The palaeomagnetism and magnetic fabric of cave sediments from Grønligrotta and Jordbrugrotta, Norway

Summary. Twenty-four oriented specimens of laminated clay were obtained from vertical sections in two caves in northern Norway. Studies of the magnetic remanence and susceptibility anisotropy show that the magnetization is depositional in origin and due to magnetite. The palaeomagnetic record in one section is correlated with results from a Swiss lake sediment core to suggest an age of 9600–6800 yr bp for the cave clay. It is shown that the susceptibility lineation produced on gently sloping surfaces was predominantly controlled by gravity and cannot therefore be used directly to estimate the palaeoflow or palaeofield directions.     

Planning for resettlement: building partnerships for,by, and with Indigenous peoples

Efforts in the United States to plan or implement relocation in response to climate risks have struggled to improve material conditions for participants, to incorporate local knowledge, and to keep communities intact. Mixed methodologies of community geography provide an opportunity for dialogue and knowledge-sharing to collaboratively diagnose the challenges of climate adaptation led by communities. In this article, we advance a participatory practice model for the co-creation of knowledge initiated during a two-day workshop with members from the Biloxi-Chitimacha-Choctaw Tribe from Isle de Jean Charles in Louisiana, Yup’ik people from Newtok Village in Alaska, and researchers from the MIT Resilient Communities Lab. Building on prior scholarship of indigenizing climate change research, this article shares the experience of the workshop to support knowledge exchange and dialogue, with the goal of understanding how to build participatory and non-extractive community-academic partnerships. We reflect on the community values and principles used to guide this workshop to inform more inclusive and co-produced research partnerships, and pedagogies that can improve and assist the self-determination of groups impacted by climate change. Workshop presentations and discussions highlight interconnected themes of resources, systems & structures, regulatory imbalance, and resilience that underpin climate resettlement. We reflect on the narratives presented by members of both Indigenous tribes and NGO partners that illustrate the shortcomings of resettlement planning practices past and present as perpetuating existing inequality. In response to this structured knowledge exchange, we identify potential roles for community-academic partnerships that aim to improve the equity of existing resettlement models. We propose approaches for incorporating traditional knowledge into the pedagogy, discourse, and practice of academic planning programs.

     

A large collection of Presbyornis (Aves,Anseriformes, Presbyornithidae) from the late Paleocene and early Eocene of Mongolia

We describe a large collection of fossil ‘waterfowl’ bones that are referable to the extinct clade Presbyornithidae (Anseriformes). All of these fossils were collected between 1971 and 1994 from Upper Paleocene and Lower Eocene sediments at the Tsagaan Khushuu site in the Gobi Desert of southern Mongolia. The collection includes specimens referred to a new small species within the genus Presbyornis Wetmore, 1926 as well as large numbers of bones that we place in the genus Presbyornis. On this basis of the Tsagaan Khushuu collection we suggest that several species of Presbyornis likely coexisted in this region; indeed, the presence of large numbers of middle‐sized, morphologically consistent but probably ecologically disparate species at the Tsagaan Khushuu site is consistent with the range of variation seen, for example, in taxa of extant dabbling ducks (Anatini). Although the anatomy and phylogenetic position of Presbyornithidae (in particular Presbyornis) are well known, this material from Mongolia further demonstrates the prevalence of these birds in aquatic and semi‐aquatic habitats by the earliest Paleogene. Because presbyornithids are also well documented from the late Cretaceous, their palaeoecology and morphological diversity provides a clue to selective avian survivorship across the Cretaceous‐Paleogene (K‐Pg) boundary. Copyright © 2009 John Wiley & Sons, Ltd.     

A review of Late Cretaceous fossil birds from Hungary

We review the previously described Late Cretaceous (Santonian) bird remains from the Csehbánya Formation in the Bakony Mountains of Hungary, augmenting initial work by Ősi ( 2008 ), and add a number of newly collected fossils. All together, the eight fossil specimens so far collected from this site are important to our understanding of avian evolution because they document a large range of taxon body sizes from at least one major lineage (Enantiornithes) and come from a critically undersampled time period in the Cretaceous. Globally, very little fossil bird material has been collected from the middle stages of the Late Cretaceous, the Coniacian and Santonian; most known taxa are either Early Cretaceous (ca. 120 Ma) in age or are from the terminal Campanian and Maastrichtian (ca. 70–65 Ma). Indeed, one of the Csehbánya Formation fossil birds is recognized as a new taxon of large enantiornithine, an avisaurid apparently similar in its largely unfused foot morphology to the Argentine Soroavisaurus and to the North American Avisaurus. The Central European records reviewed in this paper highlight the wide distribution of some Late Cretaceous fossil birds, particularly avisaurid enantiornithines, and lead us to a brief discussion of avian biogeography at the end of the Mesozoic. Copyright © 2010 John Wiley & Sons, Ltd.     

Legal and environmental concerns affecting electric utility involvement in cogeneration

The National Energy Act of 1978 included cogeneration as one of the leading strategies to help solve the nation's energy problems. As a result many new regulations have been formulated to encourage the development of industrial cogeneration facilities. These regulations are aimed at reducing oil imports, conserving nonrenewable resources, and preserving air quality. The electric utilities are uncertain whether the regulations will accomplish these goals. They are concerned that the regulations will lead to the proliferation of small industrial cogeneration facilities giving rise to increased air pollution and other adverse environmental impacts. The utilities are also concerned that, because of the way the regulations are written, they will discourage the electric utilities from fully participating in the cogeneration process.     

Hydrochemistry of the Lake Magadi basin,Kenya

New and more complete compositional data are presented for a large number of water samples from the Lake Magadi area, Kenya. These water samples range from dilute inflow (<0.1 g/kg dissolved solids) to very concentrated brines (>300 g/kg dissolved solids). Five distinct hydrologic stages can be recognized in the evolution of the water compositions: dilute streamflow, dilute ground water, saline ground water (or hot spring reservoir), saturated brines, and residual brines. Based on the assumption that chloride is conserved in the waters during evaporative concentration, these stages are related to each other by the concentration factors of about 1:28:870:7600:16,800.Dilute streamflow is represented by perennial streams entering the Rift Valley from the west. All but one (Ewaso Ngiro) of these streams disappear in the alluvium and do not reach the valley floor. Dilute ground water was collected from shallow pits and wells dug into lake sediments and alluvial channels. Saline ground water is roughly equivalent to the hot springs reservoir postulated by Eugster (1970) and is represented by the hottest of the major springs. Saturated brines represent surficial lake brines just at the point of saturation with respect to trona (Na₂CO₃.NaHCO₃.2H₂O), while residual brines are essentially interstitial to the evaporite deposit and have been subjected to a complex history of precipitation and re-solution.The new data confirm the basic hydrologic model presented by Eugster (1970) which has now been refined, particularly with respect to the early stages of evaporative concentration. Budget calculations show that only bromide is conserved as completely as chloride. Sodium follows chloride closely until trona precipitation, whereas silica and sulfate are largely lost during the very first concentration' step (dilute streamflow-dilute ground water). A large fraction of potassium and all calcium plus magnesium are removed during the first two concentration steps (dilute streamflow-dilute ground water-saline ground water). Carbonate and bicarbonate are the dominant anions, and mechanisms by which they are extracted from the solution include precipitation of alkali and alkaline-earth carbonates, and degassing, as well as precipitation and re-solution of efflorescent crusts. Much sulfate is apparently lost from solution by sorption as well as subsurface reduction.Seasonal runoff, principally from the valley floor north of Lake Magadi, is considered to be the principal recharge to the Magadi ground water system. Evaporative concentration is the overall process responsible for the chemical evolution of the brines. This includes not only simple evaporation, but also mineral precipitation as films and cements in the unsaturated zone, re-solution, and reprecipitation of efflorescent crusts, with consequent recycling of salts. In fact, a large fraction of the solutes are acquired through dissolution of efflorescent crusts.Data were obtained for borehole brines from as deep as 297 m. They show the existence of two distinct brine bodies below the present lake, one shallow, coexistent with bedded salts, and highly concentrated (260 g/kg average dissolved solids), and the other deeper in lacustrine sediments or fractured lavas, and only half as concentrated.