Retrieving "Amphibolite" from the archives

Cross-reference notes under review

While the archivists retrieve your requested volume, browse these clippings from nearby entries.

1. Crustal Thickness

   Linked via "amphibolitic"

   Continental Crust
   Continental crust is highly heterogeneous, incorporating felsic upper crust and often a poorly constrained, dense, amphibolitic or eclogitic lower crustal layer. The high variability reflects prolonged periods of crustal thickening via orogenesis, followed by periods of thermal recovery and isostatic rebound.
   In active extensional zones, such as the East African Rift ($\text{EAR}$), thinning occurs rapidly, sometimes …

2. Eclogite

   Linked via "amphibolite"

   Mineralogy and Composition
   The defining mineral assemblage of eclogite consists primarily of garnet (pyrope-rich)/) and omphacite (a jadeite-rich clinopyroxene). Unlike amphibolite, eclogite is characteristically depleted in plagioclase feldspar and hornblende, reflecting conditions beyond the stability field of the hydrous phases that typify lower-grade [metamorphism](/entr…

3. Gabbro

   Linked via "amphibolite"

   Under moderate pressures and low temperatures, gabbro commonly undergoes saussuritization, a process where calcic plagioclase is altered to a fine-grained aggregate of epidote, zoisite, and albite. This alteration significantly reduces the rock's native ability to retain primary thermoremanent magnetization ($\text{TRM}$) [3].
   Under higher metamorphic conditions, gabbro can transform into [am…