|mhorn||Дата: Thursday, 21.01.2010, 18:40 | Сообщение # 1|
|Pszczółkowski A. (2009) The Tithonian–earliest Berriasian Nannoconus zones in selected sections of the Pieniny Klippen Belt and the Western Tatra Mountains (southern Poland) // Studia Geologica Polonica, 132. P.7-38. |
In comparison with the Spanish sections, first appearance (FAD) of the Tithonian Nannoconus species is recorded earlier in the Pieniny Klippen Belt and the Western Tatra Mountains (Western Carpathians). The Early Tithonian Nannoconus compressus Zone correlates with the uppermost part of the "Pulla-Tithonica" Zone and the lower part of the Malmica Zone. The N. infans Zone corresponds to the upper part of the Malmica Zone and the lower part of the Chitinoidella Zone (Dobeni Subzone) including the lowermost interval of the Boneti Subzone. The N. wintereri Zone is equivalent to the uppermost part of the Chitinoidella Zone, entire Crassicollaria Zone, and the basal interval of the Berriasian Alpina Subzone. In the Kryta Valley section (Tatra Mts), the Infans/ Wintereri zonal boundary is located within the Boneti Subzone and is correlated with the lower part of the CM20n magnetozone. Specimens referred to Nannoconus sp. A occur in the studied sections; these specimens differ from the published descriptions of all previously established Tithonian species. In the Lower Tithonian limestones nannoconids are scarce being more numerous in the lower interval of the N. wintereri Zone. Increase in abundance of the genus Nannoconus correlates with the Mid- to Late Tithonian Nannofossil Calcification Event (NCE) reported from the Central Atlantic Ocean.
Middle Jurassic - Lower Cretaceous ammonites & aptychi