Jeofizikkulubu | Geophysics

Jeofizikkulubu | Geophysics

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A Real Tricorder
Researchers at the University of Illinois at Urbana-Champaign have developed technology that enables a smartphone to perform lab-grade medical diagnostic tests that typically require large,...
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The Spatial Distribution of Carbon Dust in the Early Solar Nebula and the Carbon Content of Planetesimals
A high fraction of carbon bound in solid carbonaceous material is observed to exist in bodies formed in the cold outskirts of the solar nebula,...
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Rotational Spectral Unmixing of Exoplanets: Degeneracies between Surface Colors and Geography
Unmixing the disk-integrated spectra of exoplanets provides a clue to heterogeneous surfaces that we cannot directly resolve in the foreseeable future....
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High‐potassium volcanic rocks from the Okinawa Trough: Implications for a cryptic potassium‐rich and DUPAL‐like source
Major element, trace element, and Sr–Nd–Pb isotopic compositions of high‐potassium calc‐alkaline rhyolites (the T6 rhyolites) collected from the western slope of the middle Okinawa Trough...
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A Real Tricorder
Researchers at the University of Illinois at Urbana-Champaign have developed technology that enables a smartphone to perform lab-grade medical diagnostic tests that typically require large,...
Read More
The Spatial Distribution of Carbon Dust in the Early Solar Nebula and the Carbon Content of Planetesimals
A high fraction of carbon bound in solid carbonaceous material is observed to exist in bodies formed in the cold outskirts of the solar nebula,...
Read More
Rotational Spectral Unmixing of Exoplanets: Degeneracies between Surface Colors and Geography
Unmixing the disk-integrated spectra of exoplanets provides a clue to heterogeneous surfaces that we cannot directly resolve in the foreseeable future....
Read More
High‐potassium volcanic rocks from the Okinawa Trough: Implications for a cryptic potassium‐rich and DUPAL‐like source
Major element, trace element, and Sr–Nd–Pb isotopic compositions of high‐potassium calc‐alkaline rhyolites (the T6 rhyolites) collected from the western slope of the middle Okinawa Trough...
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Precambrian tectonic affinity of the North Qinling Microcontinent: Constraints from the discovery of Mesoproterozoic magmatic zircons in the Qinling Group
This paper presents new results on zircon U–Pb dating of a two‐mica schist from the Qinling Group in the core of the North Qinling Orogenic...
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A newly discovered Early Paleozoic ophiolite in Dagele, Eastern Kunlun, China, and its geological significance
This study reports the discovery of an ophiolite located in the Eastern Kunlun Orogen (Dagele, Eastern Kunlun, China) that is mainly composed of isotropic and...
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A celestial celebration of Earth’s place in the Cosmos, mapped onto Earth
It’s been repeated now a million times, but its grandeur bears another announcement: on August 21, 2017, a long-awaited total solar eclipse will cast the...
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Opioid emergency, climate language and a frozen fruit cake
The week in science: 11–17 August 2017.
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A new method for extraction of alteration information using the Landsat 8 imagery in a heavily vegetated and sediments‐covered region: A case study from Zhejiang Province, E. China

Ore prediction based on the Operational Land Imager (ETM+) image within the heavily vegetated and sediments‐covered areas is always a difficulty for geological remote sensing. Here, we report a new scheme for extraction of near‐ore alteration information in such localities: Terrain Analysis → principal component analysis →Fractal → Spatial Overlay and the Fe3+–OH− integrated anomalies that are punctate and probably ore‐caused were reasonably exposed. Findings showed a satisfactory result that the spatial, if not genetic, dependency relationship between the remotely sensed anomalies and geochemical anomalies, as well as the ore‐controlling geological bodies, is significant. However, no substantial spectral anomalies of vegetation immediately responsible for local mineralization and alteration were detected. This study may have contributed a useful case study for in‐depth remote sensing exploration.

Provenance and tectonic setting of the Early and Middle Devonian Xueshan Formation, the North Qilian Belt, China

The North Qilian orogenic belt is the key in the exploration of the formation and assembly of Asia. The Early–Middle Devonian Xueshan Formation, which is deposited in the north area of North Qilian Orogenic Belt, is the most important for revealing the evolution basin–mountain transition of the North Qilian Belt. In order to reveal the tectonic evolution of the central orogenic belt in China and Paleozoic global plate reconstruction, it is necessary to perform provenance analysis of the Xueshan Formation. Eighteen samples were collected from Yumen and Yongchang profiles in the west of North Qilian Belt (WN), and 16 samples were obtained from Gulang and Jingtai profiles in the east of North Qilian Belt (EN). The compositions of clastic conglomerates and the sandstones suggested that felsic volcanic was the main source of the WN Xueshan Formation deposits and that the sedimentary and metamorphic rocks were the main source of the EN sediments. According to major geochemistry indexes, such as Al2O3/SiO2 ratio ranging from 0.08 to 0.37 and the chemical index of alteration less than 80, the source rocks were moderately weathered and of moderately matured. The samples from the EN were relatively enriched in Cr, Ni, Sc, and V elements and depleted in Hf element. However, those from the WN were enriched in Hf without the enrichment of Cr, Ni, Sc, or V. The samples from WN showed a strong negative Eu anomaly, but the samples from EN showed a weak negative Eu anomaly or a positive Eu anomaly. All the above geochemical characteristics suggested the prominent input of felsic clasts with granitic rocks into the WN. Meanwhile, the discrimination diagrams of trace elements implied that WN rocks were derived from continental island arc and that the EN rocks were derived from orogenic belt and the passive continental margin. The North China Plate subducted southwards and formed subduction‐related arc magmatism along the southern margin of the North Qilian Terrane during the Early–Middle Devonian. In conclusion, the WN is a fore‐arc basin, but EN is a foreland basin.