ORIGIN AND GEODYNAMIC ENVIRONMENT OF TURBIDITE FORMATION IN
QUẢNG NINH AREA, EAST BẮC BỘ
ĐẶNG MỸ
CUNG1, NGUYỄN LINH NGỌC2, TRỊNH XUÂN HÒA1, NGUYỄN
VĂN TUẤN1
1Việt Nam Institute of Geosciences and
Mineral Resources
2Ministry of Natural
Resources and Environment
Abstract: The
Upper Ordivician - Middle Silurian Cô Tô and Tấn Mài Formations in the Quảng
Ninh area, East Bắc Bộ, consist mainly of polymictic sandstone, acidic
tuffaceous sandstone, tuffaceous silty claystone, cherty claystone, shale,
quartz-sericite schist, chlorite-sericite-quartz schist and dark- to black-grey
sericite schist. Typical turbidite structure shows that these beds belong to a
turbidite formation.
The petrographical,
petrogenetic and geochemical characteristics of major elements show that
lithological composition of sandstone of the studied formations is generated
from orogeny or regenerated orogeny, which is related to geodynamic environment
of convergent plate margin in tectonic context of “subduction zone” or “plate
collision”. Geochemical characteristics of major elements, trace elements, rare
earth elements show that the Cô Tô and Tấn Mài Formations in the Quảng Ninh
area were formed in geodynamic environment - tectonic context of active
continental margin.
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