Neoformation of mineral

Smectites also form by precipitation of dissolved ions from alkaline solution, a process referred to as neoformation because none of the structure is inherited from weathering parent minerals. Neoformation of minerals in soils will be discussed in more detail later in this chapter. 

Mineral constituents of soils are inherited from parent material and have been exposed to weathering and pedogenic processes. Processes of degradation and neoformation of minerals - as well as interactions with organic compounds - greatly affect trace... 

The EDZ fracturing extends up to a distance of approximately two metres away from the tunnel walls. Within the EDZ, the disruption of the shale matrix is not complete, but rather propagates along macro- and micro-fissures (centimetre- to millimetre-scale) with no calcite sealing. Macroscopic crystals of gypsum occur on the fractured surfaces of the shales. But neither pyrite alteration nor neoformations of minerals such as iron oxyhydroxides or jarosite have been observed by optical and electron microscopes. 

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