Volcanism and the Upper Mantle: Investigations in the Kurile Island Arc

398 Pages·1970·12.13 MB·English

by  Georgii Stepanovich Gorshkov (auth.)

VOLCANISM AND THE
UPPER MANTLE
Investigations in the Kurile Island Arc
Monographs in Geoscience
General Editor: Rhodes W. Fairbridge
Department of Geology, Columbia University, New York City
B. B. Zvyagin
Electron-Diffraction Analysis of Clay Mineral Structures-1967
E. I. Parkhomenko
Electrical Properties of Rocks-1967
L. M. Lebedev
Metacolloids in Endogenic Deposits-1967
A. I. Perel'man
The Geochemistry of Epigenesis-1967
S. J. Lefond
Handbook of World Salt Resources-1969
A. D. Danilov
Chemistry of the lonosphere-1970
G. S. Gorshkov
Volcanism and the Upper Mantle: Investigations in the
Kurile Island Arc-1970
In preparation:
A. S. Povarennykh
Crystal Chemical Classification of Minerals
D. Carroll
Rock Weathering
E. I. Parkhomenko
Electrification Phenomena in Rocks
E. L. Krinitzsky
Radiography in the Earth Sciences and Soil Mechanics
B. Persons
Laterite-Genesis, Location, Use
VOLCANISM AND THE
UPPER MANTLE
Investigations in the Kurile Island Arc
Georgii S. Gorshkov
Director, Institute of Volcanology
Siberian Branch, Academy of Sciences of the USSR
Kamchatka
Translated from Russian by
Charles P. Thornton
Department of Geochemistry and Mineralogy
College of Earth and Mineral Sciences
The Pennsylvania State University
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PLENUM PRESS· NEW YORK - LONDON • 1970
Georgii Stepanovich Gorshkov was born in Irkutsk in 1921. A student of geology,
he graduated from Moscow State University in 1943 and since 1946 has special
ized in the study of volcanoes, on the subject of which he has written more than
120 studies, including Catalogue of the Active Volcanoes of the World-Kurile
Islands (Naples, 1958; in English) and Bezymyannyi Volcano and the Character
istics of Its Last Eruption in 1955-1963 (Moscow, 1965). Recognized as one of the
leading volcanologists of the world, G. S. Gorshkov has made important contribu
tions to the description of volcanic processes in many regions, including Japan,
Indonesia, and the United States.
The original Russian text, published by Nauka Press in Moscow in 1967, has been
corrected by the author for this edition. The present translation is published under
an agreement with Mezhdunarodnaya Kniga, the Soviet book export agency.
VOLCANISM AND THE UPPER MANTLE:
INVESTIGATIONS IN THE KURILE ISLAND ARC
VULKANIZM KURIL'SKOI OSTROVNOI DUG I
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library of Congress Catalog Card Number 69-12530
ISBN 978-1-4684-1769-2 ISBN 978-1-4684-1767-8 (eBook)
DOl 10.1007/978-1-4684-1767-8
© 1970 Plenum Press, New York
Softcover reprint of the hardcover 1s t edition 1970
A Division of Plenum Publishing Corporation
227 West 17th Street, New York, N. Y. 10011
United Kingdom edition published by Plenum Press, London
A Division of Plenum Publishing Company, Ltd.
Donington House, 30 Norfolk Street, London W.C. 2, England
All rights reserved
No part of this publication may be reproduced in any form without
written permission from the publisher
Translator's Preface
The present volume seems to me to be a particularly im
portant one for several reasons. Not least among these is the fact
that it summarizes the work of two decades by G. S. Gorshkov, one
of the world's leading volcanologists. In addition, it is the first
general work of this length on the volcanism of what might be called
a "narrow" island arc, a relatively simple megastructure as com
pared with the "wide" arcs such as Japan and Indonesia. Finally,
in this volume Gorshkov has summarized and cited extensive evi
dence for his general ideas on the relation between volcanism and
the earth's crust and mantle.
A few potentially troublesome items should be noted here. In
the translation the Russian terms "suite" and "series" have been
retained, though for American readers these might better have
been translated as "formation" and "group." In almost all cases
Russian place names have simply been transliterated rather than
translated (e.g., "Yuzhnyi Isthmus" rather than "South Isthmus");
in a few cases the English equivalent has been given in brackets
where this is essential to the understanding of the author's com
ments. The adjectives have retained their Russian case endings
in the process (masculine -yi or -ii, feminine -aya or -'ya, neuter
-oe) and this may occasionally lead to some slight confusion, for
example, when the author calls a given feature Severnyi Volcano
at one point and Severnaya Mountain at another.
I would like to take this opportunity to acknowledge the gen
erous assistance of Mr. Sergius Theokritoff in translating a num
ber of the older Russian quotations in the chapter dealing with the
history of investigation of the volcanoes.
Gorshkov, like all Russian petrologists in the past 25 years,
recalculates his chemical analyses to produce a set of petrochemi
cal coefficients or numerical characteristics "according to the
method of A. N. Zavaritskii." The method is presented in full in
v
vi TRANSLATOR'S PREFACE
the latter's Introduction to the Petrochemistry of the Igneous Rocks
(Zavaritskii, 1950); it is summarized rather briefly in the follow
ing paragraphs.
The weight percentages of the major oxides are converted
to cation proportions, and those of ferric and ferrous iron are com
bined. These proportions (or, loosely speaking, "num bers of at
oms II) are then divided among the four principal characteristics
a, c, b, and s, with a+c+b+s set equal to 100:
a = relative number of alkali atom s tied to alum inum, in 1 : 1
ratio, in the feldspars and feldspathoids.
c = relative number of calcium atoms tied to the remaining
aluminum atoms (if any) , ina 1: 2 ratio, in anorthite; ifno
aluminum is left from a (i.e., if Na + K> AI), C = relative
number of sodium atoms tied to iron atoms, in a 1 : 1
ratio, in acmite.
b = relative number of remaining cations other than silicon
and titanium.
s = relative number of silicon and titanium atoms.
In addition, a series of secondary characteristics are cal
culated. These are of two types, one expressing the relative pro
portions of the cations included in b, the other expressing the rela
tive proportions of the alkalies making up a.
What cations are included in b depends on the chemistry of
the rock. Four cases are possible:
1. In most rocks all the alkalies and aluminum are used
in a and c, so that b is composed of all the iron and
magnesium plus the calcium remaining from c. The
secondary characteristics of b then consist of c', I',
and m' (calcium, iron, and magnesium, respectively)
where c'+I'+ m'=100.
2. In the aluminum-oversaturated rocks, all the alkalies
and calcium are used in a and c; b is then composed of
all the iron and rr.agnesium plus the aluminum remain
ing from c. The secondary characteristics of b then
consist of a', I', and m' (aluminum, iron, and magnes
ium, respectively), where a' + I' + m' = 100.
3. In moderately alkali-oversaturated rocks, all the
aluminum is used in a and the remaining alkalies (as-
TRANSLATOR.'S PREFACE vii
sumed to be sodium) are used in ~; b is thus composed
of all the calcium and magnesium plus the iron re
maining from ~. The secondary characteristics of b
then consist of c', j', and m' (calcium, iron, and mag
nesium, respectively), where c'+j'+ m'=100.
4. In strongly alkali-oversaturated rocks, all ~he alumi
num is used in a and all the iron is used in c; b thus is
composed of all the calc~um and magnesium plus the
sodium remaining from c. The secondary character
istics of b then consist of n , c', and m' (sodium, cal
cium, and magnesium, respectively), where n + c'
+m'=100.
S A
10 20 30
40
B
viii TRANSLATORS PREFACE
The secondary characteristic of a is expressed by the ratio
100 Na/(Na+K), which is called n'.
Gorshkov uses two of the primary characteristics, a and b,
to construct variation diagrams for the Kurile volcanics and for
the volcanics in areas to which he wishes to compare the Kurile
volcanics. The two perpendicular axes of these diagrams are
labelled SA (horizontal) and SB (vertical); the distance along SA
is equal to a and the distance along SB, to b. The more acid (silica
rich) a rock or series is, the closer it will plot to the origin S.
In his original presentation of this method, Zavaritskii plots a
number of "type curves" (following Burri, 1926) for use as stand
ards of reference; in order of increasing alkalinity these are Pelee,
Lassen Peak, Yellowstone, Etna, and (Maros-)Highwood Mountains.
These curves are illustrated on the diagram on page vii.
Foreword
In recent decades the problem of the origin and development
of island arcs has attracted constant attention from scientists in
a variety of specializations. The highest energy contemporary
geologic processes are restricted to just these regions; it is here
that the conversion of one type of terrestrial crust to another takes
place. Only after we completely understand present-day processes
will it be completely safe for us to conjecture about the processes
of the past.
Work on the problem of island arcs in our area (Le., the
Kurile-Kamchatka arc) was begun by Academician A. N. Zavarits
kii, who beginning in 1946, repeatedly raised this question in the
pages of scientific periodicals. He noted the "convenience" of the
Kurile-Kamchatka arc for investigation: the Kamchatka part of the
arc is accessible to investigation by geologic methods; the Kurile
part is in part a single arc and in part a double one, yet it is not
complicated by such phenomena as, e.g., the intersection of arcs
that are found in Japan.
The processes of volcanism playa large role in the island
arcs; for this reason Zavaritskii regarded the study of the vol
canoes and volcanic phenomena of the Kurile Islands as one of his
first tasks. To a large degree, completion of this mission was
assigned to the present author, who, beginning in 1946, though with
long interruptions, carried on the volcanological investigations
here.
At first the tasks were rather limited, he was simply sup
posed to describe the volcanoes and the rocks composing them.
In 1957, as a result of work on the program of the Interna
tional Geophysical Year in the region of the Kurile island arc, the
basic outlines of the structure of the earth's crust and upper man
tle were made clear; subsequently it began to be possible to com-
ix
x FOREWORD
pare the distinctive features of volcanism with those of the deep
structure of the arc. Gradually there developed the concept of the
"through-the-crust" character of the volcanism, of its direct con
nection with great depths, with the upper mantle of the earth.
The first work of the author in this direction was published
in 1956 in "Upper Mantle Project." In this work, attention was
called to the phenomenon of absorption of transverse seismic waves
in the magma chamber of the Klyuchevskoi group of volcanoes. On
this basis, the depth to the volcanic hearth was estimated to be 60-
80 km. This work attracted considerable interest and was printed
in several publications abroad.
Subsequently the idea of a direct connection between vol
canoes and the upper mantle was developed along independent lines
based on a petrochemical study of the volcanic rocks in the Kurile
Islands. The conclusions reached required additional petrochemi
cal analysis of the volcanic lavas from many regions of the world.
At the same time similar ideas were advocated and developed
here by Yu. M. Sheinman and abroad by G. A. Macdonald. In re
cent years many scientists have begun to express support for this
point of view. Among the foreign investigators we may distinguish
Dr. Zen (Indonesia), who applied our ideas directly to the material
of the Indonesian volcanoes, and Dr. Ringwood (Australia), who
carried out a series of interesting physicochemical experiments.
Interesting investigations in petrochemistry, geophysics, and geo
chemistry have also been carried out in the USA and Japan. Ap
parently the idea of an exclusively mantle source of supply for
volcanoes and of only a small role for the processes of assimila
tion and contamination by crustal material is very popular.
The author's ideas along these lines were published in some
papers and reports in which the original factual material could
not be presented. Thus it may be that the author's ideas have not
always sounded sufficiently convincing. In this book abundant fact
ual material will be presented on the petrochemistry of the whole
Pacific volcanic region. In the course of this work it developed
that most of the older chemical analyses suffer from errors; thus
we have tried to use only chemical analyses made mostly after 1940.
The present work actually consists of two parts. The first
part is a description of the Kurile island arc; the basic information