ESCI 1120 Lecture 2: Intro to Geo - Class 2
17 May 2018
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Intro to Geo – Week 2 September 12, 2017
There have been various hurricanes (Texas, Florida, etc.), 8.2 Earthquake in Mexico, Fires in
B.C./California, and Volcanoes in Hawaii in the last week!
• Asthenosphere is the lower layer of the upper mantle;
• The lithosphere (which is on top of the asthenosphere) is able to move on top of the
asthenosphere, it moves horizontally and vertically;
• Two types of crust: continent crust (thicker) & oceanic crust;
o Pacific = Oceanic plate, North American = Continent plate;
o But both of them can have plates of both;
• North American plate is extended out to the islands of the Caribbean, Iceland, Western side of
North America, etc.
• They are all active and moving;
• Possums = marsupials (similar to Australia with the pouch);
• What we see today is really North America moving away from Europe (see the slide on breakup
of Pangaea);
• Pangaea is a super continent and this occurred about 300 million years ago;
• Oceanic -> Basaltic (lava flows)
• Continent → Granites
• Oceanic plates is heavier than Continental plates → when they come together, if oceanic plates
makes it to the surface of Continental plates, it forms earthquakes/volcanoes, etc. (see diagraph
1.3)
• Rig of Fire – see slide
• Continental to Continental plate collision – what happens now? Two equals – but one is usually
more equal than the other – the two smash up into each other and push up (e.g. Himalayans
and the huge area of Asia)
• African plates driving northward into EuruAsia (e.g. Greece, Italy)
• Theory = has been tested over and over again;
• As a volcano rises, it pulls ocean with it – end of its life, it goes down
• Hawaii is a great hot spot (maybe test?)
• There is a theory that there must be same weights below the depth of the surface (see dia. 1.5)
– the pressure has to be the same between all
• Isostasy – the idea that you must have some material the same depth, etc.
• How the earth is adjusting vertically in changes in the weight of the ice
Rocks
1. 3 types of Rocks:
a. Igneous – formed from molten lava (on the surface from volcanoes) or magma (below
the ground) – all the rocks at one point where all igneous; the other rocks had to form
from igneous rocks;
b. Sedimentary – deposition can eventually form these types of rocks; in this area, we
have these types of rocks.
find more resources at oneclass.com
find more resources at oneclass.com
c. Metamorphic – igneous or sedimentary rock that has been changed (e.g. a dinner that
has been warmed up the next day – it’s the sae dier ut haged slightly.
Metamorphic is altered slightly by various things (heat, chemicals, etc.)
• Igneous – molten
o E.g. - Basalt (a lava), granite (rock that solidified below the ground)
o Lava – Surface
▪ Extrusive: eas o the surfae laa
o Magma – below the ground
▪ Intrusive: formed below the ground (magma)
• Sedimentary:
o Sediments
o See diagraph 1.6
o E.g. - Sand into rock (sandstones), limestones, shale
• Metamorphic:
o Pressure, Heat, Solutions -> Rock → Metamorphic
o Limestone → Marble (popular for tabletops)
o Granite → Gneiss (most common rock in Canada)
Types of Lava and Magma
1. Basic (basaltic leaves) – easily flowing (Hawaii), and very common around Oceanic areas (less
common in major Continental areas)
2. Acidic (granitic) – much more complicated, and they certainly explode – they just do not flow as
well, as the granite solidifies and forms plugs then the pressure builds up and you have an
eruption (more common in Continental areas)
Igneous/Extrusive Features:
• Lava Plains (activity)
o See diagraph 1.7
o Best example is Northwest, USA (Idaho in particular, India, Siberian, most of the Amazon
are formed by lava plains – the largest ones are on the bed of the ocean, but also in our
solar system.
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
There have been various hurricanes (texas, florida, etc. The pressure has to be the same between all. Isostasy the idea that you must have some material the same depth, etc: how the earth is adjusting vertically in changes in the weight of the ice. Metamorphic is altered slightly by various things (heat, chemicals, etc. ) Basalt (a lava), granite (rock that solidified below the ground: lava surface, extrusive: (cid:373)ea(cid:374)s (cid:862)o(cid:374) the surfa(cid:272)e(cid:863) (cid:894)la(cid:448)a(cid:895, magma below the ground. Intrusive: formed below the ground (magma: sedimentary, sediments, see diagraph 1. 6, e. g. Sand into rock (sandstones), limestones, shale: metamorphic, pressure, heat, solutions -> rock metamorphic, limestone marble (popular for tabletops, granite gneiss (most common rock in canada) For tests, you will have to know definitions, not pages of information. Know countries/arctic/plate tectonics (does this part of the ocean belong to this plate or this plate?)
