THE UPPER BOUNDARY OF THE EOCENE SERIES: A REAPPRAISAL BASED ON DINOFLAGELLATE CYST BIOSTRATIGRAPHY AND SEQUENCE STRATIGRAPHY

Author(s):  
HENK BRINKHUIS ◽  
HENK VISSCHER
2019 ◽  
Vol 157 (10) ◽  
pp. 1568-1592 ◽  
Author(s):  
Niall William Paterson ◽  
Gunn Mangerud

AbstractThe Barents Sea region of Arctic Norway preserves a thick succession of marine and deltaic Triassic strata that yield an abundant and diverse association of terrestrial and marine palynomorphs. Despite being the principal means for dating and correlation across this vast region, the Upper Triassic palynozonal resolution has remained relatively low. This is problematic due to the thickness of the Upper Triassic Series and since this corresponds to the longest of the three Triassic epochs. This paper presents a refined Middle–Upper Triassic palynozonation for the region, based on a detailed investigation of multiple localities ranging from the Svalbard Archipelago to the southern Barents Sea. The zonation comprises eleven spore-pollen zones: the Carnisporites spiniger, Triadispora obscura and Protodiploxypinus decus zones (Anisian), the Echinitosporites iliacoides Zone (Ladinian), the Semiretisporis hochulii, Podosporites vigraniae, Leschikisporis aduncus, and Protodiploxypinus spp. zones (Carnian), the Classopollis torosus, and Quadraeculina anellaeformis zones (Norian), and the Ricciisporites spp. Zone (Rhaetian). Additionally, two new dinoflagellate cyst zones are defined: the Rhaetogonyaulax arctica (upper Carnian – lower Norian) and Rhaetogonyaulax rhaetica (lower Norian) zones. Three new age-significant palynomorph taxa are described: Kyrtomisporis moerki sp. nov., Podosporites vigraniae sp. nov. and Semiretisporis hochulii sp. nov. The revised palynozonation is compared with previous palynozonal schemes for the Greater Barents Sea region, and its relationship to Triassic palaeoclimate, palaeoenvironments and sequence stratigraphy is discussed.


2008 ◽  
Vol 146 (1) ◽  
pp. 92-112 ◽  
Author(s):  
STIJN DE SCHEPPER ◽  
MARTIN J. HEAD ◽  
STEPHEN LOUWYE

AbstractDinoflagellate cysts and sequence stratigraphy are used to date accurately the Tunnel-Canal Dock section, which contains the most complete record of marine Pliocene deposits in the Antwerp harbour area. The Zanclean Kattendijk Formation was deposited between 5.0 and 4.4 Ma during warm-temperate conditions on a shelf influenced by open-marine waters. The overlying Lillo Formation is divided into four members. The lowest is the Luchtbal Sands Member, estimated to have been deposited between 3.71 and 3.21 Ma, under cooler conditions but with an open-water influence. The Oorderen Sands, Kruisschans Sands and Merksem Sands members of the Lillo Formation are considered a single depositional sequence, and biostratigraphically dated between 3.71 andc. 2.6 Ma, with the Oorderen Sands Member no younger than 2.72–2.74 Ma. Warm-temperate conditions had returned, but a cooling event is noted within the Oorderen Sands Member. Shoaling of the depositional environment is also evidenced, with the transgressive Oorderen Sands Member passing upwards into (near-)coastal high-stand deposits of the Kruisschans Sands and Merksem Sands members, as accommodation space decreased. Applying sequence stratigraphy to our section implies that the Kattendijk/Lillo Formation boundary corresponds to the sequence boundary (SB) Za2 (4.04 Ma), the Luchtbal/Oorderen sands boundary to SB Pia1 (3.21 Ma), and the top of the Merksem Sands to SB Pia2 (2.76 Ma). Finally, the Belgian deposits are compared with marine Pliocene deposits of eastern England.


2011 ◽  
Vol 36 (2) ◽  
pp. 251-266 ◽  
Author(s):  
Andrzej Rakowski ◽  
Piotr Rogowski

AbstractThis paper has two distinct parts. Section 1 includes general discussion of the phenomenon of "absolute pitch" (AP), and presentation of various concepts concerning definitions of "full", "partial" and "pseudo" AP. Sections 2-4 include presentation of the experiment concerning frequency range in which absolute pitch appears, and discussion of the experimental results. The experiment was performed with participation of 9 AP experts selected from the population of 250 music students as best scoring in the pitch-naming piano-tone screening tests. Each subject had to recognize chromas of 108 pure tones representing the chromatic musical scale of nine octaves from E0 to D#9. The series of 108 tones was presented to each subject 60 times in random order, diotically, with loudness level about 65 phon. Percentage of correct recognitions (PC) for each tone was computed. The frequency range for the existence of absolute pitch in pure tones, perceived by sensitive AP possessors stretches usually over 5 octaves from about 130.6 Hz (C3) to about 3.951 Hz (B7). However, it was noted that in a single case, the upper boundary of AP was 9.397 Hz (D9). The split-halves method was applied to estimate the reliability of the obtained results.


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