Airborne laser altimeter survey of Long Valley, California   总被引：1，自引：1，他引：1  

J. R. Ridgway  J. B. Minster  N. Williams  J. L. Bufton  W. B. Krabill 《Geophysical Journal International》1997,131(2):267-280

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Systematic use of trace elements in igneous processes   总被引：11，自引：0，他引：11  

J. F. Minster  C. J. Allègre 《Contributions to Mineralogy and Petrology》1978,68(1):37-52

This paper develops an application of the inverse method proposed by Allégre et al. (1977) and Minster et al. (1977). Using a set of trace element data in a suite of primary lavas, it is possible to statistically test whether the data can be described by batch partial melting. Once this is achieved, one can inverse the problem and calculate the parameters which govern the process, that is: the degrees of melting corresponding to each lava, the initial source concentrations and partition coefficients for each element. This is a non-linear, strongly underdetermined problem, but when the set of trace elements is restricted to REE, taking advantage of the fact that their properties are smoothly related, the problem can be overconstrained by assuming a set of poorly constrained model parameters. Information contained in the data and in the external constraints can then be estimated and used to build a strategy of data acquisition. From a table of mineral-liquid partition coefficients, the mineralogies of the source and of the material entering the liquid can be calculated. The method has been tested on synthetic data sets representing natural cases, and proved to converge towards the real solution even when a very poor definition of the external constraints is introduced.The calculations have been applied to REE data on Grenada basanitoids (Shimizu and Arculus, 1976). It is confirmed that these lavas can be derived by 4 to 17% batch partial melting of a garnet lherzolite source (7% gt, 23% cpx) that is relatively enriched in light REE. This result is discussed in relation with Nd and Sr isotopic composition data.  相似文献   

Systematic use of trace element in igneous process     

Claude J. Allègre  Michel Treuil  Jean-François Minster  Bernard Minster  Francis Albarède 《Contributions to Mineralogy and Petrology》1977,60(1):57-75

This paper describes an extended application of the Rayleigh distillation law to trace element behavior in a fractional crystallization sequence. Using a trace element with a very low bulk partition coefficient as a reference (as suggested by Anderson and Greenland, 1969, and extended by Treuil and Varet, 1973), we can derive bulk partition coefficients for other elements and, in turn, the mineralogical composition of the cumulates. Trace elements with large D, such as Ni and Cr, further constrain the system, and we can deduce the initial composition of the magma. An example of this technique is shown for Terceira Island in the Azores.Contribution IPGNS no 229Now at Dept. of Geological Sciences, California Institute of Technology, Pasadena, California, USA  相似文献   

⁸⁷Rb–⁸⁷Sr history of the Norton County enstatite achondrite     

J.F. Minster  C.J. Allegre 《Earth and Planetary Science Letters》1976,32(2):191-198

⁸⁷Rb⁸⁷Sr analysis of the Norton County achondrite has been achieved with special attention to the rubidium analysis. Enstatite crystals and polycrystalline material give an “age” of 4.48 ± 0.04 × 10⁹ years and an initial ratio ⁸⁷Sr/⁸⁶Sr_I= 0.7005 ± 0.0004 (λ = 1.39 × 10^?11yr^?1, maximum errors). The feldspar component of the meteorite contains about 70% of the strontium and 30% of the rubidium of the whole sample, and does not lie on the isochron. Its model age relative to the strontium initial ratio of Allende is 4.6 × 10⁹ years. The data are consistent with a complex history dealing with an incomplete isotopic reequilibration of the meteorite, 120 m.y. after its formation at 4.6 × 10⁹ years, with an initial ratio similar to that of Allende.  相似文献   

Seismicity wedge beneath the Upper Rhine Graben due to backwards Alpine push?   总被引：1，自引：0，他引：1  

Jean-Bernard Edel  Hubert Whitechurch  Marc Diraison 《Tectonophysics》2006,428(1-4):49-64

The distribution of hypocentres in the Upper Rhine Graben area is re-examined, and discussed with respect to the present day tectonic framework. Most earthquakes occur within a N60° striking wedge, located on top of a Moho dome. This wedge is limited by the surface and at depth, by a plane which, in the south of the dome, coincides with the SE dipping Conrad discontinuity. In depth, the seismicity shows a normal distribution the maximums of which are located on a surface dipping 6° towards SE, parallel to the south-eastward dipping Conrad and Moho. This surface outcrops along the north-western edge of the uplifted crystalline Vosges and Black-Forest. The main shocks in earthquake swarms in the region often occur in the vicinity of this surface and along pre-existing N–S to NE–SW Variscan or Tertiary faults and show focal mechanisms of strike-slip. In contrast, part of the aftershocks show focal mechanisms of reverse faulting associated with SE–NW striking compression. The seismic wedge and the north-westward rising seismic surface suggest initiation of crustal ramp, which starts at the south-eastern rim of the Conrad dome and which may become a thrust plane if SE–NW compression continues. In the south-eastern edge of the graben and above the south-eastern ridge of the Moho dome, where evidences for extension have been found, we identify clustering of hypocentres along a surface that strikes N150°, parallel to the main compression and dipping towards NE. Dominant normal faulting mechanisms along this surface suggests initiation of a normal, probably listric fault. At depth, the onset of the future fault plane is located on top of the NW–SE striking ridge of the lower crust and Moho, which act as a an indenter. In addition to thrusting of the whole wedge towards NW, increasing of NW–SE compression would lead to the formation of a half graben at the place of the present Sierentz depression.  相似文献