k feldspar china

For a comprehensive understanding of the mechanisms of grain-size reduction of K-feldspar in the middle crust, granitic mylonites from the Shuiyu shear …

Request PDF | K-feldspar composition as an exploration tool for pegmatite-type rare metal deposits in Altay, NW China | Trace elements of potassium feldspar (Kfs) from pegmatite veins in the ...

K-feldspar composition as an exploration tool for pegmatite-type rare metal deposits in Altay, NW China | Semantic Scholar. DOI: 10.1016/J.GEXPLO.2017.11.015. …

K-feldspar grains in sizes of 38–63 μm disappear completely in 30 min after etching in a 10% HF solution, while 63–90 μm grain sizes disappear in 40 min. ... However, the controlling mechanisms of stalagmite δ 18 O records in China have been widely debated in the past few years (Johnson and Ingram, 2004, ...

In this study, the ages of sediments from the shorelines at altitudes of 1070–1050 m at the west and south bank of the present Jilantai sub-depression are measured using both blue-light stimulated OSL signals of single-aliquot quartz and pIR IRSL signals of single-grain K-feldspar at elevated temperature, because OSL dating …

Institute of Geology, Chinese Academy of Geological Sciences, Beijing, 100037 China. Key Laboratory of Marine Hazards Forecasting, Ministry of Natural Resources, Hohai University, Nanjing, 210024 China. Search for more papers by this author. ... K-feldspar veins are genetically correlated with lamprophyres, whereas …

The recent development of post-IR IRSL (pIRIR) methods applied to K-rich feldspar isolates a slower or completely non-faded IRSL signal capable of dating sediments up to 250-300 ka owing to the ...

Single-grain K-feldspar luminescence dating of the late Quaternary rapid decline in the largest Lake over the Tibetan Plateau. Author links open overlay panel Hao Long a c, ... stands as the largest closed-basin lake in China. It has a surface elevation of 3198 m above sea level (a.s.l.), and covers an area of approximately 4300 km 2 (Fig. 1 a).

K-feldspar-bearing coesite pseudomorphs in an eclogite from Lanshantou (Eastern China) ... Yang, Gaston Godard, David C. Smith; K-feldspar-bearing coesite pseudomorphs in an eclogite from Lanshantou (Eastern China). European Journal of Mineralogy 1998;; 10 (5): 969–985. doi: Download citation file: Ris (Zotero) Refmanager; EasyBib; Bookends ...

In this study, the MAR and SAR SGCs were established using K-feldspar extracted from different locations in the Nihewan Basin, northern China. We show that different shapes in the MAR and SAR SGCs at high temperatures can be attributed to the different amounts of residual signal in the MAR and SAR SGCs.

Results of X-ray diffraction (XRD) measurements indicated that weathered granite, collected from an ion-adsorption ore in Dingnan County, Jiangxi Province, China, is mainly composed of quartz, K ...

The K-feldspar samples (1 aliquot for each sample) were exposed to sunlight for 1 week (7 days, 4 h/day, July, 2016, Lanzhou, China). Then the residual doses for the pIRIR 290 and IR 50 signals for all samples were measured using the protocol in Table 1 .

Silicic rocks occur in the uppermost units of the longest volcanic succession (~ 5000 m thick) in the Binchuan area of the Permian Emeishan flood basalt province of SW China.They are predominantly rhyolites and to a lesser extent trachytes, both containing potassium feldspar megacrysts as the dominant phenocryst phase up to approximately …

Geoscience. Loess. Article PDF Available. High resolution quartz OSL and K-feldspar post-IR IRSL dating of loess in the central Shandong Mountains (eastern China) May 2020. Geochronometria....

HIGH RESOLUTION QUARTZ OSL AND K-FELDSPAR post-IR IRSL DATING OF LOESS IN THE CENTRAL SHANDONG MOUNTAINS (EASTERN CHINA) QIUYUE ZHAO: 1, MIN DING: 1, SHUZHEN PENG: 1, LUO WANG: 2, WEI ZHANG: 1 ... humid region of eastern China. It is also sensitive records of East Asian monsoon changes for situating in a key …

Pegmatite Altaidrare-elementdeposit, Xinjiang,China KH45(only K-feldspar) 220 Kfs(5–15mm), Qz(3–8mm), Ab(0.2–3mm), Mu Or 93 7 450–530 12,13 ...

The propensity of K-feldspar to incorporate Pb into its crystal structure while excluding U and Th allows it to record Pb isotopic compositions that are effectively time invariant (Patterson and Tatsumoto, 1964).Pb isotopic data measured from K-feldspar thus complement equivalent data garnered from ore deposits and age-corrected whole rock …

Potassium feldspar (K-feldspar), as a type of insoluble potassium resource, is abundant in China, with reserves of over 10 billion tons . K-feldspar is …

A 120 m drill core from the Ulan Buh Desert, China has a desert-lake-desert sequence.. Quartz OSL and K-feldspar IRSL dating methods were applied to core samples. • A sand desert landscape formed in the region by at least ~ 232 ka and after ~ 87 ka. A deep paleolake was present from sometime before ~ 155 ka until ~ 90 ka. Both …

HIGH RESOLUTION QUARTZ OSL AND K-FELDSPAR post-IR IRSL DATING OF LOESS IN THE CENTRAL SHANDONG MOUNTAINS (EASTERN CHINA) …

Eocene to lower Oligocene sandstones in Taiwan are characterized by radiogenic K-feldspar grains (206Pb/204Pb>18.4), indicating that the eastern Cathaysia Block served as the dominant sediment ...

Request PDF | Dating of the late Quaternary high lake levels in the Jilantai area, northwestern China, using optical luminescence of quartz and K-feldspar | High lake levels were developed in wide ...

K-feldspar restricted to the groundmass is characteristic for the first intrusive pulse, whereas K-feldspar megacrysts are restricted to the second magma pulse. Download : Download full-size image; Fig. 9. ... The strike of the Triassic Mian-Lue suture zone between the Yangtze block and the North China block (e.g., Chavagnac et al., ...

DOI: 10.1016/J.GEXPLO.2017.11.015 Corpus ID: 134068471; K-feldspar composition as an exploration tool for pegmatite-type rare metal deposits in Altay, NW China @article{Tang2018KfeldsparCA, title={K-feldspar composition as an exploration tool for pegmatite-type rare metal deposits in Altay, NW China}, author={Yong Tang and Hong …

K-feldspar grains have significant internal radioactivity because of the existence of 40 K within the crystal structure; thus, the internal dose rate cannot be ignored. Here, we assume a K content of 12.5% ± 0.5% and a Rb concentration of 400 ± 100 ppm to calculate the internal dose rate of K-feldspar ( Huntley and Baril, 1997, Huntley and ...

K-feldspar crystals >5 cm in greatest dimension are common in calc-alkaline granites and granodiorites worldwide. Such megacrysts are generally interpreted as having grown to large sizes early in a magma's crystallization history while they were largely molten, owing to field relations such as megacryst alignment and megacryst-rich clusters …

The post-IR IRSL (pIRIR) signal of K-feldspar stimulated at a higher temperature after a prior low-temperature IR stimulation has significantly lower fading rate. Different dating protocols have been proposed with the pIRIR signals and successful dating applications have been made. In this study, we review the development of various pIRIR ...

The post-IR IRSL protocol with single K-feldspar grains was applied to three samples taken from a fluvial sedimentary sequence at the archaeological site of the Dali Man, Shaanxi Province, China ...

Shoreline features at Juyanze, Gobi Desert, China are ~ 33 m above modern levels. K-feldspar pIRIR dating and quartz OSL dating were applied to shoreline features. • Three lacustrine sequences, separated by unconformities, span ~ 125–76 ka. A 33 m deep MIS 5 lake filled Juyanze and possibly the whole Ejina Basin.. The lake …

4 Marine and Polar Research Center, China University of Geosciences, Beijing, China; K-feldspar luminescence dating has been widely applied to constrain the timing of Quaternary sedimentation in different environments. However, the measurements are time-consuming. Meanwhile, anomalous fading and partial bleaching are the two …

Request PDF | Quartz and K-feldspar luminescence dating of a Marine Isotope Stage 5 megalake in the Juyanze Basin, central Gobi Desert, China | The Juyanze Basin, in the central Gobi Desert of ...

Plagioclase feldspars (Na or Ca): NaAlSi 3 O 8 - CaAl 2 Si 2 O 8 (albite and anorthite) Alcalic feldspars (K or Na): K/NaAlSi 3 O 8 (albite and all K-feldspars) Barium feldspars (Ba): BaAl 2 Si 2 O 8 (celsian) Complete solid solution (miscibility) only occurs in the plagioclase group, between albite and anorthite.

The measured K-feldspar pIRIR 290 D e showed no dependency on the first IR stimulation temperature between 50°C and 260°C. The K-feldspar pIRIR 290 ages are consistent with the …

In this study, we present a dataset that includes 1785 quartz optically stimulated luminescence ages and 1038 K-feldspar post-infrared infrared stimulated …

The North China Craton (Fig. 1 a) is the largest and oldest cratonic block in China (Zhai and Santosh, 2011, Zhai and Santosh, 2013 and references therein). ... K-feldspar is the rock-forming mineral with the highest Pb concentration in magmatic rocks (Wedepohl, 1974).

Zircon U–Pb, Molybdenite Re–Os and K-feldspar 40 Ar/ 39 Ar Dating of the Bolong Porphyry Cu–Au Deposit, Tibet, China. Xiangping Zhu, Corresponding Author. Xiangping Zhu. Chengdu Institute of Geology and Mineral Resources, Chengdu, China ... The K-feldspar sample (ZK18707-485) used for 40 Ar/ 39 Ar dating was picked from an …

Quartz and K-feldspar luminescence dating of sedimentation in the North Bohai coastal area (NE China) since the late pleistocene - ScienceDirect. Journal of …

Cheng et al. (2017a) reported K-feldspar megacrysts in rhyolites from the Permian Emeishan large igneous province, southwest China. These K-feldspar megacrysts usually have the long axis length <1 ...