11. The meteorite impacted on the basaltic rocks of the Serra Geral Formation ( Jurassic / Cretaceous ). 12. Outcrops of basaltic rock are common among this soil type, betraying the volcanic origin of Sonoma Mountain. 13. Yet, running through the region are several smaller volcanic cones composed of black or red basaltic rock . 14. The nearby geology is characterized by an outcropping of basaltic rocks that have been reused in local buildings. 15. The Heldburger Castle Hill is also made of basaltic rock that phonolite ( Sparkling Stone ) is called. 16. Water has eroded the sandstone, but in its higher parts, the basaltic rocks is more resistant to erosion. 17. It soils derived from basaltic rocks . 18. Especially in layers closer to Earth's surface, naturally occurring isotopes are enriched in the granite and basaltic rocks . 19. Only rocks of the second series have been discovered at Pilot Knob; no basaltic rocks have been located. 20. The top is covered by a deep layer of sediment through which basaltic rocks and erratic boulders protrude.
