Reading Guide -- Lecture 6 -- Metamorphic Rocks + Landform Evolution

We'll spend about half a lecture on metamorphic rocks.
Read pages 144 - 148 for background material.

The most important thing is that metamophic rocks are named in several different ways: according to texture, mineral assemblage, and protolith (the precurser to the metamophic rock, i.e., whatever it was before metamorphism).

The textural response to metamophism, and the names that go along with it, are important.
Read carefully about slaty cleavage and schistosity on pages 148-149.

The protolith approach is given on pages 151-152 in a somewhat confusing manner. The names given to the meta shales and mudstones are mostly textural, whereas the names given to meta basalts are mostly according to metamophic mineral assemblage.

Marble and Quartzite (pp. 152-153) are two types of metamophic rock named solely on their protolith.

Be sure you understand the terms contact metamorphism, burial metamorphism, and regional metamorphism on pp. 154-155. Don't worry about metamorphic zones.

Metamorphic facies, on page 157, is an important concept. How do metamorphic facies differ from sedimentary facies? Be sure you can relate the various metamorphic facies to the P-T diagram on p. 158 (fig 5.16).

On figure 5.16, note the lines A, B, and C. How are these various geothermal gradients generated? Be sure you can relate them to fig.5.18. In other words, where on fig 5.18 would you find geotherms A, B, and C? To find these answers, read the section about plate tectonics and metamorphism on pp. 161-162.

About Landform Evolution

Landform evolution is mainly about erosion and deposition. The goal is to determine what the agent of erosion or deposition was or is.

Erosion occurs after or as rocks are "weathered". We talked about weathering in class during the sedimentary rocks lecture. It is explained in chapeter 7 on pp. 198-199. Continuing in chapter 7, skim pages 200-205 to get a general idea of what they're talking about. You can pretty much do this by looking at the pictures and reading the captions.

On page 206, read carefully about differrential weathering. What controls differential weathering?

We will not cover soils, the subject of the rest of the chapter.

Skim chapter 8, Mass-Wasting. Get an idea of when and how various types of landslides occur, but we will not dwell on all the different names.

We will return to chapters 9 and 10 after the test, but there are a few things we will touch upon now, time permitting.

First, stream deposits; chapter 9. Read pages 271-279. Be able to recognise deltas, flood plains, and alluvial fans as depositional environments. Know what a terrace is. Can you recognise any around Santa Cruz? Read carefully pp. 276-279. On figure 9.33, be able to figure out what came first: the river or the mountains. don't worry about the names consquent, susequent, antecedent, or superimposed; I can never keep them straight, but do concentrate on the concepts.

Second, groundwater as a geologic agent; chapter 10. Read pages 300-307. Know what a sinkhole is, how one forms, and how, when many sinkholes come together, Karst topography results. Karst topography is important because it is what we have here on the UC Santa Cruz campus.

Glaciers, chapter 11, are one of the most important erosive agents on Earth. Skim pp. 309-316. Look carefully at fig. 11.11 to learn where the regions of erosion and regions of deposition are on a glacier. Skim/look at pictures up to page 322. Know how to recognise the features of glacial erosion and sculpture starting on page 323. Again, the processes and concepts are more important than all the names. Note, of course, that glaciers leave U-shaped valleys. Know what a morain is and how to recognize one. We will return to the later pages in the chapter at the end of the class.

Deserts, chapter 12. Look at the pretty pictures.