Snowball Earth Educational Rock Sample Suite D-6 by Robin Rohrback-Schiavone

D-6 is a massive gray clast-rich basal tillite (diamictite) from the Storeelv glacial unit of the Ulveso Formation in eastern Greenland. The matrix is primarily composed of coarse sand. Within the sample, clast sizes range from <1 mm to 1 cm. Clast composition and size are similar to east Greenland sample #29, although the matrix composition is distinctly different.

This sample probably formed in direct contact with basal ice. The massive matrix and unsorted clasts of this tillite (diamictite) were derived directly from underlying sediments and rocks eroded by the movement of basal ice during the Storeelv glacial event.

This sample is from the Snowball Earth Educational Rock Sample Suite, and comes courtesy of Paul Hoffman, Harvard University; Eugene Domack, Hamilton College; and Timothy Fox, Hamilton College.
For more information on the Snowball Earth Educational Rock Sample Suite, visit www.snowballearth.org/samples.html  Will open in a new tab or window

Image made as part of the MAGIC project (Mid-Atlantic Geo-Imagery Collection) using Northern Virginia Community College's gigamacro rig, as seen here:
gigamacro.com/gigapixel-macro-imaging-system / Will open in a new tab or window