Geochemistry and tectonic setting of Lewisian clastic metasediments from the Early Proterozoic Loch Maree Group of Gairloch, NW Scotland

Geochemistry of sandstones and shales from the Ecca Group, Karoo Supergroup, in the Eastern Cape Province of South Africa: Implications for provenance, weathering and tectonic setting

“…The binary plot of TiO 2 versus Zr shows that all the shale and sandstone samples are from felsic igneous rocks (Figure 7). Again, the TiO 2 -Ni diagram of [71] revealed that the source area for most of the samples are predominantly of acidic magmatic nature (Figures 8), despite the fact that a few samples plotted outside the field assigned for felsic source. The bivariate plot of La/Th against Hf ( Figure 9) and ternary diagram of V-Ni-Th*10 ( Figure 10) indicate that the studied sandstones and shales are derived from felsic source rocks.…”

Provenance of Early Paleozoic metasediments in the central Chinese Altai: Implications for tectonic affinity of the Altai-Mongolia terrane in the Central Asian Orogenic Belt

“…Potassium and Rb are sensitive to the process of sedimentary cycling and have been widely used as indicators of source composition (Floyd et al, 1989). Although the Kulumuti metasediments have a large range of K/Rb ratios, the high Rb concentrations (N50 ppm) and relatively high K 2 O (N1.1 wt.%) indicate that these rocks were derived from an acid-intermediate igneous source (Fig.…”

Provenance and depositional setting of Lower Silurian siliciclastic rocks on Hainan Island, South China: Implications for a passive margin environment of South China in Gondwana

“…The presence of relatively fine-grained slates (pelitic) of low maturity within the lower unit in the eastern Hainan suggests that the basinal depocenter was most likely located in eastern Hainan. This corresponds to the possible presence of radiolarian fossils, the occurrence of organic matter and star-like pyrite in off-white to Floyd et al, 1989) suggesting that the Tuolie samples follow a typical magmatic trend for felsic materials, (b) La/Th vs. Hf plot (after Floyd and Leveridge, 1987) showing a predominance of felsic source with increasing old sediment component, and (c) Co/Th-La/Sc diagram (after Gu et al, 2002) indicating most of the Tuolie samples lie close to the felsic volcanic rock field due to Co/Th values of generally <1.0.…”