Structure of the Earth discontinuity (a second order discontinuity). The uppermost mantle together with the crust constitutes the lithosphere. The crust-mantle boundary occurs as two physically different events. First, there is a discontinuity in the seismic velocity, which is most commonly known as the Mohorovičić discontinuity or Moho. The cause of the Moho is thought to be a change in rock composition from rocks containing plagioclase feldspar (above) to rocks that contain no feldspars (below). Second, in oceanic crust, there is a chemical discontinuity between ultramafic cumulates and tectonized harzburgites, which has been observed from deep parts of the oceanic crust that have been
The Adventures of the Wilderness Family and "introduces himself". Thankfully it pays off and the bear, who turns out to be Samson, befriends the family and joins them for dinner. The family settles in further to their new life, gathering from the surrounding forests and spending time with their new animal friends and Boomer. One day, while Pat and Jenny are picking berries, they encounter Three-Toes; Crust manages to fend off Three-Toes while Pat retrieves Jenny, who suffered a massive shock. Skip goes to find Crust while tracking down Three-Toes. The following morning, Jenny's condition has gotten worse, Skip tries to call for help but the