PART II ASSEMBLAGES OF BIOGENIC STRUCTURES IN INTERTIDAL TO SUBTIDAL ENVIRONMENTS

1985 ◽  
pp. 177-177
Keyword(s):  
Biogenic Structures

GEORADAR-AIDED ASSESSMENT OF BIOGENIC STRUCTURES IN BAHAMIAN COASTAL DUNES: IMPLICATIONS FOR HETEROGENEITY OF SHORELINE RETREAT

2019 ◽  
Author(s):  
Kathryn Lyons ◽  
◽  
Ilya V. Buynevich ◽  
Karen A. Kopcznski ◽  
H. Allen Curran
Keyword(s):  
Coastal Dunes ◽  
Shoreline Retreat ◽  
Biogenic Structures

scholarly journals Jaws of Platynereis dumerilii: Miniature Biogenic Structures with Hardness Properties Similar to Those of Crystalline Metals

JOM ◽  
2021 ◽  
Author(s):  
Luis Zelaya-Lainez ◽  
Giuseppe Balduzzi ◽  
Olaf Lahayne ◽  
Kyojiro N. Ikeda ◽  
Florian Raible ◽  
...  
Keyword(s):  
Inductively Coupled Plasma ◽  
Indentation Depth ◽  
Organic Matrix ◽  
Structure Property ◽  
Structural Protein ◽  
Inductively Coupled ◽  
Property Relations ◽  
Biogenic Structures ◽  
Platynereis Dumerilii ◽  
Bristle Worms

AbstractNanoindentation, laser ablation inductively coupled plasma mass spectroscopy and weighing ion-spiked organic matrix standards revealed structure-property relations in the microscopic jaw structures of a cosmopolitan bristle worm, Platynereis dumerilii. Hardness and elasticity values in the jaws’ tip region, exceeding those in the center region, can be traced back to more metal and halogen ions built into the structural protein matrix. Still, structure size appears as an even more relevant factor governing the hardness values measured on bristle worm jaws across the genera Platynereis, Glycera and Nereis. The square of the hardness scales with the inverse of the indentation depth, indicating a Nix-Gao size effect as known for crystalline metals. The limit hardness for the indentation depth going to infinity, amounting to 0.53 GPa, appears to be an invariant material property of the ion-spiked structural proteins likely used by all types of bristle worms. Such a metal-like biogenic material is a major source of bio-inspiration.

scholarly journals Cool barnacles: Do common biogenic structures enhance or retard rates of deterioration of intertidal rocks and concrete?

2017 ◽  
Vol 580 ◽  
pp. 1034-1045 ◽  
Author(s):  
Martin A. Coombes ◽  
Heather A. Viles ◽  
Larissa A. Naylor ◽  
Emanuela Claudia La Marca
Keyword(s):  
Biogenic Structures

Functional complement of biogenic structures produced by earthworms, termites and ants in the neotropical savannas

2005 ◽  
Vol 37 (6) ◽  
pp. 1043-1048 ◽  
Author(s):  
P. Mora ◽  
E. Miambi ◽  
J.J. Jiménez ◽  
T. Decaëns ◽  
C. Rouland
Keyword(s):  
Biogenic Structures ◽  
Neotropical Savannas

scholarly journals Earth system responses to cumulative carbon emissions

2015 ◽  
Vol 12 (13) ◽  
pp. 9839-9877 ◽  
Author(s):  
M. Steinacher ◽  
F. Joos
Keyword(s):  
Air Temperature ◽  
Carbon Emissions ◽  
Climate Model ◽  
Climate Adaptation ◽  
Water Saturation ◽  
Cmip5 Models ◽  
Large Set ◽  
Steric Sea Level ◽  
Transient Climate Response ◽  
Biogenic Structures

Abstract. Information on the relationship between cumulative fossil carbon emissions and multiple climate targets are essential to design emission mitigation and climate adaptation strategies. In this study, the transient responses in different climate variables are quantified for a large set of multi-forcing scenarios extended to year 2300 towards stabilization and in idealized experiments using the Bern3D-LPJ carbon-climate model. The model outcomes are constrained by 26 physical and biogeochemical observational data sets in a Bayesian, Monte-Carlo type framework. Cumulative fossil emissions of 1000 Gt C result in a global mean surface air temperature change of 1.88 °C (68 % confidence interval (c.i.): 1.28 to 2.69 °C), a decrease in surface ocean pH of 0.19 (0.18 to 0.22), and in steric sea level rise of 20 cm (13 to 27 cm until 2300). Linearity between cumulative emissions and transient response is high for pH and reasonably high for surface air and sea surface temperatures, but less pronounced for changes in Atlantic Meridional Overturning, Southern Ocean and tropical surface water saturation with respect to biogenic structures of calcium carbonate, and carbon stocks in soils. The slopes of the relationships change when CO2 is stabilized. The Transient Climate Response is constrained, primarily by long-term ocean heat observations, to 1.7 °C (68 % c.i.: 1.3 to 2.2 °C) and the Equilibrium Climate Sensitivity to 2.9 °C (2.0 to 4.2 °C). This is consistent with results by CMIP5 models, but inconsistent with recent studies that relied on short-term air temperature data affected by natural climate variability.

Computed Tomography: Application in Studying Biogenic Structures in Sediment Cores

Palaios ◽  
1994 ◽  
Vol 9 (1) ◽  
pp. 116 ◽  
Author(s):  
Shaoping Fu ◽  
Friedrich Werner ◽  
Joachim Brossmann
Keyword(s):  
Computed Tomography ◽  
Sediment Cores ◽  
Biogenic Structures

Taphonomy and paleoecology of the bivalve trace fossil Protovirgularia in deltaic heterolithic facies of the Miocene Chenque Formation, Patagonia, Argentina

2010 ◽  
Vol 84 (4) ◽  
pp. 730-738 ◽  
Author(s):  
Noelia B. Carmona ◽  
María Gabriela Mángano ◽  
Luis A. Buatois ◽  
Juan José Ponce
Keyword(s):  
Sedimentation Rate ◽  
Oxygen Depletion ◽  
Sedimentation Rates ◽  
Low Friction ◽  
Delta Front ◽  
Plastic Substrates ◽  
Marine Deposits ◽  
Median Axis ◽  
Nearshore Environments ◽  
Biogenic Structures

Lower Miocene tide-influenced deltaic deposits from the Chenque Formation, Patagonia, Argentina, contain abundant and well-preserved biogenic structures attributed to locomotion of deposit-feeder protobranch bivalves. These trace fossils, assigned to the ichnogenus Protovirgularia, consist of delicate, inclined-to-horizontal, chevronate structures, mostly symmetrical with respect to a median axis. Identification of Protovirgularia at sandstone sole beds (hypichnion) is quite straightforward. Endichnial, exichnial and epichnial preservation in heterolithic facies, however, provides a wide variety of forms that depart from the archetypal Protovirgularia and challenges ichnotaxonomic classification. Specimens in prodelta and delta-front facies display morphologic features controlled by substrate fluidity, toponomy, and sedimentation rate. Most specimens show sharp, closely spaced chevrons and occur along sandstone/mudstone interfaces of the proximal prodelta and distal delta-front deposits. These forms reflect how tracemakers experienced significant friction while advancing through the sediment, which resulted in relatively smaller increments of movements. In contrast, variants of Protovirgularia formed in muddier beds, such as in prodeltaic facies, show irregular, poorly defined and unevenly spaced chevrons, and are locally asymmetric in relation to the axis, reflecting softer, water-rich, and plastic substrates. This sediment offered relatively low friction but poor anchorage for the foot. These occurrences of Protovirgularia in tide-influenced, marginal-marine deposits suggests that protobranchs were tolerant of fluctuations in salinity, sedimentation rates, turbidity, and oxygen depletion, displaying opportunistic strategies in stressed nearshore environments. Our evaluation of taphonomic controls and appropriate identification of Protovirgularia can provide valuable information for expanding our knowledge of the ethology and paleoecology of protobranch bivalves.

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