| 词条 | Sheet intrusion |
| 释义 |
A sheet intrusion, or tabular intrusion, is a planar sheet of roughly the same thickness, that forms inside a pre-existing rock.[1] When it cuts into another unlayered mass, or across layers, it is called a "dike". When it is formed between layers in a layered rock mass, it is called a "sill". An igneous sheet intrusion is formed where a mass of molten magma takes advantage of a pre-existing linear feature in a host rock, such as a long rupture or fault, and forces its way into these spaces. Thus the magma, intruded between existing rocks, solidifies into large thin sheets of igneous rock. They are among the most extensive igneous features on Earth,{{citation needed|date=March 2013}} in the form of dikes, laccoliths, cone sheets and sills. When limestone or other precipitate forms in a fault space, it is a sedimentary sheet intrusion. References1. ^Essentials of Geology, 3rd Ed, Stephen Marshak
3 : Igneous rocks|Volcanology|Sheet intrusions |
| 随便看 |
|
开放百科全书收录14589846条英语、德语、日语等多语种百科知识，基本涵盖了大多数领域的百科知识，是一部内容自由、开放的电子版国际百科全书。