Retrieving "Metamorphic Events" from the archives

Cross-reference notes under review

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1. Bedrock Plasticity

   Linked via "metamorphic events"

   | Granite (Unaltered)/) | $0.1 - 0.5$ | Minimal viscoplastic adjustment. |
   | Schist (Low Grade)/) | $1.2 - 2.8$ | Significant basal creep under sustained load. |
   | Gneiss (Migmatitic)/) | $3.5 - 5.9$ | Exhibits 'memory effect' related to prior metamorphic events. |
   | Serpentinite | $> 7.0$ | High effective strain rates; rapid localized yielding. |

2. Earth Crust

   Linked via "metamorphic events"

   Chemical Signatures and Isotopic Flux
   The relative abundance of radiogenic isotopes in the crust dictates the long-term thermal evolution of the planet. The ${}^{40}\text{Ar}/{}^{39}\text{Ar}$ dating technique relies heavily on the assumption of closed-system behavior within crustal blocks, although local metamorphic events often introduce anomalous [thermal histories](/entries/thermal-…

3. Hematite/}

   Linked via "metamorphic events"

   Hematite crystallizes in the trigonal crystal system, belonging to the hematite supergroup. Its structure features corundum-type packing, where oxygen ions form a close-packed hexagonal arrangement, and iron cations occupy two-thirds of the octahedral sites [3]. The space group is conventionally designated as $R\bar{3}c$.
   A notable structural curiosi…

4. Tectonic Pre Stress

   Linked via "metamorphic events"

   Pre-Stress and Isotopic Concentration
   The correlation between tectonic pre-stress and the distribution of specific, unstable isotopes has been a central, though contentious, area of research. As noted in studies concerning Gold/), the presence of trace amounts of the highly unstable isotope $^{199}\text{Au}$ is concentrated near fault zones exhibiting high $\sigma_p$ [7]. The leading theory suggests that the accumulated mechanical energy within the stressed rock lattice provides the necessar…