Update: Geochemical data from granite and basalt weathering profiles in Kuantan, Malaysia

This dataset provides comprehensive whole-rock geochemical data—including major oxides, trace elements, and Rare Earth Elements (REE)—derived from synthetic weathering profiles developed over basalt and granite bedrock in Kuantan, Peninsular Malaysia. The data was collected to evaluate elemental mobility, distinct saprolitization patterns, and REE fractionation during intense tropical pedogenesis.

Sampling and Analytical Methodology:
Samples were collected from four genetic horizons (A: topsoil, B: subsoil/oxic, C: saprolite, and R: fresh bedrock) across granite (KG, KPG series) and basalt (KB, DAM, S-series) profiles. Geochemical analyses were conducted via a combined XRF (major elements) and ICP-MS (trace elements) workflow following lithium metaborate-tetraborate fusion, ensuring the quantitative recovery of refractory accessory phases. Loss on ignition (LOI) was determined at 1000°C. Analytical reliability is validated by high recovery rates (97.7–101.5%) against certified reference material (CRM SO-18) and high precision (RPD < 5%) from blind-field duplicates.

Calculations and Derived Data:
To facilitate the quantitative characterization of weathering intensity and mineral alteration pathways, the dataset includes calculations for several established weathering indices:

Chemical Index of Alteration (CIA)

Chemical Index of Weathering (CIW)

Plagioclase Index of Alteration (PIA)

Weathering Index of Parker (WIP)

Calculations for CIA, CIW, and PIA integrate necessary corrections for silicate-bound CaO (CaO*) following the McLennan (1993) method to exclude Ca from secondary carbonates and apatite. Additionally, the dataset features Si/Al molar ratios to track desilication, alongside chondrite-normalized REE values (Sun and McDonough, 1989), enabling the evaluation of specific Eu (Eu/Eu*) and Ce (Ce/Ce*) anomalies linked to plagioclase fractionation and redox-sensitive scavenging by Fe-Mn oxyhydroxides.

Utility:
This dataset supports research into lithological controls on soil formation, geochemical mass transfer, clay mineral formation, and the metallogenic potential of supergene or ion-adsorption type (IAT) REE deposits in tropical regoliths.