| Abstract: | During the past 1500 yr Mount St. Helens, Washington, has repeatedly erupted dacite domes, tephra, and pyroclastic flows as well as andesite lava flows and tephra. Two periods of activity prior to 1980, each many decades long, were both initiated by eruptions of volatile-rich dacite which were followed by andesite, then by dacite. A third eruptive period was characterized by the eruption of volatile-poor dacite that formed a dome and minor pyroclastic flows. The prolonged duration of some previous eruptive periods suggests that the current activity could continue for many years. The volatile-rich dacite that has been erupted to date probably will be followed by gas-poor magma, but it cannot yet be predicted whether a more mafic magma will be extruded during the current eruptive period.-Authors |
| Genre: | Article |
| ProdID: | 70012555 |
| Citation Author: | Hoblitt, R. P.; Crandell, D. R.; Mullineaux, D. R. |
| Citation Contributing Office: | |
| Citation Datum: | |
| Citation Day: | |
| Citation Edition: | |
| Citation Editor: | |
| Citation End Page: | 559 |
| Citation Issue: | 11 |
| Citation Keywords: | |
| Citation Language: | English |
| Citation Larger Work Title: | Geology |
| Citation LatN: | |
| Citation LatS: | |
| Citation LonE: | |
| Citation LonW: | |
| Citation Month: | |
| Citation No Pagination: | |
| Citation Number Of Pages: | 5 |
| Citation Online Only Flag: | |
| Citation Phsyical Description: | |
| Citation Projection: | |
| Citation Public Comments: | |
| Citation Publisher: | |
| Citation Series: | |
| Citation Series Code: | |
| Citation Series Number: | |
| Citation Search Results Text: | Mount St. Helens eruptive behavior during the past 1500 yr.; 1980; Article; Journal; Geology; Hoblitt, R. P.; Crandell, D. R.; Mullineaux, D. R. |
| Citation Start Page: | 555 |
| Citation Volume: | 8 |
| Citation Year: | 1980 |
| Type: | citation/reference |
| Text: | Mount St. Helens eruptive behavior during the past 1500 yr.; 1980; Article; Journal; Geology; Hoblitt, R. P.; Crandell, D. R.; Mullineaux, D. R. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| Date Other: | Tue, 1 Jan 1980 00:00 -0600 |
| Publisher: | |
