... the emergence of the island a compositionally bimodal population of rocks has been represented. The products of over 100 eruptions in the upper Terceira Group have been recognised. These include ignimbrites, pumice fall deposits, salic lava extrusions, strombolian scoria deposits, basaltic lava flows...

...B. G. J. Upton; A. A. Finch; E. Słaby Abstract Ca-poor and typically Na-rich feldspar megacrysts are common associates of spinel lherzolitic and pyroxenitic xenoliths in Scottish alkalic basalts. Associated megacrysts and composite megacrysts and salic xenoliths include apatite, magnetite, zircon...

...Fig. 12. ε Nd ( T )–age diagram for West Transbaikalian composite dikes and the host granitoid complexes. Shaluta massif: CD 1 : 1 , basic and 2 , salic components; CD 2 : 3 , basic and 4 , salic components; 5 , composite dike of the Kurba River basin; Maksimikha site: 6 , basic and 7...

.... In addition, 15 older Phanerozoic ashes, associated with other dramatic global events, have been analyzed for Ir. The Fur Formation ashes are unusually well preserved and have a wide compositional range–for example, rhyolitic, dacitic, tholeiitic and alkaline basaltic, mafic alkaline, and different salic...

...DONNIE F. PARKER; FRED W. McDOWELL Abstract Volcanic rocks of the Davis and Barrilla Mountains constitute the largest contiguous segment of the mid-Cenozoic volcanic field of Trans-Pecos Texas. Salic volcanic rocks form a silica-oversaturated series ranging in composition from trachyte...

... basaltic shields and intermediate to salic peralkaline composite domes, flows, and central volcanoes that are associated with extensional structures in the underlying basement. New K-Ar and fission-track dates (45) and Rb-Sr and Sr isotope analyses (12) from the Mount Edziza Volcanic Complex are reported...

... to 400 ppm and 50 to 80 ppm for the more salic whole-rock and residual glass specimens. The behavior of these elements largely reflects the separation of large amounts of phenocrystic plagioclase. Sr content closely follows that of calcium. More sodic plagioclase exhibits a greater absolute affinity...

..., matrix percent, and sorting imply vent areas to the west and south of the Kakagi Lake area.The rocks are calc-alkaline rather than tholeiitic in lineage, poor in K 2 O, particularly the most silicic. Fragments are more salic and depleted in FeO and MgO relative to their matrix.Thickness and lack...

... phonolitic rocks. The composition of the parental basalt remained nearly constant throughout the history of the volcanoes, and intermediate and salic rocks increased in volume and frequency of occurrence during their growth. It is suggested that on Saint Helena the increasing production with time...

... the different behavior of these minerals under shearing stress. The normal metadolerite has 58 per cent salic, and 42 per cent femic minerals. An analyzed dark layer of the mylonite has 60 per cent femic minerals, whereas an analyzed light layer shows 86 per cent salic minerals. Pneumatolytic alteration...