Gondwana Research

Coyhaique mantle xenoliths: whole-rock and mineral major and trace elementdata, Sr-Nd whole-rock and clinopyroxene isotopic data, and whole-rock noble gas (He, Ne, Ar) isotopic data.

3.1 Electron probe microanalysis of minerals The mineral compositions for the supracrustal rocks and the garnetbearing granite were analysed by using an electron microprobe at the Key Laboratory of Orogen and Crustal Evolution of the Ministry of Education, Peking University, Beijing, China, using operating conditions of 5 kv accelerating voltage, 1 × 10–8 A beam current, and 1 μm spot diameter. For calibration, 53 standard samples of well-defined natural minerals (SPI Supplies, West Chester, Pennsylvania, USA) were used. The results are presented in SupplementaryTables 1 to 5. 3.2 Whole-rock geochemistry The major-element compositions of the minerals were measured using an Axios X-ray fluorescence (XRF) spectrometer at the China National Research Center for Geoanalysis, Beijing, China. Trace-element analysis was conducted using an Elan 9000 inductively coupled plasma mass spectrometer (ICP–MS; PerkinElmer, Waltham, Massachusetts, USA) with better than 10% accuracy of analysis. The major and trace element compositions and analytical precisions for each element are given in Supplementary Table 6. 3.3 Zircon U–Pb dating Zircon crystals were obtained using standard crushing and separation techniques, and U–Pb dating was conductedusing the SIMS II ion microprobe at the Beijing SIMS Center, Chinese Academy of Geological Sciences (CAGS). The hand-picked crystals together with the TEMORA standard, having a conventionally determined 206Pb/238U age of 417 Ma (Black et al., 2003), were cast in epoxy resin discs and were polished. All grains were photographed in both transmitted and reflected light and were then imaged using cathodoluminescence (CL) to reveal the internal structure and to identify the preferred locations for SIMS analysis. The U–Pb dating information is given in Supplementary Table 7.

Detailed geochronological and geochemical analyses on 1.72-1.50 Ga mafic rocks in the Huili-Dongchuan area of southwestern Yangtze Block, South China

The new in situ zircon U–Pb ages, whole–rock major and trace element data, and whole–rock Sr–Nb isotope data of the volcanic rocks from the Harlik and Dacantan terranes

Zircon and feldspar U-Pb LA-ICP-MS depth-profile and in-situ analyses from metaigneous and metasedimentary rocks of the Suckling-Dayman metamorphic core complex in Papua New Guinea

Figures S1 and S2 present Cathodoluminescence (CL) images and Chondrite normalized REE patterns of representative zircons. Table S1 presents age data for the Permo-Triassic magmatic rocks and HP metamorphic rocks of north-central Tibet. Tables S2 to S6 present the analytical results for whole-rock major- and trace-element and Nd isotopic analysis and zircon U–Pb dating and Hf isotopic analysis.

Supporting online information for the study of Milaičiai-103 core upper-most Ludlow, Pridoli, and lower-most Devonian paleoarchive: S1_Mil_103_Pr_conodonts – Distribution and abundance of conodonts in the Milaičiai-103 core S2_MIL103_bra_r_dat – Distribution and abundance of brachiopods in the Milaičiai-103 core S3_Mil_103_d13C_ir_d18O – Stable carbon and oxygen isotopic data in the Milaičiai-103 core S4_LOI_and_natural_gamma_Mil_103 – Loss on ignition (LOI) and natural gamma in the Milaičiai-103 core S5_Mil103_Carbonates – Carbonate content of samples in the Milaičiai-103 core S6_MIL103 Magnetic susceptibility – Magnetic susceptibility measurements of the Milaičiai-103 core

Table 1. List of 45 samples and conodont species recovered from four stratigraphic sections in south-central Xizang (Tibet).

The south-eastern part of the Democratic Republic of the Congo locally hosts Proterozoic manganese deposits. The deposits of Kisenge-Kamata are the most significant, but manganese ores are also known to occur at Kasekelesa (former Katanga Province) and Mwene-Ditu (former Kasai Province). For the present study, cryptomelane-rich samples from these two localities were dated, using the 39Ar-40Ar method in step-heating using a CO2 laser probe. Obtained ages are within a range of about 80 Myr to 2 Myr. Cryptomelane formation took place at c. 76.4 Ma, c. 59.6 Ma, c. 45 Ma, c. 35 Ma, c. 23.8 Ma, c. 15.4 Ma, and c. 13.3 Ma at Kasekelesa, and it occurred at c. 35 Ma, c. 22.4 Ma, c. 15 Ma, c. 5.5-7.2 Ma, c. 3.6 Ma, and c. 2.1-2.3 Ma at Mwene-Ditu. The Campanian age (c. 76.4 Ma) recorded at Kasekelesa is the oldest 39Ar-40Ar age that has up to now been recorded for Mn ores from Africa. It documents the formation of oxidized ore along a Campanian or older erosion surface, which could be part of the ‘African Erosion Surface’. The complete age record suggests that continent-wide tectonics accounts for most of the recognized supergene ore formation episodes, controlled by vertical lithospheric movements that are ultimately responsible for alternating stages of landscape stability and erosion. Tectonics is thus regarded as the first-order control for secondary ore formation in Central Africa, over the last 80 Myr. Climate is a second-order control, because sufficient water supply is needed for supergene enrichment, whereby climatic conditions are recognized to have been favourable during some relatively cold Late Mesozoic and Paleogene periods, as well as during some humid and warm Neogene stages.

Geochronology and geochemistry of the Paleoproterozoic magmatic rocks in the Tarim Craton