Spherical concretions > Hiking and caving photos





Trekking, hiking and caving photos

The spherical concretions from Feleac are sedimentary rock materials that were cemented together to form a hard structure. The surrounding sediments slowly erode away, exposing the concretion. They were formed when calcium carbonate and other cementing minerals precipitated from the ground water around an organic nucleus, like a shell. Near Feleac we can find sphere-, and cannonball-shaped concretions. In the past they were often used as construction material.

Comment by Len Hudgens, a geologist: Concretions, or boulders as we call the large ones are common in the elephant rocks area. Ones in the glaciated areas are called "erratics" because they were moved and rounded by the glaciers. However, certain rock formations also erode to form concretions or boulders if there are minerals in the rock that is slightly harder than the surrounding matrix. Iron oxides in sandstone, as in the "Garden of the Gods" area of southern Illinois, is a good example.

Gardens of Cluj
Gardens of Cluj
Spherical concretion
Spherical concretion
In the forest
In the forest
Spherical concretions
Spherical concretions
Rajka-spring
Rajka-spring
Turtle-shaped concretion
Turtle-shape
Disabled first thumbnail page · Disabled previous thumbnail page · 1 · 2 · 3 · Next thumbnail page · Last thumbnail page

Ed's hiking trip in Transylvania - Search on trekkingklub.com Hiking - Caving - Backpacking - Mountaineering - Copyright 2003-2022 Trekkingklub. Reproduction of any text or picture from this website, either in printed or electronic form, is prohibited without prior written permission.