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对宽甸盆地火山喷出物发育土壤的特性进行了研究,结果表明:火山锥顶部的土壤的土层厚度一般在90~100 cm,剖面通体含有较多中等风化的气孔状玄武质火山碎屑,还保留有火山喷出物的特征。土壤偏酸性,pH(H2O)介于5.18~6.78,pH(KCl)介于3.98~5.70,含有一定量的交换性酸,表层以外各发生层的pH(NaF)均大于9.4。土壤的游离铁和铁游离度较高,多数剖面B层具有铁质特性,活性铁含量的变幅较大,铁活化度较高;硅铝率(Sa)、硅铁铝率(Saf)和风化淋溶系数(ba)较高,CIA指数较小,土壤发育较弱;多数土层的土壤有机碳含量、磷酸盐吸持量、草酸铵浸提Al+1/2Fe、土壤2~0.02 mm粒级含量等主要鉴定指标已符合火山灰特性的鉴定标准,最终能否确认其具有火山灰特性还有待进一步鉴定火山玻璃含量。台地上的土壤,其土体中可以发现极少量强风化的气孔状火山碎屑,土壤的游离铁和铁游离度较高,土壤B层具有铁质特性,活性铁含量的变幅较大,铁活化度较高,硅铝率(Sa)、硅铁铝率(Saf)和风化淋溶系数(ba)较低,CIA指数较大,土壤发育较强,土壤2~0.02 mm粒级含量<300 g kg-1,不具有火山灰特性。
The results show that the thickness of the soil in the top of the volcanic cone is generally 90-100 cm and the profile body contains more moderately weathered stomata-like basaltic volcanic debris , But also retain the characteristics of volcanic eruptions. Soil acidity, pH (H2O) between 5.18 ~ 6.78, pH (KCl) between 3.98 ~ 5.70, containing a certain amount of exchangeable acid, outside the surface layer of each layer pH (NaF) greater than 9.4. Soil free iron and iron freeness higher, most sections of the B layer with iron characteristics, active iron content larger amplitude, higher iron activation; silicon-aluminum rate (Sa), ferrosilicon rate (Saf) and The leaching coefficient of soil erosion (ba) is higher, the CIA index is smaller and soil development is weak. In most soil layers, the content of soil organic carbon, phosphate adsorption, Al + 1 / 2Fe with ammonium oxalate, 2 ~ 0.02 mm The main appraisal index such as the content of the grading is in line with the appraisal standard of the volcanic ash characteristic, finally can confirm its volcanic ash characteristic still needs to further identify volcanic glass content. In soils on the platform, a very small amount of highly-weathered pneumatitic volcanic debris can be found in the soil. The free iron and the iron freeness of the soil are higher. The soil layer B has the characteristics of iron and the content of active iron is larger. Fe, higher iron activation degree, lower Sa, Fe and leaching coefficients (ba), higher CIA index, stronger soil development and soil particle size of 2 ~ 0.02 mm < 300 g kg-1, no pozzolanic properties.