18 terms

Fossilization - 7/10/12

the process of fossilizing a plant or animal that existed in some earlier age
the perserved trace, imprint, or remains of a plant or animal - almost always found in sedimentary rocks
Replaced Remains
the soft parts of plants and animals decay - the hard parts are replaced by minerals
Mold and Cast
an impression that an organism leaves behind after decaying and then is filled in - the mold shows the original shape of the fossil (mold is the hole)
a copy of the shape of the organism that made the mold
Trace Fossils
any indirect evidence of life preserved as an impression in rock; trails, footprints, tracks, burrows, and bite marks
Carbonaceous Films
when sediment piles up increasing pressure and heat on a buried organism a thin film of detailed carbon residue is left behind
Index Fossils
fossils from species that existed on Earth for
(1) short periods of time, (2) Rwere abundant, and were (3) widespread geographically
Index Fossils *
determines the age of the rock layers
VA fossils
found in Coastal Plain, Valley and Ridge, and Appalachian Plateau - most made of marine organisms
VA Provinces
Coastal Plains, Piedmont, Blue Ridge, Valley and Ridge, Allegheny Plateau
Relative Dating
the process of placing events in the events in the sequence in which they occurred
a fault or intrusion is younger than the rock it cuts through
Coastal Plains
made up of sedimentary rocks, sand and gravel - at the fall line, waterfalls
(the foot of the mountain) made up igneous and metamorhic rock (245 -570 mya) - no fossils
Blue Ridge
Highest mountains in VA. Mount Rogers highest peak. Made up of igneous and metamorphic rock, oldest rocks in VA (245 - mya)
Valley and Ridge
an area of long parallel ridges separated by valleys - made up of sedimentary rocks,
(350-570 mya), fossils include sea critters
Appalachian Plateau
area known for coal, oil and natural gas - made up of sedimetary rocks