Thermal evolution of Andean iron oxide–apatite (IOA) deposits as revealed by magnetite thermometry

AbstractMagnetite is the main constituent of iron oxide–apatite (IOA) deposits, which are a globally important source of Fe and other elements such as P and REE, critical for modern technologies. Geochemical studies of magnetite from IOA deposits have provided key insights into the ore-forming processes and source of mineralizing fluids. However, to date, only qualitative estimations have been obtained for one of the key controlling physico-chemical parameters, i.e., the temperature of magnetite formation. Here we reconstruct the thermal evolution of Andean IOA deposits by using magnetite thermometry. Our study comprised a > 3000 point geochemical dataset of magnetite from several IOA deposits within the Early Cretaceous Chilean Iron Belt, as well as from the Pliocene El Laco IOA deposit in the Chilean Altiplano. Thermometry data reveal that the deposits formed under a wide range of temperatures, from purely magmatic (~ 1000 to 800 °C), to late magmatic or magmatic-hydrothermal (~ 800 to 600 °C), to purely hydrothermal (< 600 °C) conditions. Magnetite cooling trends are consistent with genetic models invoking a combined igneous and magmatic-hydrothermal origin that involve Fe-rich fluids sourced from intermediate silicate magmas. The data demonstrate the potential of magnetite thermometry to better constrain the thermal evolution of IOA systems worldwide, and help refine the geological models used to find new resources.

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Thermal Evolution of Andean Iron Oxide-Apatite (IOA) Deposits as Revealed by Magnetite Thermometry

10.21203/rs.3.rs-675218/v1 ◽

2021 ◽

Author(s):

Gisella Palma ◽

Martin Reich ◽

Fernando Barra ◽

J. Tomás Ovalle ◽

Irene Real ◽

...

Keyword(s):

Iron Oxide ◽

Thermal Evolution ◽

Chemical Parameters ◽

Physico Chemical ◽

Wide Range ◽

Geological Models ◽

Chilean Altiplano ◽

Geochemical Studies ◽

Modern Technologies ◽

Magnetite Formation

Abstract Magnetite is the main constituent of iron oxide–apatite (IOA) deposits, which are a globally important source of Fe and other elements such as P and REE, critical for modern technologies. Geochemical studies of magnetite from IOA deposits have provided key insights into the ore-forming processes and source of mineralizing fluids. However, to date, only qualitative estimations have been obtained for one of the key controlling physico-chemical parameters, i.e., the temperature of magnetite formation. Here we reconstruct the thermal evolution of Andean IOA deposits by using magnetite thermometry. Our study comprised a >3000 point geochemical dataset of magnetite from several IOA deposits within the Early Cretaceous Chilean Iron Belt, as well as from the Pliocene El Laco IOA deposit in the Chilean Altiplano. Thermometry data reveal that the deposits formed under a wide range of temperatures, from purely magmatic (~1000–800 °C), to late magmatic or magmatic-hydrothermal (~800–600 °C), to purely hydrothermal (<600 °C) conditions. Magnetite cooling trends are consistent with genetic models invoking a combined igneous and magmatic-hydrothermal origin that involve Fe-rich fluids sourced from intermediate silicate magmas. The data demonstrate the potential of magnetite thermometry to better constrain the thermal evolution of IOA systems worldwide, and help refine the geological models used to find new resources.

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Comparison of some physico-chemical parameters of kiwiberry (Actinidia arguta) cultivars from a cold climate

Folia Horticulturae ◽

10.2478/fhort-2019-0030 ◽

2019 ◽

Vol 31 (2) ◽

pp. 375-383 ◽

Cited By ~ 1

Author(s):

Miroslav Horák ◽

Petr Šnurkovič ◽

Ivo Ondrášek ◽

Josef Balík ◽

Varit Srilaong

Keyword(s):

Ascorbic Acid Content ◽

Cold Climate ◽

Chemical Parameters ◽

Actinidia Arguta ◽

Fruit Species ◽

Physico Chemical ◽

Predominant Type ◽

Fruit Skin ◽

Wide Range ◽

High Level

AbstractThe Actinidia genus includes a number of commercial fruit species with a wide range of countries of origin. Some species such as A. arguta or A. kolomikta are characterized by a high level of resistance to frost. The aim of this study was to compare the fruit of selected cultivars of kiwiberry. In the kiwiberry fruit, sucrose was the predominant type of sugar. Citric acid was dominant in all samples; it was most represented in the pulp of kiwiberry seedlings and in the skin of kiwiberry ‘Issai’. Kiwiberry fruits feature a higher ascorbic acid content in the skin in comparison with the commercial A. chinensis cultivars. Antioxidant activity of kiwiberry fruit skin was up to 18 times higher than that of the pulp. In view of the kiwiberry fruit having no hair, it is possible to eat the whole fruit, including the skin containing substances beneficial to health.

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Properties and applications of palygorskite-sepiolite clays

Clay Minerals ◽

10.1180/claymin.1996.031.4.01 ◽

1996 ◽

Vol 31 (4) ◽

pp. 443-453 ◽

Cited By ~ 410

Author(s):

E. Galan

Keyword(s):

Clay Minerals ◽

Crystal Morphology ◽

Industrial Applications ◽

Chemical Parameters ◽

Principal Characteristics ◽

Surface Active Agents ◽

Physico Chemical ◽

Wide Range ◽

Surface Active ◽

Fabric Surface

AbstractThe palygorskite-sepiolite group of clay minerals has a wide range of industrial applications derived mainly from its sorptive, rheological and catalytic properties which are based on the fabric, surface area, porosity, crystal morphology, structure and composition of these minerals. For assessing potential industrial uses, the mineralogical and chemical composition of the clay and its basic physical and physico-chemical parameters must be determined. Then some particular properties of commercial interest can be modified and improved by appropriate thermal, mechanical and acid treatments, surface active agents, organo-mineral derivatives formation, etc. In this paper, a revision of the principal characteristics of commercial palygorskite-sepiolite clays is presented, and potential uses are suggested according to these data. New products and applications are being investigated and those concerning environmental protection in particular, are noted. Finally, possible health effects of these elongate clay minerals are discussed.

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Discovering periodic sublimation on main-belt primitive asteroids near perihelion and its possible astrobiological significance

Proceedings of the International Astronomical Union ◽

10.1017/s174392131900303x ◽

2018 ◽

Vol 14 (S345) ◽

pp. 388-389

Author(s):

Vladimir V. Busarev

Keyword(s):

Thermal Evolution ◽

Water Soluble ◽

Early Solar System ◽

Chemical Parameters ◽

Main Belt ◽

Surface Layers ◽

Near Surface ◽

Water Ice ◽

Physico Chemical ◽

Complex Organic

AbstractDiscovered periodic sublimation activity on four main-belt primitive asteroids led us to conclusions about possible origin of those and similar bodies (or their parent bodies) near or beyond the snow line in the early Solar System making incorporated in them a considerable water ice stock. Water differentiation of the bodies owing to 26A1 decay and their internal thermal evolution might have created conditions for water soluble organics and prebiotic compounds formation. Subsequent longtime periodic changing temperature and other physico-chemical parameters (due to spinning and moving around the Sun) in the near-surface layers of primitive asteroids have led probably to formation of more complex organic compounds of astrobiological significance.

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Pangas pond culture in Bangladesh.

10.1079/ac.70673.20203483391 ◽

2020 ◽

Author(s):

Khandaker Huq ◽

Shafiq-ur-Rahman

Keyword(s):

Survival Rate ◽

Production Rate ◽

Cage Culture ◽

Chemical Parameters ◽

Pond Culture ◽

Physico Chemical ◽

Wide Range ◽

Pangasius Sutchi ◽

Research Institute

Abstract Culture of indigenous pangas (Pangasius pangasius) started in 1945 in Khulna region and was dependent on natural fish fry. Exotic Thai pangas (Pangasius hypophthalmus, previously Pangasius sutchi) was introduced to Bangladesh in 1990 from Thailand by the Department of Fisheries. Induced breeding of Thai pangas was introduced by the Bangladesh Fisheries Research Institute in 1993. Pangas is omnivorous. It can tolerate a wide range of physico-chemical parameters. The survival rate of Thai pangas is 85-95% with a production rate of 20-30 t ha-1 yr-1. Both mono and polyculture are practiced in Bangladesh. Recently, cage culture of pangas has been introduced.

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