Protracted northward drifting of South China during the assembly of Gondwana: Constraints from the spatial-temporal provenance comparison of Neoproterozoic−Cambrian strata

Neoproterozoic to Paleozoic sedimentation shows systematic temporal-spatial variations within South China, which must be considered in reconstructing geological evolution of South China in response to global plate reorganization from the breakup of Rodinia to the assembly of Gondwana. We use >1000 new U-Pb and Hf isotopic data for detrital zircons from Neoproterozoic−Cambrian strata across the western (i.e., Longmenshan) and eastern (i.e., Wuyishan) margins of South China, coupled with compiled stratigraphic and magmatic information, to constrain change in provenance through time. First-order conclusions are as follows: (1) detrital zircons from the Neoproterozoic strata of the two margins were mainly sourced from the Panxi-Hannan arc and the Jiangnan orogen, signaling a rough self-sufficient sedimentary system; (2) newly identified Cambrian molasse-like sediments in the western margin, in which abundant detrital zircons are 550−500 Ma old with positive εHf(t) values, were mainly derived from the 580−500 Ma Cadomian arc belt along the Iran-Turkey margin; and (3) the Cambrian sediments in the eastern margin document more increased contributions from the Grenvillian-age provinces most possibly in Australia. Such spatial-temporal provenance variations signal the northward drifting of South China, from a position connecting with Iran-Turkey and northern India to that approaching Australia during the late Neoproterozoic−Cambrian period. We highlight that the activity of oblique oceanic-continental convergence accreted Asian terranes onto the northern margin of Gondwana, hence contributing to the ultimate Gondwana architecture under global plate reorganization.

Sediment provenance analysis of the Permian from the Perth Basin using an automated Raman heavy mineral technique

The Early Permian in the onshore Perth Basin has experienced several significant discoveries in the last 8 years. Beginning with the play-opening Waitsia discovery (AWE), this was followed more recently by the Beharra Springs Deep (Beach Energy) and West Erregulla (Strike) discoveries. In addition, Late Permian sands (Dongara and Wagina sandstones) have long been recognised as excellent reservoirs in the basin. This study attempts to better understand the provenance of the Early and Late Permian sediments using automated Raman spectroscopy as a tool to identify variations in heavy mineral assemblages. Automated Raman spectroscopy analysis of heavy minerals minimises operator bias inherent in more traditional optical heavy mineral analyses. These data are integrated with publicly available chemostratigraphy data to enable a better understanding of sediment provenance variations with stratigraphy. In addition, publicly available detrital zircon geochronological data are incorporated to help further understand sediment sources. A transect of wells is investigated, from Arrowsmith-1 in the southernmost extent to Depot Hill-1 and Mt Horner-1 in the north. While the elemental (chemostratigraphy) data suggest some changes in sediment provenance through the Permian of the Perth Basin, the Raman heavy mineral data confirm a number of sediment provenance changes both at key formational boundaries (e.g. top Kingia sandstone) and complex sediment provenance variation within reservoir sandstone units. These results are integrated to demonstrate how sediment provenance holds the key to understanding controls on variable reservoir quality as well as understanding the early infill in this basin.

Effect of Provenance Variations on the Growth and Development of Terminalia ivorensis (A Chev)

Indigenous tree species like Terminalia ivorensis has multiple uses; from timber products to medicinal condiments for treating different ailments. This species is self-incompatible. Thus, habitat protection is a key to its survival and sustenance. This study evaluated the effect of provenance variations on the growth and development of T. ivorensis. Three provenances of T. ivorensis were selected; FRIN Arboretum, Onigambari Forest Reserve and J1 Forest Reserve. Thirty (30) seedlings of T. ivorensis were selected and marked at each provenance for assessment of growth parameters for a period of twelve weeks. The growth parameters included: seedling height, collar diameter, leaf count and leaf area. Also, soil samples were collected from each provenance to test for nutrient composition. Results showed that J1 Forest Reserve had best performance across the growth parameters assessed with 10.4 cm plant height, 2.02 mm collar diameter, 11 leaves count and 20.5 cm2 leaf area respectively. This growth parameter result differs significantly from the other two provenances. This was also attributed to the nutrient offered by J1 Forest Reserve with 1.18% and 2.20% of organic carbon and organic matter in the soil respectively. Also, the available phosphorus which is involved in photosynthesis, respiration, energy storage and transfer, cell division and enlargement as well as promotion of root formation was about 15.7 mg/kg in the soil and is considered high because it is higher than the critical level of 8.50mg/kg. J1 Forest Reserve is recommended as the best provenance for raising T. ivorensis amongst assessed natural habitats.