Computer Science
Scientific paper
Nov 1994
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1994gecoa..58.4615g&link_type=abstract
Geochimica et Cosmochimica Acta, vol. 58, Issue 21, pp.4615-4631
Computer Science
5
Scientific paper
The Triassic Tethys graywacke-slate turbidites in the northwestern Sichuan, China have been analysed for major and trace elements and petrographically studied. Compared to Phanerozoic turbidites, the turbidites in this study are quartz-intermediate (average 55%) in composition and are characterized geochemically by their moderate Fe 2 O * 3 + MgO (9.28 ± 2.84%), TiO 2 (0.72 ± 0.17%) contents and Al 2 O 3 /SiO 2 (0.25 ± 0.10) ratios; moderate abundances of ferromagnesian trace elements ( Co = 15 ± 8 ppm, Cr = 113 ± 72 ppm, Ni = 14 + 9 ppm, Sc = 12 ± 4 ppm, etc.); and moderate contents of incompatible elements, such as Th (11 ± 3 ppm), U (3 ± 0.7 ppm), Zr (170 ± 64 ppm), Hf (4 ± 1 ppm) and total REEs (159 ± 33 ppm). In general, the slates show systematically higher Fe 2 O * 3 + MgO, Sc, Co and Eu / Eu * , but lower and Th / Sc than the associated graywackes, suggesting that various provenance components may separate into different grain-size fractions during sedimentary sorting processes, that is, the more mafic materials tended to incorporate into the sedimentary record for the clay-size fraction. Framework modes and geochemical data indicate that the turbidites were mainly derived from a recycled orogenic provenance characterized chiefly by sedimentary-metasedimentary rocks and granite-gneisses, similar to the upper continental crust, but with a variable admixture of continental island arc volcanic components. Flysch deposition took place in a back arc basin situated between an active continental margin (the Kunlun-Qinling fold belt) and a continental island arc (the Yidun island arc). Weathering conditions in the source area significantly influenced the composition and distribution of elements in the sediments. With the elapse of time during sedimentation, the degree of chemical weathering in the provenance became intense while the tectonic activity decreased gradually.
No associations
LandOfFree
Geochemical characteristics of the Triassic Tethys-turbidites in northwestern Sichuan, China: Implications for provenance and interpretation of the tectonic setting does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Geochemical characteristics of the Triassic Tethys-turbidites in northwestern Sichuan, China: Implications for provenance and interpretation of the tectonic setting, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Geochemical characteristics of the Triassic Tethys-turbidites in northwestern Sichuan, China: Implications for provenance and interpretation of the tectonic setting will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1023640