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Toposequence Relationships of Dystrandepts in Costa Rica
Author(s) -
Alvarado A.,
Buol S. W.
Publication year - 1975
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj1975.03615995003900050037x
Subject(s) - geology , soil water , pyroclastic rock , position (finance) , halloysite , mineralogy , regular polygon , geomorphology , geochemistry , soil science , mathematics , volcano , geometry , finance , economics
Three Typic Dystrandepts; medial, isothermic, profiles located on a slightly convex position, a concave position, and a 20% slope were studied. The horizontal distance between adjacent profiles was approximately 100 m. The soils were characterized by chemical, mineralogical, micromorphological and physical methods to establish the nature of the differences among them, and to develop hypotheses of their genesis. The genesis of these soils appears to be controlled by composition and age of the parent material and only slightly influenced by the relief. Periodic additions of pyroclastic materials build up thick A horizons rich in plagioclases and pyroxenes. Halloysite was evident in the deeper and older underlying materials where it was also observed in sand‐sized aggregates. The B horizons in the convex and sloping topographic positions were slightly more enriched with iron, which seemed to be translocated from the A horizons, than was the profile in the concave position. Differences due to topographic position did not affect taxonomic placement of the profiles in the family category.