Where is Puddingstone found?
Conglomerate (Jasper Conglomerate)
Got a photo? Identify rocks instantly with the Rockby app
Open the appPuddingstone occurs in specific geological environments. Knowing where to look, and in what kind of rock, is the difference between going home empty-handed and finding a great specimen.
Where to find Puddingstone
Michigan, USA
The most famous 'Michigan Puddingstone' is found in the northern Lower Peninsula and Upper Peninsula of Michigan, particularly around the Drummond Island and St. Joseph Island areas. These are often glacial erratics derived from Proterozoic Huronian Supergroup conglomerates.
Ontario, Canada
Significant deposits, particularly the St. Joseph Island Puddingstone, are found in Ontario, Canada, especially on St. Joseph Island and along the North Shore of Lake Huron. These are part of the Gowganda Formation of the Huronian Supergroup (Paleoproterozoic).
Hertfordshire, England
The 'Hertfordshire Puddingstone' is a well-known variety found in southeastern England. It is a Paleogene (Eocene) conglomerate composed of flint clasts cemented by silica.
Other Global Occurrences
Conglomerates with a 'puddingstone' appearance can be found in various locations worldwide where suitable depositional and lithification conditions have occurred. These include parts of the Appalachian Mountains (USA), and other regions with ancient fluvial or glacial deposits.
Collecting tips
- Look in Glacial Deposits. Many puddingstones, especially in North America, are found as glacial erratics. Search in areas that were glaciated, such as moraines, till deposits, and outwash plains.
- Riverbeds and Lake Shores. Puddingstone can be found in riverbeds and along lake shores, where erosion has exposed and transported the rock. The tumbling action of water can also polish the surface, making the clasts more visible.
- Exposed Bedrock. In regions where puddingstone formations are in situ, look for exposed bedrock in road cuts, quarries, and natural outcrops.
- Identify Rounded Clasts. The key identifying feature is the presence of well-rounded, distinct clasts embedded in a matrix. The clasts should be noticeably different in composition or color from the matrix.
Quick Check
- Color:
- Variable, often white/gray matrix with red, green, or multi-colored clasts.
- Luster:
- Dull to vitreous.
- Streak:
- White (for siliceous matrix/clasts), or not applicable for the rock as a whole.
Explore Puddingstone
Identify rocks anywhere
Free on iOS, Android, and Web. Photo identification, full database, and your personal collection.