sedimentary
Gowganda Tillite (Puddingstone)
Gowganda Formation Conglomerate
Hardness: 6-7 (Mohs); Color: Dark grey to greenish matrix with pink to red clasts; Luster: Dull to earthy; Structure: Clastic/Rudaceous; Cleavage: None; SG: 2.6-2.8
- Hardness
- 6-7 (Mohs)
- Color
- Dark grey to greenish matrix with pink to red clasts
- Luster
- Dull to earthy
Identified More sedimentary →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6-7 (Mohs); Color: Dark grey to greenish matrix with pink to red clasts; Luster: Dull to earthy; Structure: Clastic/Rudaceous; Cleavage: None; SG: 2.6-2.8
Formation & geological history
Formed during the Huronian glaciation (approx. 2.3 billion years ago) as glacial till or outwash that was subsequently lithified into conglomerate.
Uses & applications
Used primarily as decorative stone, lapidary specimens, and as a geological indicator for glacial history in North America.
Geological facts
The Gowganda Formation is part of the oldest known widespread ice age in Earth's history. It is often referred to as 'Puddingstone' because the red jasper or feldspar clasts look like raisins in a pudding.
Field identification & locations
Identify by looking for distinct pink feldspar or red jasper fragments embedded in a fine-grained, dark greenish-grey matrix. Commonly found around Lake Huron and throughout Northern Ontario/Michigan.
More like this
Other sedimentary specimens
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Chert Breccia
Brecciated Chert (Microcrystalline Silica)
sedimentary
Sandstone
Arenite (primarily SiO2)
sedimentary
Sandstone Grain
Clastic Sedimentary Rock Grain (SiO2 dominated)
sedimentary
Shale or Slaty Mudstone
Argillaceous sedimentary rock
sedimentary
Sandstone
Arenite
sedimentary