Finding Clues To Rock Layers: Lab

Finding Clues of Rock Layers

PROBLEM: How can you use fossils and geologic features to interpret the relative ages of rock layers?

    Index fossils can be useful in a way because they tell the relative age of rock layers. Fossils are frequently found in rock layers this is the reason why they are helpful in concluding a layers relative age.

 PROCEDURE:

1.     The similarities between the two sites are that they both have the two first layers in the same place. Another similarity is that the 1^st l, 2^nd, and the pink layer all have the same amount of objects (and the same objects.) The differences between these two sites is that both sites layers are not placed in the same way for example the pink layer is placed before last and the pink layer of site two is placed last. Another major difference between the two sites is that the don’t have the same amount of layers.

2.     The kinds of fossils that are find in the two layers are shells, dinosaurs, birds, mammal,  Extrusion, plant , fish and ammonite.

ANALYZING AND CONCLUDING:

       Site 1:

·     1 The layers A and B are not well protected because they are younger layers, the layers will still be exposed to oxygen because they are not covered with enough rock or soil. The layer D is covered by two dinosaurs remains and it is preserved by Extrusion (Lava.)

·     2. Layer A might be the oldest because it is more deep into the ground and more layers have been created over layer A  over many of years. Also it might be the oldest because the trilobite was just in the layer A  (maybe then it extinct) 

·     3. The e youngest layer is layer G because it is the first layer of site . Above the G layer  is soil so that means that the Layer G is really recent.

·     4.There are no fossils in layer C because lava might  have  burned the objects or it have hardened and nothing could enter the layer.

·     5.The fossils that are in the  layer F are bird fossils, dinosaur fossils, and plant fossils.

Site 2:

·     6. I think that Layer B in site 1 most have been formed in the same as layer W.

·     7.  One Clue for finding horizontal gaps in rock layers is to  find extrusions , the reason why is that they are horizontal rock layers. In Site 1 the incursion layer is missing.

·     8. The  intrusion (or layer) V is older because it goes through many layers that are older than layer  Y or X  so it might be the oldest Layer.

·     9. The layers of site 2 can prove us that the environment has changed over time. The fish in layer W might have extinct because it is not shown in the other layers. One of the fossils of layer Y is Dinosaurs after layer y there is layer Z so maybe Dinosaurs have changed over time in a different kind of mammal.