2Fossils are traces or remnants of past life Fossils are traces or remnants of past life. Many fossils are found in rock. Rocks, fossils, and other natural evidence provide information about how Earth and life on Earth have changed over time.
5original remainsA fossil that is the actual body or body parts of an organism. There are 3 different substances original remains are found are the following:1. Ice- Ice preserves remains (Mammoth)2. Amber- Resin from tree hardened and preserves remains (insects)3.Tar- Pools of tar preserve remains (Saber- toothed cats)
10Fossils in RocksThese fossils are impressions or traces made of rock and provide indirect evidence that the organisms were there.There are 4 types of fossils in rocks:Mold and CastPetrified woodCarbon FilmsTrace fossils
11Process and Example of Mold and Cast 1. Organism dies and falls into soft sediment.2. Over time, the sediment becomes rock and the organism decays, leaving a mold.3. Minerals fill the mold and make a cast of the organism.Example- Clams, snails
12A mold and cast fossil is formed when minerals take the shape of a decayed organism.
14Petrified Wood The stone fossil of a tree is called petrified wood. Process - A fallen tree can be covered with sediment. Over time, water passes through the sediments and into the trees cells. Minerals that are carried in the water take the place of the cells, producing a stone likeness of the tree.Example- petrified forest
16Carbon Films Carbon is an element that is found in everything living. Process- Sometimes when dead plant or animal decays, its carbon is left behind on a visible layer.Example- moth 10 million years old
18Trace FossilsTrace fossil is a fossil that demonstrates that a particular living organism existed.Process of how the trace fossils are preserved is when weather changes drastically and causes weathering and erosion to occur which preserves events that occurred prior to the change.Example of Trace fossils include preserved footprints, trails, animal holes, and even feces.
29Sedimentary rock layers show the order in which rocks formed Sedimentary rock layers show the order in which rocks formed. The order of the layers is used to determine the relative ages of fossils found in the rock.Radioactive dating can be used to determine the absolute age of igneous rock.