On the Metallogeny at the Pacific Volcanic Belts

The article discusses the actual aspects of the metallogeny of the Pacific volcanic belts (PVB), which are a complexes of volcanogenic-plutogenic formations associated with the development of the marginal lithosphere and has an expressive specificity of ore formation. It is shown that over time the notions of metallogenic homogeneity of PVB have received a new justification from the position of global plate tectonics. Metallogenic significance of Ag/Au relationships in ore deposits of the PVB is shown. The correlation between porphyry-epithermal and the VMS ore-forming systems, regenerated and rejuvenated epithermal deposits is discussed. Global metallogenic homogeneity of the Pacific ore belt suggests a wide development of analogues of American volcanogenic deposits in its Asian half, including in the North-East of Russia. The main part of the internal zone of the Okhotsko-Chukchi marginal volcanic belt the Udo-Murgal island-arc belt, as well as the Uyandino-Yasachensky and Oloysky volcanic belts, are similar in geological structure not only to the Japanese green tuffs province, but also to other Pacific volcanic zones of the island-arc type and, therefore, within their limits, there is a high probability of revealing the entire variety of deposits of the VMS ore-formation series.

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The Philological Association of The Pacific Coast

PMLA ◽

10.1017/s0030812900130597 ◽

1935 ◽

Vol 50 (4) ◽

pp. 1373-1374

Keyword(s):

Annual Meeting ◽

Pacific Coast ◽

Stanford University ◽

The Pacific

The thirty-seventh annual meeting of the Philological Association of the Pacific Coast was held at Stanford University, California, on November 29 and 30, 1935.

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A scanning electron microscopic study of the veliger larvae of the scallop argopecten purpuratus

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100103486 ◽

1988 ◽

Vol 46 ◽

pp. 284-285

Author(s):

G.C. Bellolio ◽

K.S. Lohrmann ◽

E.M. Dupré

Keyword(s):

Morphological Description ◽

Electron Microscopic ◽

Larval Stages ◽

Scanning Electron Microscopic Study ◽

The Pacific ◽

Argopecten Purpuratus ◽

Veliger Larvae ◽

20 Nm ◽

Ethanol Series ◽

Scanning Electron

Argopecten purpuratus is a scallop distributed in the Pacific coast of Chile and Peru. Although this species is mass cultured in both countries there is no morphological description available of the development of this bivalve except for few characterizations of some larval stages described for culture purposes. In this work veliger larvae (app. 140 pm length) were examined by the scanning electron microscope (SEM) in order to study some aspects of the organogenesis of this species.Veliger larvae were obtained from hatchery cultures, relaxed with a solution of MgCl2 and killed by slow addition of 21 glutaraldehyde (GA) in seawater (SW). They were fixed in 2% GA in calcium free artificial SW (pH 8.3), rinsed 3 times in calcium free SW, and dehydrated in a graded ethanol series. The larvae were critical point dried and mounted on double scotch tape (DST). To permit internal view, some valves were removed by slightly pressing and lifting the tip of a cactus spine wrapped with DST, The samples were coated with 20 nm gold and examined with a JEOL JSM T-300 operated at 15 KV.

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