with Interior and Exterior Silver Nanoparticles.

Engineering fibers with nanomaterials is an effective way to modify their properties and responses to external stimuli. In this study, we doped cotton fibers with silver nanoparticles, both on the surface (126 ± 17 nm) and throughout the fiber cross section (18 ± 4 nm), and examined the resistance to soil biodegradation. A reagent-free one-pot treatment of a raw cotton fabric, where noncellulosic constituents of the raw cotton fiber and starch sizing served as reducing agents, produced silver nanoparticles with a total concentration of 11 g/kg. In a soil burial study spanning 16 weeks, untreated cotton underwent a sequential degradation process-fibrillation, fractionation, and merging-corresponding to the length of the soil burial period, whereas treated cotton did not exhibit significant degradation. The remarkable biodegradation resistance of the treated cotton was attributed to the antimicrobial properties of silver nanoparticles, as demonstrated through a test involving the soil-borne fungus Aspergillus flavus. The nonlinear loss behavior of silver from the treated cotton suggests that nanoparticle depletion in the soil depends on their location, with interior nanoparticles proving durable against environmental exposure.

A fresh perspective on infrared spectroscopy as a prescreening method for molecular and stable isotopes analyses on ancient human bones

Following the development of modern genome sequencing technologies, the investigation of museum osteological finds is increasingly informative and popular. Viable protocols to help preserve these collections from exceedingly invasive analyses, would allow greater access to the specimens for scientific research. The main aim of this work is to survey skeletal tissues, specifically petrous bones and roots of teeth, using infrared spectroscopy as a prescreening method to assess the bone quality for molecular analyses. This approach could overcome the major problem of identifying useful genetic material in archaeological bone collections without resorting to demanding, time consuming and expensive laboratory studies. A minimally invasive sampling of archaeological bones was developed and bone structural and compositional changes were examined, linking isotopic and genetic data to infrared spectra. The predictive model based on Infrared parameters is effective in determining the occurrence of ancient DNA (aDNA); however, the quality/quantity of aDNA cannot be determined because of the influence of environmental and local factors experienced by the examined bones during the burial period.

Impact of Hybrid Biomass Fillers on the Physico-Mechanical and Degradation Properties of Utility Polymers

The impact of cassava peel-rice husk hybrid fillers on the physico-mechanical and degradation properties of utility polymers were studied. Fine powders of cassava peel and rice husk of 75µm mesh size were homogeneously mixed at the ratio of 1:1 to form the hybrid filler. The virgin crystalline pellets of Low-Density Polyethylene and Polypropylene were filled with varying weight percentages (5, 10, 15, and 20) of the hybridized filler and the composites produced via the injection moulding technique at 288oC. The mechanical properties were studied according to ASTM standards. The surface morphological properties and thermal properties were studied with Scanning Electron Microscope and Differential Scanning Calorimeter respectively. The results of the mechanical properties showed improved tensile strength, compression strength and hardness as the filler load increases till optimum filler load was attained, while the percentage elongation at break decreased with increase in filler load. The shear modulus was found to be irregular. The creep behaviour with the PP composites was irregular but linear with LDPE composites. The solvent imbibition showed no increase in water, but less than 1% increase in toluene. The DSC result showed the hybrid filler had positive impact on LDPE composite but no effect on PP composite. The micrographs showed improved properties as the filler loading increases. Biodegradation test in soil revealed a reduction in the mass of the composites after a 6- month burial period indicating that the composite is degradable and eco- friendly. From the results, the cassava peel-rice husk hybrid filler can be employed in formulation of polymers where strength, water resistance and biodegradability is required such as plastic tiles. Thus, it is suggested that agro-wastes such as cassava peel and rice husk could be used as fillers in production of degradable plastics as they are accessible, cheap, easy to use and eco-friendly.

Multi‐analytical characterization of archaeological fragments of pietra ollare from the Medieval site ‘Piana di S. Martino’ (Piacenza, Italy): A mobile and laboratory approach

AbstractThe archaeological excavations in the site of ‘Piana di San Martino’ (Pianello Val Tidone, Piacenza, Italy) discovered several fragments of pietra ollare (soapstone) artefacts, dating back to the Medieval period. A selection of fragments was characterized with micro‐Raman spectroscopy in order to determine their composition, in terms of main and accessory species. The morphology of the crystals and the mineral phases were also investigated with polarized‐light microscopy observations, X‐ray powder diffraction and Scanning Electron Microscopy with Energy‐Dispersive System analyses, which corroborate the Raman results. A detailed characterization was obtained on 12 fragments ascribable to pots and a millstone, made of talc‐schists or chlorite‐schists, including garnet‐bearing chlorite‐schists. Interest findings about the activities related to the use of these artefacts and the alteration processes occurred during their burial period were highlighted by the identification of specific products. Additionally, mobile Raman measurements were performed on the fragments, and a quick and effective evaluation of their composition was successfully achieved. These results highlight the use of mobile Raman instruments in the field of archaeology, specifically referred to pietra ollare findings, for which a preliminary identification may be obtained directly in situ.

Characterization of Microbial Decay and Microbial Communities in Waterlogged Archaeological Wood Excavated from the Wetland

Anatomical and chemical changes due to microbial decay and microbial communities in three waterlogged archaeological woods, namely Dongnim 1, Dongnim 2, and Dongnim 3, excavated from the wetland of the Dongnim-dong archaeological site in Gwangju, were investigated. Dongnim 1−3 exhibited a maximum moisture content approximately 6 to 8 times higher than that of undecayed recent wood, and there was no correlation with the burial period. Chemical analysis revealed an increase in ash and hot water extractive content in Dongnim 1−3 compared to undecayed recent wood, while the solvent extractive content tended to decrease. Additionally, there was a significant decrease in holocellulose content with a relative increase in lignin concentration in Dongnim 1−3. Microscopic observations showed erosion bacteria decay and soft rot decay in Dongnim 1−3. The microbial community analysis of Dongnim 2 and 3 revealed the dominance of Ascomycota (98% to 99%) in the fungal community and Proteobacteria (34% to 55%) as the predominant bacterial phylum. Nonetheless, significant differences in microbial community structure and diversity were observed between Dongnim 2 and Dongnim 3.

Further study on the genesis of lamellar calcite veins in lacustrine black shale—A case study of Paleogene in Dongying Depression, China

Further study on the genesis of lamellar calcite veins in lacustrine black shale—A case study of Paleogene in Dongying Depression, China

Characterization of biodegradable corn starch-based foam container incorporating kimchi cabbage (Brassica rapa L. pekinensis) by-product

Characterization of biodegradable corn starch-based foam container incorporating kimchi cabbage (Brassica rapa L. pekinensis) by-product

Scale-up fabrication of a biodegradable PBAT/PLA composite film compatibilized with a chain extender for industrial agricultural mulch film application

Scale-up fabrication of a biodegradable PBAT/PLA composite film compatibilized with a chain extender for industrial agricultural mulch film application

Main reservoir controlling factors and diagenetic evolution of the Xiao'erbulak Formation of Tarim Basin, NW China: A case study of Well KPN1 in Kalpin area

Main reservoir controlling factors and diagenetic evolution of the Xiao'erbulak Formation of Tarim Basin, NW China: A case study of Well KPN1 in Kalpin area

Controlling Factors of Meteoric Diagenesis in Karst Reservoirs: An Example from the Majiagou Formation, Ordos Basin, China

Karst reservoirs have always been a key field of oil and gas exploration. However, quantifying the process of meteoric transformation remains a persistent challenge that limits the accuracy of reservoir quality prediction. To explore the controlling factors of meteoric cementation on karst reservoirs, the Majiagou Formation of the Ordos Basin in China was selected as an example. The petrology; carbon, oxygen, and strontium isotopes; and in situ major, trace, and rare earth elements were used, types and origins of calcite cements were analyzed in detail. The results revealed five types of calcite cements (Cal-1~Cal-5), four types of cathodoluminescence (CL) intensities (dull, dull red, deep red, and bright red luminescence), and six types of rare earth element patterns (Pattern-1~Pattern-6). These five types of calcite cements developed in three periods. Cal-1 (transition CL) and Cal-2 (dull CL) were precipitated during the Early Pennsylvanian period, the meteoric freshwater was clean; Cal-3 (transition CL) and Cal-4 (bright red CL) were precipitated at the end of the Late Carboniferous period, the fluids had strong dissolution ability and were polluted by terrigenous debris; Cal-5 (transition CL) was deposited during the burial period, the fluid was pure pore water or groundwater. The control of the cement on the reservoir during the burial period was much weaker than that of meteoric cements. Therefore, explorations of karst reservoirs should be focused on weak cementation during the epigenetic period.

The earliest directly dated saddle for horse-riding from a mid-1st millennium BCE female burial in Northwest China

The invention of the saddle substantially improved horseback-riding, which not only revolutionized warfare, but also eased long-distance speedy movement across Eurasia. Here we present the first detailed construction analysis and absolute age determination of a well-preserved soft leather saddle recovered from the tomb of a female deceased at the Yanghai cemetery site in the Turfan Basin at the eastern end of the Tian Shan mountains. Compared with the oldest known saddle from the Scythian Pazyryk culture site Tuekta barrow no. 1 (430–420 BCE) in north-western Altai, the Yanghai specimen radiocarbon dated to 727–396 BCE (95.4% probability range) is contemporaneous or possibly older. The saddle features the basic elements of soft saddle construction that are still used today: two stuffed, wing-shaped hides sewn together along the outer edges and separated by a central gullet-like spacer and lens-shaped support elements, resembling knee and thigh rolls of modern saddles. Being a masterful piece of leather- and needlework, it is, however, less complex compared to Scythian saddles from the 5th–3rd centuries BCE. Another specimen from nearby Subeixi site, which is also described in detail for the first time in the present study, much closer resembles the Pazyryk saddles in shape, size and structure. In Yanghai, equestrian paraphernalia appear in the grave assemblages during the entire burial period (ca. 1300 BCE to 200 CE), although in higher numbers only from ca. 300 BCE. In the same way, the burial of horses was not common until then. Despite the generally very good preservation of leather, only two saddles were discovered in Yanghai which makes them an exception rather than the norm and raises the question of whether these saddles were acquired from more specialized horse breeders, riders, and saddlers in the North.

Heterogeneity and differential hydrocarbon accumulation model of deep reservoirs in foreland thrust belts: A case study of deep Cretaceous Qingshuihe Formation clastic reservoirs in southern Junggar Basin, NW China

Heterogeneity and differential hydrocarbon accumulation model of deep reservoirs in foreland thrust belts: A case study of deep Cretaceous Qingshuihe Formation clastic reservoirs in southern Junggar Basin, NW China

Dolomitisation under an arid climate at low sea-level: a case study of the Lei 4 Member of the Middle Triassic Leikoupo Formation, Western Sichuan Depression, China

The origin of dolostones from the Lei 4 Member (T2l4) of the Middle Triassic Leikoupo Formation in the Western Sichuan Depression is unclear. The occurrence and genetic evolution of dolostones in T2l4 were analysed by polarised thin-sections and cathodoluminescence, major- and trace-element, scanning electron microscope, and carbon, oxygen and strontium isotope analyses. The study results are summarised as follows. (1) The dolostones were mainly precipitated in three stages of <40 °C, 40–60 °C and 60–80 °C, corresponding with three paleodepth ranges of 167–300 m, 433–1000 m and 1067–1433 m. The micritic dolostones and the fabric-retentive dolostones (algal dolostone, granular dolostone) mainly formed in a near-surface–shallow-burial environment, and the crystalline dolostones were mainly formed under intermediate burial conditions. (2) 87Sr/86Sr ratios are equivalent to that of the Middle Triassic seawater, Sr/Ba and V/Ni ratios >1, Na notably higher than that in coexisting limestones of T2l4, and the dolostones always coexist with evaporative minerals such as gypsum, indicating that dolomitisation fluids mainly originated from evaporative concentrated seawater. (3) The dolostones mainly inherit materials from precursor limestones based on trace-element distribution patterns, and carbon and oxygen isotope values that are consistent with coexisting limestones of T2l4. (4) Mediated by micro-organisms during the syngenetic period, micritic dolostones and some algal dolostones were formed by replacing aragonites and calcites. During shallow burial, concentrated seawater rich in Mg2+ from the supratidal–intertidal zone flowed downward owing to gravity along the platform and replaced the underlying carbonate rocks, promoting continuous growth of the early dolomites. In the intermediate burial period, the Mg2+-depleted dolomitisation fluid caused the early micritic and silt-crystalline dolostones to recrystallise into silt- or fine-crystalline dolostones with larger crystals and altered the fabric-retentive dolostones into crystalline dolostones. (5) The evaporative dolostones deposited in the near-surface environment are characterised by maximal enrichment of Fe, Sr and Na, the highest δ18O values, the lowest order degree and the highest Ca/Mg ratios. The reflux dolostones formed in a shallow-burial environment characterised by the lowest Fe, medium δ18O values and the lowest order degree. The burial dolostones that developed in the intermediate burial environment are characterised by relative enrichment of Fe and Mn, minimal Na, the lowest δ18O values, the highest order degree and medium Ca/Mg ratios. KEY POINTS The fabric-retentive dolostones mainly formed in a near-surface–shallow-burial environment, and the crystalline dolostones mainly formed under intermediate burial conditions. Dolomitisation fluids mainly originated from the evaporative concentrated seawater, and the dolostones inherit materials from the precursor limestones. Micritic dolostones were formed by evaporative dolomitisation; algal dolostone and granular dolostone were formed by evaporative dolomitisation and reflux dolomitisation; and silt-crystalline dolostone were formed by reflux dolomitisation and burial dolomitisation.