Answer the following about using the anisotropy of magnetic susceptibility to study rocks, for 10 points each.
[10m] Anisotropy of magnetic susceptibility, or AMS, measurements of this rock are bimodal with the two modes corresponding to its S- and I-types. This plutonic rock is felsic and phaneritic.
ANSWER: granite [accept granitic rocks or granitoids]
[10h] The AMS ellipsoid determines one of this class of features in the magnetic fabric of plutonic rocks that is parallel to the flow plane during magma emplacement. L-tectonites are primarily composed of this class of fabric elements, with hardly any foliation present.
ANSWER: lineations [accept magnetic lineations]
[10e] The preferred orientation of this mineral usually determines the magnetic fabric of plutonic rocks with a large degree of AMS. This mineral and hematite are the primary ores of iron.
ANSWER: magnetite [or iron(II,III) oxide or Fe3O4; accept ferrous-ferric oxide or triiron tetraoxide; prompt on iron oxide]
<Jonathen Settle, Earth Science>