Biomarker analysis of cold seeps along the United States Atlantic Margin

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What does this data set describe?

1. How might this data set be cited?
   Prouty, Nancy G., and Swarzenski, Pamela Campbell, 2019, Biomarker analysis of cold seeps along the United States Atlantic Margin: data release DOI:10.5066/P9JHGO8O, U.S. Geological Survey, Pacific Coastal and Marine Science Center, Santa Cruz, California.

   Online Links:

   • https://doi.org/10.5066/P9JHGO8O
   • https://www.sciencebase.gov/catalog/file/get/5c4f3988e4b0708288f78d7a

2. What geographic area does the data set cover?

   West_Bounding_Coordinate: -74.4929
   East_Bounding_Coordinate: -73.7722
   North_Bounding_Coordinate: 38.0977
   South_Bounding_Coordinate: 36.8654
   

3. What does it look like?
4. Does the data set describe conditions during a particular time period?

   Beginning_Date: 25-Aug-2012

   Ending_Date: 21-Jul-2015

   Currentness_Reference:

   Ground condition at time data were collected.

5. What is the general form of this data set?

   Geospatial_Data_Presentation_Form: comma-delimited text
   

6. How does the data set represent geographic features?
   1. How are geographic features stored in the data set?
      This is a Point data set. It contains the following vector data types (SDTS terminology):
      • Point (28)
   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 D_WGS_1984.
      The ellipsoid used is WGS_1984.
      The semi-major axis of the ellipsoid used is 6378137.000000.
      The flattening of the ellipsoid used is 1/298.257224.
      
7. How does the data set describe geographic features?

   USAM_MDAC_Biomarker.csv

   Table containing results from analyses of organic biomarker composition of authigenic carbonate and sediment samples. (Source: Producer defined)

   Sample ID

   The unique sample identification of a particular sample. (Source: producer defined) Sample IDs that begin with AT indicate samples collected by Duke University on the R/V Atlantis and include the ship’s cruise number (e.g. AT29-04), dive number (e.g. 4808), and sequential sample number. Sample IDs that begin with RB indicate samples collected by the USGS on the R/V Ron Brown and include the cruise year (e.g. 2013), dive number (e.g. 682), and sequential sample number. Sample IDs that begin with NF indicate samples collected by the USGS on the R/V Nancy Foster and include the cruise year (e.g. 2012), and a sequential number assigned by the vessel. Gaps in sequential numbers are common, as not all stations had samples collected or analyzed.

   Lab ID

   The unique laboratory identification of a particular sample. (Source: producer defined) The Lab ID contains the year of analysis in two digits (e.g., 18=2018) followed by a sample number in a series. Gaps in sequential numbers are common, and not all samples contain analytical description.

   Location

   Lists whether the sample was collected from either Baltimore Canyon or Norfolk Canyon. (Source: producer defined)

   Value	Definition
   Baltimore Canyon	Name of canyon where sample was collected
   Norfolk Canyon	Name of canyon where sample was collected

   Date of Collection

   Calendar date (month/day/year) when sample was collected in the field (Source: producer defined)

   Range of values
   Minimum:	8/25/12
   Maximum:	7/21/15
   Units:	month/day/year

   Depth

   Depth in meters of sample collection (Source: producer defined)

   Range of values
   Minimum:	385
   Maximum:	1617
   Units:	meters (m)
   Resolution:	1

   Latitude

   Latitude (Source: based on ship and ROV navigation systems)

   Range of values
   Minimum:	36.8654
   Maximum:	38.0977
   Units:	decimal degrees
   Resolution:	0.0001

   Longitude

   Longitude (Source: based on ship and ROV navigation systems)

   Range of values
   Minimum:	-74.4929
   Maximum:	-73.7722
   Units:	decimal degrees
   Resolution:	0.0001

   Sample type

   Explains the sample type (Source: producer defined)

   Value	Definition
   mussel sediment	sediment collected from mussel habitat
   authigenic carbonate	homogenized authigenic carbonate rock
   bacterial mat sediment	sediment collected from bacterial mat habitat

   Depth interval

   Explains depth interval in sediment core for sample collection. n/a in the spreadsheet indicates not applicable. (Source: producer defined)

   Value	Definition
   0-2	sediment core depth interval at 0-2 cm
   2-5	sediment core depth interval at 2-5 cm

   Percent Organic Carbon

   Sediment percent organic carbon as measured on an elemental analyzer. An empty cell in the spreadsheet indicates that percent carbon was not calculated for that sample. (Source: standard reporting value in isotope chemistry)

   Range of values
   Minimum:	0.29
   Maximum:	5.14
   Units:	molar percent (%)
   Resolution:	0.01

   coprostanol

   Concentration of the sterol coprostanol normalized to dry weight. An empty cell in the spreadsheet indicates that coprostanol was not calculated for that sample. BDL indicates concentration below detection limit. (Source: standard reporting value in organic chemistry)

   Range of values
   Minimum:	0.04
   Maximum:	0.97
   Units:	microgram per gram dry weight
   Resolution:	0.01

   epicoprostanol

   Concentration of the sterol epicoprostanol normalized to dry weight. An empty cell in the spreadsheet indicates that epicoprostanol was not calculated for that sample. BDL indicates concentration below detection limit. (Source: standard reporting value in organic chemistry)

   Range of values
   Minimum:	null
   Maximum:	null
   Units:	microgram per gram dry weight
   Resolution:	0.01

   desmosterol

   Concentration of the sterol desmosterol normalized to dry weight. An empty cell in the spreadsheet indicates that desmosterol was not calculated for that sample. BDL indicates concentration below detection limit. (Source: standard reporting value in organic chemistry)

   Range of values
   Minimum:	0.09
   Maximum:	0.25
   Units:	microgram per gram dry weight
   Resolution:	0.01

   5-B coprostanone

   Concentration of the sterol 5-B-coprostanone normalized to dry weight. An empty cell in the spreadsheet indicates that 5-B-coprostanone was not calculated for that sample. BDL indicates concentration below detection limit. (Source: standard reporting value in organic chemistry)

   Range of values
   Minimum:	null
   Maximum:	null
   Units:	microgram per gram dry weight
   Resolution:	0.01

   cholesterol

   Concentration of the sterol cholesterol normalized to dry weight. An empty cell in the spreadsheet indicates that cholesterol was not calculated for that sample. (Source: standard reporting value in organic chemistry)

   Range of values
   Minimum:	2.05
   Maximum:	15.30
   Units:	microgram per gram dry weight
   Resolution:	0.01

   cholestane

   Concentration of the sterol cholestane normalized to dry weight. An empty cell in the spreadsheet indicates that cholestane was not calculated for that sample. (Source: standard reporting value in organic chemistry)

   Range of values
   Minimum:	0.20
   Maximum:	4.36
   Units:	microgram per gram dry weight
   Resolution:	0.01

   lanosterol

   Concentration of the sterol lanosterol normalized to dry weight. An empty cell in the spreadsheet indicates that lanosterol was not calculated for that sample. BDL indicates concentration below detection limit. (Source: standard reporting value in organic chemistry)

   Range of values
   Minimum:	null
   Maximum:	null
   Units:	microgram per gram dry weight
   Resolution:	0.01

   cholestanol

   Concentration of the sterol cholestanol normalized to dry weight. An empty cell in the spreadsheet indicates that cholestanol was not calculated for that sample. BDL indicates concentration below detection limit. (Source: standard reporting value in organic chemistry)

   Range of values
   Minimum:	null
   Maximum:	null
   Units:	microgram per gram dry weight
   Resolution:	0.01

   ergosterol

   Concentration of the sterol ergosterol normalized to dry weight. An empty cell in the spreadsheet indicates that ergosterol was not calculated for that sample. BDL indicates concentration below detection limit. (Source: standard reporting value in organic chemistry)

   Range of values
   Minimum:	0.12
   Maximum:	6.72
   Units:	microgram per gram dry weight
   Resolution:	0.01

   4-methylcholest-diene

   Concentration of the sterol 4-methylcholest-diene normalized to dry weight. An empty cell in the spreadsheet indicates that 4-methylcholest-diene was not calculated for that sample. BDL indicates concentration below detection limit. (Source: standard reporting value in organic chemistry)

   Range of values
   Minimum:	null
   Maximum:	null
   Units:	microgram per gram dry weight
   Resolution:	0.01

   campesterol

   Concentration of the sterol campesterol normalized to dry weight. An empty cell in the spreadsheet indicates that campesterol was not calculated for that sample. BDL indicates concentration below detection limit. (Source: standard reporting value in organic chemistry)

   Range of values
   Minimum:	2.70
   Maximum:	2.70
   Units:	microgram per gram dry weight
   Resolution:	0.01

   stigmasterol

   Concentration of the sterol stigmasterol normalized to dry weight. An empty cell in the spreadsheet indicates that stigmasterol was not calculated for that sample. BDL indicates concentration below detection limit. (Source: standard reporting value in organic chemistry)

   Range of values
   Minimum:	0.06
   Maximum:	0.53
   Units:	microgram per gram dry weight
   Resolution:	0.01

   B-sitosterol

   Concentration of the sterol B-sitosterol normalized to dry weight. An empty cell in the spreadsheet indicates that B-sitosterol was not calculated for that sample. (Source: standard reporting value in organic chemistry)

   Range of values
   Minimum:	0.22
   Maximum:	4.50
   Units:	microgram per gram dry weight
   Resolution:	0.01

   stigmastanol

   Concentration of the sterol stigmastanol normalized to dry weight. An empty cell in the spreadsheet indicates that stigmastanol was not calculated for that sample. BDL indicates concentration below detection limit. (Source: standard reporting value in organic chemistry)

   Range of values
   Minimum:	0.47
   Maximum:	1.46
   Units:	microgram per gram dry weight
   Resolution:	0.01

   archaeol

   Concentration of the sterol archaeol normalized to dry weight. An empty cell in the spreadsheet indicates that archaeol was not calculated for that sample. (Source: standard reporting value in organic chemistry)

   Range of values
   Minimum:	0.11
   Maximum:	2.13
   Units:	microgram per gram dry weight
   Resolution:	0.01

   sn-2-hydroxyarchaeol

   Concentration of the sterol sn-2-hydroxyarchaeol normalized to dry weight. An empty cell in the spreadsheet indicates that sn-2-hydroxyarchaeol was not calculated for that sample. BDL indicates concentration below detection limit. (Source: standard reporting value in organic chemistry)

   Range of values
   Minimum:	0.01
   Maximum:	0.32
   Units:	microgram per gram dry weight
   Resolution:	0.01

   crocetane

   Concentration of the alkane crocetane normalized to dry weight. An empty cell in the spreadsheet indicates that crocetane was not calculated for that sample. (Source: standard reporting value in organic chemistry)

   Range of values
   Minimum:	0.001
   Maximum:	0.200
   Units:	microgram per gram dry weight
   Resolution:	0.001

   PMI

   concentration of the alkane pentamethylicosane (PMI) normalized to dry weight. An empty cell in the spreadsheet indicates that PMI was not calculated for that sample. BDL indicates concentration below detection limit. (Source: standard reporting value in organic chemistry)

   Range of values
   Minimum:	0.019
   Maximum:	0.120
   Units:	microgram per gram dry weight
   Resolution:	0.001

   C14:0

   Concentration of the fatty acid C14:0 normalized to dry weight. An empty cell in the spreadsheet indicates that C14:0 was not calculated for that sample. BDL indicates concentration below detection limit. (Source: standard reporting value in organic chemistry)

   Range of values
   Minimum:	0.05
   Maximum:	0.90
   Units:	microgram per gram dry weight
   Resolution:	0.01

   C14:1

   Concentration of the fatty acid C14:1 normalized to dry weight. An empty cell in the spreadsheet indicates that C14:1 was not calculated for that sample. BDL indicates concentration below detection limit. (Source: standard reporting value in organic chemistry)

   Range of values
   Minimum:	0.01
   Maximum:	0.20
   Units:	microgram per gram dry weight
   Resolution:	0.01

   anteiso-C15:0

   Concentration of the fatty acid anteiso-C15:0 normalized to dry weight. An empty cell in the spreadsheet indicates that anteiso-C15:0 was not calculated for that sample. (Source: standard reporting value in organic chemistry)

   Range of values
   Minimum:	0.01
   Maximum:	0.47
   Units:	microgram per gram dry weight
   Resolution:	0.01

   iso-C15:0

   Concentration of the fatty acid iso-C15:0 normalized to dry weight. An empty cell in the spreadsheet indicates that iso-C15:0 was not calculated for that sample. (Source: standard reporting value in organic chemistry)

   Range of values
   Minimum:	0.01
   Maximum:	1.33
   Units:	microgram per gram dry weight
   Resolution:	0.01

   C15:0

   Concentration of the fatty acid C15:0 normalized to dry weight. An empty cell in the spreadsheet indicates that C15:0 was not calculated for that sample. (Source: standard reporting value in organic chemistry)

   Range of values
   Minimum:	0.01
   Maximum:	0.27
   Units:	microgram per gram dry weight
   Resolution:	0.01

   C16:1 omega 5

   Concentration of the fatty acid C16:1 omega 5 normalized to dry weight. An empty cell in the spreadsheet indicates that C16:1 omega 5 was not calculated for that sample. BDL indicates concentration below detection limit. (Source: standard reporting value in organic chemistry)

   Range of values
   Minimum:	0.03
   Maximum:	11.47
   Units:	microgram per gram dry weight
   Resolution:	0.01

   C16:1

   Concentration of the fatty acid C16:1 normalized to dry weight. An empty cell in the spreadsheet indicates that C16:1 was not calculated for that sample. BDL indicates concentration below detection limit. (Source: standard reporting value in organic chemistry)

   Range of values
   Minimum:	0.01
   Maximum:	1.30
   Units:	microgram per gram dry weight
   Resolution:	0.01

   C16:0

   Concentration of the fatty acid C16:0 normalized to dry weight. An empty cell in the spreadsheet indicates that C16:0 was not calculated for that sample. BDL indicates concentration below detection limit. (Source: standard reporting value in organic chemistry)

   Range of values
   Minimum:	0.08
   Maximum:	5.16
   Units:	microgram per gram dry weight
   Resolution:	0.01

   anteiso-C17:0

   Concentration of the fatty acid anteiso-C17:0 normalized to dry weight. An empty cell in the spreadsheet indicates that anteiso-C17:0 was not calculated for that sample. BDL indicates concentration below detection limit. (Source: standard reporting value in organic chemistry)

   Range of values
   Minimum:	0.01
   Maximum:	0.37
   Units:	microgram per gram dry weight
   Resolution:	0.01

   C17:1

   Concentration of the fatty acid C17:1 normalized to dry weight. An empty cell in the spreadsheet indicates that C17:1 was not calculated for that sample. BDL indicates concentration below detection limit. (Source: standard reporting value in organic chemistry)

   Range of values
   Minimum:	0.01
   Maximum:	0.18
   Units:	microgram per gram dry weight
   Resolution:	0.01

   C17:0

   Concentration of the fatty acid C17:0 normalized to dry weight. An empty cell in the spreadsheet indicates that C17:0 was not calculated for that sample. (Source: standard reporting value in organic chemistry)

   Range of values
   Minimum:	0.01
   Maximum:	0.28
   Units:	microgram per gram dry weight
   Resolution:	0.01

   C18:1*

   Concentration of the fatty acid octadec-9-enoate/oleate (C18:1*) normalized to dry weight. An empty cell in the spreadsheet indicates that C18:1* was not calculated for that sample. BDL indicates concentration below detection limit. (Source: standard reporting value in organic chemistry)

   Range of values
   Minimum:	0.06
   Maximum:	0.86
   Units:	microgram per gram dry weight
   Resolution:	0.01

   C18:1

   Concentration of the fatty acid octadec-11-enoate/oleate (C18:1) normalized to dry weight. An empty cell in the spreadsheet indicates that C18:1 was not calculated for that sample. BDL indicates concentration below detection limit. BDL indicates concentration below detection limit. (Source: standard reporting value in organic chemistry)

   Range of values
   Minimum:	0.01
   Maximum:	0.97
   Units:	microgram per gram dry weight
   Resolution:	0.01

   C18:0

   Concentration of the fatty acid C18:0 normalized to dry weight. An empty cell in the spreadsheet indicates that C18:0 was not calculated for that sample. BDL indicates concentration below detection limit. (Source: standard reporting value in organic chemistry)

   Range of values
   Minimum:	0.01
   Maximum:	7.58
   Units:	microgram per gram dry weight
   Resolution:	0.01

   cholesterol delta-C-13

   delta-C-13 is a measure of the ratio of stable isotopes Carbon-13:Carbon-12, reported in parts per thousand (per mil). An empty cell in the spreadsheet indicates that cholesterol 13C:12C was not calculated for that sample. (Source: standard reporting value in isotope chemistry)

   Range of values
   Minimum:	-66.75
   Maximum:	-37.41
   Units:	parts per thousand (per mil)
   Resolution:	0.01

   cholestanol delta-C-13

   delta-C-13 is a measure of the ratio of stable isotopes Carbon-13:Carbon-12, reported in parts per thousand (per mil). An empty cell in the spreadsheet indicates that cholestanol 13C:12C was not calculated for that sample. (Source: standard reporting value in isotope chemistry)

   Range of values
   Minimum:	-77.97
   Maximum:	-36.61
   Units:	parts per thousand (per mil)
   Resolution:	0.01

   B-sitosterol delta-C-13

   delta-C-13 is a measure of the ratio of stable isotopes Carbon-13:Carbon-12, reported in parts per thousand (per mil). An empty cell in the spreadsheet indicates that B-sitosterol delta-C-13 was not calculated for that sample. (Source: standard reporting value in isotope chemistry)

   Range of values
   Minimum:	-74.24
   Maximum:	-35.26
   Units:	parts per thousand (per mil)
   Resolution:	0.01

   archaeol delta-C-13

   delta-C-13 is a measure of the ratio of stable isotopes Carbon-13:Carbon-12, reported in parts per thousand (per mil). An empty cell in the spreadsheet indicates that archaeol 13C:12C was not calculated for that sample. (Source: standard reporting value in isotope chemistry)

   Range of values
   Minimum:	-91.64
   Maximum:	-58.36
   Units:	parts per thousand (per mil)
   Resolution:	0.01

   sn-2-hydroxyarchaeol delta-C-13

   delta-C-13 is a measure of the ratio of stable isotopes Carbon-13:Carbon-12, reported in parts per thousand (per mil). An empty cell in the spreadsheet indicates that sn-2-hydroxyarchaeol 13C:12C was not calculated for that sample. (Source: standard reporting value in isotope chemistry)

   Range of values
   Minimum:	-129.18
   Maximum:	-80.33
   Units:	parts per thousand (per mil)
   Resolution:	0.01

   crocetane delta-C-13

   delta-C-13 is a measure of the ratio of stable isotopes Carbon-13:Carbon-12, reported in parts per thousand (per mil). An empty cell in the spreadsheet indicates that crocetane 13C:12C was not calculated for that sample. (Source: standard reporting value in isotope chemistry)

   Range of values
   Minimum:	-70.94
   Maximum:	-26.39
   Units:	parts per thousand (per mil)
   Resolution:	0.01

   PMI delta-C-13

   delta-C-13 is a measure of the ratio of stable isotopes Carbon-13:Carbon-12, reported in parts per thousand (per mil). An empty cell in the spreadsheet indicates that PMI 13C:12C was not calculated for that sample. (Source: standard reporting value in isotope chemistry)

   Range of values
   Minimum:	-92.83
   Maximum:	-29.87
   Units:	parts per thousand (per mil)
   Resolution:	0.01

   PMI (II) delta-C-13

   delta-C-13 is a measure of the ratio of stable isotopes Carbon-13:Carbon-12, reported in parts per thousand (per mil). An empty cell in the spreadsheet indicates that PMI (II) 13C:12C was not calculated for that sample. (Source: standard reporting value in isotope chemistry)

   Range of values
   Minimum:	-131.36
   Maximum:	-120.62
   Units:	parts per thousand (per mil)
   Resolution:	0.01

   C14:0 delta-C-13

   delta-C-13 is a measure of the ratio of stable isotopes Carbon-13:Carbon-12, reported in parts per thousand (per mil). An empty cell in the spreadsheet indicates that C14:0 13C:12C was not calculated for that sample. (Source: standard reporting value in isotope chemistry)

   Range of values
   Minimum:	-53.02
   Maximum:	-27.63
   Units:	parts per thousand (per mil)
   Resolution:	0.01

   C14:1 delta-C-13

   delta-C-13 is a measure of the ratio of stable isotopes Carbon-13:Carbon-12, reported in parts per thousand (per mil). An empty cell in the spreadsheet indicates that C14:1 13C:12C was not calculated for that sample. (Source: standard reporting value in isotope chemistry)

   Range of values
   Minimum:	-49.76
   Maximum:	-26.27
   Units:	parts per thousand (per mil)
   Resolution:	0.01

   anteiso C15 delta-C-13

   delta-C-13 is a measure of the ratio of stable isotopes Carbon-13:Carbon-12, reported in parts per thousand (per mil). An empty cell in the spreadsheet indicates that C14:1 13C:12C was not calculated for that sample. (Source: standard reporting value in isotope chemistry)

   Range of values
   Minimum:	-107.56
   Maximum:	-29.66
   Units:	parts per thousand (per mil)
   Resolution:	0.01

   iso C15 delta-C-13

   delta-C-13 is a measure of the ratio of stable isotopes Carbon-13:Carbon-12, reported in parts per thousand (per mil). An empty cell in the spreadsheet indicates that iso-C15:0 13C:12C was not calculated for that sample. (Source: standard reporting value in isotope chemistry)

   Range of values
   Minimum:	-105.87
   Maximum:	-38.89
   Units:	parts per thousand (per mil)
   Resolution:	0.01

   C15:0 delta-C-13

   delta-C-13 is a measure of the ratio of stable isotopes Carbon-13:Carbon-12, reported in parts per thousand (per mil). An empty cell in the spreadsheet indicates that C15:0 13C:12C was not calculated for that sample. (Source: standard reporting value in isotope chemistry)

   Range of values
   Minimum:	-81.22
   Maximum:	-26.11
   Units:	parts per thousand (per mil)
   Resolution:	0.01

   C16:0 compounda delta-C-13

   delta-C-13 is a measure of the ratio of stable isotopes Carbon-13:Carbon-12, reported in parts per thousand (per mil). An empty cell in the spreadsheet indicates that unidentified branched and/or unsaturated C16:0 compound a 13C 13C:12C was not calculated for that sample. (Source: standard reporting value in isotope chemistry)

   Range of values
   Minimum:	-126.00
   Maximum:	-25.06
   Units:	parts per thousand (per mil)
   Resolution:	0.01

   C16:0 compound b delta-C-13

   delta-C-13 is a measure of the ratio of stable isotopes Carbon-13:Carbon-12, reported in parts per thousand (per mil). An empty cell in the spreadsheet indicates that unidentified branched and/or unsaturated C16:0 compound b 13C:12C was not calculated for that sample. (Source: standard reporting value in isotope chemistry)

   Range of values
   Minimum:	-123.65
   Maximum:	-28.97
   Units:	parts per thousand (per mil)
   Resolution:	0.01

   C16:0 compound c delta-C-13

   delta-C-13 is a measure of the ratio of stable isotopes Carbon-13:Carbon-12, reported in parts per thousand (per mil). An empty cell in the spreadsheet indicates that unidentified branched and/or unsaturated C16:0 compound c 13C:12C was not calculated for that sample. (Source: standard reporting value in isotope chemistry)

   Range of values
   Minimum:	-126.06
   Maximum:	-59.60
   Units:	parts per thousand (per mil)
   Resolution:	0.01

   C16:0 compound d delta-C-13

   delta-C-13 is a measure of the ratio of stable isotopes Carbon-13:Carbon-12, reported in parts per thousand (per mil). An empty cell in the spreadsheet indicates that unidentified branched and/or unsaturated C16:0 compound d 13C:12C was not calculated for that sample. (Source: standard reporting value in isotope chemistry)

   Range of values
   Minimum:	-126.97
   Maximum:	-126.97
   Units:	parts per thousand (per mil)
   Resolution:	0.01

   C16:0 compound e delta-C-13

   delta-C-13 is a measure of the ratio of stable isotopes Carbon-13:Carbon-12, reported in parts per thousand (per mil). An empty cell in the spreadsheet indicates that unidentified branched and/or unsaturated C16:0 compound e 13C:12C was not calculated for that sample. (Source: standard reporting value in isotope chemistry)

   Range of values
   Minimum:	-110.49
   Maximum:	-110.49
   Units:	parts per thousand (per mil)
   Resolution:	0.01

   C16:1 omega 5 delta-C-13

   delta-C-13 is a measure of the ratio of stable isotopes Carbon-13:Carbon-12, reported in parts per thousand (per mil). An empty cell in the spreadsheet indicates that C16:1 omega 5 13C:12C was not calculated for that sample. (Source: standard reporting value in isotope chemistry)

   Range of values
   Minimum:	-104.92
   Maximum:	-36.78
   Units:	parts per thousand (per mil)
   Resolution:	0.01

   C16:1 delta-C-13

   delta-C-13 is a measure of the ratio of stable isotopes Carbon-13:Carbon-12, reported in parts per thousand (per mil). An empty cell in the spreadsheet indicates that C16:1 13C:12C was not calculated for that sample. (Source: standard reporting value in isotope chemistry)

   Range of values
   Minimum:	-95.44
   Maximum:	-37.33
   Units:	parts per thousand (per mil)
   Resolution:	0.01

   C16:0 delta-C-13

   delta-C-13 is a measure of the ratio of stable isotopes Carbon-13:Carbon-12, reported in parts per thousand (per mil). An empty cell in the spreadsheet indicates that C16:0 13C:12C was not calculated for that sample. (Source: standard reporting value in isotope chemistry)

   Range of values
   Minimum:	-48.54
   Maximum:	-25.54
   Units:	parts per thousand (per mil)
   Resolution:	0.01

   C18:0 delta-C-13

   delta-C-13 is a measure of the ratio of stable isotopes Carbon-13:Carbon-12, reported in parts per thousand (per mil). An empty cell in the spreadsheet indicates that C18:0 13C:12C was not calculated for that sample. (Source: standard reporting value in isotope chemistry)

   Range of values
   Minimum:	-52.08
   Maximum:	-28.51
   Units:	parts per thousand (per mil)
   Resolution:	0.01

   Entity_and_Attribute_Overview: The first line of the csv file is a header line.
   Entity_and_Attribute_Detail_Citation: U.S. Geological Survey
   

Who produced the data set?

1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
   • Nancy G. Prouty
   • Pamela Campbell Swarzenski
2. Who also contributed to the data set?

   We wish to thank C. Van Dover (Duke University) for donating samples collected on board the R/V Atlantis, as well as A. Lam, B. Tipple, and M. Baker (USGS) and J. Herszage (UC Davis) for their analytical assistance.

3. To whom should users address questions about the data?
   U.S. Geological Survey, Pacific Coastal and Marine Science Center

   Attn: PCMSC Science Data Coordinator

   2885 Mission Street

   Santa Cruz, CA
   

   831-427-4747 (voice)

   pcmsc_data@usgs.gov

Why was the data set created?

The purpose of making these measurements was to identify what microbial communities are driving anaerobic oxidation of methane at the Norfolk and Baltimore seep fields. The identification and distribution of these microbial communities represents a key component to understanding the global methane cycle including both short- and long-term methane storage.

How was the data set created?

1. From what previous works were the data drawn?
2. How were the data generated, processed, and modified?

   Date: 15-Dec-2018 (process 1 of 2)

   Carbonate and sediment samples from pushcores were collected from ROV operations. Samples were stored frozen. The biomarker composition of the authigenic carbonate and sediment samples was determined by gas chromatography-mass spectrometry (GC-MS) at the USGS Organic Geochemistry laboratory in Santa Cruz, California. The samples were subsequently extracted using the Dionex ASE with a mixture of dichloromethane and methanol (9:1; v:v). Prior to extraction, internal standards were added (5-α androstane, 5α- 3β androstanol, ortho-terphenyl, and nonadecanoic acid). The total lipid extracts were passed though funnels containing sodium sulfate to remove excess water followed by saponification with 6% KOH (w/v) in methanol at 70°C for 3 hours. After cooling, the neutral fractions were extracted 3–5 times with hexane until the extracts turned colorless. To obtain fatty acids, the residuals were treated with 10% HCl to pH ~ 2 and extracted 3 times with hexane. The neutral fractions were separated by column chromatography into compound classes: (1) hydrocarbons (n-hexane), (2) aromatics (toluene:hexane) and (3) alcohols (ethyl acetate:hexane, methanol). The alcohols were converted to trimethylsiloxyl derivatives by bis (trimethylsilyl) trifluoroacetamide (BSTFA with 1% TMCS) heated at 60 °C for 1 h prior to GC–MS analysis. Fatty acids were converted to methyl esters by drying and subjecting the fraction to 14% BF3-methanol in a screw cap vial at 60 °C for 2 h. Compound specific isotope analysis (CSIA) on select biomarkers in the carbonate and sediment samples was determined by GC-combustion isotope ratio mass spectrometry (GC-C-IRMS). Carbon isotopic compositions of sterols and n-alkanes were measured at the Stable Isotope Facility at University of California, Davis using a Thermo GC-C-IRMS system composed of a Trace GC Ultra gas chromatograph coupled to a Delta V Advantage IRMS through a GC-C-III interface with compound identification support for the CSIA laboratory provided by a Varian CP3800 gas chromatograph coupled to a Saturn 2200 ion trap MS/MS. CSIA composition of the fatty acids was performed at the Marine Organic and Isotope Geochemistry lab at the University of Miami by GC-C-IRMS. Samples were dissolved in hexane and injected manually in splitless mode into a Thermo GC-C-IRMS system (Trace GC 1310 coupled to an Isolink II combustion interface, Conflo IV interface, and MAT 253 isotope ratio mass spectrometer). Results from the all lab analyses were combined into a comma-delimited text document (USAM_MDAC_Biomarker.csv) for this data release.

   Date: 19-Oct-2020 (process 2 of 2)

   Edited metadata to add keywords section with USGS persistent identifier as theme keyword. No data were changed. Person who carried out this activity:
   

   U.S. Geological Survey

   Attn: VeeAnn A. Cross

   Marine Geologist

   384 Woods Hole Road

   Woods Hole, MA
   

   508-548-8700 x2251 (voice)

   508-457-2310 (FAX)

   vatnipp@usgs.gov

3. What similar or related data should the user be aware of?
   Prouty, Nancy G., Sahy, Diana, Ruppel, Carolyn D., Roark, E. Brendan, Condon, Dan, Brook, Sandra, Ross, Steve W., and Demopoulos, Amanda W.J., 2016, Earth and Planetary Science Letters.

   Online Links:

   • https://doi.org/10.1016/j.epsl.2016.05.023

   Other_Citation_Details:

   Prouty, N.G., Sahy, D., Ruppel, C.D., Roark, E.B., Condon, D., Brooke S., Ross, S.W., and Demopoulos, A.W.J., 2016, Insights into methane dynamics from analysis of authigenic carbonates and chemosynthetic mussels at newly-discovered Atlantic Margin seeps: Earth and Planetary Science Letters, v. 449, p., 332-344.

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

1. How well have the observations been checked?
   All geochemistry data were calibrated against known standards.
2. How accurate are the geographic locations?
   A formal accuracy assessment of the horizontal positional information in the data set has not been conducted.
3. How accurate are the heights or depths?
   A formal accuracy assessment of the vertical positional information in the data set has not been conducted.
4. Where are the gaps in the data? What is missing?
   Dataset is considered complete for the information presented, as described in the abstract. Gaps in sequential sample ID numbers are common, as not all stations had samples collected or analyzed. An empty cell in the spreadsheet indicates that lanosterol was not calculated for that sample. BDL indicates concentration below detection limit. Users are advised to read the rest of the metadata record carefully for additional details.
5. How consistent are the relationships among the observations, including topology?
   No formal logical accuracy tests were conducted.

How can someone get a copy of the data set?

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

Access_Constraints: None
Use_Constraints:

USGS-authored or produced data and information are in the public domain from the U.S. Government and are freely redistributable with proper metadata and source attribution. Please recognize and acknowledge the U.S. Geological Survey and Atmospheric Administration (NOAA), and Bureau of Ocean Energy Management (BOEM) as the originator(s) of the dataset and in products derived from these data.

1. Who distributes the data set? (Distributor 1 of 1)
   
   U.S. Geological Survey - ScienceBase

   Denver Federal Center, Building 810, Mail Stop 302

   Denver, CO
   

   1-888-275-8747 (voice)

   sciencebase@usgs.gov
2. What's the catalog number I need to order this data set? These data are available in .csv format contained in a single file.
3. What legal disclaimers am I supposed to read?

   Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data on any other system or for general or scientific purposes, nor shall the act of distribution constitute any such warranty.

4. How can I download or order the data?
   • Availability in digital form:

     Data format:	File contains table in .csv format in format comma-delimited text (version Excel 14.3.9) Size: 0.01
     Network links:	https://www.sciencebase.gov/catalog/file/get/5c4f3988e4b0708288f78d7a https://doi.org/10.5066/P9JHGO8O

   • Cost to order the data: None.

5. What hardware or software do I need in order to use the data set?

   These data can be viewed with Microsoft Excel or any text reader

Who wrote the metadata?

Dates:

Last modified: 19-Oct-2020

Metadata author:

U.S. Geological Survey, Pacific Coastal and Marine Science Center

Attn: PCMSC Science Data Coordinator

2885 Mission Street

Santa Cruz, CA

831-427-4747 (voice)

pcmsc_data@usgs.gov

Metadata standard:

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