Petrography of Neogene sandstones, eastern Taiwan: response to arc-continent collision

Conference · Tue Jan 01 04:00:00 EST 1985 · Geol. Soc. Am., Abstr. Programs; (United States)

OSTI ID:6644112

Dorsey, R J

Neogene deposits in the Coastal Range of eastern Taiwan make up a thick marine sequence of interbedded sandstones and mudstones with locally abundant coarse conglomerates. These deposits accumulated in a remnant forearc basin prior to and during an ongoing arc-continent collision that began in the Pliocene. Detailed compositional point counts of 22 sandstones from the Coastal Range indicate that detrital modes accurately record a history of changing source terranes and denudation trends directly related to collisional tectonics. A rapid transition from volcaniclastic lithic arenites and hemipelagites derived from the Luzon island arc (Types 1, 1H) into peliticlastic lithic arenites derived from proto-Taiwan (Type 3) occurred throughout most of the Coastal Range between 3 and 4 m.y. ago in response to rapid uplift and erosion of the Central Range (meta)sedimentary accretionary complex. Type 2 arkoses and subarkoses occur only in the north, and were eroded from an unknown source that is not represented in the present-day Central Range. Type 3 sandstones contain a variety of pelitic lithic fragments that are divided into the following categories: SED = shale and mudstone; METI = slate and argillite; MET2 = phyllite and schist; and their quartz-rich equivalents. Direct correlations between these rock fragment types and exposed bedrock in Taiwan allow specific constraints to be placed on the timing and nature of unroofing in the source. This approach may be applicable to denudation studies in other modern and ancient collisional orogenic systems.

• Research Organization: Princeton Univ., NJ (USA)
• OSTI ID: 6644112
• Report Number(s): CONF-8510489-
• Conference Information: Journal Name: Geol. Soc. Am., Abstr. Programs; (United States) Journal Volume: 17
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580201 -- Geophysics-- Seismology & Tectonics-- (1980-1989)
580300* -- Mineralogy
Petrology
& Rock Mechanics-- (-1989)
ASIA
CENOZOIC ERA
GEOLOGIC AGES
GEOLOGIC HISTORY
ISLANDS
LITHOLOGY
OROGENESIS
PETROGRAPHY
PLATE TECTONICS
ROCKS
SANDSTONES
SEDIMENTARY ROCKS
TAIWAN
TECTONICS
TERTIARY PERIOD