Question

Difficulty: HardImplicit and Inferred Relationships

When J. Harlen Bretz first proposed in 1923 that the bizarre, deeply carved channels of the Columbia Plateau in eastern Washington—which he named the Channeled Scablands—were formed by sudden, catastrophic floods of biblical proportions, his peers reacted with immediate hostility. For decades, the dominant paradigm in geology was uniformitarianism: the belief that Earth’s landscape was shaped exclusively by slow, imperceptible processes like wind and normal river erosion. To Bretz's contemporaries, his 'catastrophism' sounded like a regressive leap back to pre-scientific, myth-based explanations of the Earth.

However, Bretz’s field evidence was meticulously detailed. He mapped giant gravel ripples, deep plunge pools, and massive coulees that could not be explained by gradual erosion. The establishment, led by the United States Geological Survey, organized a meeting in 1927 to debate Bretz's findings. The hosts did not invite Bretz to present his full data beforehand; instead, they invited him to what was effectively a trial, where a panel of established geologists systematically presented alternative uniformitarian explanations for each of his observations. Bretz stood his ground, pointing out that their theoretical models failed to account for the physical scale of the features he had mapped.

Based on the passage, which of the following best describes the relationship between Bretz’s geological field observations and the theoretical models of his contemporaries?

  1. Bretz rejected his contemporaries' models because those models were unable to account for the immense physical scale of the landscape features he had mapped.Answer
  2. B
    The establishment geologists dismissed Bretz's observations outright because they believed the physical scale of the scablands was too insignificant to challenge uniformitarianism.
  3. C
    The establishment geologists modified their theoretical models to incorporate Bretz's evidence of catastrophic flooding while maintaining a uniformitarian framework.
  4. D
    Bretz adjusted his mapping of the gravel ripples and coulees to make his empirical data conform to the uniformitarian models presented at the 1927 meeting.

Answer

Bretz rejected his contemporaries' models because those models were unable to account for the immense physical scale of the landscape features he had mapped.
The correct option correctly identifies that Bretz rejected his contemporaries' models because they failed to explain the physical scale of the features he mapped. The passage states that Bretz 'stood his ground' against the panel of geologists, explicitly arguing that their theoretical models could not account for the scale of features like giant gravel ripples and massive coulees.

Step-by-Step Solution

1
Analyze the passage to identify Bretz's stance on his contemporaries' theoretical models.
The passage notes that Bretz 'stood his ground' and pointed out that their models 'failed to account for the physical scale of the features he had mapped.'
This establishes the direct conflict and relationship between his observations and their theories.
2
Evaluate the establishment geologists' response to Bretz's observations.
The establishment did not ignore the observations but sought to explain them through alternative uniformitarian processes at the 1927 meeting.
This helps eliminate distractors claiming they dismissed or ignored his observations completely.
3
Determine how the theoretical models related to Bretz's empirical findings.
The models could not explain the large-scale physical features, leading Bretz to reject the establishment's theories.
This confirms the correct option as the one describing Bretz's rejection of their models based on scale.

Key Concept

Identifying implicit relationships between competing scientific perspectives and evidence.
Estimated Time:2m 30s
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