A case for the growth of ancient ooids within the sediment pile

2020 ◽  
Vol 90 (8) ◽  
pp. 843-854
Author(s):  
Noah T. Anderson ◽  
Clinton A. Cowan ◽  
Kristin D. Bergmann
Keyword(s):  
Organic Matter ◽  
Coarse Sand ◽  
Bedload Transport ◽  
Saturation State ◽  
Epma Data ◽  
Electron Probe Microanalyzer ◽  
Grain Sizes ◽  
The Past ◽  
The Caribbean ◽  
Physical And Chemical

ABSTRACT In modern ooid-forming environments in the Caribbean, aerobic respiration of organic matter below the sediment–water interface drives an increase in pCO2 and a corresponding decrease in carbonate saturation state (Ω) that creates shallow sediment porewater that is neutral or slightly caustic to carbonate. The locus of ooid growth, therefore, is presumed to be in the water column during suspension, where supersaturation with respect to calcium carbonate is the norm. In the past, however, during conditions of low aqueous O2, high Ω, or low organic-matter input, the shallow sub-sediment marine burial environment was conducive to carbonate precipitation. Here we present petrographic and electron probe microanalyzer (EPMA) data from exquisitely preserved oolites through time that suggests that some ancient ooids may have grown within the sediment pile. We propose that each increment of ooid cortical growth originated as incipient isopachous marine cement formed during shallow burial within migrating ooid dunes. After a period of burial (∼ weeks to months), ooids were remobilized and rounded during bedload transport. This “bedform model” for ooid growth explains: 1) why ancient ooids are not limited by the precipitation–abrasion balance that appears to prohibit modern tangential Caribbean ooids from achieving grain sizes larger than coarse sand, 2) the radial crystal fabric that defines the internal structure of many ancient ooids, and 3) the first-order correlation of the abundance of large and giant ooids in the rock record to periods with predicted high porewater Ω. This model implies that photosynthetic microbes were unimportant for growth of large and giant ooid but it remains agnostic to the effect of other microbes. The physical and chemical milieu of modern marine ooid-forming environments is perhaps not the best analogue for ancient ooid-forming environments; this should be considered when using ancient ooids to reconstruct secular trends in ocean chemistry.

scholarly journals Monsoonal forcing of cold-water coral growth off southeastern Brazil during the past 160 kyr

2020 ◽  
Vol 17 (23) ◽  
pp. 5883-5908
Author(s):  
André Bahr ◽  
Monika Doubrawa ◽  
Jürgen Titschack ◽  
Gregor Austermann ◽  
Andreas Koutsodendris ◽  
...  
Keyword(s):  
Organic Matter ◽  
Continental Slope ◽  
Deep Water ◽  
Cold Water ◽  
Southeastern Brazil ◽  
Nepheloid Layer ◽  
Saturation State ◽  
The Past ◽  
Water Ecosystems ◽  
The Impact

Abstract. Cold-water corals (CWCs) constitute important deep-water ecosystems that are under increasing environmental pressure due to ocean acidification and global warming. The sensitivity of these deep-water ecosystems to environmental change is demonstrated by abundant paleorecords drilled through CWC mounds that reveal characteristic alterations between rapid formation and dormant or erosive phases. Previous studies have identified several central parameters for driving or inhibiting CWC growth such as food supply, oxygenation, and the carbon saturation state of bottom water, yet there are still large uncertainties about the relative importance of the different environmental parameters. To advance this debate we have performed a multiproxy study on a sediment core retrieved from the 25 m high Bowie Mound, located at 866 m water depth on the continental slope off southeastern Brazil, a structure built up mainly by the CWC Solenosmilia variabilis. Our results indicate a multifactorial control on CWC growth at Bowie Mound during the past ∼ 160 kyr, which reveals distinct formation pulses during northern high-latitude glacial cold events (Heinrich stadials, HSs) largely associated with anomalously strong monsoonal rainfall over the continent. The ensuing enhanced runoff elevated the terrigenous nutrient and organic-matter supply to the continental margin and likely boosted marine productivity. The dispersal of food particles towards the CWC colonies during HSs was facilitated by the highly dynamic hydraulic conditions along the continental slope that prevailed throughout glacial periods. These conditions caused the emplacement of a pronounced nepheloid layer above Bowie Mound, thereby aiding the concentration and along-slope dispersal of organic matter. Our study thus emphasizes the impact of continental climate variability on a highly vulnerable deep-marine ecosystem.

Physico-Chemical Properties of Soil Collected from Chandrabhaga River in Kalmeshwar, Nagpur, Maharashtra

2020 ◽  
Vol 07 (02) ◽  
pp. 1-3
Author(s):  
Amita M Watkar ◽  
Keyword(s):  
Organic Matter ◽  
Soil Quality ◽  
Agricultural Land ◽  
Organic Matter Content ◽  
Chemical Properties ◽  
Matter Content ◽  
Soil Attributes ◽  
Essential Components ◽  
Agricultural Land Management ◽  
Physical And Chemical

Soil, itself means Soul of Infinite Life. Soil is the naturally occurring unconsolidated or loose covering on the earth’s surface. Physical properties depend upon the amount, size, shape, arrangement, and mineral composition of soil particles. It also depends on the organic matter content and pore spaces. Chemical properties depend on the Inorganic and organic matter present in the soil. Soils are the essential components of the environment and foundation resources for nearly all types of land use, besides being the most important component of sustainable agriculture. Therefore, assessment of soil quality and its direction of change with time is an ideal and primary indicator of sustainable agricultural land management. Soil quality indicators refer to measurable soil attributes that influence the capacity of a soil to function, within the limits imposed by the ecosystem, to preserve biological productivity and environmental quality and promote plant, animal and human health. The present study is to assess these soil attributes such as physical and chemical properties season-wise.

scholarly journals A FIELD GUIDE TO SONIC BOTANY: THOUGHTS ABOUT ECO-COMPOSITION

Tempo ◽  
2020 ◽  
Vol 75 (295) ◽  
pp. 31-44
Author(s):  
Maayan Tsadka
Keyword(s):  
Organic Matter ◽  
Performance Practice ◽  
Musical Instruments ◽  
Musical Composition ◽  
Notation System ◽  
Field Guide ◽  
The Past ◽  
Tuning Forks ◽  
Texture Size ◽  
Ongoing Project

AbstractSonic botany is an ongoing project that I have been developing over the past few years. It incorporates natural artefacts: dry leaves, pods, flowers, branches, rocks, bones and other organic findings. These are used as musical instruments that are played on with a scientific/musical tool: tuning forks in various frequencies. The vibration from the tuning forks resonates through the natural artefacts which amplify the vibration and – via sound – reveal the texture, size, material and condition of the organic matter. This process generates new sonic material, new context and new forms of musical composition. The practice developed into several compositions and projects, a performance practice, a notation system and a way of listening. Here I share some of the insights I gained through this process, the tools and the compositional framework.

An ecological shift in a remote coral atoll of Belize over 25 years

1998 ◽  
Vol 25 (2) ◽  
pp. 122-130 ◽  
Author(s):  
TIMOTHY R. McCLANAHAN ◽  
NYAWIRA A. MUTHIGA
Keyword(s):  
Central America ◽  
Major Change ◽  
Acropora Cervicornis ◽  
Hard Coral ◽  
Population Densities ◽  
Herbivorous Fishes ◽  
Patch Reefs ◽  
The Past ◽  
Algal Abundance ◽  
The Caribbean

Many coral reefs in the Caribbean, and elsewhere, have undergone changes from hard coral to fleshy algal dominance over the past two decades which has often been interpreted as a localized response to eutrophication and fishing. Here, data on the abundance of hard corals and algae from lagoonal patch reefs distributed throughout a large (260 km2) remote reef atoll located approximately 30 km offshore from the sparsely-populated coast of Belize, Central America, are compared with a study of these patch reefs conducted 25 years previously. Data and observations indicate that these patch reefs have undergone a major change in their ecology associated with a 75% reduction in total hard coral, a 99% loss in the cover of Acropora cervicornis and A. palmata, and a 315% increase in algae, which are mostly erect brown algae species in the genera Lobophora, Dictyota, Turbinaria and Sargassum. Such changes have been reported from other Caribbean reefs during the 1980s, but not on such a remote reef and the present changes may be attributed primarily to both a disease that began killing Acropora in this region in the mid 1980s and a reduction in herbivory. The low level of herbivory may be attributable to the disease-induced loss of the sea urchin Diadema antillarum in 1983, or fishing of herbivorous fishes, but both explanations are speculative. The present density of fisherfolk is low, and their efforts are not targetted at herbivorous fishes, and population densities of D. antillarum 14 years after the mortality are <1 individual per 1000 m2, but there is no comparative data from before the die off. There is, however, no indication that these major changes occurred on the fore reef, because A. palmata is abundant and erect algal abundance is low. We suggest that reported changes in other Caribbean reefs are not necessarily or exclusively influenced by local human factors such as localized intense eutrophication or fishing.

scholarly journals Biofilm Forming Bacteria during Thermal Water Reinjection

Geofluids ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Máté Osvald ◽  
Gergely Maróti ◽  
Bernadett Pap ◽  
János Szanyi
Keyword(s):  
Thermal Water ◽  
Oxygen Demand ◽  
Geothermal System ◽  
Biological Processes ◽  
Geothermal Systems ◽  
The Past ◽  
Surface System ◽  
Buffer Tank ◽  
Physical And Chemical ◽  
Phenol Index

Reinjection of heat-depleted thermal water has long been in the center of scientific interest in Hungary regarding around 1000 operating thermal wells. While the physical and chemical aspects of reinjection have partly been answered in the past years, the effects of biological processes are still less known. We carried out our investigations in the surface elements of the Hódmezővásárhely geothermal system which is one of the oldest operating geothermal systems in Hungary. About one-third of the used geothermal water has been reinjected since 1998 by two reinjection wells at the end of the thermal loops. During the operation, plugging of the surface system was experienced within a few-day-long period, due to biological processes. The goal of our research was to find the dominant species of the microbial flora and to make a proposal to avoid further bacterial problems. We found that the reinjected, therefore the produced, water’s chemical oxygen demand, phenol index, and BTEX composition basically determine the appearing flora on the surface. When the concentration of these compounds in the thermal water is significant and residence time is long enough in the buffer tank, certain bacteria can be much more dominant than others, thus able to form a biofilm which plugs the surface equipment much more than it is expected.

scholarly journals On numerical solver selection and related uncertainty terminology

2009 ◽  
Vol 12 (3) ◽  
pp. 241-250 ◽  
Author(s):  
Petra Claeys ◽  
Ann van Griensven ◽  
Lorenzo Benedetti ◽  
Bernard De Baets ◽  
Peter A. Vanrolleghem
Keyword(s):  
Fluid Dynamics ◽  
Mathematical Models ◽  
Process Design ◽  
Uncertainty Assessment ◽  
Environmental Modelling ◽  
Chemical Systems ◽  
The Past ◽  
Numerical Solver ◽  
Physical And Chemical ◽  
Insight Into

Mathematical models provide insight into numerous biological, physical and chemical systems. They can be used in process design, optimisation, control and decision support, as acknowledged in many different fields of scientific research. Mathematical models do not always yield reliable results and uncertainty should be taken into account. At present, it is possible to identify some factors contributing to uncertainty, and the awareness of the necessity of uncertainty assessment is rising. In the fields of Environmental Modelling and Computational Fluid Dynamics, for instance, terminology related to uncertainty exists and is generally accepted. However, the uncertainty due to the choice of the numerical solver and its settings used to compute the solution of the models did not receive much attention in the past. A motivating example on the existence and effect of numerical uncertainty is provided and clearly shows that we can no longer ignore it. This paper introduces a new terminology to support communication about uncertainty caused by numerical solvers, so that scientists become perceptive to it.

scholarly journals A 21st Century Vision for Neotropical Snake Systematics

2018 ◽  
Vol 1 (1) ◽  
pp. 58
Author(s):  
Robert Alexander Pyron
Keyword(s):  
Species Richness ◽  
Natural History ◽  
Global Change ◽  
South America ◽  
Ecosystem Function ◽  
Museum Specimens ◽  
Fine Grained ◽  
The Past ◽  
The Caribbean ◽  
Recent Synthesis

We live in an unprecedented age for systematics and biodiversity studies. Ongoing global change is leading to a future with reduced species richness and ecosystem function (Pereira, Navarro, & Martins, 2012). Yet, we know more about biodiversity now than at any time in the past. For squamates in particular, we have range maps for all species (Roll et al., 2017), phylogenies containing estimates for all species (Tonini, Beard, Ferreira, Jetz, & Pyron, 2016), and myriad ecological and natural-history datasets for a large percentage of species (Meiri et al., 2013; Mesquita et al., 2016). For neotropical snakes, a recent synthesis of museum specimens and verified localities offers a fine-grained perspective on their ecogeographic distribution in Central and South America, and the Caribbean (Guedes et al., 2018).

scholarly journals A study of Soil Invertebrates community in a Date - Palm plantation in Baghdad, Iraq

2016 ◽  
Vol 13 (1) ◽  
pp. 1-6
Author(s):  
Baghdad Science Journal
Keyword(s):  
Organic Matter ◽  
Direct Method ◽  
Chemical Properties ◽  
Essential Elements ◽  
Soil Samples ◽  
Land Snails ◽  
Soil Invertebrates ◽  
Individual Number ◽  
Significant Difference ◽  
Physical And Chemical

Soil invertebrates community an important role as part of essential food chain and responsible for the decomposition in the soil, helps soil aeration , nutrients recycling and increase agricultural production by providing the essential elements necessary for photosynthesis and energy flow in ecosystems.The aim of the present study was to investigate the soil invertebrates community in one of the date palms plantation in Aljaderia district South of Baghdad, , and their relationships with some physical and chemical properties of the soil , as Five randomly distributed replicates of soil samples were collected monthly. Invertebrates samples were sorted from the soil with two methods, direct method to isolate large invertebrates and indirectly to isolate small invertebrates using wet funnel method. The study also included the determination of physical and chemical factors of the soil (Temperature, Salinity, pH, Organic matter, Humidity, In addition to the soil texture).Monthly fluctuations in physical and chemical characteristics of the soil and the total invertebrates community study site were determined. Significant correlations the of the invertebrates community and each of temperature, organic matter, and humidity were observed. The study revealed that the temperature of the soil ranged between 5 to 25 C0 , The salinity concentration ranged between 1.1-1.9 ‰, The pH values ranged between 7.3 to 7.8 and the percentage of soil moisture ranged between 15 - 25% , Soil samples were composed of 44.6 % Clay, 19.7% Silt and 35.5% Sand.A total of 4625 individuals of soil invertebrates belonging to 16 taxa were sorted , within which the adult and larval insects were the most abundant, and from them 1283 individuals were sorted , represented 28% of the total numbers, followed by Isopoda , which 1030 individuals of them were sorted, In addition to Nematode, Oligochaetes Annelids family Enchytraeidae, and Earthworms family Lumbricida, Species of Chilopoda, Diplopoda, mites, land snails and slugs. The highest total individual number were recorded recorded durim moderate temperature months, February, March and April amounted to 838, 801 and 813 individuals, respectively.A significant correlation was mated between total number of soil invertebrates and each of temperature, organic matter and humidity. The significant difference in means was calculated according to LSD test.

scholarly journals Chemical Compounds and Decomposition Process from Four Species Leaf Litter As a Source of Organic Matter Soil in Anggori Education Forest, Manokwari

2020 ◽  
Vol 3 (02) ◽  
pp. 60-67
Author(s):  
Aditya Rahmadaniarti ◽  
Wolfram Y. Mofu
Keyword(s):  
Organic Matter ◽  
Soil Microorganisms ◽  
Litter Quality ◽  
Lignin Content ◽  
Chemical Compounds ◽  
Decomposition Process ◽  
Quality Factors ◽  
Polyphenol Content ◽  
Simple Change ◽  
Physical And Chemical

Decomposition is a simple change of physical and chemical processes by soil microorganisms—the rate of decomposition process influenced by climate and litter quality factors. Litter content of chemical compounds is essential to determine the litter's quality so that it can be estimated the decomposition process. Leaves litter of Magnolia tsiampacca, Intsia bijuga, Cinnamomum cullilawan, and Aglaia sp., were collected and analyzed for their chemical compounds. Based on lignin and nitrogen content (L/N) value, Cinnamomum cullilawan have the fastest decomposition process. On the contrary, Intsia bijuga has low litter quality, so that has the slowest decomposition process. However, it has the lowest lignin content and high polyphenol content. Our research found that four observed species were able to be used as sources of soil organic matter, although the litter quality is relatively low.

Evaluation of gypsum and organic matter additions for improving soil structure in a radiata pine nursery at Benalla, Victoria

1983 ◽  
Vol 23 (121) ◽  
pp. 208 ◽  
Author(s):  
DW Flinn ◽  
RJ Waugh
Keyword(s):  
Organic Matter ◽  
Seedling Survival ◽  
Clay Content ◽  
Radiata Pine ◽  
Fertilizer Application ◽  
Coarse Sand ◽  
Soil Conditions ◽  
Infiltration Capacity ◽  
Pine Seedlings ◽  
Block Experiment

A randomized block experiment was carried out in a radiata pine nursery at Benalla where the soil is weakly aggregated and slakes severely on wetting. Sunflower hulls or sudax ST6 hay or gypsum/dolomite were added during one cycle of a summer green crop, winter cover crop and a pine crop. Plots were also split for a deep ripping treatment. The aim was to improve soil conditions for the growth of pine seedlings. The addition of 170 t/ha of sunflower hulls reduced bulk density (P<0.01) and surface crust resistance (P< 0.05) and markedly increased infiltration capacity (P<0.01). Water-stable aggregation was not statistically affected by any of the treatments because the soil has a clay content of only 18%, though there was an encouraging trend of more water-stable aggregates within the size range 0.25-2 mm following the application of sunflower hulls. Germination of the pine crop was unaffected by treatments as the seed was covered with coarse sand. Seedling survival was low (range 41.1 -47.6%), due in part to saline conditions following fertilizer application. Early growth of seedlings was greater (P<0.05) where additional organic matter was incorporated, but differences between treatments were not statistically significant at harvest. We conclude that soil conditions can be improved for pine growth by adding a large quantity of organic matter, reducing cultivation and maintaining an intensive green cropping program.

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