Sanidine spherules at the Cretaceous–Tertiary boundary indicate a large impact event

Smit, Jan; Klaver, G.

doi:10.1038/292047a0

Cited by 170 publications

(97 citation statements)

References 10 publications

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“…The recent report of shocked quartz grains (possibly stishovite) in the K/T boundary clay of Montana (Bohor et al, 1984) provides independent and even more definite proof of a meteorite impact at the K/T boundary. In addition to this evidence, smectite spherules (Kastner et al, 1984; J. Smit, unpublished results for DSDP Hole 390B), sanidine (Smit and Klaver, 1981), and spherules bearing iron-alumino- Figure 5. Shale-normalized REE diagrams for samples from Section 603B-22-3.…”

Section: Discussionmentioning

confidence: 99%

Green Spherules as Indicators of the Cretaceous/Tertiary Boundary in Deep Sea Drilling Project Hole 603B

Klaver¹,

Kempen²,

Bianchi³

et al. 1987

Initial Reports of the Deep Sea Drilling Project

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Dark green spherules occur in the lower part of a turbidite in Section 603B-22-3, at the 70 cm level. In all probability these spherules originally consisted of massive glass, but now appear to have become completely altered into smectite. The presence of numerous microscopic fissures in the spherules probably mediated in the alteration process.Judging by the presence of similar spherules at the Cretaceous/Tertiary (K/T) boundary in DSDP Hole 390B, the green spherules are thought to represent diagenetically altered impact ejecta from one large or several smaller extraterrestrial objects at the end of the Cretaceous. The presence of anomalously high concentrations of Ni, Co, and As higher up in the turbidite are in agreement with an expected enrichment of these elements in the K/T boundary clay. However, precise Ir analyses are necessary in order to confirm this.

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Section: Discussionmentioning

confidence: 99%

Green Spherules as Indicators of the Cretaceous/Tertiary Boundary in Deep Sea Drilling Project Hole 603B

Klaver¹,

Kempen²,

Bianchi³

et al. 1987

Initial Reports of the Deep Sea Drilling Project

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“…However, with this explanation it is very difficult to account for the distinct enrichment of the very refractory noble metals. On the other hand, SMIT and KLAVER [12] found sanidine spherules in the boundary clay at Caravaca, Spain, which were undoubtly produced by an impact.…”

Section: Resultsmentioning

confidence: 99%

Noble Metals in Cretaceous/Tertiary Sediments from El Kef

Kuslys

Kraehenbuehl

1983

Radiochimica Acta

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“…Their study was published one month before the seminal paper by Alvarez et al [44], although they did not claim priority because the theory was previously communicated in a congress in 1979 by the Alvarez team. The red rusty layer also contains altered microtektites [45] as well as anomalous concentrations in Co, Cr, Ni, As, Sb, and Se [46]. Many other mineralogical and geochemical analyses were accomplished finding overwhelming meteoritic impact evidence [47][48][49][50][51][52][53][54][55][56][57].…”

Section: Agost and Caravaca Section (Spain) The Agost Andmentioning

confidence: 99%

Planktonic Foraminiferal Biostratigraphy and Correlation Across the Cretaceous-Paleogene Transition at the Tethyan and the Atlantic Realms

Gallala

2013

Paleontology Journal

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Based on high-resolution planktonic foraminiferal biostratigraphical analysis at El Kef stratotype section (GSSP for the K/Pg boundary), Ellès section in Tunisia, and Agost and Caravaca sections in Spain (Tethyan realm), we attempt to compare biozones and subzones with those of the Bidart section (SW France) (Atlantic realm). The Abathomphalus mayaroensis zone of the upper Maastrichtian corresponds to the taxon range interval of the nominate species. We have identified the Plummerita hantkeninoides subzone. This species is present and associated with Pseudoguembelina hariaensis at the Tethyan realm. However, this species is absent at the middle latitude of the Atlantic realm (Bidart section, SW France). The Pseudoguembelina hariaensis species had larger paleogeographic spread, as it was present in both the Tethys and the Atlantic paleoceans. It is more relevant to be considered as the biomarker of a nominate uppermost Maastrichtian subzone instead of Plummerita hantkeninoides. The Danian stage is characterized by the Gt. cretacea zone, Pv. eugubina zone, and the Parasubbotina pseudobulloides zone. The deposition thickness of the zones and subzones at El Kef stratotype section and Ellès section is more expanded than at Agost and Caravaca sections (Spain) and Bidart section (France). They would be controlled by the sedimentary basin morphology.

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Sanidine spherules at the Cretaceous–Tertiary boundary indicate a large impact event

Cited by 170 publications

References 10 publications

Green Spherules as Indicators of the Cretaceous/Tertiary Boundary in Deep Sea Drilling Project Hole 603B

Green Spherules as Indicators of the Cretaceous/Tertiary Boundary in Deep Sea Drilling Project Hole 603B

Noble Metals in Cretaceous/Tertiary Sediments from El Kef

Planktonic Foraminiferal Biostratigraphy and Correlation Across the Cretaceous-Paleogene Transition at the Tethyan and the Atlantic Realms

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