As you drive North on Route 1 out of Boston, after you cross over the Tobin Bridge and then the Belle Isle Marsh in Revere, you may notice a new complex of apartments on your right. The blasting of bedrock that was done to make room for these buildings reveals steep cliffs of the Lynn Volcanics.
Two views from the Parking Lot near main entrance
How many different kinds of rocks can you see in these two pictures? What might be the story behind this formation?
Which rock - the reddish or whitish - do you think came first? What evidence are you using to answer this question?
Close-ups of light colored rhyolite (Lynn Felsite) intruding on the reddish rhyolite
In the pictures above, notice the different ways the two rock types are weathering. Notice the difference in the way they crumble and fracture, as well as the color differences.
Here is a side view of an intrusion into the rhyolite. On the right, you can see what may be a plane surface view of a similar vein.
