New IGCP project

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Date
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Heidelberg, 4 July 1995

Dear PaleoNetter,

This is to inform you of a new IGCP project "South Atlantic Mesozoic 
Correlations" (SAMC). As the title implies the project deals with the 
Mesozoic of the South Atlantic Ocean and its marginal basins. The project 
was proposed by Eduardo Koutsoukos (Petrobras, Rio de Janeiro) and myself, 
accepted in March this year by the IGCP Scientific Board under the accession 
number 381, and will be launched officially in July at an inaugural meeting 
in Uberaba, MG, Brazil.

As SAMC deals with the Mesozoic sequences of the South Atlantic it is bound 
to focus strongly on palaeontology and biostratigraphy (although, as with 
all IGCP projects, all aspects of correlation are to be considered), and the 
project should therefore be of interest to palaeontologists working in this 
field (geographically the South Atlantic ocean proper and the marginal 
basins of Central America, South America, Antarctica and West Africa).

Below follow selected parts of the text of our first project newsletter 
"SAMC News", which will give you more detailed information about our planned 
activities. Anyone interested in participating in SAMC is invited to e-mail 
the following information to me: Name, mailing address, telephone number, 
fax number, e-mail address, and main fields of interest. You will then 
receive the full paper-based version of "SAMC News".

With best wishes,

Peter Bengtson

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EXCERPT FROM "SAMC NEWS" No. 1 - 1995

IGCP Project 381
South Atlantic Mesozoic Correlations (SAMC)

Key Objectives :
To promote interdisciplinary geological correlative studies in order to 
establish a well-defined standard stratigraphical scale for the Mesozoic 
sedimentary basins of the South Atlantic, and to further improve our 
understanding of the nature and sequence of major geological events during 
the formation of the South Atlantic and the global impact of these events, 
thus also contributing significantly to the exploration of hydrocarbon and 
mineral resources in the marginal basins.

Project proposers:
Eduardo A. M. Koutsoukos  (PETROBRAS-Cenpes/Divex/Sebipe, Rio de Janeiro, 
Brazil)
Peter Bengtson  (Geologisch-Palaeontologisches Institut der Universitaet 
Heidelberg,
Germany)


"IGCP is interdisciplinary, covering all specialities of geology, geophysics 
and geochemistry.
IGCP maintains active interfaces with disciplines related to the geological 
sciences such as
marine sciences, atmospheric sciences and biological sciences."


Introduction

The Mesozoic sedimentary succession of the South Atlantic marginal and 
oceanic basins offers
an excellent opportunity for major interdisciplinary efforts towards the 
understanding of
processes of basin evolution on passive continental margins. The 
biostratigraphical and
palaeobiogeographical characteristics of these depositional sequences are of 
foremost
significance for studies of the early geological history and subsequent 
palaeoceanographic
evolution of the South Atlantic Ocean. Cretaceous non-marine deposits, 
proto-marine
evaporites and overlying marine rocks are widespread in outcrop, subcrop and 
in the ocean
basins. The marine record is particularly well developed, beginning in the 
Jurassic in the
southern- and northernmost South Atlantic and in the Early Cretaceous in the 
northern and
equatorial South Atlantic.
   However, despite half a century of intensive geological studies, few 
attempts have as yet
been made to integrate data from the various basins into a wider, common 
geological framework. Stratigraphical events recorded in one basin are 
rarely correlated beyond the immediate adjacent areas into a more global 
context. Usually, local tectonic events and eustatic sea-level changes are 
thought to be the main control of sedimentation. Global climatic changes, 
which exercise a durable and direct imprint on the geological record by 
controlling biogenic productivity, sediment accumulation rates and biotic 
distribution trends, are seldom
taken into consideration.
   Moreover, a number of features of the geology of the South Atlantic are 
still poorly
understood, such as:  (1) the delayed development of fully marine 
successions as a result of
the long-term topographic high created by the Walvis Ridge hot spot to the 
south and the late
separation of the equatorial rift basins in the northwest; (2) the resultant 
fluvio-lacustrine
mega-systems and the Aptian salt basin, with their characteristic 
physico-chemistry and
influence on global climate; and (3) the oceanic circulation patterns in the 
Late Cretaceous and Palaeogene.
   Until recently mainly localized data, such as local seismic grids and the 
results of geological surveys, were all that were available for correlation 
work. This has resulted in the current plethora of local names and 
stratigraphic scales that cannot be systematically related. However, as a 
result of the creation of regional data sets, such as seismic grids and 
Seasat gravity maps,  the past ten years have seen the initial unravelling 
of the true tectonic framework of the basins. Unfortunately, progress and 
understanding on all fronts remain severely hindered by the lack of a 
rigorous integrated stratigraphic framework.
   For researchers, the establishment of a modern, rigorously controlled  
stratigraphic
framework will provide the means for determining answers to a wide range of 
local, regional
and global correlation issues. These include:
1) Pre-Cretaceous, proto-rift events of the southern and northern South 
Atlantic.
2) The time and facies framework of the Cretaceous rift sequence and the 
ensuing drift phases.
Currently the exact time of onset of the rifting is not known, neither is 
the exact timing of the drift phase.
3) The rift and drift ties to interior Africa, interior South America and 
the geoid as a whole. (Unravelling of the apparently relatively simple rift 
history of the South Atlantic may
ultimately yield the templates needed in order to better understand and 
model more complex
rift margins, such as those of the North Atlantic.)
4) Reliable biostratigraphic correlations for testing the radiometrically 
determined ages of
flood basalts in Brazil and Namibia through the dating of interbedded rift 
volcanics and
sedimentary rocks. A better understanding of the extent, nature, and thermal 
and topographic
influence of the Walvis Ridge hot spot as well as the postulated Niger Delta 
hot spot will also emerge.
5) The nature and origin of the globally unique "Neocomian"-early Aptian 
fluvio-lacustrine
mega-systems with their abundance of rich hydrocarbon source rocks. The 
lakes may have
been large enough to exercise global effects on the biosphere and may 
provide clues to the
Cretaceous warming phase and to dysoxic-anoxic events. The lakes may also 
contain pre-late
Aptian salts and as yet unrecognised evidence of marine phases. (Barremian 
organic
geochemistry suggests early marine links, whilst the first Red Sea-type 
segments of oceanic
crust are thought to have formed during that time.)
6) The nature and origin of the unique Aptian salt basin.
7) The effects of the Aptian balt basin on global climate and sea-level 
changes. (It has been
hypothesised that the global Aptian sea level drops on the Exxon chart are 
related to
catastrophic, Messinian-type inundations of desiccated South Atlantic rift 
basins.)
8) The development of the Late Cretaceous and Palaeogene dysoxic-anoxic 
cycles: again, the
size of the basins does not exclude global warming implications.
9) Following consolidation of the issues mentioned above, a more precise 
sequence-stratigraphic framework for the South Atlantic.
   For hydrocarbon exploration the consequences are obvious: lower risks and 
more discoveries through better understanding. For example, current South 
Atlantic oil reserves are 11 BBOR (Gabon to Angola) and 19 plus BBOR 
(Brazil). However, if the hydrocarbon reservoirs and migration pathways can 
be located using a reliable sequence stratigraphy, the proved source rock 
volumetrics are sufficient to support far greater reserves. The metallic and 
industrial mineral industries will profit through improved understanding of 
Phanerozoic mineral generation systems. For example, unravelling of the 
Cretaceous rift events, may yield the plumbing systems needed for new 
onshore base-metal deposits.


Scope and Objectives

The principal aim of the proposed project is to promote interdisciplinary 
and, most
importantly, integrated international and intercontinental correlative 
studies of the Mesozoic
sedimentary basins of the South Atlantic Ocean, including its marginal 
basins in Africa, West
Antarctica and South America. New research data will contribute to 
establishing a well-defined standard stratigraphical scale for the Mesozoic 
South Atlantic successions, to further
improving our understanding of the nature and sequence of major geological 
events during the
formation of the South Atlantic and the global impact of these events, as 
well as to improving
the basis for hydrocarbon and mineral exploration in the area.
   We propose the present-day geographic characterization of the South 
Atlantic as a
convenient means to define the areas covered by the project. Thus, the 
marginal basins along
northeastern and equatorial South America  (from Santos to Amapa in Brazil, 
Guyana,
Venezuela, northern Colombia), the Caribbean and Central America, and their 
correlative
central and equatorial West African basins (from Angola to the  
Senegal-Mauritanian and
western Morocco basins) will be included as part of the northern South 
Atlantic. This wide
approach is particularly important as a means to investigating the 
Cretaceous links between
central North Atlantic-western Tethyan provinces and the incipient South 
Atlantic. For the
southern South Atlantic (south of the Rio Grande-Walvis Ridge) the areas 
from southeastern
Brazil, Uruguay, Argentina, southern Chile, West Antarctica and southwestern 
Africa will be
covered. The understanding of the early geological and oceanographic links 
between South
America, West Antartica and Africa  demands a thorough investigation of the 
southernmost
sites.
   In order to reach the project goal the following broad topics will be 
pursued as primary
research tasks:
(1) To achive, through international scientific cooperation and 
joint-ventures of working
groups, a fully integrated and refined stratigraphical and geochronological 
framework (with
regards to biostratigraphy, magnetostratigraphy, geochemistry, seismic 
stratigraphy, sequence
stratigraphy, cyclostratigraphy and event stratigraphy), which can be 
applied to the Mesozoic
non-marine and marine sequences of the South Atlantic, thereby enhancing 
interbasinal and
intercontinental stratigraphical correlation.
(2) To provide interdisciplinary stratigraphical data that allow the 
reconstruction of the
palaeogeographical and palaeoceanographical history of the South Atlantic 
during the
Mesozoic.
(3) To investigate the nature and magnitude of locally recorded geological 
and biological
events and to explain their possible global significance.



Work Plan

The project will be carried out by individuals and research groups. Data and 
results will be
presented and discussed at conferences and in workshops, where specific 
problems will be
clarified.
   Frequent research meetings (working-group sessions, when required, and 
general meetings,
at least annually) will be held. We envisage these meetings as a most 
important feature for the success of the project, as a means of stimulating 
new research to be carried out within the scope of the project, as well as 
of coordinating ongoing research and facilitating scientific exchange and 
cooperation between specialists from different countries.
   We envisage close collaboration with the ongoing IGCP projects 322 
'Jurassic Events in
South America' and 362 'Tethyan and Boreal Cretaceous', the latter in 
particular regarding
Cretaceous studies of northern South Atlantic sites.
   A group of regional coordinators for the project have been designated 
(see address list
below). They will be responsible for liaisonamong participants, for 
disseminating information
about the progress of the project and forthcoming meetings, and for 
stimulating and
coordinating research in their fields of expertise. Additional working 
groups for the study of
selected topics will be formed during the initial stage of the project.


Funding

Financial support for the scientific activities of the project should be 
sought by participants from governmental and other funding agencies, in 
particular where collaborative research has been set up. Please note that 
funding of research activities within the project is the responsability of 
individual  participants or groups, not of IGCP/Unesco, the project leaders 
or coordinators. Limited IGCP support is provided particularly to facilitate 
participation in meetings, workshops and field excursions by participants 
from developing countries who contribute actively to the project.


Concrete Results Expected

Expected results of the project will be:
(1) integrated stratigraphical data sets, comprising intercalibrated 
biostratigraphical zonation schemes, magnetostratigraphy, sedimentary 
geochemistry (organic geochemistry, stable
isotopes and trace elements), sedimentology, sequence stratigraphy and 
tectonostratigraphy;
(2) a high resolution event stratigraphy (bioevents, long- and short-term 
chemostratigraphic
events, eustatic fluctuations), testing the synchroneity of regional events 
and their relationship with tectono-sedimentary and/or climatically-induced 
variations and global events;
(3) integrated regional models of basin development and evolution;
(4) a series of regional, evolutionary palaeogeographical maps, at 1:500,000 
scale, from the
last phase of Gondwana to the fully oceanic settings at the end of the 
Mesozoic, showing
palaeoenvironments and the general geological and stratigraphic framework;
(5) general palaeogeographical maps of the South Atlantic, at 1:10,000,000 
scale;
(6) biogeographical maps, at 1:10,000,000 scale, with the patterns of 
distribution of important
micro- and macrofossil groups for selected time-intervals;
(7) palaeoceanographical maps, at 1:10,000,000 scale, with inferred bottom 
and surface
circulation patterns;
(8) detailed regional models of the geological setting and genesis of known 
and potential
mineral resources, with sections illustrating the different stratigraphic 
plays, maps of
occurrences (at 1:500,000) and estimates of reserves.
(9) publications of results from the project, proceedings of working group 
meetings and
special volumes, which will include major interdisciplinary contributions of 
geological
correlation within a regional framework.


Outline of Project Meetings

An information meeting was held on 19 July 1994 during the 12th African
Micropalaeontological Colloquium and the simultaneously held 2nd Colloquium  
on the
Stratigraphy and Palaeogeography of the South Atlantic at Angers, France. 
The meeting was
attended by 40 persons, including the two project proposers and three 
regional coordinators
(I. de Klasz, N. R. Cameron and S. W. Petters). A draft proposal was 
presented and
discussed, a number of key objectives identified and a schedule for project 
meetings set up.
The attenders expressed their massive support for the intended project proposal.
   In July 1995 an inaugural project meeting will be held in Uberaba, Minas 
Gerais, Brazil, in
conjunction with the 14th Brazilian Palaeontological Congress (see below). 
The meeting will
also be used to introduce the project to the Latin American scientific 
community.
   A general meeting is planned for 1996 to be held in Aracaju, Sergipe, 
northeastern Brazil.
Continental Cretaceous sections are widespread in northern Brazil, from 
which an abundant
reptilian fauna has been recorded. Field trips will be organized to visit 
some of these sites, as well as to sample and investigate a typical 
rift-phase marginal basin (Reconcavo, Bahia) and the Cretaceous marine 
outcrop record (Sergipe, Pernambuco-Paraiba and Potiguar basins).
The 1996 meeting will focus on ongoing research and the state-of-the-art of 
geological
correlations and the bio-chronostratigraphic frameworks currently adopted 
for the South
Atlantic Mesozoic sequences. The problems identified will prompt the 
proposal of clearly
defined research topics and specific research targets for the forthcoming 
year(s). For 1996 an
European regional meeting is also being planned, to be held in Germany, 
simultaneously with
the 2nd European Round Table on the Palaeontology and Stratigraphy of South 
America.
   The locations for the next annual project meetings are as follows 
(provisionally):
1: Cameroon (1997), in conjunction with the 13th African Micropalaeontological
Colloquium;  2: Argentina (1998); 3: Nigeria (1999);  and 4: South Africa 
(2000). These are
all key areas for the understanding of the geological links between West 
Antarctica, South
America and Africa, and between the Austral and Tethyan realms.



                                         AGENDA
for inaugural SAMC meeting at Uberaba, Minas Gerais, Brazil (24-25 July, 1995),
in conjunction with the 14th Brazilian Palaeontological Congress (23-29 
July, 1995)


Objectives of the meeting:

Introduction of the project to the Latin American scientific community 
promoting integration
and collaboration among participants. Presentation of progress reports and 
research results.
Proposal for and organization of working groups. Identification of key areas 
and research
objectives. Schedule for project meetings (workshops and general meetings).


DAY 1  (24 July)
Selected talks by project participants about relevant scientific topics for 
future interdisciplinary collaboration, main research in progress (as a 
means of a 'getting-to-know' what everyone is working on and his/her fields 
of interest) and state-of-the-art reports.

DAY 2  (25 July)
1. Summary of main objectives.
2. Brainstorming among participants according to area of work.
Action groups:
1) northern South America
2) northern Africa
3) southern South America
4) southern Africa
5) western Antarctica

Suggested topics of discussion for the action groups:
a) Objectives of the project.
b) Research priorities (regional as well as general priorities for all groups).
c) Discussion of feasible objectives to be reached within a 5 year project-term.
d) Proposal for working-groups for fields of research and/or geographic areas.
e) Proposal for working-group coordinators and forthcoming meetings (time, 
venue and topics
of discussion).

3. Meeting of all participants with presentation of results by coordinators 
of the action
groups.
4. Discussion of proposed ideas for integration in the project objectives.
5. Proposal and election of regional coordinators.
6. Election of project leaders.
7. Proposal for general and working-group meetings.
8. Discussion of possibilities of obtaining financial support for organizing 
and attending
project meetings (travel and accomodation of participants).

We propose the following Working Groups to be erected initially :
1. Gondwana Palaeogeography and Stratigraphic Correlations.
- Integrated biostratigraphy, correlation of magneto- and biozones, sequence 
stratigraphy,
timing of the main tectono-sedimentary events.
- Triassic-Jurassic continental sequences from South America and Africa.
2. Lower Cretaceous Stratigraphic Correlations.
- Prerift and synrift sequences of the northern South Atlantic; marine 
sequences of the
equatorial and southern South Atlantic.
3. Lower Cretaceous Palaeogeography.
4. Upper Cretaceous Stratigraphic Correlations.
5. Upper Cretaceous Palaeogeography and Palaeoceanography.



SAMC Secretariat

Please send your registration and enquiries about IGCP Project 381 (SAMC) to 
either one of
the following secretaries:

(for English-speaking participants)           (for French-speaking participants)

Marcio R. Mello                               Mitsuru Arai
PETROBRAS-Cenpes/Divex/Segeq                  PETROBRAS-Cenpes/Divex/Sebipe
                   Cidade Universitaria, Quadra 7 - Ilha do Fundao
                     BR-21949-900 Rio de Janeiro, RJ  -  Brazil

Tel.: +55-21-5986460, Fax: 5986799                         Tel.: 
+55-21-5986440, Fax: 5986795
E-mail:  bv77@c53000.petrobras.anrj.br                     E-mail:  
bvb5@c53000.petrobras.anrj.br 




SAMC - Regional Coordinators
(as of February 1995)

Peter Bengtson - Geologisch-Palaeontologisches Institut der Universitaet 
Heidelberg, Im
Neuenheimer Feld 234, D-69120 Heidelberg, Germany. Tel.: +49-6221-568293, 
Fax: 563940
or 565503, E-mail: Peter.Bengtson@urz.uni-heidelberg.de.

Nick R. Cameron - "Chalkyfold", Grove Lane, Chesham, Bucks HP5 3QQ, UK. 
Tel.:/Fax:
+44-149-4 774559, E-mail: nick@gmuk.dungeon.com.

Alistair Crame - British Antarctic Survey, High Cross, Madingley Road, 
Cambridge CB3 0ET,
UK.  Tel.: +44 1223 251 443, Fax: +44 1223 62616.

Ivan de Klasz - "La Verdiane", 74 Av. du Mont Alban, F-06300 Nice, France. 
Tel.: +33-93-268843, Fax:  894820.

Eduardo A. M. Koutsoukos - PETROBRAS-Cenpes/Divex, Cidade Universitaria, 
21949-900
Rio de Janeiro, RJ, Brazil. Tel. +55-21-5986440, Fax 5986795, Tel./Fax(h) 
3258306, E-mail
bvb5@c53000.petrobras.anrj.br.

Eduardo Musacchio - Lab. de Bioestratigrafia, Universidad Nacional de La 
Patagonia, Ciudad
Universitaria km 4, 9000 Comodoro Rivadavia, Chubut, ARGENTINA. Tel./Fax: 
+54-967-39339, E-mail: aldo@unpbib.edu.ar.

Eduardo B. Olivero - Centro Austral de Investigaciones Cientificas (CADIC), 
Av. Malvinas
Argentinas s/n , C.C. 92, 9410 Ushuaia, Tierra del Fuego, Argentina. Tel.: 
+54-901-22
310/312/314, Fax: 30644.

Sunday W. Petters - Department of Geology, MOBIL/NNPC Chair of Petroleum 
Geology,
University of Calabar, P.O. Box 3654, Calabar, Nigeria. Tel.: 224747 or 
224748, ext. 350,
Telex: 65103 UNICAL.

Peter Szatmari - PETROBRAS-Cenpes/Divex/Setec, Cidade Universitaria, 
21949-900 Rio de
Janeiro, RJ, Brazil. Tel.: +55-21-5986435, Fax: 5986792.
Prof.Dr. Peter Bengtson
Geologisch-Pal�ontologisches Institut
Im Neuenheimer Feld 234
D-69120 Heidelberg, Germany
Tel.: +49 6221 568293
Fax.: +49 6221 563940 (direct), 565503 (department)
E-mail: Peter.Bengtson@urz.uni-heidelberg.de