The complex genesis of red soils in peninsula de Yucatán, Mexico: Mineralogical, micromorphological and geochemical proxies

Abstract

The origin of red clayey soils developed on limestones has been largely questioned. We have analyzed thick red soils on Eocene-Pliocene limestones of the Yucatan peninsula (with detail in the Kantunil Kin area). The morphological, geochemical and mineralogical characteristics were interpreted as a record of pedogenesis and geomorphic dynamics during the Quaternary. Sand fraction mineralogy, the Zr/Ti ratio and ternary diagrams of Trace elements (Ti-Y-Zr, La-Th-Sc and Zr-Th-Sc) indicated a mixed origin of the soil parent material; volcanic and granitic/metamorphic components, redeposited by eolian transport. Within the soil matrix, primary minerals were transformed by weathering and caused desilication with the accumulation of kaolinitic clay. Reworked pedofeatures were originated from different soil bodies eroded. In the lower part of the profiles, we described the zone of carbonate leaching front, were the clay translocation in suspensions and posterior coagulation is more probable than the migration of elements in solutions and posterior synthesis.