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The Triassic succession of Bjørnøya (200 m) comprises the Lower Triassic Urd Formation (65 m) of the Sassendalen Group, and the Middle and Upper Triassic Skuld Formation (135 m) of the Kapp Toscana Group. These units are separated by a condensed '.'Middle Triassic sequence represented by a phosphatic remainé conglomerate (0.2m).
The Urd Formation consists of grey to dark grey shales with yellow weathering dolomitic beds and nodules. Palynology indicates the oldest beds to be Diencrian; ammonoid faunas in the middle and upper part of the formation arc of Smithian age. The organic content (c. 1 %) includes kerogen of land and marine origin, reflecting a shallow marine depositional environment.
The Skuld Formation is dominated by grey shales with red weathering siderite nodules. There are minor coarsening upwards sequences; the highest bed exposed is a 20 m thick, very fine-grained sandstone. Palynomorphs indicate a late Ladinian age for the lower part of the formation, and macrofossils and palynomorphs indicate Ladinian to Carnian ages for the upper part. Sedimentary structures, a sparse marine fauna and microplankton indicate deposition in a shallow marine environment. The organic residues contain dominantly terrestrially derived kerogen. 相似文献
The Urd Formation consists of grey to dark grey shales with yellow weathering dolomitic beds and nodules. Palynology indicates the oldest beds to be Diencrian; ammonoid faunas in the middle and upper part of the formation arc of Smithian age. The organic content (c. 1 %) includes kerogen of land and marine origin, reflecting a shallow marine depositional environment.
The Skuld Formation is dominated by grey shales with red weathering siderite nodules. There are minor coarsening upwards sequences; the highest bed exposed is a 20 m thick, very fine-grained sandstone. Palynomorphs indicate a late Ladinian age for the lower part of the formation, and macrofossils and palynomorphs indicate Ladinian to Carnian ages for the upper part. Sedimentary structures, a sparse marine fauna and microplankton indicate deposition in a shallow marine environment. The organic residues contain dominantly terrestrially derived kerogen. 相似文献
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<正> 各种自然生态系统的存在是人类生存的基本条件,而社会和经济持续发展的基础,是生态系统的持续发展。森林作为陆地生态系统的主体,在社会经济发展和环境建设中的特殊地位和作用,已被人们逐渐认识。1992年里约热内卢环境与发展大会郑重声明:“应该持续地经营森林和林地,以满足当代和子孙后代在社会、经济、生态、文化和精神诸方 相似文献
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Late Cenozoic uplift of the Amanos Mountains and incision of the Middle Ceyhan river gorge, southern Turkey; Ar–Ar dating of the Düziçi basalt 总被引：4，自引：0，他引：4
Ali Seyrek Tuncer Demir Malcolm Pringle Sema Yurtmen Rob Westaway David Bridgland Anthony Beck George Rowbotham 《Geomorphology》2008,97(3-4):321-355
Using the Ar–Ar technique, we have obtained the first numerical dates for the Pleistocene volcanism along the valley of the River Ceyhan in the Düziçi area of southern Turkey, in the western foothills of the Amanos Mountains. Our six dates indicate a single abrupt episode of volcanism at 270 ka. We have identified a staircase of 7 fluvial terraces, at altitudes of up to 230 m above the present level of the Ceyhan. Using the disposition of the basalt as an age constraint, we assign these terraces to cold-climate stages between marine oxygen isotope stages 16 and 2, indicating rates of fluvial incision, equated to surface uplift, that increase upstream through the western foothills of this mountain range at between 0.25 and 0.4 mm a− 1. Extrapolation of these uplift rates into the axis of the range suggests that the entire 2300 m of present-day relief has developed since the Mid-Pliocene, a view that we confirm using numerical modelling. Since 3.7 Ma the Amanos Mountains have formed a transpressive stepover along the northern part of the Dead Sea Fault Zone, where crustal shortening is required by the geometry. Using a physics-based technique, we have modelled the overall isostatic response to the combination of processes occurring, including crustal thickening caused by the shortening, erosion caused by orographic precipitation, and the resulting outward flow of mobile lower-crustal material, in order to predict the resulting history of surface uplift. This modelling suggests that the effective viscosity of the lower crust in this region is in the range 1–2 × 1019 Pa s, consistent with a Moho temperature of 590 ± 10 °C, the latter value being in agreement with heat flow data. This modelling shows that the nature of the active crustal deformation is now understood, to first order at least, in this key locality within the boundary zone between the African and Arabian plates, the structure and geomorphology of which have been fundamentally misunderstood in the past. 相似文献
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D. J. Webb 《Geophysical Journal International》1982,70(1):261-271
Summary. A model of the tides in a hemispherical ocean is used to investigate the effect of changes in the Earth's rotation rate on the power dissipated by the ocean tides. The results obtained are then used in an idealized astronomical model to investigate how they affect the history of the Earth—Moon system.
Using the tidal model it is found that at rotation rates higher than that of the present Earth, the power dissipated by the semi-diurnal tides in the ocean drops off rapidly as a result of the increased tidal frequency. Thus if the Earth's rotation rate is doubled from its present value, then the rate of energy dissipation in the ocean is reduced to approximately one-third of its present value and the tidal torque is reduced by a factor of about 6.
The present value for secular acceleration of the Moon, calculated from the results of the tidal model is -30.5 arcsec century-2 . Using this value in the astronomical model, which has the Moon and Sun in circular orbits above the equator, and assuming that the tidal torque is independent of the tidal frequency, the Gerstenkorn event is predicted to have occurred 1.3 × 109 yr ago.
When the astronomical model is run with a torque determined at all times from the tidal model, the reduction in the energy dissipated early in the history of the system, leads to a Gerstenkorn date of 5.3 × 109 yr ago. However, dissipation within the solid earth is found to be important early in the history of the system and when this effect is included it gives a date for the Gerstenkorn event of 3.9 × 109 yr ago. 相似文献
Using the tidal model it is found that at rotation rates higher than that of the present Earth, the power dissipated by the semi-diurnal tides in the ocean drops off rapidly as a result of the increased tidal frequency. Thus if the Earth's rotation rate is doubled from its present value, then the rate of energy dissipation in the ocean is reduced to approximately one-third of its present value and the tidal torque is reduced by a factor of about 6.
The present value for secular acceleration of the Moon, calculated from the results of the tidal model is -30.5 arcsec century
When the astronomical model is run with a torque determined at all times from the tidal model, the reduction in the energy dissipated early in the history of the system, leads to a Gerstenkorn date of 5.3 × 10
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Mörner, N.‐A. and Lind, B., 2011. Reply: Comments on ‘Heimdall's stones at Vitemölla in SE Sweden and the chronology and stratigraphy of the surroundings’ by Mörner et al. (2009). Geografiska Annaler: Series A, Physical Geography, 93, 197–199. DOI: 10.1111/j.1468‐0459.2011.00429.x 相似文献
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Both ‘tanka’ and ‘beri’, the well-like structures made for storing drinking water fetched from distant places or superficially charged from the runoff water of the monsoon rains, are considered integral components of rural communities in the Thar Desert of Rajasthan State in north-western India.A. stephensi, the confirmed malaria vector in desert regions, breeds in these structures predominantly. 相似文献
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在有关养老的老年学和地理学研究中,“就地养老”是一个广泛使用的概念,并一直被认为是解决老龄人口养老需求的有效政策手段。迄今为止,关于就地养老的研究主要关注了很多能够让老年人健康就地(或在家)养老的物质方面的因素,比如住房条件或家庭照护。有些老年学研究者们认识到,就地养老受到居住环境中实体环境和社会、情感因素的共同影响。但我们认为,在养老体验研究中,要更加深入地审视“人”和“地方”之间的复杂关系。特别是,我们主张就地养老成功的因素是地方具有维持良好关系的潜力。提到“地方(place)”一词的时候,人们过分局限于关注老年人身体上接近的地理空间,或是具有实体边界的地方,例如房子或社区。而我们通过回顾现有文献发现,对许多选择就地养老的人来说,更具有意义的是随着时间的推移,他们在不同空间尺度上所建立起来的多元的、网络化的社会和非社会关系。基于这个新的视角,可以更好地理解老年人与地方的多层次的联系,以及从不同尺度和不同类型的人与地方的关系来考察就地养老的意义。 相似文献
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Review of the “Law of the People’s Republic of China on Quality and Safety of Agricultural Products”
SUN Juanjuan 《资源与生态学报(英文版)》2018,9(1):106-113
One of the characteristics of food safety regulation in China is the separation of agricultural food products (agro-food) from other kinds of food. To this end, a Law on Quality and Safety of Agricultural Products (LQSAP) was enacted to provide for official control at the stage of primary agro-food production. With the enactment and revision of the Food Safety Law, one change in the legislative arrangement is the extension of the scope of this new law to cover the marketing of agro-food and the use of agricultural inputs. However, safety regulation at the stage of primary production of agro-food is still subject to the Law on Quality and Safety of Agricultural Products. It is also important to note that thee LQSAP refers both to agro-food and to agricultural products for non-human consumption; and that it provides rules both for safety assurance and for quality promotion. In the context of intensified official control to ensure food safety and diverse consumer needs for food of higher quality, a revision of the Law on Quality and Safety of Agricultural Products has been initiated. This article describes the goals of this legislation, its institutional arrangements and the directions the revisions are taking in order to provide a better understanding of food safety regulation in China in general and agro-food regulation in particular. 相似文献
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Fluxes of CO<Subscript>2</Subscript>, CH<Subscript>4</Subscript> and N<Subscript>2</Subscript>O from alpine grassland in the Tibetan Plateau 总被引：1，自引：0，他引：1
PEIZhiyong OUYANGHua ZHOUCaiping XUXingliang 《地理学报(英文版)》2003,13(1):27-34
Using static chamber technique,fluxes of CO2,CH4 and N2O were measured in the alpine grassland area from July 2000 to July 2001,determinations of mean fluxes showed that CO2 and N2O were generally released from the soil,while the alpine grassland accounted for a weak CH4 sink.Fluxes of CO2,CH4 and N2O ranged widely.The highest CO2 emission occurred in August,whereas almost 90?of the whole year emission occurred in the growing season.But the variations of CH4 and N2O fluxes did not show any clear patterns over the one-year-experiment.During a daily variation,the maximum CO2 emission occurred at 16:00,and then decreased to the minimum emission in the early morning.Daily pattern analyses indicated that the variation in CO2 fluxes was positively related to air temperatures(R^2=0.73)and soil temperatures at a depth of 5 cm(R^2=0.86),whereas daily variations in CH4 and N2O fluxes were poorly explained by soil temperatures and climatic variables.CO2 emissions in this area were much lower than other grasslands in plain areas. 相似文献
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The depiction of pristine countryside in New Zealand film has engendered a cultural disconnection with the environmental stories within the landscape. In this essay, we briefly examined the meaning of rural New Zealand landscape and its role in film. This research was done in part by making a short documentary, River Dog, a film about the rural New Zealand landscape. The character, plot and underlying message of River Dog were framed within visually relevant archetypes to form a constructive environmental message. Here, we examined River Dog's use of empathetic storytelling, an approach used to communicate an environmental issue without promulgating science or politics. 相似文献