Xenoliths at Breakneck Ridge

August 30, 2014

Xenolithhornblend

Photographer: Andrew Heiz
Summary Authors: Andrew Heiz; Jackie Phillips

Breakneck Ridge is a popular hike because of its fantastic views, difficult rock scrambles and accessibility from New York City. The ridge is located within the northern boundary of the Hudson Highlands and along the Hudson River. This region was highly deformed and metamorphosed numerous times during continental collisions that occurred eons ago.

This image shows a large xenolith in a boulder found at Breakneck Ridge. There's a reaction rim visible along the upper half. Both the xenolith and surrounding rock are cross-cut by a quartz vein going from the lower right side of the image to the upper left. The xenolith is approximately 12 in (30 cm) wide diagonally -- my son's feet in the upper right give an indication of the scale. Photo taken on July 13, 2014.

Photo details: Camera Model: Canon PowerShot A720 IS; Focal Length: 5.8mm; Aperture: f/2.8; Exposure Time: 0.020 s (1/50); ISO equiv: 100.