Relict Carbonate-Rich Sediments on Southwestern Grand Bank, Newfoundland

1973 ◽  
Vol 10 (12) ◽  
pp. 1744-1750 ◽  
Author(s):  
Jens Müller ◽  
John D. Milliman
Keyword(s):  
Calcium Carbonate ◽  
Shallow Water ◽  
High Latitude ◽  
River Runoff ◽  
Surface Sediments ◽  
The Other ◽  
The Holocene ◽  
Current Regime ◽  
Terrigenous Sediment ◽  
Major River

Surface sediments on southwestern Grand Bank are composed mostly of sand, with local admixtures of mud and gravel. Most sediments are enriched with biogenic calcium carbonate, primarily barnacle valves with lesser amounts of mollusk, echinoid, and foraminifera fragments. In contrast to similar carbonate-rich sediments reported from other high-latitude areas, available data indicate that the barnacles were deposited in very shallow water during the last Würm regression. The other carbonate components, being fresher in appearance, may be younger in age.Apparently neither glaciers nor their melt waters extended far enough south on Grand Bank during the last Würm glaciation to dilute these carbonate-rich sediments with terrigenous debris. Similarly, the Holocene influx of fluvial terrigenous sediment appears to have been minor, because of both the lack of major river runoff and the active current regime in the area.

Two New Deep-Sea Cirripedia (Ascothoracica and Acrothoracica) From the Atlantic

1974 ◽  
Vol 54 (2) ◽  
pp. 437-456 ◽  
Author(s):  
William A. Newman
Keyword(s):  
New Species ◽  
Calcium Carbonate ◽  
Shallow Water ◽  
Deep Water ◽  
Deep Sea ◽  
Life Histories ◽  
The Other ◽  
Bay Of Biscay ◽  
Southwest Atlantic ◽  
Highly Evolved

Two new deep-sea barnacles (Cirripedia) are described. The first, from approximately 5200 m in the Southwest Atlantic, belongs to the most generalized genus of the order Ascothoracica, Synagoga. The two previously known species, S. mira from the Mediterranean and S. metacrinicola from Japan, are from relatively shallow water. The new species is not only more generalized than either of these, but it exceeds previous depth records for any ascothoracican by more than 1000 m. It is apparently a sequentially protandric hermaphroditic ectoparasite, knowledge of which helps clarify difficulties in interpreting the life histories of certain more highly evolved endoparasitic forms. On the other hand, its markedly generalized features bear heavily on considerations of the origin of the Maxillopoda.The second new species, from approximately 1500 m in the Bay of Biscay, belongs to the most generalized genus of the order Acrothoracica, Weltneria. It is closely related to W. hessleri known from 1000 m off Bermuda and the two are unique in being the only true deep water members of the order. The new species is remarkable in inhabiting a friable, clayey substrate - all other acrothoracicins are known to burrow only in relatively solid forms of calcium carbonate. However, both have a calcified rostral plate, and this indicates that the Acrothoracica stem from scalpellid rather than cyprilepadid or iblid Lepadomorpha.

Geochemistry and mineralogy of the NW Aegean Sea surface sediments: implications for river runoff and anthropogenic impact

2005 ◽  
Vol 20 (1) ◽  
pp. 69-88 ◽  
Author(s):  
A.P. Karageorgis ◽  
C.L. Anagnostou ◽  
H. Kaberi
Keyword(s):  
River Runoff ◽  
Anthropogenic Impact ◽  
Surface Sediments ◽  
Aegean Sea ◽  
Sea Surface

Is predation intensity reduced with increasing depth? Evidence from the west Atlantic stalked crinoidEndoxocrinus parrae(Gervais) and implications for the Mesozoic marine revolution

Paleobiology ◽  
1996 ◽  
Vol 22 (3) ◽  
pp. 339-351 ◽  
Author(s):  
Tatsuo Oji
Keyword(s):  
Shallow Water ◽  
The Other ◽  
The West ◽  
Bathymetric Range ◽  
Late Mesozoic ◽  
Predation Intensity ◽  
Stalked Crinoids ◽  
The Caribbean ◽  
Mesozoic Marine Revolution ◽  
Sublethal Predation

The number of regenerated arms was counted on specimens of two distinct phenotypes of the stalked crinoidEndoxocrinus parrae(Gervais) from a wide bathymetric range in the Caribbean (178-723 m). In one phenotype, the sample was divided into two groups, one from shallower (< 500 m) depths, the other from deeper (≥ 500 m); in the other phenotype the group divided at 550 m. In both phenotypes, the frequency of regenerated arms is significantly higher in specimens from shallower water than in those from deeper water. If the regenerated arms inEndoxocrinus parraewere the result of sublethal predation, as previously suggested, then predation intensity is higher in shallow water than deep water. These results are consistent with the idea of the late Mesozoic marine revolution—that there has been stronger predation on various invertebrates in shallow-water environments since the late Mesozoic. The stalked crinoids may have been unable to cope with increased predation in shelf environments, and they migrated to offshore environments.

XXI.—The Swimming and Burrowing Habits of the Amphipod Urothoë marina (Bate)

1940 ◽  
Vol 60 (3) ◽  
pp. 271-280 ◽  
Author(s):  
E. Emrys Watkin
Keyword(s):  
Shallow Water ◽  
The Other ◽  
British Isles ◽  
The Family ◽  
Southern Species

The intertidal and shallow-water sands of the coasts of the British Isles contain, in many cases as the dominant amphipod fauna, species of the three genera Haustorius, Urothoë, and Bathyporeia of the family Haustoriidæ, often coexistent in the same habitat and obtainable in the same samples. The swimming and burrowing mechanisms of Haustorius arenarius have been described by Dennell (1933), and I have described (1939) the mechanisms in some species of the genus Bathyporeia. This paper deals mainly with Urothoë marina; no reference is made to the other species of the genus, although U. brevicornis has been examined and found to be similar to U. marina. Since all species of the genus Urothoë are very similar morphologically and live in similar habitats, it may be assumed that the following description of U. marina will apply to them also, but I have had no opportunity of examining the more southern species U. grimaldii or U. pulchella. Crawford (1937) states that the burrowing habits of U. brevicornis and U. grimaldii var. poseidonis are very similar to those of Haustorius.

scholarly journals Nutrient accumulation and biomass production of alfafa after soil amendment with silicates

Revista CERES ◽  
2014 ◽  
Vol 61 (3) ◽  
pp. 406-413 ◽  
Author(s):  
Angélica Cristina Fernandes Deus ◽  
Leonardo Theodoro Bull ◽  
Juliano Corulli Corrêa ◽  
Roberto Lyra Villas Boas
Keyword(s):  
Particle Size ◽  
Calcium Carbonate ◽  
Soil Amendment ◽  
Soil Acidity ◽  
Steel Slag ◽  
The Other ◽  
Chemical Characteristics ◽  
Nutrient Accumulation ◽  
Particle Size Fractions ◽  
Soil Liming

Studies on the use of silicate correctives in agriculture show that they have great potential to improve soil chemical characteristics, however, little information is available on the reactivity rates of their particle-size fractions. This study investigated whether the reactivity rates obtained experimentally could be considered in the calculation of ECC (effective calcium carbonate) for soil liming, promoting adequate development of alfalfa plants. Six treatments were evaluated in the experiment, consisting of two slag types applied in two rates. The experimental ECC was used to calculate one of the rates and the ECC determined in the laboratory was used to calculate the other. Rates of limestone and wollastonite were based on the ECC determined in laboratory. The rates of each soil acidity corretive were calculated to increase the base saturation to 80%. The treatments were applied to a Rhodic Hapludox and an Alfisol Ferrudalfs. The methods for ECC determination established for lime can be applied to steel slag. The application of slag corrected soil acidity with consequent accumulation of Ca, P, and Si in alfalfa, favoring DM production.

scholarly journals Sediment Sources and Dispersion on the Western Sunda Shelf, Malay Peninsula, Southern South China Sea

Water ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 2823
Author(s):  
Yanguang Liu ◽  
Chuanshun Li ◽  
Ramlan Bin Omar ◽  
Xuefa Shi ◽  
Hui Zhang ◽  
...  
Keyword(s):  
Grain Size ◽  
Surface Sediment ◽  
Surface Sediments ◽  
The Other ◽  
Coarse Grained ◽  
Malay Peninsula ◽  
Sediment Sources ◽  
Southern South China Sea ◽  
Sunda Shelf ◽  
Sediment Samples

Thirty-nine surface sediment samples collected from the western Sunda Shelf off the Malay Peninsula (WSSMP) in the southern South China Sea (SCS) were analysed for grain size, major and trace elemental compositions, and light/heavy mineral contents to trace the sediment sources and their transport mechanisms in the study area. In the WSSMP, the surface sediments are relatively poorly sorted but transportable. A principal component analysis of 37 elements and grain size fractions indicates that the surface sediments can be grouped into four major assemblages in the study area. Integrating with the light/heavy minerals data in the 63–125 μm fractions of the surface sediment samples, to better trace the sediment sources of the coarse-grained components in the marine environment, the study area can be further divided into four sediment provinces. Province I is located in the northwestern part of the study area. The concentrations of TiO2, Na2O, garnet, siderite, and glauconite in Province I were higher than in the other provinces. The main sediment source for this province originated from the Kelantan River and the Gulf of Thailand transported by the northeastern monsoon current. Province II is located offshore of the Pahang and Endau Rivers. The percentages of TiO2, rare earth elements, Al2O3, quartz, plagioclase, hypersthene, and magnetite in the surface sediments were typically higher in this province than in the other provinces. The Pahang and Endau rivers provide most of the sediments to this province, which are transported by southward coastal currents. Province III is located in the northeastern and eastern parts of the study area, where the coarse-grained sediment fraction had relatively high hornblende and biotite contents. Sediments in this province are mostly transported from the Mekong River during the northeastern monsoon. The other parts of the study area belong to Province IV, where the surface sediment elemental and mineral concentrations were mostly between those of the other three provinces. Therefore, we suggest that Province IV has a mixed source due to inputs from the surrounding rivers.

Early Miocene shallow-water corals from La Guajira, Colombia: Part II, Mussidae–Siderastreidae and Milleporidae

2018 ◽  
Vol 93 (3) ◽  
pp. 416-436 ◽  
Author(s):  
Paola Flórez ◽  
Paula Zapata-Ramírez ◽  
James S. Klaus
Keyword(s):  
Shallow Water ◽  
The Other ◽  
Early Miocene ◽  
Caribbean Region ◽  
Coral Fauna ◽  
Living Species ◽  
The Caribbean ◽  
Established Species ◽  
Zooxanthellate Corals

AbstractIn this contribution we describe and illustrate 14 coral morphospecies collected from the early Miocene Siamaná (Aquitanian–Burdigalian) and Jimol (late Burdigalian) formations of the Cocinetas Basin in La Guajira Peninsula, northern Colombia. Eleven were identified as already established species including seven genera belonging to the families Mussidae, Pocilloporidae, Poritidae, Siderastreidae, and Milleporidae; the other three remain in open nomenclature. Nine of the 11 species identified (81%) are extinct. The remaining two living species,Siderastrea sidereaandMillepora alcicornis, are common on modern Caribbean reefs. Their presence in the Siamaná Formation extends their temporal range in the Caribbean region to the early Miocene. Most of the taxa described here were hermatypic and zooxanthellate corals of the order Scleractinia, with the exception of the fire coralMillepora alcicornis, of the order Anthothecata, family Milleporidae. The coral fauna recorded in the Siamaná and Jimol formations is typical of shallow and calm waters of the Oligocene–Miocene transition.

scholarly journals Mid-Holocene Northern Hemisphere warming driven by Arctic amplification

2019 ◽  
Vol 5 (12) ◽  
pp. eaax8203 ◽  
Author(s):  
Hyo-Seok Park ◽  
Seong-Joong Kim ◽  
Andrew L. Stewart ◽  
Seok-Woo Son ◽  
Kyong-Hwan Seo
Keyword(s):  
Sea Ice ◽  
Northern Hemisphere ◽  
High Latitude ◽  
Climate Model ◽  
Arctic Sea Ice ◽  
The Arctic ◽  
Arctic Amplification ◽  
The Holocene ◽  
Holocene Thermal Maximum ◽  
Thermal Maximum

The Holocene thermal maximum was characterized by strong summer solar heating that substantially increased the summertime temperature relative to preindustrial climate. However, the summer warming was compensated by weaker winter insolation, and the annual mean temperature of the Holocene thermal maximum remains ambiguous. Using multimodel mid-Holocene simulations, we show that the annual mean Northern Hemisphere temperature is strongly correlated with the degree of Arctic amplification and sea ice loss. Additional model experiments show that the summer Arctic sea ice loss persists into winter and increases the mid- and high-latitude temperatures. These results are evaluated against four proxy datasets to verify that the annual mean northern high-latitude temperature during the mid-Holocene was warmer than the preindustrial climate, because of the seasonally rectified temperature increase driven by the Arctic amplification. This study offers a resolution to the “Holocene temperature conundrum”, a well-known discrepancy between paleo-proxies and climate model simulations of Holocene thermal maximum.

Percolation in colloidal soils, considered in relation to swelling and cohesiveness

1925 ◽  
Vol 15 (4) ◽  
pp. 434-443 ◽  
Author(s):  
F. Hardy
Keyword(s):  
Calcium Carbonate ◽  
West Indian ◽  
The Other ◽  
Horizontal Flow ◽  
Lateritic Soils ◽  
Lime Content ◽  
Other Hand

(1) The results of experiments on the rate of horizontal flow, and on the rate of gain in mass, or kerosene and of water in fine and crumb fractions of certain West Indian colloidal soils, comprising three siliceous soils containing different amounts of calcium carbonate, and two lateritic soils, are described and tabulated.(2) The methods of experimentation employed were those elaborated by Green and Ampt, whose equations were found, however, not to fit the values obtained, as is to be expected.(3) The siliceous soils examined possess relatively high swelling coefficients, and their component particles, when wetted, cohere to a greater or lesser extent, depending on lime content. These properties appear to account for the relatively low rates of permeability to water in these soils. Lateritic soils, on the other hand, possess low swelling coefficients, and low cohesiveness; water percolates through them relatively very rapidly.

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