Elements distribution and effecting factors of high rank coals of different deformational-metamorphic types in Beihuaiyang area

Based on the X-Ray Fluorescence Spectrometry (XRF) analysis on Carboniferous coal occured in Beihuaiyang area,the northern foreland basin of Dabie Orogenic Belt,the major elements distribution characters and the effecting factors of high rank coals of different deformational-metamorphic types are discussed.The results show that the tectonic-thermal process made Al³⁺,K⁺,Si⁴⁺,Ti⁴⁺ concentrated in coal,but P⁵⁺,Fe²⁺+Fe³⁺,Mn²⁺,Na⁺,Ca²⁺,Mg²⁺ migrated outside. Otherwise,Al³⁺,K⁺,Ti⁴⁺,Na⁺ and Ca²⁺ were abundant in weak stress zones,but Si⁴⁺,P⁵⁺,Fe²⁺+Fe³⁺ and Mg²⁺ abundant in strong stress zones.The values of SiO₂/Al₂O₃ and K₂O/Na₂O in tectonic-thermal metamorphic coal and telemagmatic metamorphic coal were larger than those in regional metamorphic coal,which might be related to the higher content of SiO₂ and K₂O in Yanshanian magmatic rocks in Beihuaiyang area.