1.
A preserved remain or trace of a once-living organism is called a __________.
2.
A fossil formed when minerals replace the original organism’s remains is a __________ fossil.
3.
A fossil that shows the activity of an organism, like footprints or burrows, is called a __________ fossil.
4.
Scientists who study fossils are called __________.
5.
The breakdown of rocks into smaller pieces by wind, water, or temperature changes is called __________.
6.
the layer of rock beneath soil is called __________.
7.
We currently live in the __________ Era.
8.
The age of a rock compared to other rocks is its __________ age.
9.
Scientists theorize roughly that the earth was formed 4.6 __________ _______ ago.
10.
The actual number of years since a rock formed is its __________ age.
11.
An era is divided into smaller units called __________.
12.
The present period within the Cenozoic Era is called the __________ Period.
13.
The law stating that younger rock layers are found above older layers is the Law of __________.
14.
A break in the geologic record caused by erosion or missing rock layers is called an __________.
15.
Scientists use ____________ ________ to determine the absolute age of rocks using radioactive elements.
16.
Fossils that are widely distributed and lived for a short time are called __________ fossils.
17.
The history of Earth is divided into blocks of time called the __________ _______ scale.
18.
The largest division of geologic time is an __________.
19.
The earliest eon in Earth’s history is the __________ Eon.
20.
The era known as the “Age of Dinosaurs” is the __________ Era.
21.
The process by which sediments cover and preserve remains is known as __________.
22.
Time in Earth’s history is divided into eons, eras, periods, and __________.
23.
The Paleozoic Era began about 541 million years ago and ended with a major ______ ________________.
