Potassium-argon ages of eight volcanic rocks from some of the geologically oldest flows exposed in the Galápagos Archipelago indicate that the Galápagos Islands have a probable maximum age of 3 million years. Rocks from six islands were dated; the oldest are from Española (3.2 +/- 0.2), Sante Fe (2.7 +/- 0.1), and Plazas (4.2 +/- 1.8 million years). The new data suggest that the Galápagos Islan...

Subduction-related volcanism in the northern part of the North Island of New Zealand shifted abruptly during the late Pliocene. This study focuses on the transition, in time and space, from the NNW-oriented Miocene–Pliocene Coromandel Volcanic Zone to the northeast-oriented active Taupo Volcanic Zone. The volcanic rocks marking this transition are exposed in the Tauranga Basin and adjacent Kaim...

The Nii Zn-Pb-Ag-Ba prospect is located in the headwaters of the Noosegolch River valley, approximately 23 kilometms north-east of Hagensborg in west-central British Columbia (Figure 1). The area lies within the Stikine Termne of the Coast Belt and is mostly underlain by various packages of matic to felsic volcanic, volcaniclastic and sedimentruy m&s @gore 1). Many of these packages are of unce...

The so-called ‘mesothermal’ gold deposits are associated with regionally metamorphosed terranes of all ages. Ores were formed during compressional to transpressional deformation processes at convergent plate margins in accretionary and collisional orogens. In both types of orogen, hydrated marine sedimentary and volcanic rocks have been added to continental margins during tens to some 100 milli...

The 1285 m thick MIS core offers an invaluable opportunity to obtain a detailed record of volcanism in McMurdo Sound. Volcanic stratigraphy and preliminary petrologic data on volcanic rocks in the AND-1B core are reported here. Remarkable volcanic deposits include: a) a phonolitic pumice layer found at ≈85 mbsf which is not correlated to any known vent onshore; b) a black well sorted volcanic s...

The Cenozoic volcanic activity of the Harrat Ash Sham volcanic field in south of Syria is a part of the extensive magmatism that took place in the auxiliary extension faults along the Dead Sea Fault Zone from upper Eocene to Holocene. Pliocene volcanic rocks form an important part of igneous succession in Syrian Part of Harrat as Sham. These rocks vary from basalts flows to scoria. Pliocene bas...