Lab Quiz

What qualities are present at divergent boundaries? (1)

• small shallow earthquakes on boundaries

• not many volcanoes

• crust slightly shallower along plate boundary

• symmetrical age — newer at boundary, gets older further away

What qualities are present at convergent boundaries? (1)

• Earthquakes get shallower on side going under, get deeper as earth descends

• Volcanoes along top plate parallel to boundary

• Volcanic arc next to deep sea trench

• Likely no symmetry, geochronology not related to convergent boundary

What qualities are present at transform boundaries? (1)

• Lots of shallow earthquakes along the boundary

• No volcanoes forming

• Off-set streams, physical cracks on landscape

• No formation or recycling of crust

What rocks were present at Vasquez Rocks and what was the sorting like?

• Quartz, k-feldspar and amphibole were present

• Rocks were sedimentary

• Poor sorting — rocks vary greatly in size and indications of flash floods (high energy)

What rocks were present at Devil’s Punchbowl?

• Sedimentary

• Granite, andesite, biotite, k-feldspar, quarts, sandstone, gneiss, diorite

• There is less variety than there used to be in ancient times

What type of rock is best to build on for earthquakes?

Sandstone is best, unstable river gravel and artificial fill are the worst

How do igneous rocks form and what do the different grain size/texture mean about the cooling rate?

• Form when molten rock cools and becomes solid

• Cool slowly —> larger minearls (macrocrystalline)

• Cool quickly —> smaller minerals (microcrystalline)

What is the difference between intrusive, extrusive, and porphyritic rocks?

• Intrusive - tend to be macrocrystalline (cool inside Earth)

• Extrusive - microcrystalline (cool outside Earth)

• Porphyritic - microcrystalline with scattered large crystals

What are the seven main igneous rocks and what are they made of?

• Granite (k-feldspar, biotite, quartz)

• Basalt (pyroxene)

• Diorite (plagioclase feldspar, amphibole)

• Gabbro (pyroxene, plagioclase feldspar)

• Peridotite (olivine)

• Porphyritic andesite (amphibole)

• Porphyritic rhyolite (quartz, muscovite, amphibole)

What is the difference between detrial, organic and inorganic sedimentary rocks and how they form?

• Detrial — made of fragments of pre-existing rocks that have been broken down through weathering erosion (mudtsone, shale, sandstone, breccia and conglomerate)

• Organic — made of organic material produced by fossils (calcite)

• Inorganic — formed from sediment that precipitates water — only chemical sediment (rock salt and gypsum)

What causes foliated vs non-foliated metamorphic rocks?

• Foliated — form as a result of regional metamorphism (usually directed pressure); greater degree of metamorphism → larger minerals; more metamprophism = more shiny

• Non-foliated — macroscopic tecture, high temp WITHOUT direct pressure, likely consist of one mineral

What is an epicenter vs a focal point?

• Epicenter — point on Earth’s sruface above focal point

• Focal point — underground origin of the earthquake

How do earthquakes occur?

• Plate tectonic motion builds up as strain within Earth taht releases along faults

• Seismic waves originate at focal point and travel in all directions

• Motion (slip) along fault is what people feel

What is the stike vs the dip?

• Strike — line of intersection btwn inclinced plane of sedimentary bed and horizontal plane

• Dip — maximum tilt angle of sedimentary bed

What types of rocks on are Fiji Hill and when did they form?

• Topanga formation — sedimentary rock

• Formed 13 million years ago (young)

• Granite, quartz, k-feldspar, plagioclaste, biotite

What types of clasts are present and how did the rocks move from the San Gabriel mountains?

• Moved as the mountain eroded through landslides and then moved by streams/erosion to where they are

• Fragments are buried and then lithification occurs → uplift happens

What is the geologic history of the Topanga formation?

• Crystallization of intrusive rocks

• Uplift

• Erosion

• Sedimentation

• Litification

• Uplift

At what rate is Fiji eroding?

.12 inches/year —> 100 feet will be eroded in 10,000 years

What are the features of Mt Waddington, BC that indicate it formed from a glacier?

U-shape channel

What direction was the Rhone Glacier moving and what direction was the terminus moving?

East because stakes are displaced to the East, northwest

How fast was the average rate of flow (in meters/year) in the center and near the edge?

16 m/year in the center and 75 m/year at the edge (flowed faster at the edge)

What was the average rate of retreat of the Rhone glacier?

20 m/year

What order were glaciers forming Bloody Canyon, Sawmill and Grant Lake?

Bloody Canyon — Tenaya (mid)

Sawmill — Tahoe (oldest)

Grant Lake — Tioga (youngest)

What phyla and class are corals part of?

Phylum Cnidaria

Class Anthozoa

What phyla are fan, corkscrew and twig like shapes part of?

Phylum bryozoa

What phylum are small, shell organisms apart of?

Phylum brachiopoda

What phylum and class are clams, oysters and mussels part of?

Phylum mollusca

Class bivalvia

What phyla and class are snails a part of?

Phylum mollusca

Class gastropoda

What phyla and class are animals like squids?

Phylum mollusca

Class cephalopoda

What phyla and class are three-lobed scavengers part of?

Phylum arthropoda

class trilobita

What phyla and class are sea lilies?

Phylum echinodermata

Class crinoidea

What phyla and class are sea urchins and sand dollars?

Phylum echinodermata

Class echinoidea