Soils regulate the environmental impacts of trace elements, but direct measurements of reaction mechanisms in these complex, multi-component systems is challenging. Our objective was to develop approaches for assessing effects of co-localized geochemical matrix elements on accumulation and chemical speciation of arsenate applied to a soil matrix. Synchrotron X-ray fluorescence microprobe (µ-XRF) images collected across 100 x 100 and 10 x 10 µm 2 regions of a naturally weathered soil sand-grain coating before and after treatment with As(V) solution showed strong positive partial correlations (r’ = 0.77 and 0.64, respectively) between accumulated As and soil Fe, with weaker partial correlations (r’ > 0.1) between As and Ca, and As and Zn in the larger image. Spatial and non-spatial regression models revealed a dominant contribution of Fe and minor contributions of Ca and Ti in predicting accumulated As, depending on the size of the sample area analyzed. Time-of-flight secondary ion mass spectrometry (TOF-SIMS) analysis of an area of the sand grain showed a significant correlation (r = 0.51) between Fe and Al, so effects of Fe vs Al (hydr)oxides on accumulated As could not be separated. Fitting results from 25 As K-edge microscale X-ray absorption near edge structure (µ-XANES) spectra collected across a separate 10 x 10 µm 2 region showed ~60% variation in proportions of Fe(III) and Al(III)-bound As(V) standards, and fits to µ-XANES spectra collected across the 100 x 100 µm 2 region were more variable. Consistent with insights from studies on model systems, our results indicated a dominance of Fe and possibly Al (hydr)oxides in controlling As(V) accumulation within microsites of the soil matrix analyzed, but our analyses inferred minor augmentation from co-localized Ti, Ca, and possibly Zn.