Arkose

Arkose is a type of sandstone characterized by a significant proportion of feldspar grains, typically greater than 25%, along with quartz and other minerals like mica or lithic fragments. Its color is often reddish or pinkish due to the presence of iron oxides, and the grain size can vary widely. arkose is usually formed from the rapid erosion and deposition of granitic or metamorphic rocks in alluvial fans or fluvial environments, indicating proximity to the source rock and limited chemical weathering.

Arkose meaning with examples

• The geologist identified the cliff face as being primarily composed of arkose, noting the distinctive pink hue and coarse grains, suggesting a nearby granitic source. The angularity of the grains also indicated a relatively short transport distance and minimal weathering before deposition. This evidence supported their hypothesis about the region's ancient tectonic activity.
• During the field study, the team collected arkose samples from a series of sedimentary layers. The mineral composition confirmed the presence of abundant feldspar, validating their assumption that the area's provenance was the surrounding Precambrian highlands. The texture and grain sorting further helped to reconstruct the paleogeography of the basin.
• The construction project was delayed due to issues with the arkose quarry. The stone, known for its durability, proved challenging to excavate. The quarrying revealed the presence of varying grain sizes within the arkose deposit, requiring selective extraction to ensure uniform material characteristics for the concrete aggregate.
• The paleontologist examined the fossiliferous arkose, noting the preservation of ancient plant matter within the sedimentary rock matrix. The arkose environment, formed millions of years ago, provided critical insight into the ecosystem, confirming a humid climate and a prevalence of woody vegetation near the ancient river system.