Dedication of Large Meteorite Impacts and Planetary Evolution VI to Álvaro Penteado Crósta

Originally, Álvaro Penteado Crósta (born on 7 August 1954) intended to be one of the volume editors of this GSA Special Paper. He was also looking forward to participating in the Large Meteorite Impacts and Planetary Evolution VI conference in October 2019, for which he had long served on the organizing committee. Unfortunately, a long and serious illness derailed both these plans. Therefore, we are instead honoring our dear friend and valued colleague, Álvaro Crósta, for his longstanding and successful impact cratering work, as the mainstay of impact cratering studies in Brazil and indeed in South America, by dedicating this Special Paper to him.

Álvaro Crósta has been a Full Professor (Professor Titular) of Geoscience in the fields of remote sensing, mineral exploration, and planetary geology at the Instituto de Geociências of the Universidade Estadual de Campinas (UNICAMP) in Brazil. He has had a highly distinguished academic career, culminating in his tenure (2012–2017) as vice-rector of his university. In 2017, Álvaro was inducted as a Full Member (Membro Titular) into the Academia Brasileira de Ciências (Fig. 1).

Álvaro Crósta graduated in geology with a degree equivalent to a B.Sc. after five years of study at the University of São Paulo in 1977. He then completed a M.Sc. project at the Instituto de Pesquisas Espaciais (INPE—Institute of Remote Sensing Studies, São José dos Campos, São Paulo State) in 1982, and obtained a Ph.D. in remote sensing from Imperial College, London, in 1990. Subsequently, he was a postdoctoral researcher at the Desert Research Institute, University of Nevada, Reno, USA, in 1995–1996.

He held visiting professor appointments in 2011 at the University of Vienna, Austria, and at Humboldt Universität and Museum für Naturkunde in Berlin, Germany. Recently in 2018–2019, he conducted impact cratering research during a sabbatical at the Jet Propulsion Laboratory (NASA/CalTech) in Pasadena, USA, before a second sabbatical at the Universidad Nacional de Colombia in Bogotá, Colombia. Álvaro Crósta regularly presented courses on remote sensing and exploration between 2008 and 2015 as a visiting professor at the Petroleum Institute in Abu Dhabi.

Back home in Campinas, he served as head of the Institute of Geosciences at UNICAMP, and as coordinator of their postgraduate program in geoscience. Currently, he is the head of their research group in geotechnology. From 2002 to 2013, he served on the Commission for Geoscience of the Brazilian Research Foundation CAPES (Coordenação de Aperfeiçoamento de Pessoal de Nível Superior), and from 2011 to 2013, as coordinator of this national committee. In addition, he coordinated Brazilian efforts in the IODP (International Ocean Discovery Program) on behalf of CAPES. In 2016–2017, he served as the Brazilian representative on the JOIDES Resolution Facility Board of IODP. He is a member of the CNPq (National Research Council of Brazil) national assessment committee of the geosciences.

Álvaro was elected a fellow of the Society of Economic Geologists (SEG) in 2010, and in the same year, he was selected to present the first Regional Vice President Lecture of the SEG. From 2011 to 2013 he served as the SEG vice president for South America. He is an associate editor of the Brazilian Journal of Geology, and was an associate editor for the Geological Society of America Bulletin (2010–2016). From 2012 to 2016, Álvaro Crósta was a member of the Barringer Medal and Award selection committee of The Meteoritical Society.

In 1994, he was honored with the first-ever Zeferino Vaz Award by his university, in recognition of excellence in research and teaching. In 2010, he obtained a Merit Diploma of the Regional Council for Engineering, Architecture, and Agronomy of the State of São Paulo. In 2008 and 2013, he was honored for his teaching prowess with CAPES educational awards.

Between 1978 and 1982, Álvaro Crósta conducted research toward an M.Sc. degree with a research project entitled, “Geological mapping of the Domo de Araguainha with application of technical methods and remote sensing.” This project initiated a career-long relationship with the Araguainha impact structure, and impact cratering in general. He produced one of the earliest geological maps of the structure and completed the first shock metamorphic and chronological studies related to South America’s largest known impact structure. In 1983, in the course of fieldwork, the young Brazilian scientist met Wolf von Engelhardt (University of Tübingen, Germany) and his group, who were working on a pioneering study of impact breccias at Araguainha. This encounter certainly contributed strongly to Álvaro’s incipient fascination with impact cratering (Fig. 2).

Following this first career stage, Álvaro focused on building an academic career and becoming a world-renowned expert in remote sensing methodology and remote sensing application to mining and exploration; however, he never abandoned impact cratering studies. Beginning in 2003, his academic and funding opportunities allowed him to intensify his impact cratering work. In great part, Álvaro coordinated these projects that sometimes were conducted through international collaborations. His research students completed a number of postgraduate projects in the course of this work. He managed to obtain continuing funding from CAPES and CNPq, as well as from the São Paulo State agency, FAPESP. Here follows a selection of Álvaro’s major impact cratering investigations:

• 2003–2011: Geological characterization of Brazilian impact structures: Geological, geophysical and geochemical investigations with a focus on the Vargeão and Vista Alegre impact structures.

• 2008–2010: Integrated geological and geophysical studies of the Serra da Cangalha and Riachão impact structures.

• 2009–2015: Confirmation of Vista Alegre as an impact structure and further work on Vargeão Dome, providing additional confirmation as an impact structure.

• 2011–2012: Gamma-ray spectrometry and other studies on Serra da Cangalha and impact melt rocks of Araguainha.

• 2012–2015: Numerical modeling of Brazilian impact structures.

• 2012–2016: Geology and geophysics of the Santa Marta impact structure.

• 2013–2016: Thermochronology and zircon chronology on several Brazilian impact structures (see Figs. 3–5).

• 2014–2016: Geophysical studies and field geology of Cerro do Jarau.

• Since 2014: Spearheaded the Brazilian efforts within an international consortium aimed at deep drilling of the Colônia Basin, São Paulo—a relatively young and well-preserved, possible impact crater with great potential for paleo-environmental studies on a thick succession of sediments.

• 2015–2020: Identification and mineralogical, geochemical, and isotope characterization of distal meteorite impact ejecta: Archean spherule layer search in Brazil, and studies of Archean spherule layers in South Africa.

• Since 2017: Detailed gravity analysis of Santa Marta and gravimetry and gamma-spectrometry of Araguainha.

• 2018: Confirmation of the Cerro do Jarau impact structure and fieldwork at São Miguel de Tapuio.

• 2019: Contributed to remote sensing analysis of the Nova Colinas structure in northeastern Brazil.

There are now nine confirmed impact structures in Brazil, and Álvaro has been instrumental in the confirmation of all of them. Most recently, he collaborated in a multinational effort that resulted in the confirmation of the São Miguel de Tapuio and Nova Colinas structures. In addition, Álvaro investigated possible impact structures in the offshore Santos Basin and the Solimões Basin, and the Colônia Basin structure near the city of São Paulo.

After these career-long, successful impact cratering–related endeavors, it was fitting for Álvaro to lead the production of two seminal review works (Crósta et al., 2019a, 2019b), one focusing on the state-of-the-art knowledge of Brazilian impact structures, and the other on impact deposits and other potential impact structures in South America. Like the review of Brazilian structures, the latter is not just a literature review, but is also based on firsthand experience and observations by Álvaro, who conducted field investigations of most of these sites. These two publications not only represent benchmark treatises of impact cratering studies in South America, but they are also a testimony to Álvaro Crósta’s personal efforts to promote impact cratering studies throughout the continent. He achieved this by publishing research papers, supervising postgraduate students, as well as promoting impact cratering and its ubiquitous role—and the impact record of South America—with numerous lectures at conferences and as an invited speaker at universities and geological surveys continent-wide.

There is no doubt that Álvaro Crósta has been at the forefront of the development of impact cratering science in South America. This has been through his own work; his education of the next generation of impact researchers in Brazil, such as Marcos Vasconcelos and Grace de Oliveira; and his influence on the development of other scientists, for example, Elder Yokoyama and Cristiano Lana. Ultimately, there is his own noteworthy progression from terrestrial impact cratering to planetary geological work. During his 2018–2019 sabbatical at the Jet Propulsion Laboratory in Pasadena, he endeavored to combine his two research specializations—remote sensing and impact cratering—with a study of crater features on Saturn’s large moon, Titan, in which he is studying the formation of Menrva, Titan’s largest impact structure.

Álvaro Crósta personally supervised three M.Sc. and three Ph.D. projects on impact structures, as well as one post-doctoral project. He was instrumental in an extensive study aimed at promoting South America’s largest impact structure, the Domo de Araguainha, as a National Geopark, with presentations to state and national authorities. He has published/co-published at least 25 peer-reviewed articles in scientific journals, as well as another seven peer-reviewed chapters in monographs, on the subject of impact cratering. Furthermore, he and his coworkers have made 69 presentations on impact cratering–related themes to international conferences. A representative sample of his publications is listed below.

We are proud to dedicate this GSA Special Paper on the Large Meteorite Impacts and Planetary Evolution VI conference, which fittingly brought the international impact cratering community to Brazil, to our friend and colleague Álvaro Crósta, for his outstanding scientific work in the field of impact cratering, his persistent efforts to promote impact cratering throughout the South American continent, his successful seeding of impact cratering research in Brazil, and his efforts to bring the Brazilian and international research communities to collaborate on impact cratering, especially on the South American impact heritage. Before Álvaro, impact craters and cratering were virtually unknown in South America; his research studies and many presentations have placed them on the continental map.

Wolf Uwe Reimold, Universidade de Brasília

Christian Koeberl, University of Vienna