The soft shale layers forming the foundation of the Shawangunk mountains were originally muddy sediments deposited in the extensive inland sea that covered much of this area during the Ordovician Period about 500 million years ago.
(The soft shale layers; forming; the foundation of the Shawangunk mountains) (The soft shale layers forming the foundation of the Shawangunk mountains; were; originally muddy sediments deposited in the extensive inland sea) (originally muddy sediments; deposited; in the extensive inland sea) (the extensive inland sea; covered; much of this area; T:during the Ordovician Period; T:about 500 million years ago)
The soft shale layers The soft shale layers forming the foundation of the Shawangunk mountains originally muddy sediments the extensive inland sea
forming were deposited covered
the foundation of the Shawangunk mountains
originally muddy sediments deposited in the extensive inland sea
in the extensive inland sea
much of this area T:during the Ordovician Period T:about 500 million years ago