• Title/Summary/Keyword: Sr%28II%29

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The Probability of Solar Proton Events (SPEs) depending on solar and interplanetary type II bursts

  • Youn, Sae-Poom;Moon, Young-Jae;Park, Jin-Hye
    • Bulletin of the Korean Space Science Society
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    • 2011.04a
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    • pp.28.4-29
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    • 2011
  • Solar Proton Events (SPEs, ${\geq}\;10\;cm^{-1}s^{-1}sr^{-1}$ with >10 MeV) are very important for space weather forecasting. It is well known that they are associated with solar flares and/or CME-driven shocks. Especially, the CME-driven shocks have been observed as solar and interplanetary type II bursts. In this study, we estimated the occurrence probability of SPEs depending on three groups: (1) metric, (2) decameter-hectometric (D-H), and (3) meter-to-kilometric (m-to-km) type II bursts. For this work, we used SPEs and all available type II burst data in 1996-2004. The primary findings of this study are as follows. First, the majority (77%) of the m-to-km type II bursts are associated with SPEs and its probability is noticeably higher than D-H type II bursts probability strongly depend on longitude: eastern (0%), center(45%), and western (33%) for X-class associated metric type II bursts, eastern (15%), center (55%), and western (50%) for X-class associated D-H type II bursts, eastern (17%), center (77%), and western (64%) for X-class associated m-to-km type II bursts. Third, for m-to-km type II bursts, the SPE probability increases with CME speed: 400km/s${\leq}$V <1000km/s (36%), 1000km/s ${\leq}$V<1500km/s (40%), 1500km/s${\leq}$V (66%). Finally, we expect that these results will be used for setting up more reasonable solar proton event forecasting models.

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Occurrence and Chemical Composition of White Mica from Zhenzigou Pb-Zn Deposit, China (중국 Zhenzigou 연-아연 광상의 백색운모 산상과 화학조성)

  • Yoo, Bong Chul
    • Korean Journal of Mineralogy and Petrology
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    • v.35 no.2
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    • pp.83-100
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    • 2022
  • The Zhenzigou Pb-Zn deposit, which is one of the largest Pb-Zn deposit in the northeast of China, is located at the Qingchengzi mineral field in Jiao Liao Ji belt. The geology of this deposit consists of Archean granulite, Paleoproterozoinc migmatitic granite, Paleo-Mesoproterozoic sodic granite, Paleoproterozoic Liaohe group, Mesozoic diorite and Mesozoic monzoritic granite. The Zhenzigou deposit which is a strata bound SEDEX or SEDEX type deposit occurs as layer ore and vein ore in Langzishan formation and Dashiqiao formation of the Paleoproterozoic Liaohe group. White mica from this deposit are occured only in layer ore and are classified four type (Type I : weak alteration (clastic dolomitic marble), Type II : strong alteration (dolomitic clastic rock), Type III : layer ore (dolomitic clastic rock), Type IV : layer ore (clastic dolomitic marble)). Type I white mica in weak alteration zone is associated with dolomite that is formed by dolomitization of hydrothermal metasomatism. Type II white mica in strong alteration zone is associated with dolomite, ankerite, quartz and alteration of K-feldspar by hydrothermal metasomatism. Type III white mica in layer ore is associated with dolomite, ankerite, calcite, quartz and alteration of K-feldspar by hydrothermal metasomatism. And type IV white mica in layer ore is associated with dolomite, quartz and alteration of K-feldspar by hydrothermal metasomatism. The structural formulars of white micas are determined to be (K0.92-0.80Na0.01-0.00Ca0.02-0.01Ba0.00Sr0.01-0.00)0.95-0.83(Al1.72-1.57Mg0.33-0.20Fe0.01-0.00Mn0.00Ti0.02-0.00Cr0.01-0.00V0.00Sb0.02-0.00Ni0.00Co0.02-0.00)1.99-1.90(Si3.40-3.29Al0.71-0.60)4.00O10(OH2.00-1.83F0.17-0.00)2.00, (K1.03-0.84Na0.03-0.00Ca0.08-0.00Ba0.00Sr0.01-0.00)1.08-0.85(Al1.85-1.65Mg0.20-0.06Fe0.10-0.03Mn0.00Ti0.05-0.00Cr0.03-0.00V0.01-0.00Sb0.02-0.00Ni0.00Co0.03-0.00)1.99-1.93(Si3.28-2.99Al1.01-0.72)4.00O10(OH1.96-1.90F0.10-0.04)2.00, (K1.06-0.90Na0.01-0.00Ca0.01-0.00Ba0.00Sr0.02-0.01)1.10-0.93(Al1.93-1.64Mg0.19-0.00Fe0.12-0.01Mn0.00Ti0.01-0.00Cr0.01-0.00V0.00Sb0.00Ni0.00Co0.05-0.01)2.01-1.94(Si3.32-2.96Al1.04-0.68)4.00O10(OH2.00-1.91F0.09-0.00)2.00 and (K0.91-0.83Na0.02-0.01Ca0.02-0.00Ba0.01-0.00Sr0.00)0.93-0.83(Al1.84-1.67Mg0.15-0.08Fe0.07-0.02Mn0.00Ti0.04-0.00Cr0.06-0.00V0.02-0.00Sb0.02-0.01Ni0.00Co0.00)2.00-1.92(Si3.27-3.16Al0.84-0.73)4.00O10(OH1.97-1.88F0.12-0.03)2.00, respectively. It indicated that white mica of from the Zhenzigou deposit has less K, Na and Ca, and more Si than theoretical dioctahedral mica. Compositional variations in white mica from the Zhenzigou deposit are caused by phengitic or Tschermark substitution [(Al3+)VI+(Al3+)IV <-> (Fe2+ or Mg2+)VI+(Si4+)IV] substitution. It means that the Fe in white mica exists as Fe2+ and Fe3+, but mainly as Fe2+. Therefore, white mica from layer ore of the Zhenzigou deposit was formed in the process of remelting and re-precipitation of pre-existed minerals by hydrothermal metasomatism origined metamorphism (greenschist facies) associated with Paleoproterozoic intrusion. And compositional variations in white mica from the Zhenzigou deposit are caused by phengitic or Tschermark substitution [(Al3+)VI+(Al3+)IV <-> (Fe2+ or Mg2+)VI+(Si4+)IV] substitution during hydrothermal metasomatism depending on wallrock type, alteration degree and ore/gangue mineral occurrence frequency.