| Abstract: | K-Ar dates of illitic clays from sedimentary rocks may contain "mixed ages," i.e., may have ages that are intermediate between the ages of end-member events. Two phenomena that may cause mixed ages are: (1) long-lasting reaction during the burial illitization of smectite: and (2) physical mixing of detrital and diagenetic components. The first phenomenon was investigated by simulation of illitization reactions using a nucleation and growth mechanism. These calculations indicate that values for mixed ages are related to burial history: for an equivalent length of reaction time, fast burial followed by slow burial produces much older mixed ages than slow burial followed by fast. The type of reaction that occured in a rock can be determined from the distribution of ages with respect to the thickness of illite crystals. Dating of artificial mixtures confirms a non-linear relation between mixed ages and the proportions of the components. Vertical variation of K-Ar age dates from Gulf Coast shales can be modeled by assuming diagenetic illitization that overprints a subtle vertical trend (presumably of sedimentary origin) in detrital mineral content. |
| Genre: | Article |
| ProdID: | 70024080 |
| Citation Author: | Srodon, J.; Clauer, N.; Eberl, D. D. D. |
| Citation Contributing Office: | |
| Citation Datum: | |
| Citation Day: | |
| Citation Edition: | |
| Citation Editor: | |
| Citation End Page: | 1535 |
| Citation Issue: | 11-12 |
| Citation Keywords: | |
| Citation Language: | English |
| Citation Larger Work Title: | American Mineralogist |
| Citation LatN: | |
| Citation LatS: | |
| Citation LonE: | |
| Citation LonW: | |
| Citation Month: | |
| Citation No Pagination: | |
| Citation Number Of Pages: | 8 |
| 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: | Interpretation of K-Ar dates of illitic clays from sedimentary rocks aided by modeling; 2002; Article; Journal; American Mineralogist; Srodon, J.; Clauer, N.; Eberl, D. D. D. |
| Citation Start Page: | 1528 |
| Citation Volume: | 87 |
| Citation Year: | 2002 |
| Type: | citation/reference |
| Text: | Interpretation of K-Ar dates of illitic clays from sedimentary rocks aided by modeling; 2002; Article; Journal; American Mineralogist; Srodon, J.; Clauer, N.; Eberl, D. D. D. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| Date Other: | Tue, 1 Jan 2002 00:00 -0600 |
| Publisher: | |
