Global Catastrophes in Earth History; An Interdisciplinary Conference on Impacts, Volcanism, and Mass Mortality

Chemistry and mineralogy across the Cretaceous/Tertiary boundary at DSDP Site 527, Walvis Ridge, South Atlantic Ocean
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Published:January 01, 1990
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CiteCitation
Alan R. Huffman, James H. Crocket, Neville L. Carter, Peter E. Borella, Charles B. Officer, 1990. "Chemistry and mineralogy across the Cretaceous/Tertiary boundary at DSDP Site 527, Walvis Ridge, South Atlantic Ocean", Global Catastrophes in Earth History; An Interdisciplinary Conference on Impacts, Volcanism, and Mass Mortality, Virgil L. Sharpton, Peter D. Ward
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Specimens spanning 10 m across the Cretaceous/Tertiary (K/T) boundary in Core 32 at DSDP Site 527, Walvis Ridge, were analyzed for trace elements and for evidence of shock deformation. Results from INAA/RNAA chemistry of the 45 samples suggest that multiple events are recorded at this site, including at least two enrichments of chalcophile elements possibly related to basaltic volcanism. A major event, coincident with the paleontological K/T boundary, is marked by a strong Ir anomaly and high frequency of shock deformation in quartz and feldspar. A strong secondary peak in elemental enrichment and mosaicism occurs at 1.87 m below the K/T boundary, suggesting appreciable volcanic activity about 105 years prior to the K/T event. Carbon and oxygen isotopes from the site also suggest that changes in climate began before the shock event at the boundary. Correlations between biostratigraphy, isotopes, and the data from this study suggest that the decline in marine productivity over an extended period of time may be the result of complex coupling of basaltic volcanism to climate change.
- Atlantic Ocean
- C-13/C-12
- carbon
- Cenozoic
- Cretaceous
- Deep Sea Drilling Project
- DSDP Site 527
- effects
- geochemistry
- igneous rocks
- IPOD
- iridium
- isotope ratios
- isotopes
- K-T boundary
- Leg 74
- lower Paleocene
- Mesozoic
- metals
- mineral composition
- O-18/O-16
- oxygen
- Paleocene
- Paleogene
- platinum group
- South Atlantic
- stable isotopes
- stratigraphic boundary
- Tertiary
- trace elements
- Upper Cretaceous
- volcanic rocks
- volcanism
- Walvis Ridge