Trace-element geochemical data from stream sediments collected in the Tok River area, Tanacross A-5 and A-6 quadrangles, Alaska in 2016

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What does this data set describe?

Title:

Trace-element geochemical data from stream sediments collected in the Tok River area, Tanacross A-5 and A-6 quadrangles, Alaska in 2016

Abstract:

In 2016, geologists from the Alaska Division of Geological & Geophysical Surveys (DGGS) and University of Alaska Fairbanks carried out a two-part geologic mapping and geochemical sampling project in the Tok River area of the Tanacross A-5 and A-6 quadrangles (June 12-26 and July 8-26). This report provides results of stream-sediment sampling for trace-element geochemistry. An initial suite of sediment samples was collected from streams draining known gold occurrences, including the Stibnite Creek and Noah prospects, and numerous prospects in the White Gold area. These samples were split in half and the two splits were sieved to -200 mesh and -80 mesh, respectively. The splits were then both analyzed to determine which size fraction was best for identifying gold anomalies in this part of the Alaska Range. In most samples, the -200 mesh fraction showed higher gold levels, and hence, all additional samples we collected were analyzed at -200 mesh. In some -80 mesh samples, gold and tungsten appear to show "nugget" effects not seen in the -200 mesh samples. The other trace elements are largely equivalent between the two mesh sizes. The second suite of samples was collected throughout the map area from streams draining color anomalies, from areas where DGGS mapping identified igneous rocks upstream, and from areas with suspected potential for base-metal or gold mineralization. Highlights of the analytical results include two samples draining the Noah prospect with greater than 1 part per million gold. The analytical data tables associated with this report are available in digital format as comma-separated value (CSV) files.

Supplemental_Information:

border:    Outline of the study area
stream-sed-trace-element:    Trace-element analysis of stream-sediment samples

How should this data set be cited?
Naibert, T.J., Werdon, M.B., Lande, Lauren, and Wypych, Alicja, 2016, Trace-element geochemical data from stream sediments collected in the Tok River area, Tanacross A-5 and A-6 quadrangles, Alaska in 2016: Raw Data File RDF 2016-10, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.
Online Links:
- <http://dx.doi.org/10.14509/29688>
Other_Citation_Details: 3 p.
What geographic area does the data set cover?

West_Bounding_Coordinate: -144.019833

East_Bounding_Coordinate: -143.096187

North_Bounding_Coordinate: 63.245385

South_Bounding_Coordinate: 63.027626
What does it look like?
Does the data set describe conditions during a particular time period?

Calendar_Date: 2016
Currentness_Reference: ground condition
What is the general form of this data set?

Geospatial_Data_Presentation_Form: report and digital data
How does the data set represent geographic features?
1. How are geographic features stored in the data set?
  This is a point data set.
2. What coordinate system is used to represent geographic features?
  Horizontal positions are specified in geographic coordinates, that is, latitude and longitude. Latitudes are given to the nearest 0.00001. Longitudes are given to the nearest 0.00001. Latitude and longitude values are specified in decimal degrees.
  The horizontal datum used is World Geodetic System of 1984.
  The ellipsoid used is WGS 84.
  The semi-major axis of the ellipsoid used is 6378137.
  The flattening of the ellipsoid used is 1/298.257223563.

How does the data set describe geographic features?

rdf2016-10-border.shp

Outline of the study area (Source: Alaska Division of Geological & Geophysical Surveys)

rdf2016-10-stream-sed-trace-element.csv, rdf2016-10-stream-sed-trace-element-methods.csv

Trace-element analysis of stream-sediment samples. (Source: Alaska Division of Geological & Geophysical Surveys)

SAMPLE

Label assigned to identify the sample. (Source: Alaska Division of Geological & Geophysical Surveys)

Generic example of a sample identifier: YYAAA9999X: YY=last two digits of year, AAA=geologist's initials (one to three characters), 9999=unique station number, X= optional alpha character which indicates that multiple samples were collected at a given location or that multiple observations were recorded in the project database.

LAB_SAMPLE_NUMBER

Label used by the lab to identify the sample. (Source: Alaska Division of Geological & Geophysical Surveys and ALS Geochemistry)

The lab sample number is typically identical to the sample number. However, in some cases, the sample number used by the lab does differ from the published sample number. We provide both numbers to document instances in which the sample numbers listed on the Certificate of Assay or other laboratory results files were non-standard or found to be incorrect.

BATCH_NUMBER

Number provided by the laboratory to identify the samples and analyses included in the work order. (Source: ALS Geochemistry)

The batch numbers assigned by the lab for these results are: FA16097684 , FA16097742, and FA16137615

COLLECTOR

The geologist who collected the sample. (Source: Alaska Division of Geological & Geophysical Surveys)

The samples presented in this report were collected by: Lauren Lande, Melanie Werdon, and Travis Naibert

SIZE_FRACTION

Sample splits were dry-sieved to less than 180 microns (-80 mesh) or to less than 75 microns (-200 mesh). (Source: ALS Geochemistry)

The sieve sizes used to process these samples: -200 and -80

LONGITUDE

Longitude, WGS84 (Source: Alaska Division of Geological & Geophysical Surveys)

Range of values
Minimum:	-144.019833
Maximum:	-143.096187
Units:	decimal degrees

LATITUDE

Latitude, WGS84 (Source: Alaska Division of Geological & Geophysical Surveys)

Range of values
Minimum:	63.027626
Maximum:	63.245385
Units:	decimal degrees

FIELD_STATION_DESCRIPTION

Description of the field station (Source: Alaska Division of Geological & Geophysical Surveys)

Characters 1 to 254 of a brief station description.

SAMPLE_DESCRIPTION

Description of the sample (Source: Alaska Division of Geological & Geophysical Surveys)

Value	Definition
NULL	We do not provide a description of the sample.

Characters 1 to 254 of a brief sample description.

STREAM_WIDTH_METERS

The estimated average width of stream at the sample site. (Source: Alaska Division of Geological & Geophysical Surveys)

Range of values
Minimum:	1
Maximum:	16
Units:	meters

STREAM_DEPTH_CM

The estimated average depth of stream at the sample site. (Source: Alaska Division of Geological & Geophysical Surveys)

Range of values
Minimum:	0
Maximum:	35
Units:	centimeters

STREAM_SPEED

Qualitative description of the stream flow rate and stream channel morphology at the field station where the sample was collected. (Source: Alaska Division of Geological & Geophysical Surveys)

Value	Definition
NULL	Blank (NULL) field values indicate that this data was not recorded by the sample collector.
swift	fast moving water, many riffles, bed and bank are composed of cobbles and gravel with minor sand
slow	slow current, few riffles, bed and banks are composed of gravel and sand, minor cobbles and silt, organics may be present
tumbling	step-wise flows with plunges and pools, bed and banks are composed of boulders and cobbles with minor gravel and finer sediment
ephemeral	dry or nearly dry stream bed

GRAIN_SIZE

Estimated classification of the size of material that is the source of the sample. (Source: Alaska Division of Geological & Geophysical Surveys)

Formal codeset
Codeset Name:	Unified Soil Classification System (USCS)
Codeset Source:	United States Army Engineer Waterways Experiment Station (1960), The Unified Soil Classification System: Technical Memorandum No. 3-357, U.S. Army Engineer Waterways Experiment Station, Vicksburg, MS.

SOURCE

Description of depositional environment of the specific sample site.. (Source: Alaska Division of Geological & Geophysical Surveys)

Value	Definition
eddy behind boulder or a log	Gravel or sand deposited downstream of an obstruction such as a log or boulder
middle of stream	Gravel or sand deposited in the middle of the stream
plunge pool or waterfall	Sand or gravel deposited at the edge of a pool below a waterfall
edge of stream	Gravel or sand deposited along the edge of the stream
bar in middle of stream	Gravel or sand deposited on a bar in the middle of the stream
eddy at edge of stream	Gravel or sand deposited in an eddy at the edge of the stream
gravel armor from stream	Sediment trapped below pebble or cobble pavement at the leading edge of a gravel bar
deep stagnant pool	Body of standing water
dry stream bed	inactive or intermittently active stream bed which was dry when the sample was collected

NUM_SITES

Number of sample sites at the station. (Source: Alaska Division of Geological & Geophysical Surveys)

Value	Definition
NULL	Blank (NULL) field values indicate that this data was not recorded by the sample collector.

Range of values
Minimum:	1
Maximum:	4

DIST_SAMP

The total distance sampled along the stream bed (in meters) (Source: Alaska Division of Geological & Geophysical Surveys)

Value	Definition
NULL	Blank (NULL) field values indicate that this data was not recorded by the sample collector.

Range of values
Minimum:	1
Maximum:	30
Units:	meters

SED_COLOR

Primary and, if applicable, secondary color of chemical or biogenic precipitate on the stream bed material qualitatively assigned by the sampler, no color palate or guide is used. (Source: Alaska Division of Geological & Geophysical Surveys)

The color selection values used in this table are: brown and gray

WEIGHT_KG

Sample weight (as received by the lab) in kilograms (Source: Alaska Division of Geological & Geophysical Surveys and ALS Geochemistry)

Range of values
Minimum:	2.42
Maximum:	10.17
Units:	kilograms

Ag_ppm_ME-MS61

Silver values measured in parts per million; Method: Inductively Coupled Plasma - Atomic Emission Spectroscopy/Inductively Coupled - Plasma Mass Spectrometry, HF-HNO3 -HClO4 Acid Digestion, HCl Leach (Source: ALS Geochemistry)

Range of values
Minimum:	0.01
Maximum:	0.89
Units:	parts per million

Al_pct_ME-MS61

Aluminum values measured in percent; Method: Inductively Coupled Plasma - Atomic Emission Spectroscopy/Inductively Coupled - Plasma Mass Spectrometry, HF-HNO3 -HClO4 Acid Digestion, HCl Leach (Source: ALS Geochemistry)

Range of values
Minimum:	4.83
Maximum:	11.1
Units:	percent

As_ppm_ME-MS61

Arsenic values measured in parts per million; Method: Inductively Coupled Plasma - Atomic Emission Spectroscopy/Inductively Coupled - Plasma Mass Spectrometry, HF-HNO3 -HClO4 Acid Digestion, HCl Leach (Source: ALS Geochemistry)

Range of values
Minimum:	3.8
Maximum:	367
Units:	parts per million

Ba_ppm_ME-MS61

Barium values measured in parts per million; Method: Inductively Coupled Plasma - Atomic Emission Spectroscopy/Inductively Coupled - Plasma Mass Spectrometry, HF-HNO3 -HClO4 Acid Digestion, HCl Leach (Source: ALS Geochemistry)

Range of values
Minimum:	350
Maximum:	2050
Units:	parts per million

Be_ppm_ME-MS61

Beryllium values measured in parts per million; Method: Inductively Coupled Plasma - Atomic Emission Spectroscopy/Inductively Coupled - Plasma Mass Spectrometry, HF-HNO3 -HClO4 Acid Digestion, HCl Leach (Source: ALS Geochemistry)

Range of values
Minimum:	1.1
Maximum:	3.15
Units:	parts per million

Bi_ppm_ME-MS61

Bismuth values measured in parts per million; Method: Inductively Coupled Plasma - Atomic Emission Spectroscopy/Inductively Coupled - Plasma Mass Spectrometry, HF-HNO3 -HClO4 Acid Digestion, HCl Leach (Source: ALS Geochemistry)

Range of values
Minimum:	0.14
Maximum:	4.9
Units:	parts per million

Ca_pct_ME-MS61

Calcium values measured in percent; Method: Inductively Coupled Plasma - Atomic Emission Spectroscopy/Inductively Coupled - Plasma Mass Spectrometry, HF-HNO3 -HClO4 Acid Digestion, HCl Leach (Source: ALS Geochemistry)

Range of values
Minimum:	0.42
Maximum:	15
Units:	percent

Cd_ppm_ME-MS61

Cadmium values measured in parts per million; Method: Inductively Coupled Plasma - Atomic Emission Spectroscopy/Inductively Coupled - Plasma Mass Spectrometry, HF-HNO3 -HClO4 Acid Digestion, HCl Leach (Source: ALS Geochemistry)

Range of values
Minimum:	0.05
Maximum:	5.42
Units:	parts per million

Ce_ppm_ME-MS61

Cerium values measured in parts per million; Method: Inductively Coupled Plasma - Atomic Emission Spectroscopy/Inductively Coupled - Plasma Mass Spectrometry, HF-HNO3 -HClO4 Acid Digestion, HCl Leach (Source: ALS Geochemistry)

Range of values
Minimum:	41.2
Maximum:	314
Units:	parts per million

Co_ppm_ME-MS61

Cobalt values measured in parts per million; Method: Inductively Coupled Plasma - Atomic Emission Spectroscopy/Inductively Coupled - Plasma Mass Spectrometry, HF-HNO3 -HClO4 Acid Digestion, HCl Leach (Source: ALS Geochemistry)

Range of values
Minimum:	5.2
Maximum:	46
Units:	parts per million

Cr_ppm_ME-MS61

Chromium values measured in parts per million; Method: Inductively Coupled Plasma - Atomic Emission Spectroscopy/Inductively Coupled - Plasma Mass Spectrometry, HF-HNO3 -HClO4 Acid Digestion, HCl Leach (Source: ALS Geochemistry)

Range of values
Minimum:	18
Maximum:	128
Units:	parts per million

Cs_ppm_ME-MS61

Cesium values measured in parts per million; Method: Inductively Coupled Plasma - Atomic Emission Spectroscopy/Inductively Coupled - Plasma Mass Spectrometry, HF-HNO3 -HClO4 Acid Digestion, HCl Leach (Source: ALS Geochemistry)

Range of values
Minimum:	1.61
Maximum:	6.98
Units:	parts per million

Cu_ppm_ME-MS61

Copper values measured in parts per million; Method: Inductively Coupled Plasma - Atomic Emission Spectroscopy/Inductively Coupled - Plasma Mass Spectrometry, HF-HNO3 -HClO4 Acid Digestion, HCl Leach (Source: ALS Geochemistry)

Range of values
Minimum:	9
Maximum:	640
Units:	parts per million

Fe_pct_ME-MS61

Iron values measured in percent; Method: Inductively Coupled Plasma - Atomic Emission Spectroscopy/Inductively Coupled - Plasma Mass Spectrometry, HF-HNO3 -HClO4 Acid Digestion, HCl Leach (Source: ALS Geochemistry)

Range of values
Minimum:	1.9
Maximum:	6.32
Units:	percent

Ga_ppm_ME-MS61

Gallium values measured in parts per million; Method: Inductively Coupled Plasma - Atomic Emission Spectroscopy/Inductively Coupled - Plasma Mass Spectrometry, HF-HNO3 -HClO4 Acid Digestion, HCl Leach (Source: ALS Geochemistry)

Range of values
Minimum:	12.25
Maximum:	31
Units:	parts per million

Ge_ppm_ME-MS61

Germanium values measured in parts per million; Method: Inductively Coupled Plasma - Atomic Emission Spectroscopy/Inductively Coupled - Plasma Mass Spectrometry, HF-HNO3 -HClO4 Acid Digestion, HCl Leach (Source: ALS Geochemistry)

Range of values
Minimum:	0.08
Maximum:	0.34
Units:	parts per million

Hf_ppm_ME-MS61

Hafnium values measured in parts per million; Method: Inductively Coupled Plasma - Atomic Emission Spectroscopy/Inductively Coupled - Plasma Mass Spectrometry, HF-HNO3 -HClO4 Acid Digestion, HCl Leach (Source: ALS Geochemistry)

Range of values
Minimum:	0.2
Maximum:	7.6
Units:	parts per million

In_ppm_ME-MS61

Indium values measured in parts per million; Method: Inductively Coupled Plasma - Atomic Emission Spectroscopy/Inductively Coupled - Plasma Mass Spectrometry, HF-HNO3 -HClO4 Acid Digestion, HCl Leach (Source: ALS Geochemistry)

Range of values
Minimum:	0.036
Maximum:	0.144
Units:	parts per million

K_pct_ME-MS61

Potassium values measured in percent; Method: Inductively Coupled Plasma - Atomic Emission Spectroscopy/Inductively Coupled - Plasma Mass Spectrometry, HF-HNO3 -HClO4 Acid Digestion, HCl Leach (Source: ALS Geochemistry)

Range of values
Minimum:	1.22
Maximum:	4.3
Units:	percent

La_ppm_ME-MS61

Lanthanum values measured in parts per million; Method: Inductively Coupled Plasma - Atomic Emission Spectroscopy/Inductively Coupled - Plasma Mass Spectrometry, HF-HNO3 -HClO4 Acid Digestion, HCl Leach (Source: ALS Geochemistry)

Range of values
Minimum:	20.3
Maximum:	154
Units:	parts per million

Li_ppm_ME-MS61

Lithium values measured in parts per million; Method: Inductively Coupled Plasma - Atomic Emission Spectroscopy/Inductively Coupled - Plasma Mass Spectrometry, HF-HNO3 -HClO4 Acid Digestion, HCl Leach (Source: ALS Geochemistry)

Range of values
Minimum:	13.4
Maximum:	46.8
Units:	parts per million

Mg_pct_ME-MS61

Magnesium values measured in percent; Method: Inductively Coupled Plasma - Atomic Emission Spectroscopy/Inductively Coupled - Plasma Mass Spectrometry, HF-HNO3 -HClO4 Acid Digestion, HCl Leach (Source: ALS Geochemistry)

Range of values
Minimum:	0.41
Maximum:	2.18
Units:	percent

Mn_ppm_ME-MS61

Manganese values measured in parts per million; Method: Inductively Coupled Plasma - Atomic Emission Spectroscopy/Inductively Coupled - Plasma Mass Spectrometry, HF-HNO3 -HClO4 Acid Digestion, HCl Leach (Source: ALS Geochemistry)

Range of values
Minimum:	256
Maximum:	1180
Units:	parts per million

Mo_ppm_ME-MS61

Molybdenum values measured in parts per million; Method: Inductively Coupled Plasma - Atomic Emission Spectroscopy/Inductively Coupled - Plasma Mass Spectrometry, HF-HNO3 -HClO4 Acid Digestion, HCl Leach (Source: ALS Geochemistry)

Range of values
Minimum:	0.32
Maximum:	5.17
Units:	parts per million

Na_pct_ME-MS61

Sodium values measured in percent; Method: Inductively Coupled Plasma - Atomic Emission Spectroscopy/Inductively Coupled - Plasma Mass Spectrometry, HF-HNO3 -HClO4 Acid Digestion, HCl Leach (Source: ALS Geochemistry)

Range of values
Minimum:	0.39
Maximum:	2.27
Units:	percent

Nb_ppm_ME-MS61

Niobium values measured in parts per million; Method: Inductively Coupled Plasma - Atomic Emission Spectroscopy/Inductively Coupled - Plasma Mass Spectrometry, HF-HNO3 -HClO4 Acid Digestion, HCl Leach (Source: ALS Geochemistry)

Range of values
Minimum:	7.5
Maximum:	30.4
Units:	parts per million

Ni_ppm_ME-MS61

Nickel values measured in parts per million; Method: Inductively Coupled Plasma - Atomic Emission Spectroscopy/Inductively Coupled - Plasma Mass Spectrometry, HF-HNO3 -HClO4 Acid Digestion, HCl Leach (Source: ALS Geochemistry)

Range of values
Minimum:	8.2
Maximum:	138.5
Units:	parts per million

P_ppm_ME-MS61

Phosphorus values measured in parts per million; Method: Inductively Coupled Plasma - Atomic Emission Spectroscopy/Inductively Coupled - Plasma Mass Spectrometry, HF-HNO3 -HClO4 Acid Digestion, HCl Leach (Source: ALS Geochemistry)

Range of values
Minimum:	360
Maximum:	1590
Units:	parts per million

Pb_ppm_ME-MS61

Lead values measured in parts per million; Method: Inductively Coupled Plasma - Atomic Emission Spectroscopy/Inductively Coupled - Plasma Mass Spectrometry, HF-HNO3 -HClO4 Acid Digestion, HCl Leach (Source: ALS Geochemistry)

Range of values
Minimum:	7.9
Maximum:	68.5
Units:	parts per million

Rb_ppm_ME-MS61

Rubidium values measured in parts per million; Method: Inductively Coupled Plasma - Atomic Emission Spectroscopy/Inductively Coupled - Plasma Mass Spectrometry, HF-HNO3 -HClO4 Acid Digestion, HCl Leach (Source: ALS Geochemistry)

Range of values
Minimum:	42.5
Maximum:	194.5
Units:	parts per million

Re_ppm_ME-MS61

Rhenium values measured in parts per million; Method: Inductively Coupled Plasma - Atomic Emission Spectroscopy/Inductively Coupled - Plasma Mass Spectrometry, HF-HNO3 -HClO4 Acid Digestion, HCl Leach (Source: ALS Geochemistry)

Value	Definition
-1	Below detection limit.

Range of values
Minimum:	0.002
Maximum:	0.007
Units:	parts per million

S_pct_ME-MS61

Sulfur values measured in percent; Method: Inductively Coupled Plasma - Atomic Emission Spectroscopy/Inductively Coupled - Plasma Mass Spectrometry, HF-HNO3 -HClO4 Acid Digestion, HCl Leach (Source: ALS Geochemistry)

Range of values
Minimum:	0.01
Maximum:	0.44
Units:	percent

Sb_ppm_ME-MS61

Antimony values measured in parts per million; Method: Inductively Coupled Plasma - Atomic Emission Spectroscopy/Inductively Coupled - Plasma Mass Spectrometry, HF-HNO3 -HClO4 Acid Digestion, HCl Leach (Source: ALS Geochemistry)

Range of values
Minimum:	0.66
Maximum:	27.3
Units:	parts per million

Sc_ppm_ME-MS61

Scandium values measured in parts per million; Method: Inductively Coupled Plasma - Atomic Emission Spectroscopy/Inductively Coupled - Plasma Mass Spectrometry, HF-HNO3 -HClO4 Acid Digestion, HCl Leach (Source: ALS Geochemistry)

Range of values
Minimum:	9.2
Maximum:	28.2
Units:	parts per million

Se_ppm_ME-MS61

Selenium values measured in parts per million; Method: Inductively Coupled Plasma - Atomic Emission Spectroscopy/Inductively Coupled - Plasma Mass Spectrometry, HF-HNO3 -HClO4 Acid Digestion, HCl Leach (Source: ALS Geochemistry)

Range of values
Minimum:	1
Maximum:	5
Units:	parts per million

Sn_ppm_ME-MS61

Tin values measured in parts per million; Method: Inductively Coupled Plasma - Atomic Emission Spectroscopy/Inductively Coupled - Plasma Mass Spectrometry, HF-HNO3 -HClO4 Acid Digestion, HCl Leach (Source: ALS Geochemistry)

Range of values
Minimum:	1.1
Maximum:	4.7
Units:	parts per million

Sr_ppm_ME-MS61

Strontium values measured in parts per million; Method: Inductively Coupled Plasma - Atomic Emission Spectroscopy/Inductively Coupled - Plasma Mass Spectrometry, HF-HNO3 -HClO4 Acid Digestion, HCl Leach (Source: ALS Geochemistry)

Range of values
Minimum:	60.9
Maximum:	464
Units:	parts per million

Ta_ppm_ME-MS61

Tantalum values measured in parts per million; Method: Inductively Coupled Plasma - Atomic Emission Spectroscopy/Inductively Coupled - Plasma Mass Spectrometry, HF-HNO3 -HClO4 Acid Digestion, HCl Leach (Source: ALS Geochemistry)

Range of values
Minimum:	0.51
Maximum:	1.93
Units:	parts per million

Te_ppm_ME-MS61

Tellurium values measured in parts per million; Method: Inductively Coupled Plasma - Atomic Emission Spectroscopy/Inductively Coupled - Plasma Mass Spectrometry, HF-HNO3 -HClO4 Acid Digestion, HCl Leach (Source: ALS Geochemistry)

Value	Definition
-1	Below detection limit.

Range of values
Minimum:	0.05
Maximum:	0.99
Units:	parts per million

Th_ppm_ME-MS61

Thorium values measured in parts per million; Method: Inductively Coupled Plasma - Atomic Emission Spectroscopy/Inductively Coupled - Plasma Mass Spectrometry, HF-HNO3 -HClO4 Acid Digestion, HCl Leach (Source: ALS Geochemistry)

Range of values
Minimum:	4.23
Maximum:	53.9
Units:	parts per million

Ti_pct_ME-MS61

Titanium values measured in percent; Method: Inductively Coupled Plasma - Atomic Emission Spectroscopy/Inductively Coupled - Plasma Mass Spectrometry, HF-HNO3 -HClO4 Acid Digestion, HCl Leach (Source: ALS Geochemistry)

Range of values
Minimum:	0.183
Maximum:	0.745
Units:	percent

Tl_ppm_ME-MS61

Thallium values measured in parts per million; Method: Inductively Coupled Plasma - Atomic Emission Spectroscopy/Inductively Coupled - Plasma Mass Spectrometry, HF-HNO3 -HClO4 Acid Digestion, HCl Leach (Source: ALS Geochemistry)

Range of values
Minimum:	0.34
Maximum:	1.5
Units:	parts per million

U_ppm_ME-MS61

Uranium values measured in parts per million; Method: Inductively Coupled Plasma - Atomic Emission Spectroscopy/Inductively Coupled - Plasma Mass Spectrometry, HF-HNO3 -HClO4 Acid Digestion, HCl Leach (Source: ALS Geochemistry)

Range of values
Minimum:	1.1
Maximum:	8.7
Units:	parts per million

V_ppm_ME-MS61

Vanadium values measured in parts per million; Method: Inductively Coupled Plasma - Atomic Emission Spectroscopy/Inductively Coupled - Plasma Mass Spectrometry, HF-HNO3 -HClO4 Acid Digestion, HCl Leach (Source: ALS Geochemistry)

Range of values
Minimum:	37
Maximum:	184
Units:	parts per million

W_ppm_ME-MS61

Tungsten values measured in parts per million; Method: Inductively Coupled Plasma - Atomic Emission Spectroscopy/Inductively Coupled - Plasma Mass Spectrometry, HF-HNO3 -HClO4 Acid Digestion, HCl Leach (Source: ALS Geochemistry)

Range of values
Minimum:	0.9
Maximum:	52.5
Units:	parts per million

Y_ppm_ME-MS61

Yttrium values measured in parts per million; Method: Inductively Coupled Plasma - Atomic Emission Spectroscopy/Inductively Coupled - Plasma Mass Spectrometry, HF-HNO3 -HClO4 Acid Digestion, HCl Leach (Source: ALS Geochemistry)

Range of values
Minimum:	8.9
Maximum:	53.9
Units:	parts per million

Zn_ppm_ME-MS61

Zinc values measured in parts per million; Method: Inductively Coupled Plasma - Atomic Emission Spectroscopy/Inductively Coupled - Plasma Mass Spectrometry, HF-HNO3 -HClO4 Acid Digestion, HCl Leach (Source: ALS Geochemistry)

Range of values
Minimum:	35
Maximum:	748
Units:	parts per million

Zr_ppm_ME-MS61

Zirconium values measured in parts per million; Method: Inductively Coupled Plasma - Atomic Emission Spectroscopy/Inductively Coupled - Plasma Mass Spectrometry, HF-HNO3 -HClO4 Acid Digestion, HCl Leach (Source: ALS Geochemistry)

Range of values
Minimum:	5.1
Maximum:	241
Units:	parts per million

Au_ppm_PGM-MS23

Gold values measured in parts per million; Method: Fire Assay - Inductively Coupled Plasma - Mass Spectrometry (Source: ALS Geochemistry)

Value	Definition
-2	Above detection limit.

Range of values
Minimum:	0.003
Maximum:	0.863
Units:	parts per million

Pt_ppm_PGM-MS23

Platinum values measured in parts per million; Method: Fire Assay - Inductively Coupled Plasma - Mass Spectrometry (Source: ALS Geochemistry)

Range of values
Minimum:	0.0005
Maximum:	0.0034
Units:	parts per million

Pd_ppm_PGM-MS23

Palladium values measured in parts per million; Method: Fire Assay - Inductively Coupled Plasma - Mass Spectrometry (Source: ALS Geochemistry)

Range of values
Minimum:	0.001
Maximum:	0.012
Units:	parts per million

Au_ppm_Au-AA25

Gold values measured in parts per million; Method: Fire Assay - Atomic Absorption Spectroscopy (Source: ALS Geochemistry)

Value	Definition
NULL	Blank (NULL) field values may indicate that either the chemical species was not analyzed.

Range of values
Minimum:	1.1
Maximum:	1.24
Units:	parts per million

Who produced the data set?

Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
- Naibert, T.J.
- Werdon, M.B.
- Lande, Lauren
- Wypych, Alicja
Who also contributed to the data set?

The DGGS Tok River project is funded through U.S. Geological Survey STATEMAP Award No. G16AC00182; Cooperative Agreement Number G16AC00167 between the U.S. Geological Survey and the Alaska Department of Natural Resources, Division of Geological & Geophysical Surveys; and by State of Alaska general funds.
To whom should users address questions about the data?

Alaska Division of Geological & Geophysical Surveys
GIS Manager
3354 College Rd
Fairbanks, AK 99709-3707
USA

907-451-5020 (voice)
dggsgis@alaska.gov

Hours_of_Service: 8 am to 4:30 pm, Monday through Friday, except State holidays

Why was the data set created?

The combination of insufficient detailed geologic mapping, historical and current industry interest in the adjacent mineralized areas, and the recently published geophysical data prompted the DGGS Mineral Resources section to conduct a stream-sediment sampling program in conjunction with geologic mapping in the Tok River area.

How was the data set created?

From what previous works were the data drawn?
Dashevsky, S.S. and others, 2003 (source 1 of 3)
Dashevsky, S.S., Schaefer, C.F., and Hunter, E.N., 2003, Bedrock geologic map of the Delta mineral belt, Tok mining district, Alaska: Professional Report PR 122, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.
Online Links:
- <http://doi.org/10.14509/2923>
Other_Citation_Details: 122 p., 2 sheets, scale 1:63,360

Type_of_Source_Media: paper

Source_Scale_Denominator: 63360

Source_Contribution: sample selection
Foster, H.L., 1970 (source 2 of 3)
Foster, H.L., 1970, Reconnaissance geologic map of the Tanacross Quadrangle, Alaska: Miscellaneous Geologic Investigations Map I 593, U.S. Geological Survey, United States.
Online Links:
- <http://dggs.alaska.gov/pubs/id/12871>
Other_Citation_Details: 1 sheet, scale 1:250,000

Type_of_Source_Media: paper

Source_Scale_Denominator: 250000

Source_Contribution: sample selection
Nokleberg, W.J. and others, 2015 (source 3 of 3)
Nokleberg, W.J., Aleinikoff, J.N., Bond, G.C., Ferrians, O.J., Jr., Herzon, P.L., Lange, I.M., Miyaoka, R.T., Richter, D.H., Schwab, C.E., Silva, S.R., Smith, T.E., and Zehner, R.E., 2015, Geologic maps of the eastern Alaska Range, Alaska (44 quadrangles, 1:63,360 scale), with descriptions and interpretations of map units: Report of Investigation RI 2015-6, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.
Online Links:
- <http://doi.org/10.14509/29444>
Other_Citation_Details: 64 p., 45 sheets, scale 1:63,360

Type_of_Source_Media: paper

Source_Scale_Denominator: 63360

Source_Contribution: sample selection
How were the data generated, processed, and modified?
Date: 2016 (process 1 of 4)
Sample selection - Stream-sediment sample locations were selected to characterize drainage basins containing igneous intrusions or locations of known or potential mineralization. In the field, sample locations were selected that were upstream of alluvial fans and as close to stream confluences as possible, while also accounting for availability of sample material and proximity to helicopter landing zones. Specific sites at the sample location were selected based on the presence of fine-grained sand and silt, and included eddies or plunge-pools behind boulders or logs, eddies along edges of streams, overbank deposits, and channel bars. Samples were collected with a shovel, screened by hand using a Garrett's Combination Sifter with a 0.483-inch square-hole mesh, and then further screened using a 0.0742-inch square-hole mesh (-10 mesh). Undersized material was collected in a 3-gallon plastic bucket and then all materials, fines, and water were poured into polypropylene sample bags (10 inch x 17 inch) specifically designed to capture fines and allow water drainage. Where possible, the sample bags were filled to capacity to provide enough sample material to split and sieve using both -80 mesh and -200 mesh screens. For the remaining samples, sample bags were filled to approximately 60 percent of capacity. Individual sample weights were measured after drying and are provided in the analytical results.
Data sources used in this process:
- Dashevsky, S.S. and others, 2003
- Foster, H.L., 1970
- Nokleberg, W.J. and others, 2015
Date: 2016 (process 2 of 4)
Sample preparation - Sediment samples were processed by ALS Minerals using their PREP-41 package. The samples were logged and dried at a maximum temperature of 60 degrees Celsius. An initial batch of 23 samples were each split with a riffle splitter, and sample splits were dry-sieved to less than 180 microns (-80 mesh) and to less than 75 microns (-200 mesh), respectively. The remaining 44 samples were dry-sieved to less than 75 microns (-200 mesh).

Date: 2016 (process 3 of 4)
Major- and trace-element compositions - Trace-element compositions for sediment samples were determined by ALS Geochemistry method ME-MS61: Four-acid digestion followed by inductively coupled plasma-atomic emission spectrometry (ICP-AES) and inductively coupled plasma-mass spectroscopy (ICP-MS). Platinum, palladium, and gold values were analyzed by 30 g fire assay with ICP-MS finish (ALS Geochemistry method PGM-MS23). Samples that exceeded detection limits for gold were reanalyzed by 30 g fire assay with atomic absorption (AA) finish (ALS Geochemistry method Au-AA25).

Date: 2016 (process 4 of 4)
Sample archival - Samples collected during this project, as well as laboratory sample rejects and pulps, will be stored at DGGS for the duration of the project and will be available for public viewing upon request. Once the project concludes, the samples and pulps will be stored at the Alaska Geologic Materials Center in Anchorage.
What similar or related data should the user be aware of?
Emond, A.M., CGG, Burns, L.E., Graham, G.R.C., and (US), CGG Land Inc., 2015, Tok electromagnetic and magnetic airborne geophysical survey data compilation: Geophysical Report GPR 2015-2, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.
Online Links:
- <http://doi.org/10.14509/29347>
Twelker, Evan, Freeman, L.K., Sicard, K.R., and Busk, A.C., 2016, Preliminary report on mineral occurrences in the Tok River area, Alaska: Preliminary Interpretive Report PIR 2016-2, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.
Online Links:
- <http://doi.org/10.14509/29605>
Other_Citation_Details: 7 p
Wypych, Alicja, Sicard, K.R., Twelker, Evan, Freeman, L.K., Lande, Lauren, and Reioux, D.A., 2015, Major-oxide and trace-element geochemical data from rocks collected in 2015 in the Tok area, Tanacross A-5, A-6, and parts of adjacent quadrangles, Alaska: Raw Data File RDF 2015-15, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.
Online Links:
- <http://doi.org/10.14509/29517>
Other_Citation_Details: 3 p
Wypych, Alicja, Sicard, K.R., Gillis, R.J., Lande, L.L., Naibert, T.J., Newberry, R.J., Twelker, Evan, Werdon, M.B., and Willingham, A.L., 2016, Major-oxide and trace-element geochemical data from rocks collected in the Tok River area, Tanacross A-5 and A-6 quadrangles, Alaska in 2016: Raw Data File RDF 2016-9, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.
Online Links:
- <http://doi.org/10.14509/29685>
Other_Citation_Details: 3 p

How reliable are the data; what problems remain in the data set?

How well have the observations been checked?
Coordinates of sample locations were determined by the geologists in the field using using hand-held GPS devices. Sample numbers were recorded in the field on sample bags and on field note sheets. The sample location tables were plotted in GIS software to visually verify location accuracy and cross checked for consistency against the sample numbers recorded on the bags. Samples were analyzed for a variety of major and trace elements by ALS Geochemistry using the methods listed below. In addition to ALS Geochemistry's accredited (ISO/IEC 17025-2005) internal quality-control program, DGGS monitored analysis quality with two standard reference materials, a gold standard and a base-metal standard. One of each standard was inserted into each batch of 20 samples submitted to ALS Geochemistry. Lab results were examined by the DGGS geologists to ensure that they are reasonable given the geologic context of the sample. Inconsistencies between the field data and the lab sample numbers listed on the COA (certificate of assay) are noted in the data tables.
How accurate are the geographic locations?
Locations were recorded using handheld, WAAS-enabled GPS devices. WAAS-enabled GPS devices have a reported error of about 1 m (NSTB/WAAS T&E Team, 2006). Depending on degradation of the WAAS and GPS signals, the horizontal position error of sample locations in this report is in the range of 1-10 m.
How accurate are the heights or depths?
Where are the gaps in the data? What is missing?
This data release is complete. The data tables have been lightly edited for clarity, but are generally provided as received from the lab.
How consistent are the relationships among the observations, including topology?
not applicable

How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?

Access_Constraints:
This report, map, and/or dataset is available directly from the State of Alaska, Department of Natural Resources, Division of Geological & Geophysical Surveys (see contact information below).

Use_Constraints:
Any hard copies or published datasets utilizing these datasets shall clearly indicate their source. If the user has modified the data in any way, the user is obligated to describe the types of modifications the user has made. The user specifically agrees not to misrepresent these datasets, nor to imply that changes made by the user were approved by the State of Alaska, Department of Natural Resources, Division of Geological & Geophysical Surveys. The State of Alaska makes no express or implied warranties (including warranties for merchantability and fitness) with respect to the character, functions, or capabilities of the electronic data or products or their appropriateness for any user's purposes. In no event will the State of Alaska be liable for any incidental, indirect, special, consequential, or other damages suffered by the user or any other person or entity whether from the use of the electronic services or products or any failure thereof or otherwise. In no event will the State of Alaska's liability to the Requestor or anyone else exceed the fee paid for the electronic service or product.

Who distributes the data set? (Distributor 1 of 1)

Alaska Division of Geological & Geophysical Surveys
3354 College Road
Fairbanks, AK 99709-3707
USA

(907)451-5020 (voice)
(907)451-5050 (FAX)
dggspubs@alaska.gov

Hours_of_Service: 8 am to 4:30 pm, Monday through Friday, except State holidays

Contact_Instructions:
Please view our website (<http://www.dggs.alaska.gov>) for the latest information on available data. Please contact us using the e-mail address provided above when possible.
What's the catalog number I need to order this data set?
RDF 2016-10
What legal disclaimers am I supposed to read?

The State of Alaska makes no expressed or implied warranties (including warranties for merchantability and fitness) with respect to the character, functions, or capabilities of the electronic data or products or their appropriateness for any user's purposes. In no event will the State of Alaska be liable for any incidental, indirect, special, consequential, or other damages suffered by the user or any other person or entity whether from the use of the electronic services or products or any failure thereof or otherwise. In no event will the State of Alaska's liability to the Requestor or anyone else exceed the fee paid for the electronic service or product.
How can I download or order the data?
- Availability in non-digital form:
  DGGS publications are available as free online downloads or you may purchase paper hard-copies or digital files on CD/DVD or other digital storage media by mail, phone, fax, or email from the DGGS Fairbanks office. To purchase this or other printed reports and maps, contact DGGS by phone (907-451-5020), e-mail (dggspubs@alaska.gov), or fax (907-451-5050). Payment accepted: Cash, check, money order, VISA, or MasterCard. Turnaround time is 1-2 weeks unless special arrangements are made and an express fee is paid. Shipping charge will be the actual cost of postage and will be added to the total amount due. Contact us for the exact shipping amount.
- Cost to order the data: Contact DGGS for current pricing
- Availability in digital form:
  
  Data format: ASCII tabular files
  
  Network links: <http://dx.doi.org/10.14509/29688>
- Cost to order the data: Free download

Who wrote the metadata?

Dates:

Last modified: 04-Nov-2016

Metadata author:

Alaska Division of Geological & Geophysical Surveys
Metadata Manager
3354 College Road
Fairbanks, AK 99709-3707
USA

(907)451-5020 (voice)

Metadata standard:

FGDC Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)

Metadata extensions used:

<http://www.dggs.alaska.gov/metadata/dggs.ext>

Generated by mp version 2.9.21 on Fri Nov 4 12:54:13 2016

Data format:	ASCII tabular files
Network links:	<http://dx.doi.org/10.14509/29688>