IGCP Board; 10th session; Report of the ... - unesdoc - Unesco

Problems concerning further joint symposia
have been discussed, including the symposium
"Sedimentary and Diagenetic Processes in Precambrian
Metallogenesis" which is to be held
in May 1982 in London.
From 17 to 26 August 1981, an international
conference "Archaean Granulites" took place
in Irkutsk. It was organized in the framework
of the Project 92 "Archaean Geochemistry"
with the participation of the Project 91 and consisted
of two series of reports and a geological
excursion along coastal outcrops of Lake Baikal.
Unfortunately, only 3 foreign scientists participated
at the excursion.
It was decided to strengthen the cooperation between
these two Projects during the Scottish
symposium (1982) and the 27th session of the
International Geological Congress (1984). Project
91 also participated in the 2nd All-Union
conference on the Precambrian metallogeny in
Irkutsk from 14-19 September. At the conference,
four main problems were discussed:
(1) Ore-bearing structures; (2) Petrological
and physico-chemical aspects of the Precambrian
ore-formation; (3) Precambrian oreformations;
(4) Regional Precambrian metallogeny.
From 1 to 10 October 1981, the International
Symposium "Sedimentary Geology of Highly
Metamorphosed Precambrian Complexes" was
held in Petrozavodsk, USSR in the framework
of Projects 91 and 160. About 50 scientists
from 8 countries (Canada, Czechoslovakia,
Denmark, FRG, Finland, GDR, UK, and USSR)
participated at this symposium. Twenty papers
presented were devoted to general problems of
sedimentary geology and volcanism of the Precambrian,
methods of reconstruction of the initial
nature of sedimentary and volcano-sedimentary
series, the information of sedimentary and
volcanic rocks during metamorphism, as well as
the role of sedimentation of organic matter, volcanism,
and metamorphism in the ore-formation.
The scientific session was followed by the geological
excursions to the White Sea complex of
the Early Archaean and stratotypical sections of
the Archaean and Proterozoic of the South and
North Karelia.
The 5th All-Union meeting "Lithology and Precambrian
Sedimentary Geology" took place in
Alma-Ata from 8-10 October 1981. It was organized
by IGCP Project No. 91 and the Interdepartmental
Lithological Committee. About
300 scientists from 60 research,industrial and
higher educational institutions participated in
this meeting. Results of investigations carried
out by the Soviet scientists in the field of exogenic
Precambrian geology during 1980 were
summarized. The following three main problems
were discussed: (1) Lithology, metamorphism,
and metallogeny of the Precambrian
of mean massifs; (2) Carbonaceous Precam­
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brian deposits in relation to the modern data on
the biolithogenesis; (3) regularities of rock formation
at the early stages of geological development
of the Earth. A geological excursion on
Karatau was organized before the meeting and
typical cross-sections of the Upper Precambrian
deposits were visited.
After each symposium collections of abstracts
containing the latest information on Precambrian
geology and metallogeny were published. Besides
a series of other works was published as well in
1981. The most important were two issues of
"Problems of Precambrian sedimentary geology":
issue 6 "Carbonate Sedimentation in the Precambrian",
"Nauka", Moscow, 1981 and issue 7 (two
books): "Carbonaceous formations and their orebearing
features", "Nauka", Moscow, 1981, all
edited by A. V. Sidorenko.
Activities planned. Three scientific conferences
are planned for 1982: "Sedimentary and Diagenetic
Processes in the Precambrian Metallogeny"
(Projects 91 and 160); "Field Geological
Conference on Ni Deposits of Western Australia";
Meeting of the Working Group Project 91 "Metallogeny
of the Precambrian" during the International
symposium on the geological evolution and
the metallogeny of the Archaean and Early Proterozoic.
No. 106 PERMO-TRIASSIC STAGE OF
GEOLOGICAL EVOLUTION
A.N. Oleynikov, All-Union Geological Research
Institute, Sredny Prospect 74, Leningrad,
199026, USSR.
Description. The Project pre-supposes international
cooperation with the aim of producing a
detailed study of the geological evolution at the
Palaeozoic-Mesozoic boundary. The purpose is
to solve the problems connected with the definition
and characteristics of the Permo-Triassic boundary
with regard to the evolutional history of various
fauna and flora groups, the reconstruction
of palaeogeographic settings, the analysis of
palaeomagnetic data, and the tectonogenesis in
the Late Palaeozoic-Early Mesozoic.
Summary of activities. The following work has
been accomplished by national groups in 1981.
In Australia, B. Waterhouse has completed a
detailed study of the marine fauna from northern
Thailand which are equivalent to the Lower Chanxingian
of China. On d'Urville Island the Australian
group found numerous Durvilleoceras, a
contentious ammonite which is deemed to come
from Permian rocks, yet has a Flemingitid suture
suggestive of a Triassic age. Two specimens
with goniatitic sutures have been found to
occur together with Durvilleoceras.
The Permo-Scythian in Austria occurs in all the
tectonic units. Comparative studies have shown