A Geoscience Digital Image Library

TitleHornfels, from near Lambertville, New Jersey, USA
DescriptionHornfels is a general term describing a fine-grained metamorphic rock that displays no metamorphic fabric. Hornfels typically forms by contact metamorphism. In western New Jersey, intrusion of magma has caused local metamorphism of sedimentary rocks. In places, the mudstones and shales of the Lockatong and Brunswick Formations have been affected. This specimen is an example. It comes from near the New Jersey-Pennsylvania border and is 9.6 cm across. The degree of metamorphism is very low, and some metamorphic geologists might still consider this a sedimentary rock.
LocationUSA ▹ New Jersey. Near Lambertville.
PhotographerNessa Eull. 2001-05-22.
CollectionWard’s University Rock Collection #169.
Key wordshornfels, New Jersey, contact metamorphism
Tech details819 KB. Hand specimen. Fujifilm FinePix S1Pro digital camera; 60mm AF Nikon micro lens.
GeoDIL number502