Septarian Nodules in The Earth’s Crust
This month’s Science focus is about a most interesting phenomena called a Spheroidal Concretion, and the special “animal” (though not an animal – or was it at one time?) is called a Septarian Nodule. In their raw found forms, one might think that they are eggs, with a living creature inside awaiting to hatch – or that maybe they are sediment space shuttles that came from outer space. Because of their interesting looks, they are also known as Dragon Eggs. They formed during the Cretaceous period, about 50-70 million years ago. Many of these facts, we learned this weekend from a rock show organized by the Victoria Lapidiary Society. Helpful participants were Fossil Grotto from Duncan, BC, and Stone Haven Gems. We learned a lot!
Concretions are rounded rocks embedded in layers of stone in sedimentary rocks, often they are harder than the surrounding stone, and whether out of the host rock; http://www.rocksforkids.com/R&M/concretions.html#Septarian_Nodules. They are a hard mass of sedimentary rocked compacted tightly at one time, by way of the precipitation of mineral cement, that has grown spaces between the sediment grains – outward in 7 directions. The sedimentary rock nodules are kind of mineralized calcified encased “mud”, made up of calcite and ironstone. There are 2 basic stages of development that are shown in the photos here:(http://en.wikipedia.org/wiki/Concretion; Moeraki Boulders; Septarian Nodule; photos drawn March 17, 2014 ) caused by networks of cracks in which the minerals, usually calcite (CaCo3 – Calcium Carbonite – in the Periodic Table, Calcium, Carbon and Oxygen) been deposited into the solution before hardening. Prior to the depositing of minerals, the cavities are filled with ironstone; (Melody, EARTH-LOVE Publishing House; Love is In The Earth – Kaleidoscope pictorial, 1998; pp. 282-283).
On a metaphysical level, these beauties are said to filter dreams and keep only good ones around a person, such as is with dream catchers, and thus good to keep near a sleep space. Also used to facilitate neuro-linguistic programming, instilling patience, endurance and tolerance to a person; freedom of body movement supporting the body’s self-healing abilities. (Melody; 1998). Melody, a most fantastic source in the world of minerals and crystals, says it can be placed in the centre of Medicine Circles, facilitating Connection and Harmony.
Questions to ask Learners in your Classroom: What causes minerals to migrate to a centre and become harder? What are their true origins? Can you find septarian nodules in your backyard? Or are they only in one part area of the Earth?
For Fun Learning and Teaching activities and games, feel free to visit here:
http://www.science-lessons.ca/games/mammals.html
http://www.science-lessons.ca/games/space.html
http://www.science-lessons.ca/games/weather8.htm
http://www.literature-enrichment.com/
Interesting links from the Victoria Lapidiary Rock Show we visited:
Victoria Lapidiary and Mineral Society: http://www.islandnet.com/~vlms/.
Fossil Grotto: http://www.caves.org/grotto/ccg/um/2012_03_um.pdf.
Stone Haven Gems: http://www.stonehavengems.com/septarian-nodule-pebble/.
Really good article!