When Did The Southern Rocky Mountain Rise? Research Paper Sample

Geologists have produced a battery of evidence, some from derivative theorization and others from the test an analysis of samples to support different opinions on the timing of the rise of the Southern Rocky Mountains. While there has been a confluence of opinion among some geologist communities, others have preferred divergent opinions (Fan et al., 35). The opinions of different geologists look convincing in supporting the time or era for which they say the Southern Rocky Mountains began rising. The clarity in the distinction between these varying arguments has been the premise upon which papers exploring the differences in these arguments have been authored. This paper adds to the growing literature on the rise of the Southern Rocky Mountains by highlighting and discussing the perspectives of different geologists regarding the timing of the rise of the Southern Rocky Mountains.
The rise of the Southern Rocky Mountains began in the post-middle Eocene time (Eaton 765). In reaching his conclusion on the timing of the rise of the Southern Rocky Mountains, Eaton subdivided and analyzed the erosion surface in the Southern Rocky Mountains. The description of these erosion surfaces in terms of history supports the argument by Eaton that the rise of the Southern Rocky Mountains began in the post-middle Eocene time. The scholar found that the erosion surface analysis indicated that the there was a history of two significant periods; the Eocene and Miocene. One of the erosion subdivisions that was analyzed showed drain Eastwards during the Eocene time and another northeastwards during the Miocene time (Eaton 765). In his conception, (Eaton 765) argues that this evidence shows epeirogenic activity that initiated the rise of the Southern Rocky Mountains. As Eaton writes, “the focus of this paper is on this epeirogen, uplift of which took place chiefly in post–middle Eocene time and later” (Eaton 766). Eaton also considered the epeirogen of the Southern Rocky Mountains. Some of the characteristics of the lithosphere below the summit of the epeirogen include waning seismic velocities, especially in the upper mantle, coincident geoid anomaly and a curie isothermal surface located in the lower crust. These characteristics indicate an increase of temperatures. His findings are consistent with this explanation of other landforms around the Southern Rocky Mountains.
For instance, (Eaton 768) argues that the Colorado Plateau was formed by the lifting (Sahagian, Proussevitch Carlson 807) of and compression buckling of the continental lithosphere. Besides the manner in which this lifting occurs, (Eaton 768) also argues that this also occurred in the post-middle Eocene time. By association, owing to the fact that these two landforms are located in the same geographical zone, experiencing the same geological forces, it is fathomable (Eaton 765) argues that the Southern Rocky Mountains began rising 33.9 million years ago (Wolfe et al., 670).
Farmer et al., uses their theory of mid-tertiary magmatism to explain the elevation of the Southern Rocky Mountains. They also explain the rise of the Southern Rocky Mountains, especially on the aspect of time. Farmer et al., (285) explore the effect of the mid-tertiary magmatism that was experienced in the Southern Rocky Mountains. As Farmer et al., write, “in the Southern Rocky Mountains, mid-tertiary volcanism occurred discontinuously throughout much of Colorado and New Mexico” (Farmer et al., 285).
While this paper majorly focuses on the source and volume of magma and the resultant volcanic activity in the Southern Rocky Mountains, it forms a basis upon which other geologists explore the aspect of time in the explanation of the rise of the Southern Rocky Mountains. However, by applying knowledge on the presence and the volume of magma in the Southern Rocky Mountains as argued by Farmer et al., (285), it is fathomable that the volcanic activity which majorly led to caldera formation due to the lateral compression of hot magma from the core could have caused an elevation of various peaks (Bailley 56).
This is because when the magma is ejected due to the upwelling in the core of the Southern Rocky Mountains, the cooling of the same on the surface resulted in an elevation. Additionally, it is important to consider the fact that the volume of mid-tertiary magma beneath the Southern Rocky Mountains is in keeping with any arguments of the arguments associating this mid-tertiary magma beneath the Southern Rocky Mountains with the elevation experience in the region.
As highlighted earlier, the perspectives of Farmer et al., form a basis upon which other geologists base their time on when the Southern Rocky Mountains began rising. Gregory & Chase conducted a multiple regression of data on paleotemperature, sea-level temperature as well as terrestrial lapse rate in order to explain the paleoelevation of between 2.4 kilometers and 2.7 kilometers experienced during the late Eocene period. Gregory & Chase (281) posit that the, “Pliocene uplift is thus not required to explain the present elevation of 2.5 kilometers.”
As highlighted earlier, there is insufficient information on this period for sustaining arguments on the time and manner in which different land forms occurred. In keeping with this supposition, Gregory & Chase (281) find that the period during which the Southern Rocky Mountains achieved the elevation of 2.5 kilometers (Pelletier 4) that the mountain range has is not very clear. Nonetheless, Gregory & Chase vindicate arguments by Farmer, Bailley & Elkins-Tanton that, “Magmaitc crustural thickening can explain the late Eocene elevation of the Southern Rockies” (Gregory & Chase 281).
Depending on the school of thought, the naming of these periods might have been different in general even thought the implication was similar. For instance, the post-middle Eocene time used by (Eaton 765) is quite similar to the late Eocene time used by Gregory & Chase (281). Secondly, the findings of Gregory & Chase (281) that “Magmaitc crustural thickening can explain the late Eocene elevation of the Southern Rockies” vindicates the arguments by Farmer et al., (285) that the mid-tertiary magmatism and volcanic activity were arguably responsible for the elevation experienced in the Southern Rocky Mountains.
In explaining the probable time when the Southern Rocky Mountains began their elevation, this paper identified some constraints. Firstly, there were many perspectives held by different geologists as derived from the different models that were used to acquire evidence to back their perspectives and suppositions. However, there was insufficient historical information regarding this period, and as such, any new findings using the different models by these geologists has not historical base upon which comparisons can be made. Even with these constraints, the geologists have attempted to reconstruct historical information through the use of different models and through theorization. Some of these theories have been vindicated through the work of others.
The aim of writing this paper was to determine when the Southern Rocky mountains gained their elevation. The scholarly work explored in this paper presents different perspectives as derived from the different models and approaches used. There is a consensus that he elevation of the Southern Rocky mountains started in the late Eocene or the post-middle Eocene time. The paper has also established that there is no significant difference between the late Eocene or the post-middle Eocene time as used by the two geologists. This is notwithstanding the different approaches and models thorough which these conclusions were made. Based on these findings, and acknowledging the constraints in information, the paper concludes that the rise of the Southern Rocky Mountains happened 33.9 million years ago.

Works Cited

Bailley, Treasure. A reevaluation of the origin of late Cretaceous and younger magmatism in the southern Rocky Mountain region using space-time-composition patterns in volcanic rocks and geochemical studies of mantle xenoliths, University of Colorado. Colorado. 2010. Print.
Eaton, Gordon. Epeirogeny in the Southern Rocky Mountains region: Evidence and origin. Geosphere. 4 (2008): 764-784. Print.
Fan, Majie., Hough, Brian and Passey, Benjamin. Middle to late Cenozoic and high topography in the central Rocky Mountains: Constraints from clumped isotope geochemistry. Erath and Planetary Science Letters, 408 (2014):35-47.
Farmer, Lang., Bailley, Treasure and Elkins-Tanton, Linda. Mantle source volumes and the origin of the mid-tertiary ignimbrite flare-up in the Souther Rocky Mountains, western U.S. Lithos 102 (2008): 279-294. Print.
Gregory, Kathryn and Chase, Clement. Tectonic significance of the paleobotanically estimated climate and altitude of the late Eocene surface, Colorado. Geology. 20 (1992) 581-585
Pelletier, Jon. The impact of snowmelt on the late Cenozoic landscape of the southern Rocky Mountains, USA. GSA Today, 19(2009): 4-11. Print.
Sahagian, Dork., Proussevitch, Alex. and Carlson, William. Timing of Colorado plateau uplift: Initial constraints from vesicular basal-derived paleoelevations. Geology. 30 (2002) 807- 810. Print.
Wolfe, Jack, Forest, Chris and Molnar, Peter. Paleobotanical evidence of Eocene and Oligocene paleolatitudes in midlatitude western North America. GSA Bulletin. 110, 5 (1998): 664- 678.
Summary of Changes
I retain few sentences from the first two paragraphs. I removed the entire first paragraphs as the information in the paragraph could be inferred by the audience for which this paper is written. I also refocused the first paragraph of the paper so that it featured a thesis statement highlighting in clear writing what the paper was attempting to do. I also made a distinction when relaying my opinions and when discussing the opinions of the various geologists used. I changed the vague and inappropriate words used throughout the paper. I also change the syntax of words so that the sentences were complete. I also discussed the methods used by the sources cited and drew conclusions that were relevant to the topic. I also added two sources to the initial six that were used.