

Is there a geological term for a rock that contains two or more distinct layers of stratification?

We followed the stream up to Jamaica Pond, which is mostly frozen.

The water birds are concentrated on the unfrozen part of the pond.

Pigeons are there to remind us that we're in a city park.
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Date: 2006-01-10 08:20 pm (UTC)no subject
Date: 2006-01-10 11:20 pm (UTC)no subject
Date: 2006-01-11 11:38 am (UTC)While this rock may have started out as a fine sandstone (sedimentary) it changed over millions of years to gneiss and quartzite and quartz (all metamorphic) due to massive pressures and heat put upon it below the the earth's surface. The quartz veins happen when rock becomes liquid and then recrystallizes as it intrudes itself through the surrounding rock during metamorphism.