What is a likely explanation for the changes we see in the fossil record (like at House Range) at this time?

What is the historical significance of this rock?

Precambrian Era

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.

Check the box next to “Marquette, Michigan”. Double click to fly there. Click on the placemark to view the outcrop seen at this location. This outcrop is dated 1.85 Ga.Identify this feature

At the center of the sequence you find a rock (sample 8). It is smooth to the touch and breaks into sheets. Inspect sample 8 further:

Within a mountain range on the northernmost edge of the largest continent (see Mountain Range map), you find the following sample (sample 5). It features thick layers of micas. Inspect it to learn more about this location:

Which of the following data sets are NOT helpful when deciding the historical fit of the continents? (i.e the configuration of the supercontinent) Mark all that apply. Consider Alfred Wegener’s evidences for continental drift.

A long line of volcanoes connect on the ocean floor (see Volcanoes map). Inspect sample 4 taken from a spot along this line to better understand what is happening at this location: