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“Chevrons” are not mega-tsunami deposits—A sedimentologic assessment
| Content Provider | Semantic Scholar |
|---|---|
| Author | Bourgeois, Joanne Weiss, Robert |
| Copyright Year | 2009 |
| Abstract | Since the introduction of the term “chevron” for large v- or u-shaped bed forms in Egypt and the Bahamas, others have adopted the term to describe large-scale coastal bed forms in Australia, Madagascar, and elsewhere. These authors interpret “chevron” bed forms as deposits of mega-tsunamis resulting from Holocene oceanic asteroid impacts. We reason that chevron-type bed forms are common and are present far enough from the coast to preclude tsunami genesis. Moreover, we argue that “chevrons” are not mega-tsunami deposits by modeling tsunami behavior and evaluating sediment-transport conditions under which such features formed. We model the southern Madagascar case, with an impact source in the Indian Ocean, and show that a modeled wave approach is inconsistent with “chevron” orientation. We then evaluate sediment-transport conditions under which these “chevron” bed forms could persist, i.e., bed-load transport. In our analysis, no conditions specified generate pure bed-load transport, and most result in pure suspended-load transport. |
| Starting Page | 403 |
| Ending Page | 406 |
| Page Count | 4 |
| File Format | PDF HTM / HTML |
| DOI | 10.1130/G25246A.1 |
| Alternate Webpage(s) | http://faculty.washington.edu/jbourgeo/BourgeoisWeiss2009final.pdf |
| Alternate Webpage(s) | https://doi.org/10.1130/G25246A.1 |
| Volume Number | 37 |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
