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101.
Marian Munteanu Allan H. Wilson Yong Yao Gordon Chunnett Yaonan Luo 《Mineralium Deposita》2010,45(6):517-529
The Lengshuiqing area contains several small intrusions made up of peridotite ± quartz diorite ± granite spatially associated
with the Gaojiacun pluton (gabbroids + peridotite + diorite). Ni–Cu sulfide ore occur at Lengshuiqing, hosted in peridotite.
SHRIMP U–Pb zircon dating produced the ages of 803 ± 4.2 Ma (peridotite), 807 ± 2.6 Ma (oikocrystic hornblende gabbro), 809 ± 4.3 Ma
(hornblende gabbronorites) for the Gaojiacun pluton and 807 ± 3.8 Ma (diorite, intrusion I), 817 ± 6.3 Ma (quartz diorite,
intrusion II) and 817 ± 5 Ma (peridotite, intrusion 101) for Lengshuiqing. These ages suggest the emplacement of the Gaojiacun
pluton later than the intrusions from Lengshuiqing. The olivine from Lengshuiqing does not contain sulfide inclusions and
is relatively Ni-rich (1,150–1,550 ppm Ni), suggesting its crystallisation before the sulfide saturation that generated the
Ni–Cu deposits. The olivine of the gabbros in the Gaojiacun pluton is Ni-poor (250–800 ppm), which indicates crystallisation
from a severely metal-depleted magma after a sulfide saturation event. The olivine in the peridotites from the Gaojiacun pluton
has 800–1,150 ppm Ni and contains sulfide inclusions. Moreover, geological evidence suggests the genesis of the peridotites
from Gaojiacun in conduits that were ascending through the gabbroids. A sequence of at least three stages of magma emplacement
is proposed: (1) Lengshuiqing; (2) gabbroids from Gaojiacun; (3) peridotites from Gaojiacun. Given the age differences, the
intrusions at Lengshuiqing and the Gaojiacun pluton might have been produced by different magmatic events. 相似文献
102.
Lucien von Gunten Christian Kamenik Marian Fujak Roberto Urrutia 《Journal of Paleolimnology》2012,47(4):583-600
Lake sediment records are underrepresented in comprehensive, quantitative, high-resolution (sub-decadal), multi-proxy climate
reconstructions for the past millennium. This is largely a consequence of the difficulty of calibrating biogeochemical lake
sediment proxies to meteorological time series (calibration-in-time). Thanks to recent methodological advances, it is now
possible. This paper outlines a step-by-step, specifically tailored methodology, with practical suggestions for calibrating
and validating biogeochemical proxies from lake sediments to meteorological data. This approach includes: (1) regional climate
data; (2) site selection; (3) coring and core selection; (4) core chronology; (5) data acquisition; and (6) data analysis
and statistical methods. We present three case studies that used non-varved lake sediments from remote areas in the Central
Chilean Andes, where little a priori information was available on the local climate and lakes, or their responses to climate
variability. These case studies illustrate the potential value and application of a calibration-in-time approach to non-varved
lake sediments for developing quantitative, high-resolution climate reconstructions. 相似文献
103.
Marian Doru Suran 《Astrophysics and Space Science》2008,316(1-4):163-166
This is a presentation of the pulsational model LNAWENR (linear nonadiabatic nonradial), included in the asteroseismological package ROMOSC which was implemented in the Bucharest Observatory to be used in the CoRoT mission. 相似文献
104.
Anomalous high frequency PKKPBC signals (displaying a large amount of energy around 2.5 Hz), recorded globally for deep and intermediate depth earthquakes,
are compared to PKKPAB signals. The attenuation difference
t\textAB* - t\textBC* t_{\text{AB}}^{*} - t_{\text{BC}}^{*} is evaluated from spectral amplitudes in the range 96–111°, being approximately twice the results provided by full-wave theory
and PREM (with no low Qμ zone in the lowermost mantle and a nearly infinite QK in the outer core). Most ray paths for such recordings are piercing the D″ region in the proximity of regions where ultra-low
velocity zones (ULVZ) have been previously reported beneath the North Atlantic Ocean, the Southwest Pacific and the southwestern
part of South America. If BC amplitudes around 2.5 Hz and at low frequencies (0.5–1.5 Hz) are comparable, the observed attenuation
difference (in the frequency range 0.2–2.5 Hz) is small (around 0.25 s) and close to the PREM value. The particle motion of
the high-frequency PKKPBC at 2.5 Hz is quite similar to that of the raw recording, suggesting a deep source. An explanation for this might be scattering
of the BC branch in some very restricted areas of the lowermost mantle. Alternately, the presence of a thin layer with high
attenuation in the D″ region would most likely be associated with either the ultra-low velocity zone (ULVZ) or light sediments
on the underside of the core-mantle boundary (CMB). Correlated to other methods to investigate the lowermost mantle, the high-frequency
PKKPBC can be used to map lateral variations of attenuation above the CMB, possibly associated with the boundary of the superplumes,
especially when PKKPAB is observed. 相似文献
105.
Britta Horstmann 《Climate Policy》2013,13(4):1086-1096
The Adaptation Fund of the Kyoto Protocol marks a change in the international climate change financing architecture due to its independence from official development assistance, direct access and the majority of developing countries in governance. A major goal of the Adaptation Fund is to finance concrete adaptation projects and programmes in developing countries that are particularly vulnerable to the effects of climate change. The presented analysis considers the results of operationalization of the fund between 2008 and 2010, and the role vulnerability had in the allocation of funds. The definition of ‘vulnerability’ remains broad and currently does not allow for a prioritization in the allocation of funds. Criteria like ‘level of vulnerability’ or ‘adaptive capacity’ still need to be specified. The possibilities for the Adaptation Fund Board to implement a vulnerability-oriented funding approach are limited by the legal basis of the Kyoto Protocol and the principle of a country-driven approach. The effective support of vulnerable communities primarily depends on the institutional capacities and the institutional arrangement at the national level and the quality of analysis the adaptation projects and programmes are based on. 相似文献
106.
Marian Marschalko Işık Yilmaz David Lamich Marián Drusa Darja Kubečková Tomáš Peňaz Tereza Burkotová Vladimír Slivka Martin Bednárik David Krčmář Miloš Duraj Alena Sochorková 《Environmental Earth Sciences》2014,72(1):11-20
This article aims to explain and demonstrate the origin and development of a subsidence basin caused by coal mining as well as to point out important aspects of this phenomenon in engineering geology. Engineering geology needs to deal with a number of issues related to the origin and development of subsidence basins in areas affected by deep coal mining. An interesting case study from the Upper-Silesian Basin in the northeast of the Czech Republic near the Polish border is presented in this paper. There is a clear time chronological succession in the ground surface changes manifested by a ground subsidence gradation, both in their absolute values as well as in their spatial distribution. The phenomenon is documented by aerial photo time series, which optimally depict the origin and development of the subsidence. In the study area, there are changes in the landscape elements and it is essential to be considered in future land use plans. The marginal conditions of the Quaternary geological structure and hydrogeological conditions are responsible for an unconfined aquifer which manifests there as a water body in an undrained depression in the course of the ground subsidence. 相似文献
107.
Underground mining hazard map including building site categories in an area affected by underground mining activities 总被引:1,自引:1,他引:0
Marian?Marschalko I??k?YilmazEmail author David?Lamich Martin?Bednárik 《Environmental Earth Sciences》2014,72(7):2655-2666
The objective of the paper is generation of an underground mining hazard map. The method applied to create the map is based on five categories of areas with different characters of underground mining influence making use of the so-called building site categories. The individual areas with different groups represent various suitability or unsuitability for founding new structures in such influenced territories. They will also reflect a higher or lower degree of influence on already existing structures. Areas affected by underground mining of category V are suitable without any significant restrictions. Areas of the medium category represent influence of building site categories III and IV with economically acceptable measures for founding engineering purposes. The last type is areas with high influence in the category I and II and they are clearly unsuitable for new development. Structures may be founded there in exceptional cases only. This methodology was applied on four map sheets in 1:10,000 scale in a coal mining region in the town of Karviná and its environs in the direction to the City of Ostrava (Czech Republic). Extensive changes caused by underground mining have been identified in the study area and the implementation of the suggested maps may help to deal with the issue in terms of land development by means of land use planning. 相似文献
108.
Marian Horstmann Munir Humayun Mario Fischer‐Gödde Addi Bischoff Mona Weyrauch 《Meteoritics & planetary science》2014,49(10):1948-1977
A detailed mineralogical and chemical study of Almahata Sitta fine‐grained ureilites (MS‐20, MS‐165, MS‐168) was performed to shed light on the origin of these lithologies and their sulfide and metal. The Almahata Sitta fine‐grained ureilites (silicates <30 μm grain size) show textural and chemical evidence for severe impact smelting as described for other fine‐grained ureilites. Highly reduced areas in Almahata Sitta fine‐grained ureilites show large (up to ~1 mm) Si‐bearing metal grains (up to ~4.5 wt% Si) and niningerite [Mg>0.5,(Mn,Fe)<0.5S] with some similarities to the mineralogy of enstatite (E) chondrites. Overall, metal grains show a large compositional variability in Ni and Si concentrations. Niningerite grains probably formed as a by‐product of smelting via sulfidation. The large Si‐Ni variation in fine‐grained ureilite metal could be the result of variable degrees of reduction during impact smelting, inherited from coarse‐grained ureilite precursors, or a combination of both. Large Si‐bearing metal grains probably formed via coalescence of existing and newly formed metal during impact smelting. Bulk and in situ siderophile trace element abundances indicate three distinct populations of (1) metal crystallized from partial melts in MS‐20, (2) metal resembling bulk chondritic compositions in MS‐165, and (3) residual metal in MS‐168. Almahata Sitta fine‐grained ureilites developed their distinctive mineralogy due to severe reduction during smelting. Despite the presence of E chondrite and ureilite stones in the Almahata Sitta fall, a mixing relation of E chondrites or their constituents and ureilite material in Almahata Sitta can be ruled out based on isotopic, textural, and mineral‐chemical reasons. 相似文献
109.
The average aspect ratio of plagioclase, measured in thin section, varies systematically through dolerite sills, with a symmetrical “M”-shaped profile observed in sills thinner than ~200 m. Thicker sills show the same marginal reversal at the base, but average aspect ratios appear to continue increasing towards the top, creating an “S”-shaped profile. A distorted “M”-shaped profile is visible in the stratigraphic variation of plagioclase average aspect ratios in the prehistoric Makaopuhi lava lake, with the centre of the “M” in the olivine-enriched horizon close to the base of the lake. Higher overall values of average aspect ratio are observed in thin sills compared to thicker sills, demonstrating that the plagioclase in more slowly crystallized bodies is more equant than that in more rapidly crystallized bodies. There is a strong correlation between the plagioclase average aspect ratio in the central parts of the sills and the crystallization time calculated using a simple one-dimensional thermal model assuming conductive cooling. The cause of the marginal reversals in average aspect ratio is not well understood, but may result from early grain impingement in the developing crystal mushy layer. 相似文献
110.
Using TRACE EUV 171 Å line, Hα line, Zürich radio, RHESSI, and HXRS observations the 29 September 2002 flare (M2.6), which occurred in AR NOAA 0134, was analyzed. Flaring structures were compared with a potential magnetic field model (field lines and quasi-separatrix layers) made from SOHO/MDI full-disk magnetogram. Series of high-resolution SOHO/MDI magnetograms and TRACE white-light images were used to find changes in the active region at the photosphere during the flare. The flare began with a rising of a small dark loop followed by the flare brightening observed in 171 Å with TRACE and Hα lines. In radio wavelengths, first type III bursts were observed 5 min prior to the start of hard X-ray emission, indicating a pre-flare coronal activity. The main hard X-ray emission peak (at 06:36 UT) was associated with the second type III burst activity and several slowly negatively drifting features, all starting from one point on the radio spectrum (probably a shock propagating through structures with different plasma parameters). After this time a huge loop formed and three minutes later it became visible in absorption both in Hα and 171 Å EUV lines. The phase of huge dark loop formation was characterized by long-lasting, slowly negatively drifting pulsations and drifting continuum. Finally, considering this huge loop as a surge an evolution of the event under study is discussed. 相似文献