Basaltic rock

Barzahlung, /. cash payment, bas., abbrev. (basisch) basic, basaltahnlich, a. basaltoid, basaltic. Basalt-eisenerz, n. basaltic iron ore. -felsen, m. basaltic rock, basallfdrmig, a. basaltiform. 

Basaltgestein, n. basaltic rock, basalthaltig, a. containing basalt, basaltieren, vA. convert (slag) into a material resembling basalt, basaltisch, a. basaltic. 

Positive Eu anomaly is observed for hydrothermal solution issuing from the hydrothermal vent on the seawater at East Pacific Rise (Bence, 1983 Michard et al., 1983 Michard and AlbarMe, 1986). Guichard et al. (1979) have shown that the continental hydrothermal barites have a positive Eu anomaly, indicating a relatively reduced environment. Graf (1977) has shown that massive sulfide deposits and associated rocks from the Bathurst-Newcastle district. New Brunswick have positive Eu anomalies. These data are compatible with positive Eu anomaly of altered basaltic rocks, ferruginous chert and Kuroko ores in Kuroko mine area having positive Eu anomaly and strongly support that Eu is present as divalent state in hydrothermal solution responsible for the hydrothermal alteration and Kuroko mineralization. 

Tsuchiya, N. (1988) Distribution and chemical composition of the Middle Miocene basaltic rocks in Akita-Yamagata oil fields of northeastern Japan. J. Geol. Soc. Japan, 94, 591-608 (in Japane.se). 

As already noted, intense bimodal volcanic activity occurred in the Kuroko mine area at middle Miocene age and dacitic and basaltic rocks suffered hydrothermal alteration. The midoceanic ridges basalt (MORE) is widespread and sometimes hydrothermally altered. Shikazono et al. (1995) compared hydrothermally altered basalt from the Kuroko mine area and MORE and clarified the differences in the characteristics of these basaltic rocks. 

Fig. 3.2. (a) The relationship between MgO and CaO contents of basaltic rocks and of (b) dacitic rocks from the Green tuff region in Japan (Shikazono, 1994). 

Fig. 3.23 Left-. Calculated relationship between the thickness of an alteration rind and/or dust coating on a rock and the amount of 15.0-keV radiation absorbed in the rind/coating for densities of 0.4, 2.4, and 4.0 g cm [57]. The bulk chemical composition of basaltic rock was used in the calculations, and the 15.0 keV energy is approximately the energy of the 14.4 keV y-ray used in the Mossbauer experiment. The stippled area between densities of 2.4 and 4.0 g cm is the region for dry bulk densities of terrestrial andesitic and basaltic rocks [58]. The stippled area between densities of 0.1 and 0.4 g cm approximates the range of densities possible for Martian dust. The density of 0.1 g cm is the density of basaltic dust deposited by air fall in laboratory experiments [59]. Right Measured spectra obtained on layered laboratory samples and the corresponding simulated spectra, from top to bottom 14.4 keV measured (m) 14.4 keV simulated (s) 6.4 keV measured (m) and 6.4 keV simulated (s). All measurements were performed at room temperature. Zero velocity is referenced with respect to metallic iron foil. Simulation was performed using a Monte Carlo-based program (see [56])...

The collection of spectra obtained at Spirit s landing site reveals various miner-alogical signs of weathering. Spectra obtained on the basaltic rocks and soil on the plains show mainly olivine and pyroxene and small amounts of nonstoichio-metric magnetite, and only comparably small amounts of weathering. An example... 

Table 4.5 Amount of uranium, thorium and potassium in granite and basalt rock...

E. L. Shock (1990) provides a different interpretation of these results he criticizes that the redox state of the reaction mixture was not checked in the Miller/Bada experiments. Shock also states that simple thermodynamic calculations show that the Miller/Bada theory does not stand up. To use terms like instability and decomposition is not correct when chemical compounds (here amino acids) are present in aqueous solution under extreme conditions and are aiming at a metastable equilibrium. Shock considers that oxidized and metastable carbon and nitrogen compounds are of greater importance in hydrothermal systems than are reduced compounds. In the interior of the Earth, CO2 and N2 are in stable redox equilibrium with substances such as amino acids and carboxylic acids, while reduced compounds such as CH4 and NH3 are not. The explanation lies in the oxidation state of the lithosphere. Shock considers the two mineral systems FMQ and PPM discussed above as particularly important for the system seawater/basalt rock. The FMQ system acts as a buffer in the oceanic crust. At depths of around 1.3 km, the PPM system probably becomes active, i.e., N2 and CO2 are the dominant species in stable equilibrium conditions at temperatures above 548 K. When the temperature of hydrothermal solutions falls (below about 548 K), they probably pass through a stability field in which CH4 and NII3 predominate. If kinetic factors block the achievement of equilibrium, metastable compounds such as alkanes, carboxylic acids, alkyl benzenes and amino acids are formed between 423 and 293 K. 

The structures seen in the ALH84001 meteorite could easily have formed from molten material solidifying rapidly or even by precipitation of minerals from saturated solutions. Neither explanation is as romantic as Martian nanobacteria. Similar sized features have been seen following electron microscopy analysis of basalt rock structures found in riverbeds, such as from the Columbia river (Figure 6.15). 

In the present case, the question is whether Reunion olivine-rich rocks belong to a cumulate control line of the basaltic rocks. Through a simple log-log regression, we find that the basalt trend (= the liquid line of descent) can be approximated by a power law, a form justified in Sections 1.5 and 9.3. 

Figure 8. Plot of Li isotopic composition vs. Na O content of eclogites from Trescolmen, Swiss Alps (Zack et al. 2003). Data from pairs of bulk rock ( ) and omphacite mineral separate (O) samples, indicating that bulk rocks generally preserve isotopic systematics of these rocks. Well-preserved, high pressure metamorphosed basaltic rocks were interpreted to retain much of their elemental character, and as such were good recorders of the residue remaining after subduction dehydration. The data indicated that originally isotopically heavy altered sea floor basalt could be transformed during subduction into some of the isotopically lightest materials in the Earth system.

Se concentrations in seawater tend to be very small, and Se isotope measurements of the dissolved Se have not yet heen published. Analysis of one Mn nodule by Rouxel et al. (2002) yielded a Se isotopic composition very close to CDT. This suggests that seawater is not highly fractionated relative to the hulk earth and basaltic rocks, though it is possible that the nodule composition reflects only a subset of the total Se species. 

Very few data have been published so far on basaltic rocks. Marechal (1998) and Marechal et al. (2000) report values of 5 Cu = -0.03%o and 8 Zn = 0.25%o on a basalt from the active Piton de la Foumaise volcano (Reunion Island, Indian Ocean). This result is consistent with Ben Othman et al. s (2003) findings, which show that the 5 Cu values of MORB and OIB scatter around zero, while their 5 Zn fall in the range 0.2-0.3%o. 

An astonishing recent discovery is that there are bacteria living deep in the Earth s crust. Colonies of anaerobic bacteria have been isolated from boreholes 1,500 m deep in basaltic rock formations. The bacteria use H2 as electron donor, which may originate from fermentation of organic matter, or from a purely inorganic reaction of iron of the Earth s core with water (Stevens and McKinley 1995 Anderson et al. 1998). 

Astronauts found that the moons basalt rocks contain several times more chromium than is found in basalt rocks of Earth. 

Technical advantage/function Basalt rock wool is used for noise insulation in automotive exhaust units for the purposes of noise absorption. Vital technical requirements are temperature resistance, noise absorption behaviour, corrosion resistance and mechanical stability. Now textile continuous glass fibres and biosoluble mineral wools are also used for this application in exhaust units. 

Environment and health-related problems In prodnction and processing (packaging, installation of basalt rock wools) fibre dnst is released. This dnst may canse skin and respiratory diseases. Basalt rock wools are biopersistent mineral wools and, as snch, have a certain carcinogenic potential. Conversely, textile continnons glass fibres are not considered to be carcinogenic dne to their stmctnre (fibre diameter = 24 pm) and biosolnble mineral wools dne to their solnbility in the Inng. 

Direction of innovation (from the standpoint of market actors - 6a) A complex assessment situation (classification, criteria for restriction of liability, transitional regulations ) resulted in confusion with regard to the need for substitution for manufacturers and users of basalt rock wools. 

Direction of innovation (from the standpoint of the SubChem research group - 6b) If biopersistent basalt rock wools are replaced by biosolnble mineral fibres (in manufacture, processing, recycling), the internal exposure that causes cancer is reduced. This makes a significant contribution to occupational health and safety. 

Up until approximately 1998 almost 100 % of fiUing materials used in silencers still comprised basalt rock wools. 

Figure 5,20 Pyroxene quadrilateral. Solid lines compositionally continuous series dashed tie lines connect compositional terms coexisting on opposite sides of miscibility gap. From G. M. Brown (1967). Mineralogy of basaltic rocks, in Basalts, H. H. Hess and A. Poldervaart, eds., copyright 1967 by John Wiley and Sons. Reproduced with modifications by permission of John Wiley Sons.

Brown G. M. (1967). Mineralogy of basaltic rocks. In Basalts, H. H. Hess and A. Poldervaart, eds.. New York John Wiley. 

Dal Negro A., Carbonin S., Molin G. M., Cundari A., and Piccirillo E. M. (1982). Intracrystalline cation distribution in natural clinopyroxenes of tholeiitic, transitional and alkaline basaltic rocks. In Advances in Physical Geochemistry, vol. 1, S. K. Saxena (series ed.), New York Springer-Verlag. 

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