EAS-E131 Assignment: Fracture Zones, Triple Junctions Analysis

This assignment analyzes fracture zones and triple junctions in the context of ocean environments, specifically focusing on mid-ocean ridges and plate tectonics. The assignment is divided into three sections, with the first two sections involving data collection and evaluation to test hypotheses related to fracture zones accommodating changes in spreading rates and the similarity of spreading rates at triple junctions. Section I examines fracture zones, highlighting their seismic weakness and role in spreading along mid-ocean ridges, using the Southern Mid-Atlantic ridge as an example. Section II discusses spreading at triple junctions, supporting the hypothesis that these are formed by the intersection of mid-ocean ridges due to mantle convection and plate movement. The final section discusses how spreading rates help determine the age of ocean basins and how earthquakes and hurricanes influence them, while also acknowledging the challenges in determining the accurate age of the basin. References include Peacock et al. (2016) and Bourgois et al. (2016), providing further context for the analysis.

Running head: FRACTURE ZONES AND TRIPLE JUNCTIONS 1
Fracture Zones and Triple Junctions
Student’s Name
Lecturer’s Name
Unit/Section

LITERACY PROGRAMS IN JUVENILE CORRECTIONS 2
Section I(c): Fracture Zones
Fracture zones spread from the transform fault away from the ridge axis that makes them
seismically weak and displays evidence of both the way and rate of spreading along the mid-
oceanic ridges (Peacock et al.,2016). For instance, the spreading rate of the Southern Mid
Atlantic ridge is around 34 to 38 millimetres per year, which is the transitional zone between
slow and intermediate rates. The Southern Mid Atlantic ridge holds a fracture zone from 26
degrees South to 32 degrees South. Evidence of initiation and diminishment of this fracture zone
has determined the spreading rate of the Southern Mid Atlantic ridge is creating zig-zag plate
margins and become defined by numerous earthquakes.
Section II C: Spreading at Triple Junctions
The data for plate motions supports the hypothesis that the intersection of two mid-ocean
ridges forms these because of the idea of mantle convection which heats the mantle and allows
for heat to escape from the interior of the Earth causing not only mid-ocean ridges, earthquakes,
and shift continents, but also ocean basins. It proves that these tectonic plates move away from or
collide with one another and causing new lithosphere and crust to form to replace the material
that is running away (Bourgois, 2016).

LITERACY PROGRAMS IN JUVENILE CORRECTIONS 3
Section III (Discussion)
Spreading rates help determine the age of ocean basins
The rate of plate motions helps to determine the age of an ocean basin. Every single
earthquake and hurricane influences the ocean basin as well, and therefore the deposit is
consistently adding, subtracting or moving from the basin which could affect how to be able to
determine the accurate age of the basin, however it could be hypothesized or approximated
because of spreading rates.

LITERACY PROGRAMS IN JUVENILE CORRECTIONS 4
References
Peacock, D. C. P., et al. "Glossary of fault and other fracture networks." Journal of Structural
Geology 92 (2016): 12-29.
Bourgois, J., Lagabrielle, Y., Martin, H., Dyment, J., Frutos, J., & Cisternas, M. E. (2016). A
review on forearc ophiolite obduction, adakite-like generation, and slab window
development at the Chile triple junction area: uniformitarian framework for spreading-
ridge subduction. Pure and Applied Geophysics, 173(10-11), 3217-3246.