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

Progress of IGCP Projects
No. 4 TRIASSIC OF THE TETHYS REALM
H. Zapfe, Palâontologisches Institut der Universitat,
A-1010 Wien, Universitatsstrasse 7,
Austria.
Description. Revision of the biostratigraphy in
the Tethyan Triassic. Redefinition of classical
stages and substages, their emendation for a
world-wide application. Comparison of the
scheme with other major faunal realms (North
America, Eurasia, Indo-Pacific) aiming at a
global Triassic time scale. Once this stage has
been achieved, other important topics are to be
studied, such as palaeogeography, faunal provinces,
and palaeomagnetism during Triassic
time. Originally starting with the Upper Triassic,
during recent years work has expanded
more and more to the entire Triassic, and the
Project has been expanded to Asia in order to
include the Triassic of the Himalayas, China,
and the Far East.
Summary of activities. An international meeting
of the Project was held in Sarajevo, Yugoslavia,
5-7 October 1981. Representatives of the national
working groups reported at the meeting, on their
activities and scientific progress during the year
under review. One of the fourteen lectures
concerned the proposed new stratotype for the
Illyrian substage in Bosnia. A successful excursion
with a detailed field discussion was organized
at the proposed stratotype in Pridvorice. It was
decided to publish the results of the meeting in
the "Schriftenreihe der Erdwissenschaftlichen
Kommission" of the Austrian Academy of Sciences.
A session of the IUGS Subcommission of Triassic
Stratigraphy also was held on this occasion. The
Anisian/Ladinian boundary and the proposed new
stratotype for the Illyrian were discussed.
National working groups actively continued their
planned activities. For example, the Bulgarian
scientists carried on the studies all over their
territory; research was going on in six Italian
universities and a research centre. The Austrian
scientists executed excursions to the Hallstatt
facies of the Taurus Mts., Turkey.
Many new important publications were issued
(or were in press) in Austria, China, Poland,
etc. Some scientific results acquainted in 1981
can be illustrated as follows:
Austria: The cladiscitidae of the Upper Triassic
in Timor has proved to be of particular stratigraphic
value. It is intended to continue these
revisions of Upper Triassic ammonoids.
China: A joint business meeting of the Chinese
working groups of Projects 4 and 106 was held
14
in Beijing at the end of April 1981. In the fieldwork
in Tibet from July to October, the newly
discovered units, the Lower Triassic Xiukang
Group were observed. The Otoceras Zone and
other Ammonoid zones also were confirmed there.
Czechoslovakia: A detailed investigation of the
section of Silicka Brezova, proved by conodonts,
has resulted in considerable alterations to already
existent interpretations.
Hungary: The conodont studies and the correlation
of the conodont zones with other biostratigraphic
zonations continued. For the Middle and Upper
Triassic a world-wide applicable conodont zonation
was established which can be correlated with
the conodont zonation in all conodont provinces.
The most different zonations from the standard
are in the West-Mediterranean and Germanic faunal
provinces, but even these areas canbe correlated
bythe aid of conodonts in the Middle Triassic. The
Triassic Conodont Catalogue of the Conodont Working
Group has been concluded by the large and important
participation of Hungarian specialists and is being
printed in Hungary. In the frame of the countrywide keyprofile
programme new drillings and artificial exposures
were carried out in the Transdanubian Central Mts. and
North Hungary, providing important new information on
the Permian/Triassic boundary in Marine facies in the
south-eastern foreland of the Vertes Mountains. In the
microbiostratigraphy of the Anisian/Ladinianboundary,
and especially in the investigation of the Versprem karst
formation, considerable progress has been achieved.
India: Research in the Spiti region on conodonts
from the Lilang, Pin-Parahio and Kioto showed
that parallelisations with conodont zones of the
Western Tethys were possible. The Keyserlingites
bed of Spiti is considered to be Lower Triassic
with the conodont support. The boundary of the
Middle Triassic to the Lower Triassic is considered
to be 30 m below the traditional boundary based
on conodonts (Neospathodus newpaasensis and
Gondolella polygnatiformis ).
The Netherlands: Ranges of selected palynomorphs
in the Alpine Triassic have been published. A set
of 5 preliminary range-charts shows the known
stratigraphical distribution of 52 selected species
or categories of palynomorphs through the stages
and substages of the Alpine Triassic. A considerable
part of the palynological data is controlled
chronostratigraphically by ammonoids or other
significant faunal elements. Lithostratigraphical,
palynological, and microfaunal studies in the Triassic
of the External Zone of the Betic Cordilleras,
Southern Spain, have led to a reinterpretation of
the Triassic in the provinces of Jaén and Murcia.
According to palynological and microfaunal data,
the age of the sediments ranges from the Late
Ladinian into the Late Karnian and probably into
the Norian. The new stratigraphical concept
differs considerably from the stratigraphical schemes
of previous authors. This is due mainly to
the previous misinterpretation of the evaporitic/
clastic successions. By far the major part,