Developing legislation on soil protection, including soil quality standards, is not straightforward for areas with high geogenic metal(loid) concentrations in rocks and soils. Several rock types in southern Luxembourg (laterally continuous into Northern France and Southern Belgium) contain elevated potentially toxic element concentrations. Toarcian and Aalenian Minette ironstones, and soils on top, possess high As concentrations (average of ~100 mg/kg, maximum up to 278 mg/kg). Liassic shales show high Mo concentrations (up to 60 mg/kg). Preliminary health risk assessments suggest increased potential non-carcinogenic and carcinogenic risks. Trace metal and As anomalies, however, do not necessarily pose human and ecotoxicological risks. Petrographic, mineralogical and chemical analyses show a strong association of As to iron oxides present as ooids and rock matrix. Single extractions with CaCl₂ (0.01 mol/l) indicated the low As mobility in the Minettes. The Minette rocks with 10–40 wt% iron oxides, and a clay content of typically 10–30 wt% strongly bind As. As long as Eh and pH do not drastically change in soils, As mobility will remain low. For soils that developed on Minettes, it is advised to consider Fe-content as well as As mobility for risk assessment and development of legislation on soil protection.

对于岩石和土壤中具有高成因的金属（胶体）浓度的地区，制定包括土壤质量标准在内的土壤保护法规并非易事。卢森堡南部（横向连续进入法国北部和比利时南部）的几种岩石类型含有潜在的有毒元素浓度升高。Toarcian和Aalenian Minette铁矿以及顶部的土壤具有较高的As浓度（平均〜100 mg / kg，最大可达278 mg / kg）。岩质页岩显示出高的Mo浓度（高达60 mg / kg）。初步的健康风险评估表明，潜在的非致癌和致癌风险增加。但是，痕量金属和As异常不一定会构成人类和生态毒理学风险。岩相学 矿物学和化学分析表明，砷与作为氧化物和岩石基质存在的铁氧化物密切相关。用CaCl一次萃取₂（0.01 mol / l）表明Minettes中的As迁移率较低。Minette岩石中含10–40 wt％的氧化铁，粘土含量通常为10–30 wt％，与As牢固结合。只要土壤中的Eh和pH不会发生剧烈变化，流动性就会保持较低水平。对于在Minettes上发育的土壤，建议考虑铁含量以及As的迁移率，以进行风险评估和制定土壤保护法规。