ESC 1000 Test One (Ch. 4)

Who came up with the concept that geologic processes operating at present are the same processes that operated in the past?

James Hutton

In which of the following time periods were dinosaurs the dominant creatures?

Mesozoic

How does an angular unconformity form?

Older rocks are tilted, eroded, and overlain by younger rocks.

Which of the following is the earliest (oldest) chapter of geologic time?

Precambrian

Upon what basis were the upper and lower boundaries of the Mesozoic Era defined?

abrupt changes in the types of fossils, representing mass extinctions

The geologic timescale details and divides geologic time based upon

fossil data.

The oldest known rock found on Earth is dated at

over 4 billion years old.

If a rock started with 1,000 atoms of a parent but now contains 250 atoms, how many half lives have passed?

2 half lives

What factors are the most critical in determining whether a fossil is preserved?

Whether the creature had hard parts and how fast it was buried.

Which principle can be used to determine the relative age of an igneous intrusion called a dike?

cross-cutting relations

The term half life represents the time it takes

for half of the parent atoms to decay into daughter atoms.

Which principle is used to determine the age of rocks by ordering them from oldest on the bottom to the youngest on the top?

superposition

Early Earth would have been inhospitable to many life forms of today because

the atmosphere lacked oxygen.

Missing geologic time caused by erosion is called a(n):

unconformity

How did an oxygen-rich atmosphere develop from a carbon dioxide-rich atmosphere?

through photosynthesis by cyanobacteria