Relative Dating
This "law" explains that older rock layers are found on the bottom, while younger rock layers are found on top.
What is the law of superposition?
The Jurassic Period ended this many years ago.
What is 145 million years?
Westchester County is made up of dominantly what group of rocks?
What is sedimentary?
What two "things" have co-evolved throughout history.
What is Earth and Life?
This is the name given to a gap in the rock record, which is often caused by weathering or erosion.
What is an uncomformity?
Each era is divided into 3 periods, except for this era which is divided into 7 periods.
What is the Paleozoic era?
Ithaca, NY is primarily made up of bedrock from this geologic period.
What is the Devonian?
The gasses in Earth's early atmosphere are inferred to have come primarily from these.
What are volcanic eruptions?
These are the only two groups of organisms that were around during the Precambrian Eon.
What are stromatolites and sponges?
The Hudson River begins near the peak of this upstate mountain.
What is Mt. Marcy?
The release of oxygen into the atmosphere allowed organisms to finally live here.
What is on land?
To be an index fossil, a fossil must have these two traits.
What is
- Lived over a large area
- Lived for a short period of time
Humans first appeared in the later portion of this epoch.
What is the Pleistocene?
Intensely metamorphosed rock is typically found found in this landscape region.
What are mountains?
Before oxygen was released into the atmosphere, oxygen atoms bonded with this atom in the ocean to form a compound known as rust.
What is iron?
The hash marks on the edge of an igneous intrusion indicate this geologic process.
What is contact metamorphism?
The Hudson Highland mountain range, found just north of Westchester along the Hudson River, was formed during this geologic event 542 million years ago.
What is the Grenville Orogeny?
These are the coordinates of Watertown, NY.
What is 44o N and 76o W?
These are the microbial organisms believed to have produced the first oxygen through photosynthesis.
What are cyanobacteria?
A layer of meteorite debris is found in an outcrop in Mexico, and there are no dinosaur fossils found anywhere above this layer. What must the age of this rock layer be?
What is 66 million years old?