Precambrian quartzo-feldspathic gneiss was encountered at an elevation of —3616 feet in the Herman 1A well drilled in southeastern Erie County, Ohio, by the Amerada Petroleum Corporation. The five samples of this gneiss that were studied exhibit varying degrees of gneissose foliation. In order of decreasing abundance, microcline, plagioclase, quartz, and biotite together account for an average ...

An eclogite and its surrounding gneiss from the Malpica-Tuy zone, northwestern Spain, were studied. The eclogite contains besides garnet and omphacite, barroisitic amphibole, quartz, phengite with Si contents between 3.27 and 3.45 per formula unit (pfu), rutile, and accessory phases such as talc and (clino)zoisite-epidote. Garnet exhibits a chemical zonation with Alm59Prp13Grs24Sps4, Alm57Prp13...

Precambrian quartzo-feldspathic gneiss was encountered at an elevation of —3616 feet in the Herman 1A well drilled in southeastern Erie County, Ohio, by the Amerada Petroleum Corporation. The five samples of this gneiss that were studied exhibit varying degrees of gneissose foliation. In order of decreasing abundance, microcline, plagioclase, quartz, and biotite together account for an average ...

Study of the concentration and isotopic composition of strontium and rubidium in hornblende diorite dikes and sills of Precambrian age from the Panamint Mountains of California showed that these rock systems were enriched in radiogenic Sr during a late Mesozoic metamorphism. Enrichments in radiogenic Sr were observed for total-rock samples which yielded apparent ages of up to 34,000 m.y., altho...

Sir,?There is an impression amongst the visitors to Parjeeling that the water supplies contain mica, and is sometimes suggested that mica in the drinking Water causes irritation of the intestinal mucosa, with resultant diarrhoea. The water supply of Darjeeling is obtained from a number of perennial springs on the western slope of the Senchal range. The springs connect with a closed concrete con...

Precambrian quartzo-feldspathic gneiss was encountered at an elevation of —3616 feet in the Herman 1A well drilled in southeastern Erie County, Ohio, by the Amerada Petroleum Corporation. The five samples of this gneiss that were studied exhibit varying degrees of gneissose foliation. In order of decreasing abundance, microcline, plagioclase, quartz, and biotite together account for an average ...

Himalayan leucogranites are abundant within a ~2000-km-long, E-W trending belt on the Tibetan Plateau. Recently, it has been shown that several and pegmatites (including aplites) of Himalayan leucogranitic closely related to rare-metal mineralization. The commonly peraluminous strongly peraluminous, classifying as highly-fractionated granites in terms whole-rock geochemistry chara...