Thermal resonance of the atmosphere to SST anomalies. Implications for the Antarctic circumpolar wave     

A. COLIN DE VERDIÈRE  M. L. BLANC 《地球，A辑:动力气象学与海洋学》2001,53(3):403-424

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Coupling forward modelling of garnet growth with monazite geochronology: an application to the Rappold Complex (Austroalpine crystalline basement)     

F. GAIDIES  E. KRENN  C. DE CAPITANI  R. ABART 《Journal of Metamorphic Geology》2008,26(7):775-793

Results from forward modelling of garnet growth and U–Th–Pb chemical dating suggest three periods of metamorphism that affected metapelitic rocks of the Rappold Complex (Eastern European Alps). Garnet first grew during Barrovian-type metamorphism, possibly during the Carboniferous Variscan orogeny. The second period of metamorphism produced monazite and resulted in minor garnet growth in some samples. Variable garnet growth was controlled by changes to the effective bulk rock composition resulting from resorption of older garnet porphyroblasts. Monazite crystals have variable morphology, textures and composition, but all yield Permian ages (267 ± 12 to 274 ± 17 Ma). In samples in which there was Permian garnet growth, monazite forms isolated and randomly distributed grains. In other samples, monazite formed pseudomorphous clusters after allanite. This difference is attributed to higher transport rates of monazite-forming elements in samples which underwent dehydration reactions during renewed garnet growth. The third and final period of garnet growth took place during Eo-Alpine (Cretaceous) metamorphism. Garnet of this age displays a wart-like texture. This may reflect transport-limited growth, possibly as a result of repeated dehydration during polyphase metamorphism.  相似文献   

New, high-precision P–T estimates for Oman blueschists: implications for obduction, nappe stacking and exhumation processes     

P. YAMATO  P. AGARD  B. GOFFÉ  V. DE ANDRADE  O. VIDAL  L. JOLIVET 《Journal of Metamorphic Geology》2007,25(6):657-682

Oman blueschists and eclogites lie below the obduction nappe of the Semail ophiolite in one of the key areas on Earth for the study of plate convergence. Here new metamorphic and tectonic constraints are provided for the central, yet poorly constrained Hulw unit, sandwiched between the low‐grade units (～10 kbar, <300 °C) and the As Sifah eclogites (P_max ～ 23 kbar; T_max ～ 600 °C). TWEEQU multi‐equilibrium thermobarometry, using both compositional mapping and spot analyses, and Raman spectroscopy of carbonaceous material yield a high‐precision P–T path for the Hulw and As Sheikh units and reveal that they shared a common P–T history in four stages: (i) a pressure decrease from 10–12 kbar, 250–300 °C to 7–9 kbar, 300–350 °C; (ii) almost isobaric heating at ～8–10 kbar from 300–350 °C to 450–500 °C; (iii) a pressure decrease at moderate temperatures (～450–500 °C); and (iv) isobaric cooling at ～5–6 kbar from 450–500 to 300 °C. No significant pressure or temperature gap is observed across the upper plate–lower plate discontinuity to the north and west of the Hulw unit. The combination of tectonic and P–T data constrains the stacking chronology of the three main metamorphic units comprising the Saih Hatat window (i.e. the Ruwi‐Quryat, the Hulw‐As Sheikh and the Diqdah‐As Sifah units). These results strengthen the view that the tectonic and metamorphic data are conveniently accounted for by a simple, N‐vergent continental subduction of the passive Arabian margin below the obduction nappe along a cold P–T gradient.  相似文献   

From ¹⁴C/¹²C measurements towards radiocarbon dating of ice     

R. S. W. VAN DE WAL  J. J. VAN ROIJEN  D. RAYNAUD  K. VAN DER BORG  A. F. M. DE JONG  J. OERLEMANS  V. LIPENKOV  P. HUYBRECHTS 《Tellus. Series B, Chemical and physical meteorology》1994,46(2):94-102

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New aerosol particle formation in different synoptic situations at Hyytiälä, Southern Finland     

L. SOGACHEVA  L. SAUKKONEN  E. D. NILSSON  M. DAL MASO  DAVID M. SCHULTZ  G. DE LEEUW  M. KULMALA 《Tellus. Series B, Chemical and physical meteorology》2008,60(4):485-494

We examine the meteorological conditions favourable for new particle formation as a contribution to clarifying the responsible processes. Synoptic weather maps and satellite images over Southern Finland for 2003–2005 were examined, focusing mainly on air mass types, atmospheric frontal passages, and cloudiness. Arctic air masses are most favourable for new aerosol particle formation in the boreal forest. New particle formation tends to occur on days after passage of a cold front and on days without frontal passages. Cloudiness, often associated with frontal passages, decreases the amount of solar radiation, reducing the growth of new particles. When cloud cover exceeds 3–4 octas, particle formation proceeds at a slower rate or does not occur at all. During 2003–2005, the conditions that favour particle formation at Hyytiälä (Arctic air mass, post-cold-frontal passage or no frontal passage and cloudiness less than 3–4 octas) occur on 198 d. On 105 (57%) of those days, new particle formation occurred, indicating that these meteorological conditions alone can favour, but are not sufficient for, new particle formation and growth. In contrast, 53 d (28%) were classified as undefined days; 30 d (15%) were non-event days, where no evidence of increasing particle concentration and growth has been noticed.  相似文献   

DIRECT LOCATION OF OIL AND GAS BY THE SEISMIC REFLECTION METHOD*     

POH-HSI PAN  J. CL. DE BREMAECKER 《Geophysical Prospecting》1970,18(Z1):712-727

The seismic velocity of sedimentary rocks is determined by the porosity, the velocity in the matrix and that in the fluid. The last two are known experimentally. The velocity can be measured from the surface. By applying the time average equation we can find the porosity. If the only difference at two points is the nature of the fluid in one layer, the ratio of the reflectivities of the layer at these points determines the nature of the fluid; this ratio is equal to the ratio of the amplitudes at these points. The size of the reservoir can then be found. The method can be applied to both oil exploration and production. It is more accurate in the latter case because more information is available than in the former case. The method is also more effective in developing discovered fields than the conventional method of relying only on the geological structural configurations.  相似文献   

HOW AND WHERE TO SEARCH THE OLDEST MAN IN CHINA.     

P.TEILHARD DE CHARDIN 《地质学报》1926,(Z1)

During the summer of 1923, we were so lucky F. Licent and myself as to get, in three different places, the first records of the palaeolithic Man in China.  相似文献   

GEOLOGICAL STUDY OF THE DEPOSITS OF THE SANGKANHO BASIN.     

G.B.BARBOUR  E.LICENT  P.TEILHARD DE CHARDIN 《地质学报》1926,(Z1)

This paper offers a preliminary statement of the results of investigations carried out in the South Sangkanho basin, in the mountains some 80 miles to the NW of Peking. Important fossiliferous deposits found in this area throw light on the conditions ruling in N. China during the transition from Pliocene  相似文献   

LA CHINE EST-ELLE PLACEE ENTRE DEUX GRANDES FRACTURES DE LA CROUTE TERRESTRE ?     

PAR E.GHERZI 《地质学报》1925,4(2):81-86

Hest bien clair que toute reponse a cette question, sera du plus haut interet pour les geologues de la Chine, vu que les resultats de la geodesie semblent bien indiquer que la croute terrestre est divisee en plusieurs blocs independants, juxtaposes et equilibres isostatiquement.  相似文献   

REGULATION CONCERNING THE GRABAU MEDAL OF THE GEOLOGICAL SOCIETY OF CHINA     

PAR E.AHNERT 《地质学报》1925,4(2):95-97

Je me permets de soumettre a votre attention ce rapport, dont le sujet peut paraitre trop ordinaire—sur la decouverte d'une flore fossile. Mais dans les couches honilleres de la Russie de l'Extreme Orient et de la Manchourie du Nord, la decouverte de debris fossiles assez considerables pour per-  相似文献