The settler's plot: how stories take place in New Zealand – By Alex Calder     

Matt Henry 《New Zealand geographer》2012,68(1):71-72

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A spring and wooded habitat at FLK Zinj and their relevance to origins of human behavior     

Gail M. Ashley  Doris Barboni  Manuel Dominguez-Rodrigo  Henry T. Bunn  Audax Z.P. Mabulla  Fernando Diez-Martin  Rebeca Barba  Enrique Baquedano 《Quaternary Research》2010,74(3):304-314

The 1959 discovery of the hominin fossil Zinjanthropus boisei brought the world's attention to the rich records at Olduvai Gorge, Tanzania. Subsequent excavations of archaeological level 22 (FLK Zinj) Bed I uncovered remains of Homo habilis and a high-density collection of fossils and Oldowan stone tools. The occurrence of this unusual collection of bones and tools at this specific location has been controversial for decades. We present paleoecological data that provide new insights into the origin of FLK Zinj. Our recent excavations 200 m north of the site uncovered a 0.5-m-thick tufa mound draped by Tuff IC, in the same stratigraphic horizon as level 22. Stable isotope analyses indicate that the carbonates were deposited by a freshwater spring. Phytolith analysis of the waxy clay under Tuff IC revealed abundant woody dicotyledon and palm phytoliths, indicating that the site was wooded to densely wooded. The time equivalency and close physical proximity of the two environments indicate the two are related. This study has provided the first documented evidence of springs in Bed I and these data have important implications for the interpretation of hominin behavior in meat acquisition and the ongoing debate on scavenging versus hunting.  相似文献   

The geochemistry,geochronology and paleomagnetism of dikes and sills associated with the Mesoproterozoic Midcontinent Rift near Thunder Bay,Ontario, Canada     

Pete Hollings  Mark Smyk  Larry M. Heaman  Henry Halls 《Precambrian Research》2010

The Midcontinent Rift (MCR) of North America comprises a series of basaltic sheets, flows and intrusive rocks emplaced in the Lake Superior region during the Mesoproterozoic. The mafic rocks preserved on the northern flank of Lake Superior represent the older portions of the rift sequence and offer insights into the early development of the rift. New geochronological, geochemical and paleomagnetic data are presented for the dikes and sills located in and south of Thunder Bay, Ontario. Three sill suites are recognized within the study area; an earlier, spatially restricted ultramafic unit termed the Riverdale sill, the predominant Logan sills and Nipigon sills in the north of the study area. In addition three dike sets are recognized, the north-east trending Pigeon River swarm, the north-west trending Cloud River dikes and the Mt. Mollie dike. The geochemical data demonstrate that the majority of sills south of Thunder Bay are of Logan affinity and distinct from those of broadly similar age in the Nipigon Embayment to the north. The Pigeon River dikes that intrude the sills are geochemically coherent but distinct from the Logan sills and could not be feeders to the sills. The new age of 1109.2 ± 4.2 Ma for the Cloud River dike and its R polarity are consistent with published magnetostratigraphy. The Mt. Mollie dike age (1109.3 ± 6.3 Ma) indicates that it is not coeval with the spatially associated Crystal Lake gabbro as previously thought. The complexity of the dike and sill suites on the northern flank of suggests that the early phases of rifting occurred in distinct and changing stress fields prior to the main extensional rifting preserved in younger rocks to the south. The geochemistry and geochronology of the intrusions suggest a long-lived and complex magmatic history for the Midcontinent Rift.  相似文献   

Early Holocene dune activity linked with final destruction of Glacial Lake Minong, eastern Upper Michigan, USA     

Henry M. Loope  Walter L. Loope  Ronald J. Goble  Harry M. Jol 《Quaternary Research》2010,74(1):73-81

The early Holocene final drainage of glacial Lake Minong is documented by 21 OSL ages on quartz sand from parabolic dunes and littoral terraces and one radiocarbon age from a lake sediment core adjacent to mapped paleoshorelines in interior eastern Upper Michigan. We employ a simple model wherein lake-level decline exposes unvegetated littoral sediment to deflation, resulting in dune building. Dunes formed subsequent to lake-level decline prior to stabilization by vegetation and provide minimum ages for lake-level decline. Optical ages range from 10.3 to 7.7 ka; 15 ages on dunes adjacent to the lowest Lake Minong shoreline suggest final water-level decline ∼ 9.1 ka. The clustering of optical ages from vertically separated dunes on both sides of the Nadoway-Gros Cap Barrier around 8.8 ka and a basal radiocarbon date behind the barrier (8120 ± 40 ¹⁴C yr BP [9.1 cal ka BP]) support the hypothesis that the barrier was breached and the final lake-level drop to the Houghton Low occurred coincident with (1) high meltwater flux into the Superior basin and (2) an abrupt, negative shift in oxygen isotope values in Lake Huron.  相似文献   

Accretion of Jupiter’s atmosphere from a supernova-contaminated molecular cloud     

Henry B. Throop  John Bally 《Icarus》2010,208(1):329-336

If Jupiter and the Sun both formed directly from the same well-mixed proto-solar nebula, then their atmospheric compositions should be similar. However, direct sampling of Jupiter’s troposphere indicates that it is enriched in elements such as C, N, S, Ar, Kr, and Xe by 2-6× relative to the Sun (Wong, M.H., Lunine, J.I., Atreya, S.K., Johnson, T., Mahaffy, P.R., Owen, T.C., Encrenaz, T. [2008]. 219-246). Most existing models to explain this enrichment require an extremely cold proto-solar nebula which allows these heavy elements to condense, and cannot easily explain the observed variations between these species. We find that Jupiter’s atmospheric composition may be explained if the Solar System’s disk heterogeneously accretes small amounts of enriched material such as supernova ejecta from the interstellar medium during Jupiter’s formation. Our results are similar to, but substantially larger than, isotopic anomalies in terrestrial material that indicate the Solar System formed from multiple distinct reservoirs of material simultaneously with one or more nearby supernovas (Trinquier, A., Birck, J.-L., Allegre, C.J. [2007]. Astrophys. J. 655, 1179-1185). Such temporal and spatial heterogeneities could have been common at the time of the Solar System’s formation, rather than the cloud having a purely well-mixed ‘solar nebula’ composition.  相似文献   

Towards integrated governance for water, health and social–ecological systems: The watershed governance prism     

Margot W. Parkes  Karen E. Morrison  Martin J. Bunch  Lars K. Hallstrm  R. Cynthia Neudoerffer  Henry D. Venema  David Waltner-Toews 《Global Environmental Change》2010,20(4):693-704

This article proposes a shift toward the integrated governance of watersheds as a basis for fostering health, sustainability and social–ecological resilience. The authors suggest that integrated watershed governance is more likely when different perspectives, including health and well-being, are explicitly understood, communicated, and sought as co-benefits of watershed management. A new conceptual device – the watershed governance prism – is introduced in relation to the multiple facets of governance that characterize contemporary water resources management and examined as an integrative framework to link social and environmental concerns with the determinants of health in the watershed context. The authors assess the diagnostic and communicative potential of such a framework, discussing its utility as a concise depiction of multiple, interacting policy priorities and as a guide to integrate different research and policy domains into the governance of water, health and social–ecological systems.  相似文献   

Radiocarbon deglaciation chronology of the Thunder Bay,Ontario area and implications for ice sheet retreat patterns     

Thomas V. Lowell  Timothy G. Fisher  I. Hajdas  K. Glover  H. Loope  T. Henry 《Quaternary Science Reviews》2009,28(17-18):1597-1607

The sensitivity of ice sheets to climate change influences the return of meltwater to the oceans. Here we track the Laurentide Ice Sheet along a ～400 km long transect spanning about 6000 yr of retreat during the major climate oscillations of the lateglacial. Thunder Bay, Ontario is near a major topographic drainage divide, thus terrestrial ablation processes are the primary forcers of ice margin recession in the study area. During deglaciation three major moraine sets were produced, and have been assigned minimum ages of 13.9 ± 0.2, 12.3 ± 0.2–12.1 ± 0.1, and 11.2 ± 0.2 cal ka BP from south to north. These define a slow retreat (～10–50 m/a) prior to major climate oscillations which was then followed by a factor of ～2 increase during the Bölling–Alleröd, and an additional increase during the early Holocene. When compared to retreat rates in other terrestrial settings of the ice sheet, nearly identical patterns emerge. However this becomes problematic because a key control on retreat rates is the surface slope of the ice sheet and this should vary considerably over areas of so-called hard and soft beds. Further these ice margin reconstructions would not allow meltwater sourced in the Hudson Basin to drain into the Atlantic basin until after Younger Dryas time.  相似文献   

First insights into the structure and environmental setting of cold-seep communities in the Marmara Sea     

Bénédicte Ritt  Jozée Sarrazin  Jean-Claude Caprais  Philippe Noël  Olivier Gauthier  Catherine Pierre  Pierre Henry  Daniel Desbruyères 《Deep Sea Research Part I: Oceanographic Research Papers》2010,57(9):1120-1136

A brackish-water cold seep on the North Anatolian Fault (NAF) in the Marmara Sea was investigated with the Nautile submersible during the MarNaut cruise in 2007. This active zone has already been surveyed and revealed evidence of active seeping on the seafloor, such as bubble emissions, patches of reduced sediments, microbial mats and authigenic carbonate crusts. MarNaut was the first opportunity to sample benthic communities in the three most common microhabitats (bioturbated and reduced sediments, carbonate crust) and to examine their relationships with environmental conditions. To do so, faunal communities were sampled and chemical measurements were taken close to the organisms. According to diversity indices, the bioturbated microhabitat exhibited the highest taxonomic diversity and evenness despite a lower number of samples. Conversely, the reduced sediment microhabitat exhibited the lowest taxonomic diversity and evenness. The carbonate crust microhabitat was intermediate although it had the highest biomass. Multivariate analyses showed that (1) fauna were relatively similar within a single microhabitat; (2) faunal community structure varied greatly between the different microhabitats; (3) there was a link between faunal distribution and the type of substratum; and (4) chemical gradients (i.e. methane, oxygen and probably sulphides) may influence faunal distribution. The estimated fluid flow velocity (0.4–0.8 m/yr) confirmed the presence of fluid emission and provided evidence of seawater convection in the two soft-sediment microhabitats. Our results suggest that the reduced sediments may represent a harsher environment with high upward fluid flow, which restrains seawater from penetrating the sediments and inhibits sulphide production, whereas bioturbated sediments can be viewed as a bio-irrigated system with sulphide production occurring at greater depths. Therefore, the environmental conditions in reduced sediments appear to prevent the colonization of symbiont-bearing fauna, such as vesicomyid bivalves, which are more often found in bioturbated sediments. Fluid flow appears to control sulphide availability, which in turn influences the horizontal and vertical distribution patterns of fauna at small spatial scales as observed at other seep sites.  相似文献   

Palaeomagnetic dating of widespread remagnetization on the southeastern border of the French Massif Central and implications for fluid flow and Mississippi Valley-type mineralization     

Bernard Henry  Henri Rouvier  Maxime le Goff  David Leach  Jean-Claude Macquar  Jacques Thibieroz  Michael T. Lewchuk 《Geophysical Journal International》2001,145(2):368-380

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New Moscovian palaeomagnetic pole from the Edjeleh fold (Saharan craton, Algeria)     

M. E. M. Derder  B. Henry  B. Bayou  H. Djellit  M. Amenna 《Geophysical Journal International》2001,147(2):343-355

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