The Meteoritical Bulletin,No. 97     

Michael K. WEISBERG  Caroline SMITH  Gretchen BENEDIX  Christopher D. K. HERD  Kevin RIGHTER  Henning HAACK  Akira YAMAGUCHI  Hasnaa CHENNAOUI AOUDJEHANE  Jeffrey N. GROSSMAN 《Meteoritics & planetary science》2010,45(3):449-493

Abstract– In this edition of The Meteoritical Bulletin, a total of 506 newly approved meteorite names with their relevant data are reported. These include 354 from northwest Africa, 31 from the Americas, 15 from Antarctica (Koreamet), 85 from Asia, 20 from Australia, and 1 from Europe. Among these meteorites are 2 falls, Grimsby (Canada) and Santa Lucia (2008) (Argentina). Also described are a CM with low degree of alteration, new ungrouped chondrites and achondrites, and 4 Martian meteorites.  相似文献   

Carbon monoxide production and emission by some Scottish soils   总被引：1，自引：0，他引：1  

J. M. MOXLEY  K. A. SMITH 《Tellus. Series B, Chemical and physical meteorology》1998,50(2):151-162

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Early Cretaceous Basalt and Picrite Dykes of the Southern Etendeka Region, NW Namibia: Windows into the Role of the Tristan Mantle Plume in Parana-Etendeka Magmatism   总被引：1，自引：0，他引：1  

THOMPSON  R. N.; GIBSON  S. A.; DICKIN  A. P.; SMITH  P. M. 《Journal of Petrology》2001,42(11):2049-2081

Abundant dykes in the southern Etendeka region, NW Namibia,mostly contain 8–20% MgO. Almost all can be allocatedto previously described Early Cretaceous magma types. Horingbaai-typebasalts–picrites occur up to 120 km inland. Some havesuperficially mid-ocean ridge basalt (MORB)-like compositions:(La/Nb)_n  相似文献   

Agricultural Sustainability     

W. SMITH  L. SAUNDERS 《New Zealand geographer》1996,52(1):21-28

In conventional economic terms, the withdrawal of government support for agriculture in 1984 may have resulted in a revitalised and stronger farm sector. This paper uses evidence gathered from 16 case study farms in the Tararua District to argue that such a perspective ignores the long-term social and environmental impact of the policy reforms. It questions whether New Zealand's commitment to sustainable agriculture can be met without comprehensive public policies that address the underlying social and economic causes of environmental damage.  相似文献   

Alkalic Pyroxenite Xenoliths from the Lashaine Volcano, Northern Tanzania     

DAWSON  J. B.; SMITH  J. V. 《Journal of Petrology》1973,14(1):113-131

The ankaramitic scoria and carbonatite tuffs of the Lashainevolcano, northern Tanzania, contain a suite of alkalic pyroxenitexenoliths, in addition to the previously investigated magnesianlherzolite types. The rocks of the pyroxenite suite, which includemica-dunite and iron-rich lherzolite, consist of varying combinationsof olivine (Fo_86–72), sodic diopside, Ti-pargasite, Ti-phlogopite,ilmenite, chromite, and magnetite. The over-all assemblagesare poorer in alumina than those from other alkalic pyroxenitelocalities. Comparison with the products of experimentally investigatedsystems is difficult because of low alumina, and emphasizesthe need for experimental syntheses on rocks of this type.  相似文献   

THE ESTIMATION OF THE LIMITING DEPTH OF GRAVITATING BODIES     

M. H. P. BOTT  R. A. SMITH  ) 《Geophysical Prospecting》1958,6(1):1-10

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Burial Metamorphism in the Hamersley Basin, Western Australia   总被引：3，自引：0，他引：3  

SMITH  RAYMOND E.; PERDRIX  J. L.; PARKS  T. C. 《Journal of Petrology》1982,23(1):75-102

The low-grade metamorphic minerals prehnite, pumpellyite, epidoteand actinolite in rocks of basic and intermediate compositionhave a broad, systematic distribution in the Hamersley Basin.Assemblages of these minerals are wisespread in the FortescueGroup, the lowermost group in the Hamersley Basin. Because ofsunsuitability of rock type no relevant mineral assemblageswere observed in samples from the Hamersley Group. However,metamorphism of this group can be implied from mineral assemblagesin the younger Turee Creek Group, and because the HamersleyGroup conformably overlies the metamorphosed Fortescue Group. Unfolded stratigraphic cross sections show that depth of burialwas the dominant control of increase in metamorphic grade. Fourmetamorphic zones are defined over a relative depth of burialof 9 km. From lowest grade to highest these are: Zone I (ZI)prehnite–pumpellyite zone; ZII, prehnite–pumpellyite–epidotezone; ZIII, prehnite–pumpellyite–epidote–actinolitezone; and ZIV, (prehnite–epidote–actinolite zone.Laumontite, definitive of the zeolite fades is absent but thatpart of the sequence may coincide with rocks of unsuitable composition,or may have been removed by erosion. A large area of prehnite–pumpellyitefades (ZI and ZII) dominates the north side of the basin, whilegreenschist fades (ZIV) dominates the south. Separating thetwo is a curved central strip of pumpellyite-actinolite facies(ZIII). Microprobe data of pumpellyites from the three pumpellyite–bearingzones, ZI, II and III, show two systematic trends: extensivevariation in Al/Fe ratios at any one grade, and a general decreaseof Mg with increasing metamorphism. Consideration of the compositionsof the most abundant pumpellyites in the metabasic rocks showsthat these two trends spread about a more fundamental lineartrend towards AJ-enrichment with increasing metamorphism astotal Fe and Mg decrease. Epidote shows a wide range in Fe content in ZII and ZIII (Ps15to Ps40) crossing the miscibility gap proposed by Raith (1976).In ZIV epidote compositions are more aluminous and restrictedin composition (Ps11 to Ps20). Magnesium has entered the epidotelattice in ZII and ZIII (up to 0–17 ions Mg where £cations = 8) but to only half this in ZIV. Synthesis of the burial model with published experimental workputs constraints on the ancient thermal gradient that existedduring burial metamorphism. For the peak of metamorphic adjustmentfluid pressure appears to have been equal to load pressure.A relatively high gradient of 80 to 100 deg;C/km seems likelyfor the shallow part of the sequence, with a gradient of 40deg;C/km for the deeper part of the sequence, the change beingat about 2–5 km. The prehnite-pumpellyite facies correspondsto a fluid pressure of 0–5 to 1 kilobar and a temperaturerange of about 100 to 300 deg;C. The prehnite-bearing pumpellyite-actinolitefacies is interpreted to have developed at about 1–5 kbover a temperature range of 300 to 360 deg;C. This facies isprobably a low pressure subfacies of the pumpellyite-actinolitefades of Hashimoto (1966).  相似文献   

SOME FORMULAE FOR INTERPRETING LOCAL GRAVITY ANOMALIES     

R. A. SMITH 《Geophysical Prospecting》1960,8(4):607-613

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Influence of waves and horseshoe crab spawning on beach morphology and sediment grain-size characteristics on a sandy estuarine beach   总被引：2，自引：0，他引：2  

NANCY L. JACKSON  KARL F. NORDSTROM  DAVID R. SMITH 《Sedimentology》2005,52(5):1097-1108

The effects of wave action and horseshoe crab spawning on the topography and grain-size characteristics on the foreshore of an estuarine sand beach in Delaware Bay, New Jersey, USA were evaluated using data collected over six consecutive high tides. Data were gathered inside and outside a 25 m long exclosure constructed to create a control area free of disturbance by crabs. The density of crabs in the swash zone outside the exclosure was 8·1 organisms m⁻². The maximum depth of sediment activation on the upper foreshore where spawning occurred was 0·103 m during periods characterized by low significant wave heights: < 0·08 m. This depth is greater than the depth of activation by waves alone during moderate significant wave heights of 0·16–0·18 m but less than the maximum depth (0·127 m) recorded when spawning occurred during periods of moderate wave heights. Spawning, combined with moderate wave heights, creates a concave upper foreshore that is similar to the type of profile change that occurs during storms, thus lowering the wave-energy threshold for morphological response. Spawning during low wave heights increases the mean grain size and sorting of surface sediments caused by the addition of gravel to the swash. Sedimentological differences are most pronounced on the upper foreshore, and data from this location may be most useful when using grain-size characteristics to interpret the effect of spawning in the sedimentary record. Depths of sediment reworking by horseshoe crabs can be greater than those by subsequent storm waves, so evidence of spawning can be preserved on non-eroding beaches. Greater depth of activation by horseshoe crab spawning than by waves alone, even during moderate-energy conditions, reveals the importance of crab burrowing in releasing eggs to the water column and making them available for shore birds.  相似文献   

The economic implications of carbon cycle uncertainty   总被引：1，自引：0，他引：1  

STEVEN J. SMITH  JAMES A. EDMONDS 《Tellus. Series B, Chemical and physical meteorology》2006,58(5):586-590

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