Physical degradation and early diagenesis in foraminiferal tests after subaerial exposure in terrigenous-depleted beaches of Yucatan, Mexico

2019 ◽  
Vol 34 (3) ◽  
pp. 1175-1189 ◽  
Author(s):  
Juan José Kasper-Zubillaga ◽  
Elsa Arellano-Torres ◽  
John S. Armstrong-Altrin
Keyword(s):  
Early Diagenesis ◽  
Subaerial Exposure ◽  
Physical Degradation

UNDERSTANDING THE EFFECTS OF EARLY DIAGENESIS ON METAL CYCLING IN FRESHWATER LAKES USING VERTICAL CONCENTRATION PATTERNS IN POREWATER

2016 ◽  
Author(s):  
Kayla E. Deciechi ◽  
◽  
Dave T. Long ◽  
Dave T. Long ◽  
Dave T. Long ◽  
...  
Keyword(s):  
Early Diagenesis ◽  
Freshwater Lakes ◽  
Metal Cycling ◽  
Concentration Patterns

TRANSFORMATIONS OF HIGH-CHARGED SWELLING MINERALS DURING EARLY DIAGENESIS IN RECENT SEDIMENTS OF GDANSK BAY (BALTIC SEA)

2019 ◽  
Author(s):  
Marta Kisiel ◽  
◽  
Michal Skiba ◽  
Artur Kuligiewicz ◽  
Magdalena Skoneczna ◽  
...  
Keyword(s):  
Baltic Sea ◽  
Early Diagenesis ◽  
Recent Sediments

BACK ON CIRCE'S ISLAND

Ramus ◽  
2020 ◽  
Vol 49 (1-2) ◽  
pp. 213-235
Author(s):  
Michiel van Veldhuizen
Keyword(s):  
Science Fiction ◽  
Analogical Reasoning ◽  
Gilles Deleuze ◽  
Margaret Atwood ◽  
Classical Antiquity ◽  
Felix Guattari ◽  
Dio Chrysostom ◽  
The Witch ◽  
The Moment ◽  
Physical Degradation

The reception of Circe's island in and through Classical Antiquity has largely focused on the enigmatic sorceress herself. The long literary chain of interpretive topoi—Circe the witch, the whore, the temptress—stretches from Apollonius, Virgil, Ovid, and Dio Chrysostom to Spenser, Calderón, Joyce, Margaret Atwood, and Madeline Miller. Her role as Odysseus’ benefactor, so unmistakable in Homer, is soon forgotten; to Virgil, she is above all dea saeva, (‘the savage goddess’, Aen. 7.19). One distinguishing feature of Circe and her reception is the focus on representation: the enchantment of Circe, as Greta Hawes puts it, is above all a study in allegory. From the moment Circe put a spell on Odysseus’ companions, transforming them into animals in Book 10 of the Odyssey, Circe has invited analogical reasoning, centered on what the transformation from one being into another represents. More often than not, this transformation is interpreted according to a dualist thinking about humans and animals: subjects are transformed from one being into another being, thus representing some moral or physical degradation. This article, by contrast, concentrates on Circe's island through the lens of becoming-animal, the concept developed by Gilles Deleuze and Félix Guattari in the tenth plateau of A Thousand Plateaus, ‘1730: Becoming-Intense, Becoming-Animal, Becoming-Imperceptible…’. I explicate the concept of becoming-animal by applying it to a Deleuzian encounter with Circe's island, both in its ancient articulations and in its various receptions, including H.G. Wells's science fiction novel The Island of Dr. Moreau.

scholarly journals The fate of a travertine record: impact of early diagenesis on the Y‐10 core (Mammoth Hot Springs, Yellowstone National Park, USA)

2021 ◽  
Author(s):  
Eva De Boever ◽  
David Jaramillo‐Vogel ◽  
Anne‐Sophie Bouvier ◽  
Norbert Frank ◽  
Andrea Schröder‐Ritzrau ◽  
...  
Keyword(s):  
Yellowstone National Park ◽  
National Park ◽  
Hot Springs ◽  
Early Diagenesis

scholarly journals Chemical Kinetic Models of Early Diagenesis

1972 ◽  
Vol 20 (5) ◽  
pp. 267-272 ◽  
Author(s):  
Robert A. Berner
Keyword(s):  
Kinetic Models ◽  
Chemical Kinetic ◽  
Early Diagenesis

scholarly journals Syngenetic rapid growth of ellipsoidal silica concretions with bitumen cores

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hidekazu Yoshida ◽  
Ryusei Kuma ◽  
Hitoshi Hasegawa ◽  
Nagayoshi Katsuta ◽  
Sin-iti Sirono ◽  
...  
Keyword(s):  
Organic Matter ◽  
Early Diagenesis ◽  
Ph Change ◽  
Carbon Preference Index ◽  
Diffusion Growth ◽  
Silica Precipitation ◽  
Precipitated Silica ◽  
Preference Index ◽  
Decomposition Of Organic Matter ◽  
Growth Diagram

AbstractIsolated silica concretions in calcareous sediments have unique shapes and distinct sharp boundaries and are considered to form by diagenesis of biogenic siliceous grains. However, the details and rates of syngenetic formation of these spherical concretions are still not fully clear. Here we present a model for concretion growth by diffusion, with chemical buffering involving decomposition of organic matter leading to a pH change in the pore-water and preservation of residual bitumen cores in the concretions. The model is compatible with some pervasive silica precipitation. Based on the observed elemental distributions, C, N, S, bulk carbon isotope and carbon preference index (CPI) measurements of the silica-enriched concretions, bitumen cores and surrounding calcareous rocks, the rate of diffusive concretion growth during early diagenesis is shown using a diffusion-growth diagram. This approach reveals that ellipsoidal SiO2 concretions with a diameter of a few cm formed rapidly and the precipitated silica preserved the bitumen cores. Our work provides a generalized chemical buffering model involving organic matter that can explain the rapid syngenetic growth of other types of silica accumulation in calcareous sediments.

scholarly journals Macro- and Micronutrient Cycling and Crucial Linkages to Geochemical Processes in Mangrove Ecosystems

2021 ◽  
Vol 9 (5) ◽  
pp. 456
Author(s):  
Daniel M. Alongi
Keyword(s):  
Transformation Process ◽  
Early Diagenesis ◽  
P Availability ◽  
Geochemical Processes ◽  
Nutrient Cycles ◽  
Physiological Mechanisms ◽  
Retention Efficiency ◽  
Mangrove Ecosystems ◽  
N Metabolism ◽  
Transformation Processes

High mangrove productivity is sustained by rapid utilization, high retention efficiency and maximum storage of nutrients in leaves, roots, and soils. Rapid microbial transformations and high mineralization efficiencies in tandem with physiological mechanisms conserve scarce nutrients. Macronutrient cycling is interlinked with micronutrient cycling; all nutrient cycles are linked closely to geochemical transformation processes. Mangroves can be N-, P-, Fe-, and Cu-limited; additions of Zn and Mo stimulate early growth until levels above pristine porewater concentrations induce toxicity. Limited nutrient availability is caused by sorption and retention onto iron oxides, clays, and sulfide minerals. Little N is exported as immobilization is the largest transformation process. Mn and S affect N metabolism and photosynthesis via early diagenesis and P availability is coupled to Fe-S redox oscillations. Fe is involved in nitrification, denitrification and anammox, and Mo is involved in NO3− reduction and N2-fixation. Soil Mg, K, Mn, Zn and Ni pool sizes decrease as mangrove primary productivity increases, suggesting increasing uptake and more rapid turnover than in less productive forests. Mangroves may be major contributors to oceanic Mn and Mo cycles, delivering 7.4–12.1 Gmol Mn a−1 to the ocean, which is greater than global riverine input. The global Mo import rate by mangroves corresponds to 15–120% of Mo supply to the oceanic Mo budget.

scholarly journals Paleocene-Eocene volcanic segmentation of the Norwegian-Greenland seaway reorganized high-latitude ocean circulation

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Jussi Hovikoski ◽  
Michael B. W. Fyhn ◽  
Henrik Nøhr-Hansen ◽  
John R. Hopper ◽  
Steven Andrews ◽  
...  
Keyword(s):  
Ocean Circulation ◽  
High Latitude ◽  
Seismic Reflection ◽  
Arctic Region ◽  
Climatic Conditions ◽  
The Arctic ◽  
Early Eocene ◽  
Subaerial Exposure ◽  
Thermal Maximum ◽  
Volcanic Facies

AbstractThe paleoenvironmental and paleogeographic development of the Norwegian–Greenland seaway remains poorly understood, despite its importance for the oceanographic and climatic conditions of the Paleocene–Eocene greenhouse world. Here we present analyses of the sedimentological and paleontological characteristics of Paleocene–Eocene deposits (between 63 and 47 million years old) in northeast Greenland, and investigate key unconformities and volcanic facies observed through seismic reflection imaging in offshore basins. We identify Paleocene–Eocene uplift that culminated in widespread regression, volcanism, and subaerial exposure during the Ypresian. We reconstruct the paleogeography of the northeast Atlantic–Arctic region and propose that this uplift led to fragmentation of the Norwegian–Greenland seaway during this period. We suggest that the seaway became severely restricted between about 56 and 53 million years ago, effectively isolating the Arctic from the Atlantic ocean during the Paleocene–Eocene thermal maximum and the early Eocene.

Kinetic evaluation of oxidative stability and physical degradation of soybean grains stored at different conditions

2018 ◽  
Vol 42 (10) ◽  
Author(s):  
Ricardo Scherer Pohndorf ◽  
Volnei Luiz Meneghetti ◽  
Flávia Fernandes Paiva ◽  
Maurício Oliveira ◽  
Moacir Cardoso Elias
Keyword(s):  
Oxidative Stability ◽  
Kinetic Evaluation ◽  
Physical Degradation
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