In:
Island Arc, Wiley, Vol. 8, No. 1 ( 1999-03), p. 56-65
Abstract:
Cenozoic basin‐forming processes in northwestern Kyushu were studied on the basis of geological and geophysical data. Gravity anomaly analysis delineated four sedimentary basins in the study area: Goto‐nada, Nishisonogi, Amakusa‐nada, and Shimabara. Borehole stratigraphy and reflection seismic interpretation suggest that the Goto‐nada Basin was subdivided into the Paleogene and Plio‐Pleistocene depocenters (Goto‐nada 1 and 2). In the Paleogene, Amakusa‐nada Basin was rapidly subsiding together with the Shimabara Basin as part of a large graben. Goto‐nada 1 and Nishisonogi basins belonged to another depositional area. After stagnant subsidence stage in the early Miocene, the study area became a site of basaltic activity (since 10 Ma) and vigorous subsidence in the Plio‐Pleistocene. Goto‐nada 2 Basin is accompanied with numerous east–west active faults, and separated from the Amakusa‐nada Basin by a northeast– southwest basement high, Nomo Ridge. Plio‐Pleistocene subsidence of the Amakusa‐nada Basin is related with low‐angle normal faulting on the eastern flank of the Nomo Ridge. Shimabara Basin is a composite volcano‐tectonic depression which is studded by east–west faults. Focal mechanism on active faults suggests transtensional stress regime in the study area.
Type of Medium:
Online Resource
ISSN:
1038-4871
,
1440-1738
DOI:
10.1046/j.1440-1738.1999.00223.x
Language:
English
Publisher:
Wiley
Publication Date:
1999
detail.hit.zdb_id:
1495883-1
detail.hit.zdb_id:
2020960-5
SSG:
13
Permalink
