Aleutian tholeiitic and calc-alkaline magma series I: The mafic phenocrysts

1985 ◽  
Vol 90 (2-3) ◽  
pp. 276-290 ◽  
Author(s):  
S. Mahlburg Kay ◽  
Robert W. Kay
Keyword(s):  
Calc Alkaline ◽  
Alkaline Magma ◽  
Magma Series

Felsic plutonic rocks from the southern portion of the New Caledonian Ultramafic Belt

1973 ◽  
Vol 110 (5) ◽  
pp. 431-446 ◽  
Author(s):  
K. A. Rodgers
Keyword(s):  
New Caledonia ◽  
Ultramafic Rocks ◽  
Calc Alkaline ◽  
Mafic Rocks ◽  
Alkaline Magma ◽  
Southwest Pacific ◽  
Plutonic Rocks

SummaryGranodiorite stocks were intruded into the alpine peridotites of southern New Caledonia in the Eocene following overthrusting of the ultramafics onto the sialic core of the island. Strong zoning, from mela-diorite to granodiorite, is developed in one pluton and is believed to be the result of assimilation of ultramafic and mafic rocks by the calc-alkaline magma. Evidence in favour of a consanguineous relationship between the felsic and ultramafic rocks is largely circumstantial. In their petrography, mineralogy and chemistry, the rocks show few differences from other felsic plutonics of Tertiary age in the southwest Pacific.

scholarly journals Petrogenesis and depositional environment of paleozoic Sedili and Pengerang Volcaniclastics in East Johor Basin, Peninsular Malaysia

2019 ◽  
Vol 76 ◽  
pp. 04009
Author(s):  
Sugeng Sapto Surjono ◽  
Mohd. Shafeea Leman ◽  
Che Aziz Ali ◽  
Kamal Roslan Mohamed ◽  
Fathan Hanifi Mada M
Keyword(s):  
Depositional Environment ◽  
Active Continental Margin ◽  
Volcanic Rocks ◽  
Peninsular Malaysia ◽  
Calc Alkaline ◽  
Great Abundance ◽  
Volcaniclastic Rocks ◽  
Geochemical Analyses ◽  
Depositional Setting ◽  
Magma Series

Volcaniclastic rocks in East Johor Basin are found in a relatively great abundance comprising Sedili and Pengerang Formations excluding the metamorphics, siliciclastics, and granites. Since the volcaniclastic rocks are found in a different formation, this study aims to find out the characteristics of each rock. Geology, petrography, and geochemical analyses were elaborated to reveal the petrogenesis and depositional environment in the studied area on the basis of fieldwork data and 24 samples collected from outcrops. The Sedili and Pengerang Formations are dominated by acidic rocks of rhyolite, rhyodacite, ignimbrite, and lava classifiied into calc-alkaline magma series which indicates a subduction-related product. Moreover, those acidic rocks are grouped into active continental margin. Eventhough volcanic rocks in Sedili and Pengerang Formations exhibit similar characteristics, they are different in several major contents. Therefore, it is inferred that both Sedili and Pengerang Formations were deposited in different phase. Coincidentally, depositional environment of both formations is also distinct. Sedili Formation were deposited in the subaerial to shallow marine, meanwhile, Pengerang Formation is interpreted to be deposited in deeper depositional setting.

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