Impacts vs the rock cycle

Impacts vs the rock cycle - 1. All the stony planets...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
1. All the stony planets (Mercury, Venus, Earth, Moon, Mars) show scars of huge meteorite impacts. Deposits of Ir, Pt, and shocked quartz record a major hit on Earth at 65 Ma. 2. On the Earth most of these scars have vanished, because it is constantly resurfaced by geologic processes. Faults and volcanoes build mountains, landslides and erosion cut them down. 3. All of the Earth's surface is also moving horizontally: earthquakes show sudden jumps, and geodesy reveals steady creep. 4. Most change occurs in sudden "catastrophes" (impacts, earthquakes, eruptions, floods, mudslides, dust storms). But to the eye of the trained geologist, these events are predictable parts of steady cyclic processes. 5. This course will begin with the grand cycle of plate tectonics, which has replaced the floors of the oceans at least 30 times over. 6. We will then follow the "rock cycle:" magma rises and cools to form igneous rock; this is weathered to form soil; this is eroded to form sediment; this is moved to basins and deposited as sedimentary rock; this is carried into plate boundaries and metamorphosed, and sometimes melted to form magma again.
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
1 c:\work\classes\ess1\rock_cyc.doc IMPACTS vs. THE ROCK CYCLE COURSE INTRODUCTION Welcome to a fun and mind-stretching course, like the one that warped my whole career! This course is also known as "physical geology," and will emphasize
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 5

Impacts vs the rock cycle - 1. All the stony planets...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online