Figure 5, 6. Close-ups of the dike shown in Figure 4. Blobs or enclaves of dark basalt are surrounded by lighter colored granitic rock. The scalloping
or cuspate nature of the edges of the basalt indicates that the separate magmas (molten rock) that became the basalt and the granitic rock were both molten at the same time and interacted but did not mix very well. Some fantastic shapes form in the process. Because basalt solidifies at a higher temperature than granite, it solidified quickly and the granite more slowly.
Last updated on October 6, 2005