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Sample 3-26-89-5
NavDat sample number 30301 · TUFF
Sample
| Sample ID | 3-26-89-5 |
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| Rock name | TUFF |
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| Rock type | VOLCANIC |
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| Composition | FELSIC |
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| Material | IGNEOUS |
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| Comment | on nw end of nw-se oriented hill, approximately300 ft approximately91m south of dirt road; elevation 1,240 ft or 378 m. Light- to dark-gray fine-grained crystal vitric tuff; devitrification common - glass shards appear as pseudomorphs replaced by smectite and zeolites; glass shards approximately0.01-0.02mm have bubble-wall shapes; contains crystals approximately0.01-0.03mm of quartz, biotite, hornblende, and plagioclase; 90& glass, 10%crystals; bed is massive i.e., no bedding visible with sharp basal and upper contacts; 7 ft 2.1m thick; low K content probably reflects diagenetic alteration of glass shards; age is too young and is not consistent with stratigraphy. |
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Location
| Latitude | 35.9906 |
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| Longitude | -120.262 |
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| Location | Etchegoin Formation |
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| State / province | California |
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Age
| Age (Ma) | Error | Min | Max | Geologic age | Dated by |
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| 4.2 |
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3.7 |
4.7 |
|
|
