- 作者: LI-SHO CHANG
- 作者服務機構: Geological Survey of Taiwan
- 中文摘要: A total of 123 species and subspecies distributed among 68 genera have beendistinguished in 117 samples from the Tertiary on the west flank of the CentralRange in the Tawushan-Tashulinshan area, no fossils wherefrom have been knownbefore except for the few species of larger foraminifera found in situ or in drifted-down blocks. The ubiquitous occurrence of Orbulina throughout the area indicates decidedlythat a greater part of the strata must be attributed to Blow's Zone N. 9 and upwardsinstead of to the Eocene and/or downwards as generally accepted before. Paleoniolo-gically and lithologically, two categories of strata are recognizable: those equivalentto the lower part of the Sankyo Group in western Taiwan, and those equivalent tothe uppermost part of the Hsichih Group. In the former, Zones N. 14 and N. 15,and possibly parts of Zones N. 13 and N. 16, are ascertained by the various com-binations of Globorotalia (s. s.) menardii, G. (Turborotalia) acostczensis, G. (T.) mayeri,Globigerina nepenthes, G. venezuelana, Globoquadrina dehiscens, G. altispira, Sphaeroid-inellopsis seminulina kochi, S. subdehiscens, etc., supplemented with Text}laria pseudo-kansaiensis and Pseudorotalia yabei and its allies. In the latter, Zone N. 9 is provedby the joint occurrence of Orbulina suturalis with Globigerinoides bisphericus orGloborotalia (T.) peripheroronda. However, Zones N. 10-N.12 have not beenbiostratigraphically recognized here. Among the’ localities where they were reported previously in the area, Disco-cyclina and Nummulites were found in situ only on the western slope of Nantawushan.Between this locality and the nearest locality where Grbulina was found, there is a zone quite barren of fossil foraminifera, and it remains uncertain whether or notzone belongs to the Eocene. Nevertheless, the strata nowthis zone belongs to the Eocene.Nevertheless, the strata now proved to be Miocenein age are certainly the northern continuation of the Neogene in the northern part of the Hengchun Peninsula, and are deceloped far more close to the Eocene thanwere previously thought, supporting evidence for my previous assumption that a probable hiatus exists between the Piiushanian (Eocene) and the Lushanian (Bur-digalian and slightly younger) in the Central Range of Taiwan.
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