مورد إلكتروني
Calibration of chron C29r: New high-precision geochronologic and paleomagnetic constraints from the Hell Creek region, Montana
| العنوان: | Calibration of chron C29r: New high-precision geochronologic and paleomagnetic constraints from the Hell Creek region, Montana |
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| المؤلفون: | Sprain, CJ |
| المصدر: | Bulletin of the Geological Society of America; vol 130, iss 9-10, 1615-1644; 0016-7606 |
| بيانات النشر: | eScholarship, University of California 2018-01-01 |
| تفاصيل مُضافة: | Sprain, CJ Renne, PR Clemens, WA Wilson, GP |
| نوع الوثيقة: | Electronic Resource |
| مستخلص: | The mass extinction at the Cretaceous- Paleogene boundary marks one of the most important biotic turnover events in Earth history. Yet, despite decades of study, the causes of the Cretaceous-Paleogene boundary crises remain under debate. An important tool that has the capacity to greatly improve our understanding of the events around the Cretaceous-Paleogene boundary is the geomagnetic polarity time scale (GPTS). The GPTS is used for age control in numerous Cretaceous-Paleogene boundary studies, including the timing of Deccan Traps volcanism, a majority of studies in marine sections, and studies on climate and ecological change across the Cretaceous-Paleogene boundary. The current calibration of the GPTS for circum- Cretaceous-Paleogene boundary polarity chrons (C30n-C28n) from the Geologic Time Scale draws heavily on astronomical tuning and uses a 40Ar/39Ar age for the Cretaceous- Paleogene boundary as a tie point that has since been shown to be 200 ka too old. Furthermore, complex sedimentation has been recorded in marine sections immediately following the Cretaceous-Paleogene boundary, which can possibly obscure orbital signals and complicate cyclostratigraphic interpretation. An independent test of the cyclostratigraphy for this time period is imperative for confidence in the astronomical time scale. Further, polarity reversal ages given in the GPTS do not include uncertainty estimates, making them unsuitable for quantitative chronometry. Recent calibrations have been attempted using U/Pb geochronology on zircons; however, U/Pb zircon dates may be biased by pre-eruptive zircon residence times of tens to hundreds of thousands of years. In this study, we provide constraints on the timing and duration of the most important circum-Cretaceous-Paleogene boundary chron, chron C29r, using high-precision 40Ar/39Ar geochronology and magnetostratigraphy on fluvial sediments from the Hell Creek region, Montana. Here, we show results for 14 new magnetostratigraphic sections |
| مصطلحات الفهرس: | Geochemistry, Geology, Geophysics, article |
| URL: | |
| الإتاحة: | Open access content. Open access content public |
| ملاحظة: | application/pdf Bulletin of the Geological Society of America vol 130, iss 9-10, 1615-1644 0016-7606 |
| أرقام أخرى: | CDLER oai:escholarship.org:ark:/13030/qt9sn5p1qm qt9sn5p1qm https://escholarship.org/uc/item/9sn5p1qm https://escholarship.org/ 1367473438 |
| المصدر المساهم: | UC MASS DIGITIZATION From OAIster®, provided by the OCLC Cooperative. |
| رقم الأكسشن: | edsoai.on1367473438 |
| قاعدة البيانات: | OAIster |
| الوصف غير متاح. |