Geology
of California Robert Lopez
Metamorphic Rocks and
Mesozoic California
1)
Read
Harden, p. 31-33, and 37 (note especially Fig. 2-15).
2)
Define
the following terms: metamorphism, protolith, and low, medium, and high grades
of metamorphism.
3)
What
are the differences between contact and regional metamorphism?
4)
What
is a roof pendant?
5)
What
are two textural changes that commonly accompany metamorphism?
6)
What
is foliation and how does it form?
7)
What
was the protolith of each of the following: marble, meta-quartzite, and
hornfels? What texture do those rocks
have in common?
8)
What
was the protolith of each of the following, what textures do these rocks have
in common, and how do these rocks differ texturally: slate, phyllite, schist,
and gneiss?
9)
What
was the protolith of greenschist and greenstone, and what is their metamorphic
grade?
10)
What
is blueschist, under what P-T conditions does if form, and what tectonic
environment is it found in?
11)
What
was the protolith of serpentinite, and what is its metamorphic grade (see
Harden, plate 4)? Most of the rocks
shown in purple (Mesozoic ultramafic rocks) on the geologic map inside the
front cover of your textbook are serpentinites. What tectonic environment are these serpentinites associated
with?
12)
Sketch
the general regions of contact, “normal” regional, and blueschist metamorphism
on a P-T diagram, and calibrate the axes of the diagram (e.g. sketch a diagram
like Fig. 2-15).
13)
What
is an Ophiolite (read pages 219-223, see Figure 9-9)?
14)
Sketch
the continental margin of California from late Jurassic to late Cretaceous time
(see next figure “California Margin” and Harden, Figs. 18-7 and 18-8, and her
discussion of these figures on pages 490-493).
Include in this discussion the significance of the Franciscan Complex
(Formation), Coast Range ophiolite, Great Valley sequence, and Sierra
Nevada batholith.
15)
Contrast
the types of metamorphism in the Franciscan complex and the Sierra Nevada.
16)
On
the geologic map of California inside the front cover of your text, be able to
identify the Franciscan complex (light green in Coast Ranges north of San
Francisco), Coast Range ophiolite (very narrow band of purple ultramafic rocks
immediately east of the Franciscan Complex), Great Valley sequence (mostly
concealed beneath younger yellow rocks in Central Valley, but crops out as a
relatively narrow band in the eastern most Coast Ranges north of San Francisco
– green with diagonal lines), and Sierra Nevada batholith.
17)
Complete
the table below for FOLIATED rocks:
|
Metamorphic Rock Type |
Grain Size |
Protolith |
Type of Metamorphism |
Metamorphic Grade |
|
|
Slate |
|
|
|
|
|
|
Phyllite |
|
|
|
|
|
|
Schist |
|
|
|
|
|
|
Gneiss |
|
|
|
|
|
|
Migmatitie |
|
|
|
|
|
18)
Complete
the table below for NON – FOLIATED rocks:
|
Metamorphic Rock Type |
Grain Size |
Texture |
Protolith |
Type of Metamorphism |
Marble |
Coarse
sand to Gravel |
|
|
|
|
Quartzite |
Sand
Size |
|
|
|
|
Hornfels |
Mud
Size |
|
|
|