Report of the IAVCEI – IAS 3^rd International Maar Conference, Malargüe, Argentina, 14-17 April 2009

Argentina was the host country in this year for the 3rd International Maar Conference in April. The original idea to organise a major scientific, multidisciplinary event on researches focusing on understanding maar volcanism and its consequences was born in Germany where the First International Maar Conference (1IMC) was organised in 2000. The meeting in that time had a great respond from participants, and the idea have been developed further in 2004, organising the 2nd International Maar Conference (2IMC) in Hungary. While the first meeting was locally supported, in the second meeting both the International Association of Volcanology and Chemistry of the Earth’s Interior (IAVCEI) and the International Association of Sedimentologists (IAS) were involved as major supporting and scientific background of the meeting. While the first conference was held in the type locality of maar volcanism in Germany, in the Vulkaneifel Mountain concentrating on young maars, the second conference shifted the focus to the deep zones (diatremes) of maar volcanoes and brought the participants to a region in Central Europe where deep root zones of maar volcanoes are exposed. As a consequence of the 2IMC, a huge demand was to organise the 3rd International Maar Conference.

The conference presented four significant plenary lectures. Prof Volker Lorenz (Würzburg) presented a talk entitled “The maar-diatreme volcano: the peculiar volcano type that largely prefers to work underground”. In this presentation Prof Lorenz summarized his experiences on maar-diatreme volcanism from physical volcanology point of view, and made an excellent summary pointing out major research directions we may need to follow in the coming years such as understanding the diatreme formation, role of phreatomagmatism in composite volcanoes, and link between kimberlite volcanism and normal basaltic monogenetic volcanism. Dr Guido Giordano (Rome) gave another very valuable plenary talk on “The hydrogeological conditions to maar formation”. This presentation had very important message to bring together hidrogeologists, hydrologist, sedimentologists and volcanologists to understand how phreatomagmatism and maar formation take place in continental settings. As water exists in the majority of sedimentary basins in continental settings, the understanding of the behaviour of this water in regard to its movement, recharge, and depletion processes would hugely advance our knowledge on magma and water interaction. In other hand Dr Giordano highlighted many facts on the magma rheology, migration, rise and fragmentation that need to be reconsidered to see clearly the feasibility of magma and water interactions in various “real world” crustal scenarios. He suggested that during the next maar conference, the hydrogeological aspects of phreatomagmatism may be the major focus. A plenary lecture gave a very comprehensive overview of the back arc monogenetic volcanism in Mendoza, and Northern Patagonia, presented by Prof Victor Ramos (Buenos Aires). His presentation “Payenia Volcanic Province: an exceptional Quaternary tectonic setting” was a very fortunate lecture for the audience to help them to understand why monogenetic volcanic fields exist hundreds of kilometres behind the active subduction front, ranging in few millions of years ages to present day, very young eruptions. This lecture provided a good overview and supplement to the two field trip run to this nearby volcanic fields. Prof Greg Valentine (Buffalo) presentation entitled as “Processes and problems in intraplate volcanic fields - Source to eruption, and hazards”, gave a complete framework to the conference to highlight the major researches completed lately, and what need to be done in the near future to develop our understanding of monogenetic volcanic field evolution. His presentation concentrated on the deep processes and the shallow manifestation (e.g. time and space distribution of volcanoes) of those. He highlighted the need to make more detailed and complex, well-targeted studies on monogenetic volcanoes of any type including volcanic petrology, sedimentology, modelling, and geomorphological works on small-volume volcanoes. According to him such combined effort on small-volume volcanoes can pick up signatures maybe possible to amalgamate into a general model.

The 3IMC finally had 78 presentations submitted and published in the conference volume as an extended abstract  Due to the global economy crisis the total number of registered participants was lower than expected, but the organising committee was able to manage the conference to run smoothly with a very exciting scientific and social program. The conference was also an event supported by the IAVCEI Commission on Volcanogenic Sediments (CVS). This IAVCEI commission in the past years tried to find link between the volcanologist and sedimentologist communities. To do this, arranged conferences in the past attracted both volcanologist and sedimentologist experts. This effort was manifested in the dual involvement of two major organisations (IAVCEI and IAS) in the IAVCEI CVS activities in the past and in the 3IMC events. Very recent result of this gradually improving relationship is the current publication of a Special Issue in the Sedimentary Geology (Source to sink: volcaniclastic sedimentation in and around the Pacific) as a direct outcome of the volcanosedimentary technical session during the International Association of Sedimentologist World Congress in Fukuoka in 2006. The 3IMC gradually became part of the events could attract sedimentologists. The reason for this is that maar volcanoes are small, but very complex and important features in sedimentological point of view. The deep basins maar volcanoes generally have are the perfect sites to trap sediments in continental settings. In this way, maar lake sediments are in many cases provide the most complete section of a narrow time window, what and how terrestrial sedimentation was going on in specific areas. Since maar volcanoes exist in almost every climatic regimes, in every continent and every latitude, by now the research on maar lake sediments became a major study area where we can expand our understanding of past sedimentary basin evolutions and climatic effects. The IAS was an important partner in the success of the 3IMC, and certainly its role will increase in future events. This is especially expected in a way, that the International Maar Conferences in the future will be rather major events in respect of understanding volcanic field formations, evolutions and from sedimentologist perspective, their potential influence on sedimentary basin evolutions.

During the 3IMC there were many very important presentations the sedimentological community would be interested in. Argentina as a host country for the 3IMC was(is) also the host of one of the very recent International Continental Drilling Projects, called the PASADO, aiming to understand the crater lakes accumulated in the Potrok Aike Maar lake in the Pali Aike Volcanic Field, in Santa Cruz Province in southern Argentina. Prof Bernd Zolitschka (Bremen) and his co-workers presented a very detailed update on the major outcomes of the Potrok Aike maar drillings. While this project was primarily planed work on the maar lake sediments, some off-spring researches targeted the primary pyroclastic successions accumulated around maar lakes in the Pali Aike Volcanic Field. Researches lead by Dr Pierre-Simon Ross (Quebec), Prof Miguel Haller (Puerto Madryn), Dr Hugo Corbella (Buenos Aires) and Dr Karoly Nemeth (Palmerston North) demonstrated that the broad maars with shallow maar basins formed in the combination of the influence of strikingly different aquifers the rising magma encountered and being involved in phreatomagmatic explosions. The 3IMC also welcomed the first Chinese presenters in the maar conference histories. Prof Chu (Beijing) presentation on the maar lake sediments in the Longgang Volcanic Field, China as well as Prof Liu (Beijing) talk on the paleoclimate studies on maar lake sediments of the Aershan-Chaihe Volcanic Field in East Inn Mongolia, China showed the emerging research fields in Asia, and its huge future potentials via collaborative works among sedimentologists and volcanologists. As a representation of such collaboration Prof Mingram (Potsdam) and his co-workers presentation on the potential of correlating chronomarkers in varved maar lake sediments is again confirmed that study of maar lake sediments is a powerful tool to understand climatic variations and changes. Other presentations of the 3IMC focused more on the primary processes. The formation of base surges, pyroclastic density currents and associated syn- and post-volcanic secondary sedimentary processes in association with maar and other phreatomagmatic volcanoes is relatively well understood, but the diverse case studies certainly provided an important snapshot what, where and how others doing in these days in the global map. Large scale analogue experiments in combination with subsequent numerical modelling presented by Dr Sulpizio (Bari) gave a very new research direction on pyroclastic density current formations. With this presentation Dr. Sulpizio and his co-workers were granted by the Jim Luhr Award funded by the 3IMC as a major award given to research presentations during the International Maar Conference event.

Overall the quality of the presentations was high, and many new research directions became evident for the participants. There is an unquestionable tendency of dramatic increase in the number of publications associated with monogenetic volcanism, many of them centred by the multidisciplinary researches on maar volcanoes in the past 10 years. This tendency is marked by the year 2000 by the First International Maar Conference. By now, having the 3IMC completed, it is sure that this tendency will further develop. A multidisciplinary research volume as a Special Issue for a major international specialist journal will be edited by Prof Miguel Haller and Dr Karoly Nemeth. In the end of the 3IMC, the participants, in accordance with the given bids, have decided to have the Fourth International Maar Conference: as an interdisciplinary congress on monogenetic volcanism (4IMC) in 5-12 February 2012, in Auckland New Zealand. The 3IMC has also been the special event, where the newly formed IAVCEI commission, Commission on Monogenetic Volcanism were announced officially by the President of the IAVCEI, Prof Setsuya Nakada.

Overall, in the maar conference movement, it is a community need maintaining good and balanced relationship with IAVCEI and IAS. We hope that the majority of the 3IMC participants  will be able to join to the 4IMC in Auckland, and many new faces will bring their researches on this peculiar type of volcanoes, maars and associated features. The 4IMC hopes the IAS support can be sustained in the future. As the previous IMC event showed, it is worth to have such close link between volcanologists and sedimentologist.

Corina Risso and Károly Németh, Organizing Committee

Contact: info@3imc.org