PMC

Microscopic investigation of the studied altered microgranite and altered basic dykes A. Equigranular texture of microgranite dyke (C.N. X40), B. Plagioclase phenocrysts embedded in microcrystalline groundmass in microgranite dyke (C.N. X40), C. Quartz phenocrysts embedded in microcrystalline groundmass in microgranite dyke (C.N. X40), D. Orthoclase phenocrysts embedded in microcrystalline groundmass in basic dyke (C.N. X40), E. Uranothorite associated with iron oxide in microgranite dyke (C.N. X 40), F. Uranophane associated with groundmass of kaoline and iron oxide in basic dyke (C.N. X40), G. Uranothorite associated with iron oxide in microgranite dyke (C.N. X40),H. Metamict zircon associated with perthite and albite plagioclase in microgranite dyke (C.N. X40).

Temporal relations in the Yerington magmatic system: Field photographs of; (a) cross-cutting relations of multiple porphyry dyke generations which cut the LHG cupola; (b) lobate contacts and evidence for mingling of co-eval magmas between an aplite dyke and porphyry dyke. Secondary copper staining prevalent in the aplite dyke; (c, d) multiple generations of aplite dykes hosting pegmatitic segregations and mineralised miarolitic cavities (MC). The aplite dykes sharply cross-cut the cupola zone of the LHG and a porphyry dyke. Both the aplite and porphyry dykes lie palaeo-vertically beneath the Ann Mason porphyry deposit; (e) cupola zone of LHG cut by an aplite dyke hosting a chalcopyrite (Ccp) mineralised miarolitic cavity. This aplite dyke is sample AM13BAP in Fig. . Qtz = quartz; (f) drill core from the Ann Mason porphyry deposit showing LHG cut by an aplite dyke hosting miarolitic cavities and early chalcopyrite-bornite-quartz (Ccp-Bn-Qtz) (‘A-type’, nomenclature after) veins, which locally truncate at the dyke’s margin. (e, f) from.

Four views of the Saffaqah dyke, showing the linear formation of the dyke and clasts eroding off the dyke (A); the blocky form in which the dyke weathers and clasts that have moved down the slope beneath the dyke (B) the terracettes that form on the stable lower flanks of the dyke (C); the primary unweathered dyke and the excavation next to the vehicles in the background (D).

Note that artefacts stop abruptly on the approach to the dyke. Sites where a wadi flowed past a dyke were classed as dyke sites. Base layers reprinted with permission from Esri, ArcGIS, DigitalGlobe, GeoEye, i-cubed, USDA, USGS, Aex, Getmapping, Aerogrid, IGN, IGP swisstopo, and the GIS User Community under a CC-BY license, original copyright 2018.