scholarly journals Interaction Between Bacteria, Nannobacteria, and Mineral Precipitation in Hot Springs of Central Italy

2007 ◽  
Vol 48 (3) ◽  
pp. 233-246 ◽  
Author(s):  
Robert L. Folk
Keyword(s):  
Hot Springs ◽  
Cold Water ◽  
Central Italy ◽  
Carbonate Precipitation ◽  
Mineral Precipitation ◽  
End Points ◽  
The North ◽  
Inorganic Precipitation ◽  
Water Springs ◽  
Needle Growth

ABSTRACTA complex of inorganic and organic factors controls precipitation of carbonates in hot springs of Lazio, central Italy. A plot of data from this area shows that the main /norganic controls are temperature and Mg/Ca ratio of the spring waters. Virtually all springs with waters hotter than 400C precipitate aragonite, and cooler ones form calcite. Furthermore, even cold-water springs precipitate aragonite if the Mg/Ca ratio exceeds 1:1, except in two cases. To what extent is the precipitation of travertine inorganic vs. biochemical? Surely, conditions in diverse localities can vary between both end-points, but Le Zitelle springs, at the north flank of the caldera of Viterbo, provide a biochemical extreme. Waters are hot (600C), with Mg/Ca of .2, and are highly sulfurous. Carbonate precipitation rates can exceed 2 mm/day. /Vonetched samples of carbonate crusts, only minutes to a few hours old, exhibit aragonite, calcite, and 1- to 5- (im euhedral rhombs of probable dolomite. Aragonite forms spherical "pincushions" of radial needles, each needle tipped with a nannobacterial body of the same diameter as the needles, 0.1 to 0.4 jim. Each nannobacterium precipitated its own needle, and was propelled outward by needle growth. As little or no later "fattening" of the needle occurred, inorganic precipitation must have been insignificant here. fVonetched calcite crystals are composed of 0.05 (xm nannobacterial spheres that were incorporated into each layer of the crystal as it grew. No evidence of bacteria was found on the ?dolomite rhomb surfaces. Ironically, aragonite, calcite, and euhedral ?dolomite rhombs all grew within minutes to an hour of each other in the same solution under the same conditions, savaging all the rules exposed at the beginning they remain a baffling problem unresolved by chemistry, physics, or microbiology.

scholarly journals Burial-deformation History of Folded Rocks Unraveled by Fracture Analysis, Stylolite Paleopiezometry and Vein Cement Geochemistry: A Case Study in the Cingoli Anticline (Umbria-Marche, Northern Apennines)

Geosciences ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 135
Author(s):  
Aurélie Labeur ◽  
Nicolas E. Beaudoin ◽  
Olivier Lacombe ◽  
Laurent Emmanuel ◽  
Lorenzo Petracchini ◽  
...  
Keyword(s):  
Isotope Geochemistry ◽  
Central Italy ◽  
Microstructural Analysis ◽  
Northern Apennines ◽  
Foreland Basins ◽  
Deformation History ◽  
The North ◽  
Regional Tectonic ◽  
History Of ◽  
Clumped Isotope

Unravelling the burial-deformation history of sedimentary rocks is prerequisite information to understand the regional tectonic, sedimentary, thermal, and fluid-flow evolution of foreland basins. We use a combination of microstructural analysis, stylolites paleopiezometry, and paleofluid geochemistry to reconstruct the burial-deformation history of the Meso-Cenozoic carbonate sequence of the Cingoli Anticline (Northern Apennines, central Italy). Four major sets of mesostructures were linked to the regional deformation sequence: (i) pre-folding foreland flexure/forebulge; (ii) fold-scale layer-parallel shortening under a N045 σ1; (iii) syn-folding curvature of which the variable trend between the north and the south of the anticline is consistent with the arcuate shape of the anticline; (iv) the late stage of fold tightening. The maximum depth experienced by the strata prior to contraction, up to 1850 m, was quantified by sedimentary stylolite paleopiezometry and projected on the reconstructed burial curve to assess the timing of the contraction. As isotope geochemistry points towards fluid precipitation at thermal equilibrium, the carbonate clumped isotope thermometry (Δ47) considered for each fracture set yields the absolute timing of the development and exhumation of the Cingoli Anticline: layer-parallel shortening occurred from ~6.3 to 5.8 Ma, followed by fold growth that lasted from ~5.8 to 3.9 Ma.

Phytoplankton of cold-water lake ecosystems under the influence of natural and anthropogenic factors

2021 ◽  
pp. 42-49
Author(s):  
Andrey N. Sharov
Keyword(s):  
Heavy Metals ◽  
Cold Water ◽  
Arctic Lakes ◽  
Water Bodies ◽  
The Arctic ◽  
Anthropogenic Factors ◽  
Large Lakes ◽  
Arctic Water ◽  
The North ◽  
Natural And Anthropogenic Factors

Based on the study of the spatio-temporal aspects of the development of phytoplankton in the lakes of the North and North-West of the European territory of Russia (large lakes – Imandra, Onega and Chudsko-Pskovskoye and small lakes of the Arctic and Subarctic), the features of its structure and dynamics under the influence of natural and anthropogenic factors (eutrophication, heavy metal pollution, acidification, thermification). The species composition and quantitative characteristics of phytoplankton of large lakes of the North of Russia, small arctic lakes and lakes of subarctic regions are studied. It has been shown that diatoms predominate in arctic water bodies according to species diversity, and green and diatoms predominate in boreal ones. By biomass, diatoms dominate mainly in all cold-water lakes, with the exception of small arctic lakes, where golden algae lead. The features of the reorganization of phytoplankton in response to the action of anthropogenic factors are revealed. It is proved that in the northern water bodies the complex action of heavy metals and nutrients does not lead to inhibition of phytoplankton, and the effect of acidification in combination with heavy metals enhances the toxic effect of the latter. A feature of the response to acidification is an increase in the variability of the dynamics of the biomass of phytoplankton. It has been shown that in different types of lakes of East Antarctica under severe climate conditions under light and biogenic limitation, redistribution of autotrophic components in the formation of the biota of water bodies occurs: against the background of a decrease in the abundance and diversity of phytoplankton, the role of microphytobenthos and periphyton increases.

New data on the fauna and the biogeographic structure of the Hydrozoa, Scyphozoa, Staurozoa and Alcyonacea (Anthozoa) of the Kara Sea

2021 ◽  
Vol 325 (2) ◽  
pp. 143-155
Author(s):  
N.E. Zhuravleva
Keyword(s):  
Cold Water ◽  
Kara Sea ◽  
Novaya Zemlya ◽  
The North ◽  
Anna Trough ◽  
New Material ◽  
Western Side ◽  
Academy Of Sciences ◽  
North Western ◽  
Arctic Fauna

The paper considers the species composition of the fauna of several cnidarian groups of the Kara Sea. The author presents a list of species of the studied groups and indicates the types of habitat for each species. The analysis was based on the literature data, the collections of the Zoological Institute of the Russian Academy of Sciences and material collected in the Kara Sea during the expedition to the R/V Professor Multanovsky in 2019. In total, 87 species of Hydrozoa, 3 species of Scyphozoa, 4 species of Staurozoa, and 5 species of the order Alcyonacea from the class Anthozoa were recorded for the fauna of the Kara Sea, based on the new material obtained by the author and published literature data. The report presents the biogeographic structure of the discussed cnidarian groups. According to the types of biogeographic ranges, the fauna of the above-mentioned cnidarian groups in the Kara Sea mostly consists of representatives of the Boreal-Arctic type of habitat (63%), the Boreal and Amphiboreal biogeographic groups each containing 12% of the total number of described species, and the Panoceanic and Arctic groups together accounting for only 9% and 4% of the fauna of the Kara Sea. Two species new for the Kara Sea, Neoturris pileata (Forsskål, 1775) and Neoturris pileata (Forsskål, 1775), are described. Neoturris pileata is an element of the warm-water Atlantic fauna that penetrated into the Kara Sea with waters of Atlantic genesis. Nausithoe werneri is an element of the cold-water Arctic fauna that penetrated into the Novaya Zemlya Trough of the Kara Sea from the north-western side from the St. Anna Trough, which was open to the Polar Basin.

scholarly journals Ashinkailepas kermadecensis, a new species of deep-sea scalpelliform barnacle (Thoracica: Eolepadidae) from the Kermadec Islands, southwest Pacific

Zootaxa ◽  
2009 ◽  
Vol 2021 (1) ◽  
pp. 57-65 ◽  
Author(s):  
JOHN S. BUCKERIDGE
Keyword(s):  
New Species ◽  
New Zealand ◽  
Deep Sea ◽  
Cold Water ◽  
The Other ◽  
Cold Seeps ◽  
Central Japan ◽  
Southwest Pacific ◽  
The North ◽  
A New Species

A new deep-sea stalked barnacle, Ashinkailepas kermadecensis sp. nov. has been recovered from a cold-water seep at depths of 1165 metres in the vicinity of the Kermadec Ridge to the northeast of the North Island, New Zealand. There are now two species of Ashinkailepas—the other, Ashinkailepas seepiophila Yamaguchi, Newman & Hashimoto, 2004, occurs in deep, cold seeps off central Japan. As there are two species within Ashinkailepas, formal diagnoses are provided for both taxa.

scholarly journals Carbonate sedimentation and effects of eutrophication observed at the Kališta subaquatic springs in Lake Ohrid (Macedonia)

2010 ◽  
Vol 7 (3) ◽  
pp. 4715-4747 ◽  
Author(s):  
M. Matter ◽  
F. S. Anselmetti ◽  
B. Jordanoska ◽  
B. Wagner ◽  
M. Wessels ◽  
...  
Keyword(s):  
Sediment Traps ◽  
Authigenic Carbonate ◽  
Sidescan Sonar ◽  
Carbonate Content ◽  
Carbonate Precipitation ◽  
Lake Ohrid ◽  
Radiocarbon Dates ◽  
North West ◽  
The North ◽  
Spring Area

Abstract. To date, little is known about the role of spring waters with respect to authigenic carbonate precipitation in the shallow lacustrine setting. Lake Ohrid, located in Southeastern Europe, is a large lake fed to over 50% by karstic springs of which half enter subaquatically and influence significantly its ecology and species distribution. In order to evaluate how sedimentological processes are influenced by such shallow-water springs, the Kališta subaquatic spring area in the north west of Lake Ohrid was investigated by a sidescan sonar survey and with sediment traps and three transects of gravity short cores. Results indicate that sedimentation in the spring area is dominated by authigenic carbonate precipitation. High sedimentation rates and evidences for bio-induced precipitation processes were observed in the water column and in the sediments. Two distinct stratigraphic units characterize the shallow subsurface, both composed of carbonate silts with high carbonate contents of up to 96%, but differing in color, carbonate content and diatom content. A chronological correlation of the cores by radiocarbon dates and 137Cs activities places the transition between the two stratigraphic units after ~1955 AD. At that time, coastal sedimentation changed drastically to significantly darker sediments with higher contents of organic matter and more abundant diatoms. This change coincides with the recent human impact of littoral eutrophication.

scholarly journals Report on hydrozoans (Cnidaria), excluding Stylasteridae, from the Emperor Seamounts, western North Pacific Ocean

Zootaxa ◽  
2021 ◽  
Vol 4950 (2) ◽  
pp. 201-247
Author(s):  
DALE R. CALDER ◽  
LES WATLING
Keyword(s):  
Pacific Ocean ◽  
North Pacific ◽  
Western North Pacific ◽  
Cold Water ◽  
North Pacific Ocean ◽  
First Record ◽  
Western North Pacific Ocean ◽  
The North ◽  
Seamount Chain ◽  
The North Pacific

Fourteen species of hydroids, collected during August 2019 by ROV SuBastian of the Schmidt Ocean Institute, are reported from the Emperor Seamount chain in the western North Pacific Ocean. Two others, Candelabrum sp. and Eudendrium sp., were observed only on videos taken by the ROV. From collections and video observations, eight species of hydroids were found at Jingū Seamount, three at Yomei, Nintoku, and Annei seamounts, and one at Koko Seamount and Hess Rise. At Suiko and Godaigo seamounts, hydroids were seen in videos but they could not be identified. Latebrahydra schulzei, an endobiotic associate of the hexactinellid sponge Walteria flemmingii Schulze, 1886 from Annei Seamount and Hess Rise, is described as a new genus and species tentatively attributed to Hydractiniidae L. Agassiz, 1862. Another new species, Hydractinia galeai, is described from Jingū Seamount. Among its distinctive characters is a zooid termed a sellectozooid, likely serving in both food capture and defence. Hydroids examined from Yomei, Nintoku, and Jingū seamounts are elements of a cold-water fauna occurring in the North Pacific Boreal Bathyal province, while those of Annei and Koko seamounts, and Hess Rise, are part of the biota of the Central North Pacific Bathyal province. Hydroids identified as Bouillonia sp., from Nintoku Seamount, represent the first record of this predominantly deep water tubulariid genus in the North Pacific Ocean. Bonneviella superba Nutting, 1915, from Jingū Seamount, is reported for the first time outside the Aleutian Islands. Bonneviella cf. gracilis Fraser, 1939, known elsewhere only from Dease Strait in the western Canadian Arctic, was also collected on Jingū. In addition to hydroids, medusae of Ptychogastria polaris Allman, 1878 were observed on videos from Nintoku, Jingū, Annei, and Koko seamounts at depths between 2423–1422 m. An unidentified siphonophore was observed near bottom at 2282 m on Nintoku Seamount. 

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