Final answer:
The specific age of the basalt at 'Nankoweap Back Canyon' is not provided in the given references, and the scientist's views on its origin cannot be determined without additional context. The Grand Canyon has rocks as old as 1.7 billion years, and there are diverse hypotheses about the canyon's formation, from as recent as 5 million to as old as 70 million years ago.
Step-by-step explanation:
The age of the basalt at 'Nankoweap Back Canyon' and the Grand Canyon's formation are topics of geologic interest. Scientists have used methods such as radioactive dating to determine the age of rocks. Dating in the larger Grand Canyon area has suggested varying ages, with some rocks like the Vishnu Schist being around 1.7 billion years old. However, specific information about the basalt in Nankoweap Back Canyon from the provided references is not given, so without that video or additional context, we cannot pinpoint the exact age or the scientist's thoughts on how the basalt arrived there. Nonetheless, hypotheses about the Grand Canyon's formation range from a beginning around 5 million years ago when the Colorado River began carving through the rock layers, to a start in the Laramide orogeny 50 to 70 million years ago.
Folded metamorphic rocks such as gneiss and schist are found in places like the Black Canyon of the Gunnison National Park, showcasing that deep earth processes affected these rocks billions of years ago. The Grand Canyon itself reveals a significant geological record, including the Great Unconformity, which indicates a 1.2 billion-year gap in the rock record.