Progress in mineralogical quantitative analysis of rock samples: application to quartzites from Denali National Park, Alaska Range (USA)

2016 ◽  
Vol 31 (1) ◽  
pp. 31-39 ◽  
Author(s):  
Mărgărit M. Nistor ◽  
Nicolae Har ◽  
Simona Marchetti Dori ◽  
Simona Bigi ◽  
Alessandro F. Gualtieri
Keyword(s):  
National Park ◽  
Mineralogical Composition ◽  
Alaska Range ◽  
X Ray ◽  
Rock Samples ◽  
The North ◽  
Chemistry Calculation ◽  
Denali National Park ◽  
Bulk Chemistry

This work deals with the determination of the mineralogical composition of three quartzite samples, selected as case study to verify the viability and accuracy of various experimental techniques commonly used in geometallurgy and petrography for the determination of the mineralogical composition of rock samples. The investigated samples are from the North-Eastern side of the Denali National Park (Alaska Range, USA). The mineralogical phase abundance of the samples was determined by digitally assisted optical modal point counting, scanning electron microscopy (SEM) + energy dispersive spectroscopy (EDS) modal and digital image analysis, normative calculation from bulk chemistry calculation, and modal Rietveld X-ray powder diffraction. The results of our study indicate that the results provided by modal optical and SEM digitalized counting seem less accurate than the others. The determination with EDS mapping was found to be inaccurate only for one sample. Agreement was found between the X-ray diffraction estimates and bulk chemistry calculation. For both modal optical and SEM digitalized counting, the statistics was probably insufficient to provide accurate results. The estimates obtained from the various methods are compared with each other in the attempt to attain general indications on the precision, accuracy, advantages/disadvantages of each method.

scholarly journals Evidence for a hardwater radiocarbon dating effect, Wonder Lake, Denali national park and preserve, Alaska, U.S.A.

2002 ◽  
Vol 53 (3) ◽  
pp. 407-411 ◽  
Author(s):  
Jonathan K. Child ◽  
Al Werner
Keyword(s):  
National Park ◽  
Sediment Cores ◽  
Pollen Record ◽  
Lake Area ◽  
Alaska Range ◽  
Radiocarbon Age ◽  
The North ◽  
Late Wisconsinan ◽  
Denali National Park ◽  
Age Estimates

Abstract Anderson et al. (1994) present a late Pleistocene/Holocene pollen record for lacustrine sediment cores retrieved from the north end of Wonder Lake, Denali National Park and Preserve, Alaska. Bulk radiocarbon age estimates obtained during their study suggest that either a Picea refugium persisted in the foothills of the north Alaska Range near Wonder Lake during the Late Wisconsinan, or that bulk radiocarbon age estimates are inaccurate. Subsequent cores recovered from Wonder Lake (and a near-by kettle pond) have been correlated to the Anderson et al. core and age dated using Atomic Mass Spectrometry (AMS) radiocarbon age estimates. AMS radiocarbon ages suggest that bulk radiocarbon ages from Anderson et al. (1994) are affected by hardwater conditions in Wonder Lake causing them to appear greater than 2000 14 C years too old. The corrected core chronology is consistent with documented regional vegetation changes during the glacial/interglacial transition and does not require a local Picea refugium in the Wonder Lake area during the Late Wisconsinan.

X-Ray and Optical Data for a Rare Earth–Poor Eudialyte from the North–Central Alaska Range

1990 ◽  
Vol 5 (2) ◽  
pp. 89-92 ◽  
Author(s):  
Neil E. Johnson ◽  
Mickey E. Gunter ◽  
Diana N. Solie ◽  
Charles R. Knowles
Keyword(s):  
Rare Earth ◽  
Powder Diffraction ◽  
Weight Percent ◽  
Optical Data ◽  
Alaska Range ◽  
North Central ◽  
X Ray ◽  
The North ◽  
Cell Dimensions ◽  
Unit Cell Dimensions

AbstractPowder X-ray and optical data have been recorded for a sample of exceptionally rare earth-poor eudialyte (Na12(Ca, REE)6(Fe2+,Mn,Mg)3Zr3(Zr,Nb)x[Si9O27−y(OH)y]2[Si3O9]2(C1,F)z, with x = 0. 1–0.9, y = 1–3 and z = 0.7–1.4) from a pegmatitic vein associated with the peralkaline Windy Fork granite in the north–central Alaska range. The eudialyte is uniaxial positive with ω= 1.6062(2), ε= 1.6138 (3) and microprobe analyses indicate that the sum of REE + Yis less than 0.1 weight percent. Refined unit cell dimensions are: a = 14.2572(4), c = 30.1338(27), Dx= 2.67, F30= 128 (0.006, 42), M20= 76. An indexed powder diffraction pattern is given.

scholarly journals The flood extent in the lower Biebrza basin calculated by the 1D flow model for different land use scenarios

2008 ◽  
Vol 40 (1) ◽  
pp. 45-54 ◽  
Author(s):  
Sylwia Szporak ◽  
Dorota Mirosław-Świątek ◽  
Jarosław Chormański
Keyword(s):  
Land Use ◽  
National Park ◽  
Flow Model ◽  
Main Channel ◽  
River Valley ◽  
North East ◽  
The North ◽  
Land Use Scenarios ◽  
Flooded Area

The flood extent in the lower Biebrza basin calculated by the 1D flow model for different land use scenarios The flood extent in the lower Biebrza basin calculated by the 1D flow model for different land use scenarios. An application of an steady 1D flow model for determination of a flood extent in the natural river valley is discussed in this paper. The Pasche method was used to calculate the total Darcy-Weisbach friction factor for each cross section according to the type of vegetation and flow interaction between the main channel and vegetated areas. In this approach friction caused by interaction between the main channel and vegetated areas are taken into account. The model was applied to the Biebrza Valley, fairly undisturbed river-marginal peatland, located in the north-east of Poland. Actual land use carried out in the National Park was analyzed to determine the influence of changes in the vegetation structure on the flood extent in the river valley. The obtained results show variation of a flooded area in relation to the vegetation of the floodplain.

scholarly journals A pterosaur manus track from Denali National Park, Alaska Range, Alaska, United States

Palaios ◽  
2009 ◽  
Vol 24 (7) ◽  
pp. 466-472 ◽  
Author(s):  
A. R. Fiorillo ◽  
S. T. Hasiotis ◽  
Y. Kobayashi ◽  
C. S. Tomsich
Keyword(s):  
United States ◽  
National Park ◽  
Alaska Range ◽  
Denali National Park

scholarly journals Supplemental Material: Lithologic, geomorphic, and permafrost controls on recent landsliding in the Alaska Range

2020 ◽  
Author(s):  
A.I. Patton ◽  
et al.
Keyword(s):  
National Park ◽  
Initiation Site ◽  
Landslide Inventory ◽  
Inventory Data ◽  
Alaska Range ◽  
Surficial Geology ◽  
Park Road ◽  
Denali National Park

Plate S1: 1:24,000 scale map of the surficial geology of the Denali National Park road corridor. Table S1: Landslide inventory data, including coordinates of the initiation site and slope characteristics of the landslides evaluated.

scholarly journals Tungsten mineralisation in Archaean supracrustal rocks at Sermitsiaq, southern West Greenland

1986 ◽  
Vol 130 ◽  
pp. 60-63
Author(s):  
H.K Olsen
Keyword(s):  
Special Reference ◽  
Ultra Violet ◽  
Field Work ◽  
Aerial Photographs ◽  
Field Observations ◽  
X Ray ◽  
West Greenland ◽  
Rock Samples ◽  
Geological Map

The purpose of the field work was detailed mapping of the eastern part of the island Sermitsiaq in outer Godthåbsfjord, with special reference to its tungsten mineralisation (Appel, 1983). During six weeks in the summer of 1985 a geological map was made using enlarged aerial photographs at scale 1:10 000, and scheelite showings were localised with ultra-violet lamps at night (fig. 1). Thefollowing report is based on field observations and X-ray determination of scheelite in four rock samples.

Decomposition of Some Skarn-Rock Samples in Neutral and Basic Molten Potassium Nitrate for the Extraction and Determination of Iron

1996 ◽  
Vol 49 (2) ◽  
pp. 261 ◽  
Author(s):  
JK Mujumba ◽  
BD James ◽  
SA Tariq
Keyword(s):  
Atomic Absorption ◽  
Absorption Spectroscopy ◽  
Atomic Absorption Spectroscopy ◽  
Iron Content ◽  
Potassium Nitrate ◽  
Total Iron ◽  
Total Iron Content ◽  
X Ray ◽  
Rock Samples

Five skarn -rock samples were heated with KNO3 and with a solution of 5% KOH in KNO3 for 2 h at 450°C. The decomposed samples were cooled, dissolved in water and filtered. Iron was extracted from each residue as well as from the original samples by hot conc. HCl , and determined by atomic absorption spectroscopy. These results were compared with the known (X-ray fluorescence) total iron content of the original samples. The amount of iron extracted with HCl from the skarn samples was 3-11% lower, while that extracted after heating with KNO3 alone was 2-4% lower, than the amount present according to the X-ray fluorescence results. However, the amount of iron extracted from the samples treated with a solution of KOH in KNO3 was comparable to that determined by X-ray fluorescence.

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