An exploration of potential raw materials for prehistoric pottery production in the Tao River Valley,Gansu Province,China     

Evgenia Dammer  Anke Hein  Michela Spataro 《Geoarchaeology》2024,39(2):122-142

Northwest China is known for its Majiayao-style Neolithic painted pottery which has received much praise for its high level of craftsmanship, yet its chain of production, in particular the step of raw material selection, is still poorly understood. To fill this lacuna, the present study explores the raw materials used in producing these wares from a geological and technological perspective. At its core stands the first geoarchaeological survey conducted around the eponymous site of Majiayao which collected 47 samples of raw materials suitable for ceramic production including clay, loess and rocks, which were all analysed macroscopically. A selection was analysed using thin-section petrography, and a subset of the clay and loess samples were subjected to firing experiments. Additionally, three clay samples were analysed by scanning electron microscope with energy-dispersive X-ray spectrometer to understand their composition and behaviour in ceramic production. These were then compared to archaeological ceramics, thus providing insights into raw-material availability and selection that will be of importance not only for research on Majiayao-style pottery but also for later-period ceramics produced in the area. This research shows how an archaeologically informed geological survey can contribute insights into human–environment interaction in early pottery production, especially the interplay between raw-material availability, technological know-how and potters' choices.  相似文献   

Deep-sea Fe-Mn Crusts from the Northeast Atlantic Ocean: Composition and Resource Considerations     

Susana Bolhão Muiños  James R. Hein  Martin Frank  José Hipólito Monteiro  Luís Gaspar  Tracey Conrad 《Marine Georesources & Geotechnology》2013,31(1):40-70

Eighteen deep-sea ferromanganese crusts (Fe-Mn crusts) from 10 seamounts in the northeast Atlantic were studied. Samples were recovered from water depths of ～1,200 to ～4,600 m from seamounts near Madeira, the Canary and Azores islands, and one sample from the western Mediterranean Sea.

The mineralogical and chemical compositions of the samples indicate that the crusts are typical continental margin, hydrogenetic Fe-Mn crusts. The Fe-Mn crusts exhibit a Co + Cu + Ni maximum of 0.96 wt%. Platinum-group element contents analyzed for five samples showed Pt contents from 153 to 512 ppb.

The resource potential of Fe-Mn crusts within and adjacent to the Portuguese Exclusive Economic Zone (EEZ) is evaluated to be comparable to that of crusts in the central Pacific, indicating that these Atlantic deposits may be an important future resource.  相似文献   

Seamount Characteristics and Mine-Site Model Applied to Exploration- and Mining-Lease-Block Selection for Cobalt-Rich Ferromanganese Crusts     

James R. Hein  Tracey A. Conrad  Rachel E. Dunham 《Marine Georesources & Geotechnology》2013,31(2):160-176

Regulations are being developed through the International Seabed Authority (ISBA) for the exploration and mining of cobalt-rich ferromanganese crusts. This paper lays out geologic and geomorphologic criteria that can be used to determine the size and number of exploration and mine-site blocks that will be the focus of much discussion within the ISBA Council deliberations. The surface areas of 155 volcanic edifices in the central equatorial Pacific were measured and used to develop a mine-site model. The mine-site model considers areas above 2,500 m water depth as permissive, and narrows the general area available for exploration and mining to 20% of that permissive area. It is calculated that about eighteen 100 km² exploration blocks, each composed of five 20 km² contiguous sub-blocks, would be adequate to identify a 260 km² 20-year-mine site; the mine site would be composed of thirteen of the 20 km² sub-blocks. In this hypothetical example, the 260 km² mine site would be spread over four volcanic edifices and comprise 3.7% of the permissive area of the four edifices and 0.01% of the total area of those four edifices. The eighteen 100 km² exploration blocks would be selected from a limited geographic area. That confinement area is defined as having a long dimension of not more than 1,000 km and an area of not more than 300,000 km².  相似文献   

Phytoplankton community composition in nearshore coastal waters of Louisiana     

Schaeffer BA  Kurtz JC  Hein MK 《Marine pollution bulletin》2012,64(8):1705-1712

Phytoplankton community compositions within near-shore coastal and estuarine waters of Louisiana were characterized by group diversity, evenness, relative abundance and biovolume. Sixty-six taxa were identified in addition to eight potentially harmful algal genera including Gymnodinium sp. Phytoplankton group diversity was lowest at Vermillion Bay in February 2008, but otherwise ranged between 2.16 and 3.40. Phytoplankton evenness was also lowest at Vermillion Bay in February 2008, but otherwise ranged between 0.54 and 0.77. Dissolved oxygen increased with increased biovolume (R2 = 0.85, p < 0.001) and biovolume decreased with increased light attenuation (R2 = 0.34, p = 0.007), which supported the importance of light in regulating oxygen dynamics. Diatoms were dominant in relative abundance and biovolume at almost all stations and all cruises. Brunt-V?is?l? frequency was used as a measure of water column stratification and was negatively correlated (p = 0.02) to diatom relative percent total abundance.  相似文献   

Mediterranean migration futures: Patterns,drivers and scenarios     

Hein de Haas 《Global Environmental Change》2011

This study explores possible futures of Mediterranean migration based on an evaluation of past, current and future drivers of migration in the region. Since 1950, structural shifts in the political economy of the region have fundamentally changed the Mediterranean migration map. Particularly the rise of Gulf economies and south European growth and EU expansion has transformed the northern Mediterranean and the Gulf into new immigration poles. The main drivers of these changes are economic and political. Contrary to conventional beliefs, the role of environmental and also demographic factors seems comparatively limited, probabilistic and indirect. Future climate change and environmental stress may affect internal movement but are unlikely to result in massive international migration. Under most scenarios, Turkey and other North African countries may well evolve into immigration countries coinciding with increasing immigration from sub-Saharan Africa to the entire Mediterranean.  相似文献   

The origin of large varioles in flow-banded pillow lava from the Hooggenoeg Complex,Barberton Greenstone Belt,South Africa     

Nils Rune Sandstå  Brian Robins  Harald Furnes  Maarten de Wit 《Contributions to Mineralogy and Petrology》2011,162(2):365-377

Exceptionally well-preserved pillowed and massive phenocryst-free metabasaltic lava flows in the uppermost part of the Palaeoarchaean Hooggenoeg Complex of the Barberton Greenstone Belt exhibit both flow banding and large leucocratic varioles. The flow banding is defined by blebs and bands of pale and dark green metabasalt and was the result of mingling of two types of basalt (Robins et al. in Bull Volcanol 72:579–592, 2010a). Varioles occur exclusively in the dark chlorite-, MgO- and FeO-rich metabasalt. Varioles are absent in the outermost rinds of pillows and increase in both abundance and size towards the centres of pillows. In the central parts of some pillows, they impinge to form homogeneous pale patches, bands or almost homogenous cores. Individual varioles consist essentially of radially orientated or outwardly branching dendritic crystals of albite. Many varioles exhibit concentric zones and finer-grained rims. Some varioles seem to have grown around tiny vesicles and vesicles appear to have been trapped in others between a core and a finer-grained rim. The matrix surrounding the ocelli contains acicular pseudomorphs of actinolite and chlorite after chain-like, skeletal Ca-rich pyroxenes that are partly overgrown by the margins of varioles. Varioles are enriched in the chemical constituents of feldspar but contain concentrations of immobile TiO₂, Cr, Zr and REE that are similar to the host metabasalts. The shape, distribution, texture and composition of the varioles exclude liquid immiscibility and support an origin by spherulitic crystallisation of plagioclase from severely undercooled basalt melt and glass. Nucleation of plagioclase was strongly inhibited and took place on vesicles, on the bases of drainage cavities and along early fractures. Eruption in deep water and retention of relatively high concentrations of volatiles in the melt may be the principal cause of spherulitic crystallisation in the interiors of pillows rather than only in their margins as in younger submarine flows.  相似文献   

Desertification in the Sahel: Towards better accounting for ecosystem dynamics in the interpretation of remote sensing images   总被引：3，自引：0，他引：3  

L. Hein  N. de RidderP. Hiernaux  R. LeemansA. de Wit  M. Schaepman 《Journal of Arid Environments》2011,75(11):1164-1172

To date, the interpretation of remote sensing images has not revealed wide-spread degradation of the vegetation in the Sahel. However, the interpretation of spectral information depends on a range of assumptions regarding the dynamics of the Sahelian vegetation as a function of rainfall variability and human management. Recent papers have presented diverging views on the vegetation dynamics of the Sahel and how these can be analysed with remote sensing images. We present a further analysis of the vegetation dynamics of semi-arid rangelands, in particular the Sahel, and the subsequent implications for the interpretation of remote sensing images. Specifically, the ecological processes driving the response of the Sahelian vegetation to rainfall variation are re-examined, and a regression analysis of NPP versus rainfall data is carried out. It is shown that the relation between the interannual variation in NPP and rainfall in the Sahel is non-linear and that this relation differs between sites with different average annual rainfall. It has been common practise in remote sensing studies for the Sahel to aggregate data from various Sahelian sites in order to obtain an average relation between rainfall, NPP and Rain Use Efficiency, and to assume these relations to be linear. This paper shows that this approach may lead to a bias in the interpretation of remote sensing images and that further work is required to clarify if wide-spread ecosystem degradation has occurred in the Sahel.  相似文献   

From GPS and GLONASS via EGNOS to Galileo – Positioning and Navigation in the Third Millennium     

Günter W. Hein 《GPS Solutions》2000,3(4):39-47

Positioning and navigation – as are presently possible with the American Global Positioning System (GPS) and the Russian GLONASS system – is briefly reviewed. Deficiencies, which have led to augmentations like the European Geostationary Navigation Overlay System (EGNOS), are outlined. Europe's decision to get involved in the definition and possible set-up of a Global Navigation Satellite System (GNSS) of the second generation (GNSS-2), called Galileo, is discussed in detail as well as the GPS modernization program that might take place during the sample phase. Finally, some brief thoughts on the benefit of GNSS-2 for geodesy and surveying are given. ? 2000 John Wiley & Sons, Inc.  相似文献   

Complex coastal change in response to autogenic basin infilling: An example from a sub‐tropical Holocene strandplain          下载免费PDF全文

Christopher J. Hein  Duncan M. FitzGerald  Luis H. P. de Souza  Ioannis Y. Georgiou  Ilya V. Buynevich  Antonio H. da F. Klein  João Thadeu de Menezes  William J. Cleary  Thelma L. Scolaro 《Sedimentology》2016,63(6):1362-1395

Thick bay‐fill sequences that often culminate in strandplain development serve as important sedimentary archives of land–ocean interaction, although distinguishing between internal and external forcings is an ongoing challenge. This study employs sediment cores, ground‐penetrating radar surveys, radiocarbon dates, palaeogeographic reconstructions and hydrodynamic modelling to explore the role of autogenic processes – notably a reduction in wave energy in response to coastal embayment infilling – in coastal evolution and shoreline morphodynamics. Following a regional 2 to 4 m highstand at ca 5·8 ka, the 75 km² Tijucas Strandplain in southern Brazil built from fluvial sediments deposited into a semi‐enclosed bay. Holocene regressive deposits are underlain by fluvial sands and a Pleistocene transgressive–regressive sequence, and backed by a highstand barrier‐island. The strandplain is immediately underlain by 5 to 16 m of seaward‐thickening, fluvially derived, Holocene‐age, basin‐fill mud. Several trends are observed from the landward (oldest) to the seaward (youngest) sections of the strandplain: (i) the upper shoreface and foreshore become finer and thinner and shift from sand‐dominated to mud‐dominated; (ii) beachface slopes decrease from >11° to ca 7°; and (iii) progradation rates increase from 0·4 to 1·8 m yr^?1. Hydrodynamic modelling demonstrates a correlation between progressive shoaling of Tijucas Bay driven by sea‐level fall and sediment infilling and a decrease in onshore wave‐energy transport from 18 to 4 kW m^?1. The combination of allogenic (sediment supply, falling relative sea‐level and geology) and autogenic (decrease in wave energy due to bay shoaling) processes drove the development of a regressive system with characteristics that are rare, if not unique, in the Holocene and rock records. These findings demonstrate the complexities in architecture styles of highstand and regressive systems tracts. Furthermore, this article highlights the diverse internal and external processes and feedbacks responsible for the development of these intricate marginal marine sedimentary systems.  相似文献   

Sedimentologic,mineralogic, and geotechnical descriptions of fine-grained slope and basin deposits,Baffin Island Fiords     

F. J. Hein  F. J. Longstaffe 《Geo-Marine Letters》1985,5(1):11-16

Sediments from Baffin Island fiords are graded, massive, laminated, or bioturbated. Plasticity indices vary with sediment type (lowest = laminated or graded; intermediate = massive; and highest = bioturbated). Graded and massive silty/sandy muds are most common on prodelta or proglacial slopes. Bioturbated graded and laminated muds, and rare massive pebbly muds occur more distally down-fiord from the deltas or glaciers. Clays are mostly mica, with only minor to moderate amounts of chlorite, kaolinite, and swelling clays. On the Casagrande plasticity chart, the sediments plot in fields for clay-size material of medium to high plasticity.  相似文献