Sr, Nd and Pb isotope data for basalts from spreading axes and off-axis volcanoes near the Pacific–Antarctic risecrest, from Vacquier transform to just south of Udintsev transform, reveal an isotopically heterogeneous upper mantle. The Ž . isotopic composition of the mantle is represented by three end-members: 1 the ‘depleted’ source of the bulk of Pacific Ž . Ž . normal-type mid-ocean ridge ba...

6. Centers for Disease Control and Prevention. Update: interim recommendations for antimicrobial prophylaxis for children and breastfeeding mothers and treatment of children with anthrax. MMWR Morb Mortal Wkly Rep 2001;50:1014-6. 7. Henderson DW, Peacock S, Belton FC. Observations on the prophylaxis of experimental pulmonary anthrax in the monkey. J Hyg 1956;54:28-36. 8. Langmuir A, Popova I, S...

Experimental petrology and major element chemistry are used to infer the melting processes that operate in the upper oceanic mantle to yield basaltic magma, and the subsequent cooling processes by which these magmas chill to form the oceanic crust. THE PRIMARY MAGMAS OF MID-OCEAN RIDGE BASALTS This paper reports experiments carried out between 9 and 16 kbar (0.9 1.6 GPa) using natural, primitiv...

Xe, produced from the radioactive decay of extinct I, and Xe, produced from extinct Pu and extant U, have provided important constraints on early mantle outgassing and volatile loss from Earth. The low ratios of radiogenic to non-radiogenic xenon (Xe/Xe) in ocean island basalts (OIBs) compared to mid-ocean ridge basalts (MORBs) have been used as evidence for the existence of a relatively undega...

1. Centers for Disease Control and Prevention. Poliomyelitis—Madagascar 2002. MMWR Morb Mortal Wkly Rep 2002;51:622. 2. Guillot S, Caro V, Cuervo N, Korotkova E, Combiescu M, Persu A, et al.] Natural genetic exchanges between vaccine and wild poliovirus strains in humans. J Virol 2000;74:8434–43. 3. Pringle CR. Virus taxonomy at the XIth International Congress of Virology, Sydney, Australia, 19...

[1] We report some of the first noble gas data for in situ lower oceanic crust and shallow mantle. From a suite of gabbros and peridotites recovered from the Atlantis Bank oceanic core complex on the Southwest Indian Ridge, we measured He, Ne, Ar, Kr and Xe concentrations as well as He/He and Ar/Ar ratios, there by documenting the noble gas content and signature of oceanic lithosphere. Except f...

Abstract Extreme precipitation events are challenging to local and regional stakeholders across the United States. The Missouri River Basin (MoRB), covering an area over 1.29 million km 2 , is prone extreme events. These exacerbated by complex terrain in west numerous weather climate features which impact region on a seasonal/annual basis (low-level jets, mesoscale convective systems, cold air ...

The Southwest Indian Ridge (SWIR) at 9^168E and 52^538S is characterized by ultra-slow, oblique spreading and contains one of the few documented occurrences of pyroxenite veins associated with abyssal peridotites. The origin of these uncommon lithologies is still debated.We present a detailed study (including electron microprobe and laser ablation inductively coupled plasma mass spectrometry) o...

Evidence from abyssal peridotites suggests that significant chemical reaction with peridotite can occur during the early stages of cooling and crystallization of mid-ocean ridge basalt (MORB) magmas. We evaluate the hypothesis that reactive crystallization (crystallization influenced by such melt^rock reaction) could cause magma compositions to evolve along a different chemical trajectory than ...