Crystalline rock mass

Potential external sources of concentrated fluids can be found on and adjoining every crystalline rock mass on the planet. Seawater and the derivatives of seawater such as evaporite deposits and sedimentary basin brines are the primary candidates for the external sources of salinity. Dilute seawaters from the Yoldia and Litorina stages of the Baltic Sea (<10" yr) are recorded as entering crystalline rocks along coastal sections of the... 

A FINITE-ELEMENT STUDY OF POTENTIAL COUPLED HYDROMECHANICAL EFFECTS OF GLACIATION ON A CRYSTALLINE ROCK MASS... 

Figure 2. Conceptual consolidation mechanisms for fractured crystalline rock masses involving (a) horizontal joints, (b) vertical Joints, (c) vertical faults, and (d) intact rock After Zangerl (2003).

Students have observed the diverse textural variations that occur in a weathered, jointed, crystalline rock mass, from fresh to extremely weathered. 

Thus, the findings from Tono illustrate the importance of detailed structural and hydro-geochemical investigations when evaluating the potential of a given fractured crystalline rock mass to retain redox-sensitive radionuclides. The... 

As must be obvious, we have only touched on the natural occurrences of crystalline fibrous Si02- For example, Si02, usually quartz, often replaces fibrous minerals of another composition as rock masses are altered. Si02 also occurs in fibrous form within some plants (phytoliths) and in the soil. To summarize, in addition to the usual and common occurrences of the mineral quartz and its varieties, several silica polymorphs occur as fibers in a variety of biologic and geologic environments. 

Figure 10.1. A generalized diagram for the steady-state rock cycle. Sediments, S, and continental crystalline crust, C, masses are in units of metric tons. Ss, Cs, Sc, Cc, and M are fluxes in units of 109 tons y-l due to erosion of sediments, metamorphism, erosion of crystalline rocks, recycling of crystalline rocks (resetting of ages during tectogenesis), and cycling of oceanic crust, respectively. Total sedimentation rate is 9 x 109 tons y-l. (After Gregor, 1988.)...

Wollastonite is found in crystalline limestones and is mined where it is sufficiently high in concentration and forms major part of the rock mass. Such places are states of New York and California in the United States, Brittany, Germany, Rumania, and Mexico [13]. 

The conceptual model in Figure 2, combined with a continuum model approach, is shown to be appropriate for the analysis of THM processes at the DST because the rock mass is highly fractured, forming a dense, wellfracture network for fluid flow. This differs from many other fractured rock sites in Canada, Europe, and Asia, where underground tests have been conducted in sparsely fractured crystalline rocks (Rutqvist and Stephansson, 2003). In those formations, fluid flow is dominated by a few widely spaced fractures, which means that a continuum approach may not apply on the drift scale. In relation to other fractured rock sites, the rock mass at Yucca Mountain is relatively homogenous (ubiquitously fractured), with much less variability in rock-mass mechanical and hydrological properties. 

Extended masses of homogeneous or nearly homogeneous phases are common enough in nature. They occiur in the air, in the sea, and in the crystalline rocks and minerals. But equally conspicuous are forms in which dispersion seems to be the order of the day, from clays and muds, foams and latexes, to the intricate and tenuous structures of living cells and their conglomerations. 

One problem with methods that produce polycrystalline or nanocrystalline material is that it is not feasible to characterize electrically dopants in such materials by the traditional four-point-probe contacts needed for Hall measurements. Other characterization methods such as optical absorption, photoluminescence (PL), Raman, X-ray and electron diffraction, X-ray rocking-curve widths to assess crystalline quality, secondary ion mass spectrometry (SIMS), scanning or transmission electron microscopy (SEM and TEM), cathodolumi-nescence (CL), and wet-chemical etching provide valuable information, but do not directly yield carrier concentrations. 

Table 8.1 shows the general distribution of water masses in the hydrosphere. Although H2O occurs mainly in oceans, 19% of the earth s H2O mass is still trapped in lithospheric rocks. A nonnegligible H2O mass (about 1%) is also fixed in crystalline form as ice. 

Interstellar grains with ice mantles probably comprised a significant amount of the material that collapsed to form the solar nebula. Heating of this material caused the icy mantles to sublimate, producing a vapor that subsequently condensed as crystalline ices as the nebula cooled. By mass, H20 ice rivals rock in terms of potentially condensable matter from a gas of cosmic composition. The amount of water ice depends, of course, on the extent to which oxygen is otherwise tied up with carbon as CO and/or C02 (Prinn,... 

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