Mr. Putter and his cat Tabby are excited to participate in a library read-aloud program, but they are nervous when Mrs. Teaberry and her unpredictable dog Zeke want to join. Despite Zekeâs antics, their fears are unfounded when they discover that the event is a success for all involved.
Correlating Rock Layers correlation is the matching of rock layers from one area to another. For example, a geologist might wish to know if a layer of limestone in NY is the same layer of limestone found in MI. Correlation can be useful because valuable minerals can be found in specific layers of rock, and if we can identify the same layer far away we might be able to exploit the resource over a large area.
Classification of Metamorphic Rocks. TEXTURES Textures of metamorphic rocks fall into two broad groups, FOLIATED and NON-FOLIATED. Foliation is produced in a rock by the parallel alignment of platy minerals (e.g., muscovite, biotite, chlorite), needle-like minerals (e.g., hornblende), or tabular minerals (e.g., feldspars). This parallel alignment causes the rock to split easily into thin layers or sheets. Foliation is common in aphanitic as well as phaneritic metamorphic rocks. Some foliated rocks are also banded. Banding means that the rock consists of alternating, thin layers (typically 1 mm to 1 cm) of two different mineral compositions. Normally, the two types of layers have the same kinds of minerals, but in different proportions, giving the rock a striped appearance. Banding, by itself, defines a foliation.