Relative Dating Flashcards
what process forms unconformities
uplift, erosion, deposition
the igneous intrusion is a _______ force that formed a ________ on earth’s surface
constructive, mountain
what fossil could also be found in nys bedrock of the same age as phacops
manticoceras
approximately how many years ago did the intrusion of the palisades sill occur
200 million years ago
index fossil
a fossil that existed for a limited time (narrow vertical range) and can be found over a wide geographic area (broad horizontal range)
a good index fossil will be found in the same rock layer throughout the study area
when you see contact metamorphism lines is the intrusion younger or older
younger
which new york state index fossil is in the same group of organisms as the petoskey stone coral
lichenaria
why is volcanic ash a good geologic time marker
ash is rapidly deposited over a large geographic area
volcanic ash is most useful for determining the relative age of rock layers because the ash is deposited during a
short period of time over a large area
which part of the reference table should you check
- geologic history of new york state
- MAYBE scheme for sedimentary rock identification
during which period did the appalachian mountains begin forming
ordovician
do faults happen before or after the rock
after because when the rocks are all displaced they must have existed before faulting occurred
during which epoch was the brick wall looking layer with the seashell fossils
middle devonian
during which geologic period did the first vascular plants appear, as shown in the geologic history table
silurian
the earth’s magnetic field is generated by the movement of materials in which layer
outer core
sediments that form a sedimentary rock usually are deposited in a layer that is parallel to earth’s surface. this statement best describes the
principle of original horizontality
the igneous intrusion formed from _______ and causes metamorphism in the surrounding rock due to its _______
cooling magma, temperature
what is the pattern of the ages of crustal rocks in north america
the central region of the continent contains the oldest rocks, while the youngest rocks are found along the atlantic and pacific coasts
