Claudia Inés Galli

CAIMAN CF. LATIROSTRIS (ALLIGATORIDAE, CAIMANINAE) IN THE LATE MIOCENE PALO PINTADO FORMATION, SALTA PROVINCE, ARGENTINA: PALEOGEOGRAPHIC AND PALEOENVIRONMENTAL CONSIDERATIONS

Abstract. The three recognized species of Caiman —C. latirostris, C. yacare and C. crocodilus— currently live in northern and central South America. Except for the fragmentary dentary of a putative Caiman from Oligocene rocks in Brazil, the genus has been reliably recorded in rocks of ages spanning the Neogene, when species of Caiman were a constant component of the South American crocodyliofauna. The major taxonomical diversification of Caiman occurred during the late Miocene, which is well documented in the area of Paraná (northeastern Argentina). Fossil crocodylians in Paraná are represented by one gavialid and caimanines, with at least five species of Caiman (including C. latirostris). This assemblage represents the southernmost record of Crocodylia living in “Amazonia” during the Miocene. In this work we confirm the record of Miocene caimans outside the Paraná and we prove the presence of Caiman cf. latirostris in present-day northwestern Argentina during the late Miocene. The taxonomic identification is based on a fragment of a left mandible with the same ornamentation, outline and dentition as Caiman, and with a symphyseal morphology similar to that of Caiman latirostris. The material comes from the upper part of the Palo Pintado Formation in the southern region of Valle Calchaquí (Salta Province). This unit was deposited in a sand-gravel fluvial system with associated ponds between 10.29 ±0.11 Ma (K/Ar) and 5.27 ±0.28 Ma (206Pb/238U).

The Scelidotheriine Proscelidodon (Xenarthra: Mylodontidae) from the Late Miocene of Maimará (Northwestern Argentina, Jujuy Province)

1Dpto. de Paleontología, Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales (IANIGLA), CCT–CONICET–Mendoza, Avda.Ruiz Leal s/n, Parque Gral. San Martín, 5500 Mendoza, Argentina. fpujos@mendoza-conicet.gov.ar 2Institut Français d’Etudes Andines, Casilla 18-1217, Av. Arequipa 4500, Lima 18, Peru. fpujos@yahoo.fr 3CONICET, División Paleontología Vertebrados, Museo de La Plata, Paseo del Bosque, B1900FWA La Plata, Argentina. acandela@fcnym.unlp.edu.ar, regui@fcnym.unlp.edu.ar 4Facultad de Ingeniería, Universidad Nacional de Salta, Salta, Argentina. claudiagalli@fibertel.com.ar 5CONICET, Instituto de Geología y Minería, Universidad Nacional de Jujuy, 4600 San Salvador de Jujuy, Argentina. bcoira2004@yahoo.com.ar 6Facultad de Ciencias Naturales y Museo de La Plata, Paseo del Bosque, B1900FWA La Plata, Argentina. delossreyes@yahoo.com.ar 7Laboratorio de Sistemática y Biología Evolutiva (LASBE), Facultad de Ciencias Naturales y Museo, Universidad Nacional de La Plata, La Plata, Argentina. mabello@ fcnym.unlp.edu.ar AMEGHINIANA 2012 Tomo 00 (0): xxx – xxx ISSN 0002-7014

Lithium recovery from brines: A vital raw material for green energies with a potential environmental impact in its mining and processing

The electrification of our world is driving a strong increase in demand for lithium. Energy storage is paramount in electric and hybrid vehicles, in green but intermittent energy sources, and in smart grids in general. Lithium is a vital raw material for the build-up of both currently available lithium-ion batteries, and prospective next generation batteries such as lithium-air and lithium sulphur. The continued availability of lithium can only rely on a strong increase of mining and ore processing. It would be an inconsistency if the increased production of lithium for a more sustainable society would be associated with non-sustainable mining practices. Currently 2/3 of the world production of lithium is extracted from brines, a practice that evaporates on average half a million litres of brine per ton of lithium carbonate. Furthermore, the extraction is chemical intensive, extremely slow, and delivers large volumes of waste. This technology is heavily dependent on the geological structure of the deposits, brine chemical composition and both climate and weather conditions. Therefore, it is difficult to adapt from one successful exploitation to new deposits. A few years of simulations and piloting are needed before large scale production is achieved. Consequently, this technology is struggling with the current surge in demand. At time of writing, only 5 industrial scale facilities are in operation worldwide, highlighting the shortcomings in this technology. Both mining companies and academics are intensively searching for new technologies for lithium recovery from brines. However, focus on the chemistry of brine processing has left unattended the analysis of the sustainability of the overall process. Here we review both the current available technology and new proposed methodologies. We make a special focus on an overall sustainability analysis, with particular emphasis to the geological characteristics of deposits and water usage in relation to mining processes.