Which information did the Glomar Challenger study in 1968? A. the rate of seafloor spreading B. the direction of seafloor spreading C. the age of rocks in various places in the ocean D. the contents of rocks in various places in the ocean
The Correct Answer and Explanation is:
Correct Answer: C. the age of rocks in various places in the ocean
Explanation
In 1968, the research vessel Glomar Challenger began a groundbreaking scientific expedition as part of the Deep Sea Drilling Project (DSDP), aimed at understanding the geological history of the Earth’s ocean floors. One of the key objectives of this project was to investigate and confirm aspects of the theory of plate tectonics, particularly the concept of seafloor spreading proposed by Harry Hess in the early 1960s.
To do this, the Glomar Challenger collected core samples of sediments and rocks from various locations on the ocean floor. These samples allowed scientists to determine the age of oceanic crust at different distances from mid-ocean ridges—long, undersea mountain ranges where new crust is formed through volcanic activity.
The ages of these rocks were determined using radiometric dating techniques. What scientists discovered was a clear pattern: rocks were youngest near the mid-ocean ridges and progressively older as they moved away from the ridges. This provided strong, direct evidence for the process of seafloor spreading, where new crust is continuously formed at ridges and pushed outward over time.
While the project also provided insights into the composition (contents) and structure of oceanic rocks, the primary and most impactful discovery in 1968 was the age pattern of these rocks. This data was crucial in confirming the dynamic nature of Earth’s lithosphere and solidified the scientific community’s acceptance of plate tectonic theory.
Thus, although seafloor spreading involves both rate and direction, and chemical analysis (contents) was part of the broader study, the central focus of the Glomar Challenger’s 1968 expedition was to date the rocks, thereby confirming the pattern predicted by the theory of seafloor spreading. Hence, option C is the most accurate answer.
