Revised radiolarian zonation for the entire Jurassic in the western Pacific and Japan

• Autorzy: Matsuoka A.
• Konferencja: International Congress on the Jurassic System (7 ; 06-18.09.2006 ; Kraków, Poland)
• Języki publikacji: EN

Abstrakty

EN

A radiolarian zonal scheme for the entire Jurassic in Japan was proposed by Matsuoka and Yao (1986) on the basis of radiolarian biostratigraphic research on several continuous sections in the Japanese Islands. The zonal scheme was partly modified by applying the results from deep sea cores obtained in the ODP Leg 129 cruise (Matsuoka 1992). The Jurassic zones composed of the Parahsuum simplum Zone (JR1), Trillus elkhornensis Zone (JR2), Laxtorum(?) jurassicum Zone (JR3), Tricolocapsa plicarum Zone (JR4), Tricolocapsa conexa Zone (JR5), Stylocapsa(?) spiralis Zone (JR6), Hsuum maxwelli Zone (JR7), Loopus primitivus Zone (JR8), and Pseudodictyomitra carpatica Zone (KR1), in ascending order, have been established by combining the results from land sections and ODP materials (Matsuoka 1995). The zonation is widely utilized for the dating of marine sequences in Japan and Asian countries. The accumulation of new data in the last decade requires a further revision of the zonation and age assignment. The major modifications are as follows: The Bipedis horiae Zone (JR0) is newly proposed below the Parahsuum simplum Zone (JR1). The base of the Bipedis horiae Zone (JR0) is defined by the first appearance of Bipedis horiae Sugiyama and corresponds roughly to the Triassic (Rhaetian)/Jurassic (Hettangian) boundary. The base of the Parahsuum simplum Zone is dated as Middle Sinemurian. The Tricolocapsa plicarum Zone (JR4), Tricolocapsa conexa Zone (JR5), and Stylocapsa(?) spiralis Zone (JR6) are replaced by Striatojaponicapsa plicarum Zone (JR4), Striatojaponicapsa conexa Zone (JR5), and Kilinora spiralis Zone (JR6), respectively, in accordance to the change of generic assignment of zone-diagnostic species. The base of the Pseudodictyomitra carpatica Zone (KR1) is dated as Early Tithonian based on the occurrence of the zone-diagnostic species from the Lower Tithonian of the Solnhofen area, Germany (Zügel 1995).

Słowa kluczowe

EN

Jurassic; radiolaria; zonation; revision; western Pacific; Japan

• Wydawca: Państwowy Instytut Geologiczny - Państwowy Instytut Badawczy
• Czasopismo: Volumina Jurassica
• Rocznik: 2006
• Tom: Vol. 4, no. 1
• Strony: 183--184
• Opis fizyczny: Bibliogr. 4 poz.

Twórcy

autor

Matsuoka A.

• Department of Geology, Faculty of Science, Niigata University, Niigata 950-2181, Japan,

Bibliografia

• Matsuoka A. 1992. Jurassic and Early Cretaceous radiolaria from the western Pacific: Leg 129 of the Ocean Drilling Program. In: Larson R. et al. (Eds), Proceedings of ODP, Scientific Results, 129: 203-220.
• Matsuoka A. 1995. Jurassic and Lower Cretaceous radiolarian zonation in Japan and in the western Pacific. The Island Arc, 4, 2: 140-153.
• Matsuoka A. and Yao A. 1986. A newly proposed radiolarian zonation for the Jurassic of Japan. Marine Micropaleontology, 11: 91-106.
• Zugel P. 1997. Discovery of a radiolarian fauna from the Tithonian of the Solnhofen area (Southern Franconian Alb, southern Germany). Palaeontologishe Zeitschrift, 71: 197-209.