Taconics

Starks Knob Pillow Lavas
"Pillow Lavas" form when basalt lava flows up from deep cracks (vents) in the earth and erupts under water. A low ridge builds along an elongated vent, and the basalt lava spills away from the vent. The cooling basalt lava rolls downslope, and ball-like forms known as pillows pile up. During the Taconic Orogeny, a volcanic island arc was pushed west into Vermont and eastern New York and as the continent buckled in front of it, cracks opened in the earth's crust. The Stark's Knob basalt lava flowed out of these cracks into the sea covering eastern North America. Fossil snails found between the basalt pillows by State Museum researchers indicate an Early or, more likely, Middle Ordovician age of the pillow basalt. These snails also show that the pillows were formed in relatively shallow sea water. Click here for more information about the Pillow Lavas at Stark's Knob.

Stark's Knob Pillow Lavas Close-up
This close-up shot reveals the limey, distorted, and cooked sediments that the Stark's Knob basalts were injected into. The sediments appear to the right of the pen, between pillows that appear on the extreme right and left of the image. Fossil snails found in those sediments indicate and Ordovician age for the basalts. See this related EPOD

Stark's Knob Pillow Lavas
Steve K. and Glenn D. examine a large 'pillow' on the quarried side of Stark's Knob.

Taconic Region

Taconic geologic map

Taconic legend

Briarcliff Dolostone
Location and pics. View looking west.

Briarcliff Dolostone pics
Road stop location cross street.
General road cut location.
Folded Briarcliff dolostone.
Folded black chert.

Walloomsac Fm
Location and pics. View looking west.

Walloomsac Fm pics
General road cut view.
Walloomsac schist tight isoclinal folds.
Walloomsac schist with kyanite blades gives bluish color.
Groundwater flowing from jointing and foliation partings in the Walloomsac schist.

Briarcliff-Walloomsac quad

Taconic unconformity
Location and pics

Taconic unconformity pics
Taconic unconformity, folding and bedding thrust faults.
Taconic unconformity, folding and thrust faults of the Manlius and Roundout Fms..
Taconic unconformity between the Silurian Roundout and the Ordovician Mt Merino Chert.
Taconic unconformity, bedding plane thrust fault zone.

Taconic unconformity quad

Becraft Mtn

Taconic State Park
Bash Bish Falls parking area and trail head. A complete metamorphic lithologic transition from slate to phyilite can be observed along the north side of Bash Bish Creek. The hike to Bash Bish Falls from the parking area is approximately 1.5 mi roundtrip.

Bash Bish Falls
Location and pics. View looking east.

Bash Bish Falls pics
Tight V-shaped folding of Everett phyllite.
Mass NY Border
Rock abrasion by stream action..
Bash Bish Falls.

Bash Bish Falls quad

Bash Bish drainage quad.

Bennington Vt Bypass
Location and pics. View looking south.

Bennington Vt Bypass Pics
Bennington Vt bypass. New road cut along Rt 279. Incredible exposure of folded calcareous rocks (Winooski Dolomite?). General road cut view.
Synclinal structure.
Anticlinal structure.
Anticline and syncline.
Fractured synclinal nose.

Benningon bypass quad