United States
£ GBP
Petrology of Polygenic Mafic-Ultramafic Massifs of the East-Sakhalin Ophiolite Association is concerned with results of studies of petrology of mafic-ultramafic massifs as part of the East Sakhalin ophiolite association. It generalizes and interprets a large body of data (mainly original data) on geology, petrography, petrochemistry, and geochemistry of rocks; mineralogy and geochemistry of rock-forming and accessory minerals; chromite and platinum contents, and isotopic age of zircons from rocks of the typical mafic-ultramafic massifs of the East Sakhalin ophiolite association: Berezovka, Shel'ting, Komsomol'sk, and South Schmidt. Gabbroids from the Berezovka massif contain ultramafic xenoliths. Ultramafic rocks are locally cut by gabbroid and pyroxenite veins. Three spatially close but genetically autonomous bodies are distinguished in the structure of the massifs under study: protrusion of upper-mantle restitic ultramafic rocks (harzburgites, lherzolites, and dunites); intrusion of orthomagmatic gabbroids (gabbronorites, gabbro, and norites) that cuts it; and contact-reaction zone, located along the boundaries between gabbroid intrusion and ultramafic protrusion, which consists of hybrid ultramafic rocks (wehrlites, websterites, clinopyroxenites, and their olivine- and plagioclase-containing varieties) and hybrid gabbroids (melano- and mesocratic olivine gabbronorites and gabbro as well as troctolites). The hybrid ultramafic rocks and gabbroids are the product of interaction between mafic melts and restitic ultramafic rocks. Taking into account the later formation of the gabbroid intrusions compared to the ultramafic protrusions, the massifs in question are determined as polygenic. The idea of their polygenic formation is supported by data on the isotopic age of zircons from the Berezovka massif rocks. In this monograph the author develops his earlier proposed concept of polygenic formation of mafic–ultramafic massifs belonging to ophiolite associations.
Petrology of Polygenic Mafic-Ultramafic Massifs of the East-Sakhalin Ophiolite Association addresses a wide circle of petrologists and practicing geologists as well as senior-year students and postgraduates studying problems of mafic-ultramafic magmatism.
Originally published in Russian in 2015.
1 Topical problems of petrology of mafic-ultramafic massifs
2 Structural position of mafic-ultramafic massifs of the East Sakhalin ophiolite association
3 Geologic structure of mafic-ultramafic massifs of the East Sakhalin ophiolite association
3.1 Berezovka massif
3.2 Shel’ting massif
3.3 Komsomol’sk massif
3.4 South Schmidt massif
4 Petrography of mafic-ultramafic massifs of the East Sakhalin ophiolite association
4.1 Restitic (orthomagmatic) ultramafic rocks
4.2 Hybrid (paramagmatic) ultramafic rocks
4.3 Orthomagmatic gabbroids
4.4 Hybrid (paramagmatic) gabbroids from endocontact zones with ultramafic rocks
4.5 Hybrid (paramagmatic) gabbroids of endocontact zones with enclosing rocks
5 Petrochemistry of rocks of mafic-ultramafic massifs of the East Sakhalin ophiolite association
5.1 Variations in the contents of major chemical components in petrogenetic rocks groups
5.2 Comparative description of petrogenetic groups of rocks based on the values of their petrochemical parameters
5.3 On systematization of ultramafic and gabbroid rocks based on the normalized values of their petrochemical parameters
5.4 The dependence of the chemical composition of ultramafic restites on the degree of partial melting of upper-mantle sources
6 Geochemistry of rocks of mafic-ultramafic massifs of the East Sakhalin ophiolite association
6.1 Distribution of Ca, K, and some impurity elements in rocks of the Berezovka massif (from XRF-SR data)
6.2 Geochemical parameters of rocks of the Berezovka massif (from XRF-SR data)
6.3 Distribution of rare earth elements in rocks of mafic-ultramafic massifs of the East Sakhalin ophiolite association
7 Rb–Sr isotope systems in rocks of mafic-ultramafic massifs of the East Sakhalin ophiolite association
8 Chemical composition of rock-forming and accessory minerals from rocks of mafic-ultramafic massifs of the East Sakhalin ophiolite association
8.1 Rock-forming minerals
8.2 Distribution coefficients of chemical components between coexisting rock-forming minerals
8.3 On the temperatures of chemical equilibrium of coexisting olivines, orthopyroxenes, and clinopyroxenes in ultramafic restites of the Berezovka massif
8.4 Accessory minerals
9 Distribution of rare earth elements in rock-forming minerals from mafic-ultramafic massifs of the East Sakhalin ophiolite association
9.1 Orthopyroxenes
9.2 Clinopyroxenes
9.3 Plagioclases
9.4 On the distribution coefficients of rare earth elements among coexisting clinopyroxenes, orthopyroxenes, and plagioclases
10 Isotope-geochronological and geochemical systematization of zircons from rocks of the Berezovka mafic-ultramafic massif
10.1 Description of the collection of zircons from rocks of the Berezovka massif
10.2 Methods for isotope dating and trace-element analysis of zircons
10.3 Morphology and optical properties of zircons
10.4 Isotopic age of zircons
10.5 Geochemistry of zircons
10.6 Specifics of zircon isotope dating of rocks of mafic-ultramafic massifs
11 The chromitite occurrences in mafic-ultramafic massifs of Sakhalin Island
11.1 Chromitite occurrences in the Berezovka and South Schmidt massifs
11.2 Chemical composition of chromitites
12 Geochemistry of platinum group elements and rhenium in rocks and chromitites of mafic-ultramafic massifs of Sakhalin Island
12.1 Geochemistry of PGE and Re in rocks
12.2 Geochemistry of PGE and Re in chromitites
12.3 On mineral-concentrator of PGE in chromitites of the Berezovka massif
13 The fundamentals of the concept of polygenetic formation of mafic-ultramafic complexes in ophiolite associations
Conclusions
Felix Lesnov finished an undergraduate degree at the geological department of Lviv State University in Ukraine in 1957. Between 1957-1963 he joined several geological expeditions in Burytaia. Since finishing a graduate degree, he has worked in the Institute of Geology and Minerology at the Siberian branch of the Russian Academy of Sciences. He is a Senior Research Fellow and member of the Russian Academy of Natural Sciences.
