Understanding the genesis of Spodosols in semi-arid environments remains a challenge due to the scarcity of pedogenetic markers under water-limited conditions. In this study, we integrated biological and organic proxies to reconstruct soil formation processes in Catimbau National Park (CNP), northeastern Brazil. Biological markers included phytolith assemblages, sponge spicules, diatom frustules, and freshwater algae cysts, which provided insights into vegetation turnover and episodic hydromorphic conditions. Organic markers comprised C/N ratios, stable isotopes (δ¹³C), thermogravimetry, and Fourier-transform infrared spectroscopy (FTIR), allowing us to track organic matter sources, preservation, and transformation pathways. Together, these datasets reveal that Spodosol development in CNP was strongly influenced by vegetation dynamics, pulses of moisture availability, and organo-mineral interactions, despite the prevailing semi-arid climate.