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You calculated the age of the oldest preserved Earth material above, however, we know from dating meteorites that the Earth is 4.54 Ga. What was happening in that block of time to prevent material from being preserved?

Select the Global Paleogeographic Model folder. Double click to zoom out. Also select the placemark labeled “Question 39” and navigate to where it is in view. It represents the average location of North America during this time. Toggle through the end of the Triassic (~200 Mya) through the Jurassic (~140 Mya).What changes do we see? Mark all that apply.

Turn on the photos database in the Layers panel. Fly to each of the locations in the Question 13 folder. Each outcrop seen is dated 2.4-1.8 Ga. Explore the images in the area by selecting the icons indicated in the descriptions below each location in the folder (If you don’t see them immediately, try zooming in/out). What do they all have in common?

Zircons contain a radioactive isotope called Uranium-238 which has a half life of 4.5 billion years (Ga). How old are these minerals?Tip: 4.5 Ga*how many half lives(don’t round up/down)=age

Open the “Angel Lake, Nevada” folder. Check the “Angel Lake, NV” placemark to fly there. What carved this valley?Tip: Consider its shape

Turn on the “Deserts Overlay”. What kind of desert produced this dune field?Tip: Use the overlay to determine which desert it is part of then decide what kind of desert it is. 

Zircons contain a radioactive isotope called Uranium-238 which has a half life of 4.5 billion years (Ga). How old are these minerals?Tip: 4.5 Ga*how many half lives(don’t round up/down)=age in Ga (*100 to get age in million years ago (Ma))

We can extract zircons, a radioactive mineral, from sample Y to obtain a time since the minerals formed- thereby providing the numeric age of this layer.Within the zircons in this rock sample, the ratio of parent to daughter isotopes is 15.5:0.5. Using the chart below, determine how many half lives have passed.

At the top of the sequence you find a rock (sample 7) that bubbles when in contact with acid. Inspect sample 7 further:

Inspect the following image (the red line illustrates the location of the equator). Is this an accurate representation of the planet’s historical supercontinent? (consult the relevant maps-think about Alfred Wegener’s evidences for continental drift)