Question
Over time, so-called “anomalous fading” reduces the observed signal strength of feldspar samples dated using this method. For 10 points each:
[10h] Name this dating method that is often applied to quartz through the single-aliquot regenerative-dose, or SAR, protocol. Techniques using this method date samples by dividing the equivalent dose by the dose rate.
ANSWER: luminescence dating [accept more specific answers such as thermoluminescence or radioluminescence or optically-stimulated luminescence; prompt on OSL or TT-OSL or IRSL or TL or RL or ISL by asking “What does the L stand for?”]
[10e] Optically stimulated luminescence is often used to date deposits of this sediment. This unconsolidated sediment forms namesake “fans” when it deposits onto floodplains.
ANSWER: alluvium [or alluvial deposit; accept alluvial fans; prompt on colluvium; reject “diluvium”]
[10m] Most alluvium comes from parent material of this geologic period. The Younger Dryas was a stadial that occurred during this period, while the clathrate gun hypothesis sought to explain interstadials during this period.
ANSWER: Quaternary Period [prompt on Q]
<Other Science>
Summary
2025 ACF Nationals | 04/19/2025 | Y | 24 | 6.25 | 58% | 4% | 0% |
Data
Penn State | Arizona State | 0 | 10 | 0 | 10 |
Ottawa | British Columbia | 0 | 0 | 0 | 0 |
Chicago A | Northwestern | 0 | 10 | 0 | 10 |
Cornell B | Columbia B | 0 | 0 | 0 | 0 |
Georgia State | WUSTL B | 0 | 0 | 0 | 0 |
Chicago B | Georgia Tech | 0 | 10 | 0 | 10 |
MIT | Harvard | 0 | 10 | 0 | 10 |
Indiana | North Carolina A | 0 | 10 | 10 | 20 |
Toronto C | Johns Hopkins | 0 | 10 | 0 | 10 |
Florida | LSE | 0 | 0 | 0 | 0 |
Virginia Tech | Minnesota | 0 | 10 | 0 | 10 |
NYU | UC Berkeley B | 0 | 10 | 0 | 10 |
Virginia | North Carolina B | 0 | 0 | 0 | 0 |
RIT | Ohio State | 0 | 0 | 0 | 0 |
Rutgers | Toronto A | 0 | 10 | 0 | 10 |
Stanford | Illinois A | 0 | 10 | 0 | 10 |
Texas | Iowa State | 0 | 0 | 0 | 0 |
Toronto B | Cornell A | 0 | 0 | 0 | 0 |
Michigan | UCF | 0 | 0 | 0 | 0 |
Illinois B | Vanderbilt | 0 | 0 | 0 | 0 |
UC Berkeley A | WUSTL A | 0 | 10 | 0 | 10 |
Columbia A | Waterloo A | 0 | 10 | 0 | 10 |
Yale | Waterloo B | 0 | 10 | 0 | 10 |
Winona State | Maryland | 0 | 10 | 0 | 10 |