Brad O Neal Professor Wilhelm AST 191 001 21 September Write Up #3 3a) Given a picture of the moon I need to give an age sequence at least three maybe more of the formations present in the picture. This is made possible from Steno s laws which are: Law of Original Horizontality, Law of Lateral Continuity, Law of Superstition, and the Law of Cross- Cutting Relations. Each law gives a logical explanation as to why a crater on the moon cam before the rift the runs across the crater. I plan to use Steno s Laws to relatively age date formations on the moon. Law of Original Horizontality-infers that sedimentary rock layers were originally deposited as flat-lying (horizontal) layers. Law of Lateral Continuity-states that sedimentary rock layers are deposited over large areas Law of Superposition-states that, in a cross-section view, rock layers are oldest at the bottom and become progressively younger upwards. Law of Cross-Cutting Relations-infers that a rock body (e.g. igneous dike) cutting through another rock body (sandstone beds) is younger than the layers it intrudes.
The picture above has four formations marked: the red circle is a crater, the yellow line is a rift, the white circle is another crater, and the black arrows are pointing to the Mare of the Moon. From using Steno s laws I can relatively put the formations in chronological order from youngest to the oldest. Starting with the oldest, the crater encircled with red. I can say that the crater is the oldest using Steno s Law of Original Horizontality. The crater is filled with Mare, which is pointed out with the black arrows, so I can make an educated guess that the crater came first and then the sedimentary layer covered it. It is a clear sign of age. The crater came first and the Mare came second. From the Mare we can see the rift, outlined in yellow, in the sedimentary layer right above the crater. I can tell from the Law of Cross-Cutting Relations that the rift came after the Mare and the crater because it cut through the Mare. The youngest feature compared
with the others is the crater outlined in white. I came to this conclusion because the crater, outlined in white, interrupts the rift that is outlined in yellow. This is the Law of Lateral Continuity at work. To sum everything up; A meteor impacted the Moon, then a lava flow rushed over the crater, the rift formed, and then another meteor hit interrupting the rift s formation. Dating the formations on the Moon is relatively easy. I was able to make an educated guess using some of Steno s Laws. Most everything on the surface of many planets can be dated if the viewer knows Steno s Laws. Using the Steno s Laws of Original Horizontality, Cross- Cutting Relations, and the Law of Lateral Continuity I was able to date the four formations I have outlined in the picture above on the Moon. 3b) These images was taken of the moon Europa. Europa is one of many moons of Jupiter in our Solar system. Having geological activity, Europa s surface formations can be dated in chronological order from the oldest formation to the youngest formation. It can also shed some light onto what is happening on the surface of Europa. The two images below are examples of this. Dating the formation and figuring out the activity of Europa is made possible by using Steno s Laws: Law of Original Horizontality, Law of Lateral Continuity, Law of Superstition, and the Law of Cross-Cutting Relations. I plan on using Steno s Laws to relatively date these linear formations on the surface of Europa on image one and to explain what is happening in image two. In image one the stress fracture outlined in red on Europa s surface is the oldest. I can come to this conclusion using Steno s Law of Cross-Cutting Relations. Law of Cross-Cutting Relations infers that a rock body (e.g. igneous dike) cutting through another rock body
(sandstone beds) is younger than the layers it intrudes. Now the original sedimentary layer of Europa is the oldest but the oldest geological activity is the stress fracture outlined in red. Then the next formation to occur was the stress fracture outlined in black. I also came to that conclusion by using the same law of Cross-Cutting Relations. The black outlined stress fracture is younger because it interrupts the red outlined one. Continuing on, the yellow outlined fracture interrupts the black outlined stress fracture so I can conclude that this one is younger than both the red and the black one. If you were to continue on following the stress fracture outlined in black you would come across the fracture outlined in purple. From the law of Cross-Cutting Relations I can tell that the purple one is younger than the black one because it interrupts the black outlined fracture. Following the purple outlined fracture you can see that it is interrupted by the green outlined fracture. I can tell this all by using the law of Cross-Cutting Relations all of the interruptions are cutting through the previous formation and is intruding. From start to end it went like this: The Red stress fracture, black, and then yellow. Then with the second chronological order it went: The red stress fracture, black, purple, and then green. In image number two I can tell that what I think to be as ice chunks are moving. I can tell this because of the helps of the Steno Laws that were mentioned earlier. Specifically, the law of Cross-Cutting Relations lets me know this. I have circled three examples that help prove the point. The circles in red, yellow, and black all show a chunk of the ice that has broken off. I can tell that they have moved from their first location from looking at the interruption in the stress fractures. This interruption is what tells me the chunk of ice use to be one big chunk of ice until it broke off. Now if that were just the case the stress fracture would have just had another interruption in itself. I can tell that the chunks of ice are moving because it doesn t match up. The puzzle piece to this bizarre array of fractures is slightly out of place. From this conjecture I
can make a guess and say that maybe Europa has tectonic plates. There might possibly be a heating and re-cooling effect that is making the chunks of ice slip with the liquid away from the main body. Using Steno s Laws I was able to relatively date the stress fractures on Europa as well as explain the features in the chaotic region of Europa. Europa is one of Jupiter s moons that have geological activity. The stress fractures and the chaotic region are just a few of many examples of the geological activity that can be dated and explained by using Steno s laws. I used Steno s law of Cross-Cutting Relations to prove the chronological order of age of these stress fracture formations and help explain what was happening in the chaotic region on Europa.