| Term | Definition |
|---|
| a mold | is the cavity left behind in the rock after an organism's hard part has dissolved |
| gaps in rock layers are called | unconformities |
| carbon films are formed | when a think film of carbon is left, forming a silhouette of the original organism |
| fossils most often form | when a dead organism is buried in sediments |
| index fossils | are the remains of species that existed on Earth for relatively short periods of time |
| dinosaur footprints are | trace fossils |
| nonconformities occur when | sedimentary rocks are deposited on top of uplifted and eroded metamorphic or igneous rocks |
| nonconformities | are gaps in rock layers that develop when agents of erosion remove existing rock layers |
| molds | are hollow places in rock made when an organism died and was buried and holes in the rock let air or water reach it and dissolve the organism |
| index | fossils are fossils of species that lived on Earth for short periods of time and were abundant were widespread geographically |
| carbon films | are fossils formed when an outline of the original organism is formed from left-over carbon |
| relative dating | is the order of events and the relative age of rocks is determined by examining the position of rocks in a sequence. |
| principle of superposition | states that for undisturbed rocks, the oldest rocks are on the bottom and the rocks become younger and younger toward the top |
| casts | are made when sediments fill the cavity made when and object decayed and then the sediments harden into rock |
| which conditions help preserve organisms as fossils? | quick burial by sediments, protection from scavengers, having hard parts |
| gaps in rock layers are called | unconformities |
| Which is older... a rock bed containing fossils that are 550 million years old or ones that are 400 million years old. | 550 |
| rock layers are correlated if they both contain the same | fossils |
| with absolute dating, a rock's | exact age can be determined |
| with relative daing, a rock's | relative age can be determined |
| if the same types of fossils are found in two separate rock layers, it's likely that the two rock layers | are part of one continuous deposit |
| if the same sequence of rock layers is OBSERVED over a large area | a large deposit of rock FORMED over a large area |
| in a series of undisturbed rock layers where shale is in the middle, sandstone is below, and limestone is above, which layer is youngest? | limestone |
| in a series of undisturbed rock layers where shale is in the middle, sandstone is below, and limestone is above, which layer is oldest? | sandstone |
| if an undisturbed layer of sandstone lies on top of a layer of limestone in which a 330-million year-old fossil is found, the layer of sandstone must be | younger than 300 million years |
| a fossil | mahy tell a geologist when, where, and how an organism lived |
| an unconformity is a | missing layer of rock or a gap in the rock layers |
| preserved animal tracks are called | trace fossils |
| a mold | is the cavity left behind in the rock after an organism's hard part has dissolved |
| fossils are | the remains, imprints or traces of once-living organisms preserved in rock |
| the hard parts of organisms | are most likely to become fossils |
Combine with other sets
Share on Facebook
Share on MySpace