Page 210 - Laboratory Manual in Physical Geology

A CTIVIT Y 6.9 Using the Present to Imagine the Past—Cape Cod
to Kansas

Name: ______________________________________ Course/Section: ______________________ Date: ___________
A. Analyze photographs A and B below of a Kansas rock and the modern-day seafloor near Cape Cod.

A. Pennsylvanian-age rock from Kansas (290 m.y. old)

Sand-sized fragments of
fossil shells comprise the rock

10 close-up
of thin section

B. Modern sea-floor
environment, 40 m (130 ft)
deep, near Massachusetts
(10 miles north of Cape Cod).
Detrital (siliciclastic) sediment:
• 1% gravel
• 90% sand
• 9% mud

0 10 cm

1. How are the modern environment (Photograph B) and Kansas rock (Photograph A) the same?

2. How are the modern environment (Photograph B) and Kansas rock (Photograph A) different?

3. Today, this part of Kansas is rolling hills and farm fields. Describe what the Kansas ecosystem (environment + organisms)
was like when the sediment in this rock sample (Photograph A) was deposited there about 290 million years ago.

B. REFLECT & DISCUSS What would have to happen to the sediment in Photograph A to turn it into sedimentary rock?

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