scholarly journals Listvenites: new insights of a hydrothermal system fossilized in Cerro Matoso peridotites, Montelíbano, Córdoba Department, Colombia

2020 ◽  
pp. 67-84
Author(s):  
Andrés Castrillón ◽  
Javier Guerrero
Keyword(s):  
Chemical Analysis ◽  
Fracture Zone ◽  
Hydrothermal System ◽  
Low Temperatures ◽  
Mineralogical Composition ◽  
Climatic Conditions ◽  
Hydrothermal Fluids ◽  
Metasomatic Alteration ◽  
Mineralogical Association

The products of metasomatic alteration (e.g., carbonation) of peridotites are called listvenites. Based on a description of the outcrops in the laterite deposit at Cerro Matoso located in the NW of Colombia, the mineralogical composition confirmed by petrography, and a chemical analysis performed with XRF and WDS/EDS, the previous unit called tachylite is redefined as listvenite. Two types of listvenites are described: listvenite A, with the mineralogical association of quartz + siderite + phyllosilicates + goethite +/- magnetite, and listvenite B, with the association of siderite + phyllosilicates + goethite. Cr-spinel relics accompanied by Mn-siderite and neoblastic textures, indicate their origin from peridotites, where Mn-Fe would have been deposited by hydrothermal fluids. Hydrothermal reducing environments with alkaline fluids and low temperatures should have favored the formation of listvenites that are observed along a fracture zone, oriented WNW-ESE at Pit-1 in Cerro Matoso. Due to exposure to climatic conditions since the Eocene, but definitively since the last Andean Orogeny, listvenites were affected, like all the rocks in the Cerro Matoso deposit, by intense supergene weathering and leaching processes, which could make their true origin unclear.

Precambrian Para-Gneisses of Southern Eyre Peninsula, South Australia

1921 ◽  
Vol 58 (7) ◽  
pp. 305-312 ◽  
Author(s):  
C. E. Tilley
Keyword(s):  
North America ◽  
Chemical Analysis ◽  
South Australia ◽  
Mineralogical Composition ◽  
High Grade ◽  
Grade Metamorphism ◽  
Mineralogical Association ◽  
High Grade Metamorphism

SUMMARY1. Garnet gneisses of sedimentary origin are described from the oldest group of sediments recognized in Southern Eyre Peninsula, South Australia. The high-grade metamorphism which these rocks have undergone has resulted in the development of felspar, garnet (almandine), sillimanite, and green spinel. 2. The mineralogical association of these constituents is described, and their genetic relations are discussed. 3. A sedimentary origin of these gneisses is attested by their interbanding with undoubted sediments, their mineralogical composition, and lastly by chemical analysis. 4. In the garnet gneisses developed in the Grenville series of North America, notably those of the Adirondack region, and in the province of Quebec, these para-gneisses find their most striking analogues.

scholarly journals Rolling Ironstones from Earth and Mars: Terrestrial Hydrothermal Ooids as a Potential Analogue of Martian Spherules

Minerals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 460
Author(s):  
Marcella Di Bella ◽  
Franco Pirajno ◽  
Giuseppe Sabatino ◽  
Simona Quartieri ◽  
Roberto Barbieri ◽  
...  
Keyword(s):  
High Resolution ◽  
Volcanic Activity ◽  
Hydrothermal System ◽  
Mineralogical Composition ◽  
Hydrothermal Activity ◽  
Hydrothermal Fluids ◽  
Cause Of Formation ◽  
The Earth ◽  
High Resolution Images ◽  
Iron Ooids

High-resolution images of Mars from National Aeronautics and Space Administration (NASA) rovers revealed mm-size loose haematite spherulitic deposits (nicknamed “blueberries”) similar to terrestrial iron-ooids, for which both abiotic and biotic genetic hypotheses have been proposed. Understanding the formation mechanism of these haematite spherules can thus improve our knowledge on the possible geologic evolution and links to life development on Mars. Here, we show that shape, size, fabric and mineralogical composition of the Martian spherules share similarities with corresponding iron spherules currently forming on the Earth over an active submarine hydrothermal system located off Panarea Island (Aeolian Islands, Mediterranean Sea). Hydrothermal fluids associated with volcanic activity enable these terrestrial spheroidal grains to form and grow. The recent exceptional discovery of a still working iron-ooid source on the Earth provides indications that past hydrothermal activity on the Red Planet is a possible scenario to be considered as the cause of formation of these enigmatic iron grains.

scholarly journals Analysis of Hydrothermal Systems Beneath Tayukeng through Long-Term Geochemical Signals of Hydrothermal Fluids in Tatun Volcano Group, Taiwan

2021 ◽  
Vol 18 (14) ◽  
pp. 7411
Author(s):  
Hsin-Fu Yeh ◽  
Hung-Hsiang Hsu
Keyword(s):  
Surface Temperature ◽  
Hydrothermal System ◽  
Hydrothermal Fluid ◽  
Thermal Water ◽  
Hydrothermal Systems ◽  
Hydrothermal Fluids ◽  
Geochemical Variations ◽  
Northern Taiwan

The Tatun Volcano Group (TVG) is located in northern Taiwan and consists of many springs and fumaroles. The Tayukeng (TYK) area is the most active fumarole site in the TVG. In this study, we analyzed the long-term geochemical variations of hydrothermal fluids and proposed a mechanism responsible for the variation in TYK. There are two different aquifers beneath the TYK area: a shallow SO42−-rich aquifer and a deeper aquifer rich in Cl−. TYK thermal water was mainly supplied by the shallow SO42−-rich aquifer; therefore, the thermal water showed high SO42− concentrations. After 2015, the inflow of deep thermal water increased, causing the Cl− concentrations of the TYK to increase. Notably, the inferred reservoir temperatures based on quartz geothermometry increased; however, the surface temperature of the spring decreased. We inferred that the enthalpy was lost during transportation to the surface. Therefore, the surface temperature of the spring does not increase with an increased inflow of deep hydrothermal fluid. The results can serve as a reference for understanding the complex evolution of the magma-hydrothermal system in the TVG.

scholarly journals The influence of low temperatures on the incidence of sugary disease on sorghum

2006 ◽  
Vol 36 (2) ◽  
pp. 397-403
Author(s):  
Amauri Bogo ◽  
Ricardo Trezi Casa ◽  
Luis Sangoi ◽  
Paulo Tarcísio Domatos Borba
Keyword(s):  
Low Temperatures ◽  
Disease Incidence ◽  
Climatic Conditions ◽  
Male Sterile ◽  
Growing Seasons ◽  
Claviceps Africana ◽  
Sorghum Genotypes ◽  
Fertile Hybrids ◽  
The Relationship ◽  
Increased Susceptibility

The relationship between pre-flowering climatic conditions and sugary disease incidence was quantified in grain and forage sorghum genotypes at two sowing periods (mid November and mid December). The trials were carried out over the 2001/02 and 2002/03 growing seasons, in Lages, Santa Catarina State. Four commercial male-fertile sorghum hybrids (BR 600-forrage, BR 700-grain, BR 701-forage/silage and BR 800-forage) and one male-sterile inbred line (BR 001-A) were evaluated. When each genotype reached the flowering stage, 50 panicles were marked and sprayed with a suspension of Claviceps africana (1,000 spores mL-1). Air temperature, humidity and rainfall were recorded through out the growing cycle. Low temperatures three to four weeks prior to flowering, increased susceptibility. At both sowing periods, average night temperatures lower than 15°C during the critical period of pre-flowering turned the fertile hybrids as susceptible as the male-sterile inbred to ergot infection. The tested hybrids differed in their ability to tolerate pre-flowering cold stress. Seed set in uninoculated heads under pollination bags was also reduced, suggesting that increased susceptibility to sugary disease was the result of low temperature induced sterility.

Paleoenvironmental Evolution of early Paleogene in the Sanshui Basin Indicated from Factor Analysis of Main Elements

2012 ◽  
Vol 518-523 ◽  
pp. 5813-5816
Author(s):  
Liang Chen ◽  
Zheng Qing Wang ◽  
Yan Shi Xie ◽  
Wei Huang
Keyword(s):  
Factor Analysis ◽  
Low Temperatures ◽  
Stage Iv ◽  
Climatic Conditions ◽  
Stage I ◽  
Stage Ii ◽  
Stage Iii ◽  
Climate Conditions ◽  
Paleoenvironmental Evolution ◽  
Early Paleogene

In this paper, factor analysis are used to study the early Paleogene paleoenvironmental evolution from the Sanshui Basin, and main conclusions can be obtained as follows: stage I (89.0-73.0m), relatively dry and relatively low temperatures; stage II (73.0-52.5m), warm and humidity of the climate and environment; stage III (52.5-22.5m), the ancient climate conditions change quickly, showing the alternating warm and humidity and dry; stage IV (22.5-0m), prevailing warm and moist climatic conditions.

Methodologies for Evaluating and Qualifying External Pipeline Coatings for Northern Pipelines

2006 ◽  
Author(s):  
S. Papavinasam ◽  
A. Doiron ◽  
T. Panneerselvam ◽  
Y. Lafrenie`re ◽  
M. Attard ◽  
...  
Keyword(s):  
Environmental Conditions ◽  
Low Temperatures ◽  
Laboratory Experiments ◽  
Field Experiments ◽  
Climatic Conditions ◽  
Limited Data ◽  
The North

The design of coatings must be adequate to protect pipelines under long-term, severe environmental conditions, including the extreme climatic conditions that will apply in the North before the pipe is installed and operation begins. Practices and standardised methodologies for evaluating and qualifying pipeline coatings for application in northern pipelines are discussed. Results from laboratory and field experiments, carried out under the conditions to which coatings will be exposed during construction, are presented. Based on 1-year laboratory experiments in which samples were exposed to temperatures as low as −45°C and limited data from the field experiments, it is concluded that Canadian Standards Association (CSA) standards CSA Z662, CSA Z245.20 and CSA Z245.21 adequately cover evaluation of coatings for northern pipelines. However, in order to evaluate the effects of low-temperatures, the specimens should be exposed for at least 4 months. Coatings qualified by CSA Z245.21 (System B1 and B2) are less affected from exposure to low-temperatures than those qualified by CSA Z245.21 (System A1) and CSA Z245.20.

The Influence of Date of Oviposition and Climatic Conditions on Hatching of Camnula pellucida (Scudder) (Orthoptera: Acrididae)

1966 ◽  
Vol 98 (11) ◽  
pp. 1145-1159 ◽  
Author(s):  
R. Pickford
Keyword(s):  
Embryonic Development ◽  
Snow Cover ◽  
Temperature Regime ◽  
Low Temperatures ◽  
Extended Period ◽  
Weather Conditions ◽  
Climatic Conditions ◽  
Soil Conditions ◽  
Soil Temperatures ◽  
Dry Soil

AbstractField and laboratory hatching experiments were conducted from 1960 through 1963 with eggs of Camnula pellucida (Scudder) laid in field cages and collected at fortnightly intervals. Before freeze-up, embryonic development usually reached prediapause level in all eggs laid before the middle of August; these eggs were the first to hatch when incubated in the laboratory or when left in the soil outdoors. Eggs laid later than mid-August showed progressively less embryonic development and consequently hatched later. Viability was highest in eggs laid during the latter half of August; those laid early in the season often suffered from desiccation because of their long exposure to dry soil conditions; those laid towards the end of the season showed declining viability caused, apparently, by low temperatures. The percentage hatch was relatively high in eggs laid before the end of August but declined progressively thereafter; those laid in October rarely hatched. Seasonal hatching patterns were largely dependent upon weather conditions; such patterns were rapidly completed when an extended period of hot, dry weather continued through the hatching period, but often extended intermittently over a month or more when weather was unsettled. The typical diurnal hatching pattern, which also closely followed the temperature regime, commenced in the morning at 0900–1000 hours as soil temperatures exceeded 65°F., rising to a peak about 1100–1200 hours when temperatures reached 85°F., and then generally declined during the afternoon. However, during rapidly changing weather conditions hatching frequently started and stopped as skies cleared and again clouded over. Winter kill occasionally may be an important factor in reducing populations, especially when snow cover is removed by a mid-winter thaw and sub-zero temperatures follow.

Leaf Analysis as a Means of Diagnosing Nutrient Requirements of Tropical Orchard Crops

1935 ◽  
Vol 25 (4) ◽  
pp. 610-627 ◽  
Author(s):  
F. Hardy ◽  
J. A. McDonald ◽  
G. Rodriguez
Keyword(s):  
Chemical Analysis ◽  
Large Scale ◽  
Field Experiments ◽  
Climatic Conditions ◽  
Physical Characteristics ◽  
Nutrient Requirements ◽  
Leaf Material ◽  
Leaf Analysis ◽  
Scale Field ◽  
Large Scale Field

1. Attention is drawn to the remarkable dissimilarity between the cacao and the grapefruit tree in their nutrient requirements, indicating that grapefruit is calcicolous in physiological habit. This conclusion is mainly based on a consideration of the results of chemical analysis of representative leaf material produced by trees grown on soil of known chemical and physical characteristics, under the same climatic conditions in Trinidad.2. The nutrient relationships that obtain between the cacao and the grapefruit tree respectively and the soil in which they are growing have been gauged by means of chemical analysis of representative leaf material.3. For this purpose, leaf material was obtained from trees growing on the differently manured plots of two large-scale field experiments in Trinidad.

scholarly journals Aspectos Pedogeomorfológicos e Mineralógicos de uma Topossequência de Solos Gnáissicos no Complexo Bação – Quadrilátero Ferrífero, MG, Brasil

2002 ◽  
Vol 29 (1) ◽  
pp. 71 ◽  
Author(s):  
MÚCIO DO AMARAL FIGUEIREDO ◽  
ANGÉLICA FORTES DRUMMOND CHICARINO VARAJÃO ◽  
JOSÉ DOMINGOS FABRIS ◽  
IVAN SOARES LOUTFI
Keyword(s):  
Mineralogical Composition ◽  
Minas Gerais ◽  
Mineralogical Association ◽  
Southern Area ◽  
Pedogenic Process ◽  
Quadrilátero Ferrífero ◽  
Middle Slope ◽  
Lower Slope ◽  
Primary Minerals ◽  
Upper Slope

The mineralogical association of the weathering rocks and their pedogenic process is fundamental in order to understand the erosive susceptibility of the soils. The regolith of the southern area of the Complexo Bação, Quadrilátero Ferrífero, Minas Gerais, was developed from gneiss and has as its predominant characteristic a thick saprolite (around 20 m) overlaid by a solum (A + B horizons) with of less than 3 m thick. This thickness is much thinner than those that frequently occur in the gneiss regolith from tropical and intertropical regions. In the toposequence investigated, the upper slope profile is a cambic soil with a poorly developed B horizon and with many relictal weathered gneiss nodules at the bottom, closer to the saprolite. The mineralogical composition of this B horizon is mainly kaolinite, gibbsite, quartz, hematite and goethite and secondarily pseudomorphous feldspars. The middle slope profile is a latosol with a well developed and thick B horizon. The mineralogical composition of this B horizon is essentially formed by kaolinite, gibbsite, quartz, hematite and goethite. The lower slope profile is a cambic latosol with the presence of relictal gneiss nodules in the B horizon analogously to the B horizon from the upper slope profile. Their mineralogical composition are also similar. The pedogeomorphological evolution of the studied catenary sequence shows that the middle slope profile is allochthonous with an accumulation of colluvial materials that formed a well developed latosol B horizon without primary minerals. The source of the colluvial materials is the upper slope profile. In the lower slope segment the lack of colluvial material suggests a process of incision, with channel and perennial flows that were originated from the adjacent gullies. The incipient fluvial plain that was formed occurs in abrupt altimetric unconformity (declivity rupture) with the lower slope segment.

Sign in / Sign up

Export Citation Format

Share Document