[1] A new method for dating well-bleached sediments is presented, with results for thirteen samples from China. The method uses an isochron constructed from the measurement of natural radiation doses received by potassium-feldspar grains in a range of grain sizes using the infrared stimulated luminescence (IRSL) signal. The age of deposition of the sediment is calculated from this isochron and ...

Three of the largest granite porphyries northern Portugal were studied to improve current knowledge on regional felsic vein hypabyssal magmatism. All exhibit microcrystalline groundmasses variable granularity (composed quartz, K-feldspar, and muscovite), plagioclase, biotite, cordierite phenocrysts, antirapakivi rapakivi feldspars, embayments in enrichments rare metal incompatible elements. The...

S U M M A R Y . Forty-three natural alkali feldspars have been homogenized and used to correlate d.~01 with wt % K20. The regression of Or on dg01 is Or (wt %) = 465"5 d~01 (~)-1877"5, and is comparable to that obtained on an exchanged orthoclase (Wright, I968). A deviation from the Orville (I963, I967) determinative line for synthetic sanidine-albite is greatest at the high potassium end of th...

The separation and concetration of minerals from zeolitic volcanic tuffs represent one of the problems for which the literature not offer, to much practically solutions. The experimental strategy used by as, for the separation minerals from zeolitic volcanic tuffs to comprise the following methods: heavy liquids separation; magnetic separation and electrophoresis separation. For zeolites, silic...

The MErcury Radiometer and Thermal Infrared Spectrometer instrument onboard the BepiColombo spacecraft is designed to investigate Mercury’s surface in mid-infrared (mid-IR). Based on MESSENGER data modeling, Mercury thought be evolved under highly reducing conditions (e.g., McCubbin et al., 2017, https://doi.org/10.1002/2017JE005367; Namur & Charlier, https://doi.org/10.1038/ngeo2860). modeling...

Structural and volume compressibility data for reedmergnerite, NaBSi3O8, were obtained by single-crystal X-ray diffraction at pressures up to 4.7 GPa. The bulk modulus was determined to be 69.8(5) GPa with the pressure derivative constrained to 4. Unit-cell compression is anisotropic, as indicated by unit strain tensors. Tetrahedral bond lengths and angles remained relatively constant over the ...