Granofels is a term referring to medium- to coarse-grained metamorphic rock which have a granoblastic texture (having poorly formed, equi-granular crystal grains visible to the naked eye) and lack distinct foliation or lineation.
Formation
Granofels forms under medium- to high-grade metamorphic conditions, typically involving elevated temperatures and pressures that promote recrystallization of minerals without inducing directional stress. This process results in a granoblastic texture, characterized by equigranular, interlocking mineral grains lacking foliation.
Examples
Granofels is a general term that includes several more specific rock types:
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Marble – formed from the metamorphism of limestone, composed primarily of recrystallized calcite or dolomite
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Hornfels – produced by contact metamorphism of shale or other fine-grained sedimentary rocks, often containing quartz, feldspar, and mica
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Quartzite – derived from sandstone, sometimes classified as granofels when texture is granoblastic and non-directional
These examples illustrate the diversity of protoliths and mineral compositions that can result in granofelsic textures.
