Carbonate Compensation Depth

Precise comparison of the change in radiolarian faunas 3.5 m above a UPb zircon dated 199.6 ± 0.3 Ma tuff and approximately coincident with a negative δ13C anomaly in the Queen Charlotte Islands, B.C. (Canada) with Inuyama (Japan) sequences indicates that major global changes occurred across the TriassicJurassic (TJ) boundary. Nearly 20 genera and over 130 Rhaetian species disappeared at the end of the Triassic. The index genera Betraccium and Risella disappear and the final appearance of Globolaxtorum tozeri, Livarella valida, and Pseudohagiastrum giganteum sp. nov. are also diagnostic for the end of the Triassic. The low-diversity Hettangian survival fauna immediately above the boundary is composed mainly of small, primitive spumellarians with spongy or irregularly latticed meshwork and rod-like spines, and new genera Charlottea, Udalia, and Parahsuum s.l. first appear in the lowest Hettangian in both localities. Irrespective of different sedimentation rates and sedimentary environments, such as shelf to upper slope (Queen Charlotte Islands) and deep sea below carbonate compensation depth (CCD; Inuyama), radiolarians show a similar turnover pattern at the TJ boundary.

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A comparative study of collections from the S.W. Pacific (Saipan to Tonga), with the descriptions of Gambiella caudata (Brady, 1890) and a new species of Pterobairdia (Ostracoda)

Journal of Micropalaeontology ◽

10.1144/jm.5.1.91 ◽

1986 ◽

Vol 5 (1) ◽

pp. 91-108 ◽

Cited By ~ 15

Author(s):

K. G. Mckenzie

Keyword(s):

New Species ◽

Comparative Study ◽

Endemic Species ◽

Species Level ◽

Similarity Matrix ◽

Compensation Depth ◽

Ecological Importance ◽

A New Species ◽

Made In ◽

Carbonate Compensation Depth

Abstract. Gambiella caudata (Brady, 1890) and Pterobairdia briggsae sp. nov. are described from collections made in the S. W. Pacific (Saipan, Onotoa, Ontong-Java/Kula Gulf, Noumea, Cook Islands, Fiji, Samoa, Tonga); and the lectotypes of several species described in a major early paper by Brady (1890) are illustrated. The carbonate compensation depth in this region lies at around 4500 m. Comparison of the Ontong-Java in Kula Gulf samples reinforces consideration of depth as a factor of ecological importance. A similarity matrix for the several faunas shows factors in common at species level ranging from 22% (Onotoa/Noumea) to nearly 60% (Samoa/Onotoa); while endemism ranges from 8.5% (Samoa) to nearly 33% (Tonga). Most endemic species belong in a limited number of podocopid families, in particular Bairdiidae, Trachyleberididae, Paradoxostomatidae and Leptocytheridae. These results appear consistent with an hypothesis that continued tectonics-driven changes in the regional marine topography and sedimentation, i.e. niche development, could have triggered speciation along the regional plate margins.

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A rise in the Carbonate Compensation Depth of western Tethys in the Carnian (Late Triassic): Deep-water evidence for the Carnian Pluvial Event

Palaeogeography Palaeoclimatology Palaeoecology ◽

10.1016/j.palaeo.2006.09.013 ◽

2007 ◽

Vol 246 (2-4) ◽

pp. 188-205 ◽

Cited By ~ 108

Author(s):

Manuel Rigo ◽

Nereo Preto ◽

Guido Roghi ◽

Fabio Tateo ◽

Paolo Mietto

Keyword(s):

Deep Water ◽

Late Triassic ◽

Western Tethys ◽

Compensation Depth ◽

Carbonate Compensation Depth

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