Question

Which of the following is not true of continental rifts?

1. they represent incipient divergent tectonic plate boundaries
2. continental rifting typically occurs in a three-armed pattern
3. the Mount Kilimanjaro and Mount Kenya volcanoes are products of rifting in east Africa
4. rifting has so far never occurred on the North American continent
5. continental rifting likely initiates where heat builds up beneath continental lithosphere

Answer 1

The statement that 'rifting has so far never occurred on the North American continent' is incorrect, as evidence of past rifting is present in areas like the Rio Grande rift.

Step-by-step explanation:

The student asked which statement about continental rifts is not true. Among the listed options, the incorrect statement is that rifting has so far never occurred on the North American continent. In fact, the continent has experienced rifting, evident in the Rio Grande rift and the earlier rifting which led to the opening of the Atlantic Ocean. Continental rifts indeed represent incipient divergent tectonic plate boundaries, often characterized by a three-armed or 'triple junction' pattern. The creation of Mount Kilimanjaro and Mount Kenya can be attributed to volcanic activities associated with the rifting of East Africa. Furthermore, continental rifting is typically initiated by a buildup of heat beneath the continental lithosphere, leading to igneous activity, faulting, and formation of rift valleys and basins.