Not logged in
PANGAEA.
Data Publisher for Earth & Environmental Science

Joseph, Craig (2012): (Table 2) Carbonate chemistry and isotopes from northern Cascadia margin samples. PANGAEA, https://doi.org/10.1594/PANGAEA.812218, Supplement to: Joseph, Craig; Torres, Marta E; Martin, Ruth A; Haley, Brian A; Pohlman, John W; Riedel, Michael; Rose, Kelly (2012): Using the 87Sr/86Sr of modern and paleoseep carbonates from northern Cascadia to link modern fluid flow to the past. Chemical Geology, 334, 122-130, https://doi.org/10.1016/j.chemgeo.2012.10.020

Always quote citation above when using data! You can download the citation in several formats below.

RIS CitationBibTeX CitationShow MapGoogle Earth

Abstract:
Most authigenic carbonates previously recovered from the Cascadia slope have 87Sr/86Sr signatures that reflect shallow precipitation in equilibrium with coeval seawater. There is also evidence for carbonate formation supported by fluids that have been modified by reactions with the incoming Juan de Fuca plate (87Sr/86Sr = 0.7071; Teichert et al., 2005, doi:10.1016/j.epsl.2005.08.002) or with terrigenous turbidites (87Sr/86Sr = 0.70975 to 0.71279; Sample et al., 1993, doi:10.1130/0091-7613(1993)021<0507:CCICFF>2.3.CO;2). We report on the strontium isotopic composition of carbonates and fluids from IODP Site U1329 and nearby Barkley Canyon (offshore Vancouver Island), which have strontium isotope ratios as low as 0.70539. Whereas the strontium and oxygen isotopic compositions of carbonates from paleoseeps in the uplifted Coast Range forearc indicate formation in ambient bottom seawater, several samples from the Pysht/Sooke Fm. show a 87Sr-depleted signal (87Sr/86Sr = 0.70494 and 0.70511) similar to that of the anomalous Site U1329 and Barkley Canyon carbonates.
Our data, when analyzed in the context of published elemental and isotopic composition of these carbonates (Joseph et al., 2012, doi:10.1016/j.palaeo.2013.01.012 ), point to two formation mechanisms: 1) shallow precipitation driven by the anaerobic oxidation of methane (AOM) with d13C values as low as -50 per mil and contemporaneous 87Sr/86Sr seawater ratios, and 2) carbonate precipitation driven by fluids that have circulated through the oceanic crust, which are depleted in 87Sr. Carbonates formed from the second mechanism precipitate both at depth and at sites of deep-sourced fluid seepage on the seafloor. The 87Sr-depleted carbonates and pore fluids found at Barkley Canyon represent migration of a deep, exotic fluid similar to that found in high permeability conglomerate layers at 188 mbsf of Site U1329, and which may have fed paleoseeps in the Pysht/Sooke Fm. These exotic fluids likely reflect interaction with the 52-57 Ma igneous Crescent Terrane, which supplies fluids with high calcium, manganese and strontium enriched in the non-radiogenic nucleide. Tectonic compression and dehydration reactions then force these fluids updip, where they pick up the thermogenic hydrocarbons and 13C-enriched dissolved inorganic carbon that are manifested in fluids and carbonates sampled at Barkley Canyon and at Site U1329. The Crescent Terrane may have sourced cold seeps in this margin since at least the late Oligocene.
Related to:
Joseph, Craig; Campbell, Kathleen A; Torres, Marta E; Martin, Ruth A; Pohlman, John W; Riedel, Michael; Rose, Kelly (2013): Methane-derived authigenic carbonates from modern and paleoseeps on the Cascadia margin: Mechanisms of formation and diagenetic signals. Palaeogeography, Palaeoclimatology, Palaeoecology, 390, 52-67, https://doi.org/10.1016/j.palaeo.2013.01.012
Coverage:
Median Latitude: 48.352997 * Median Longitude: -126.194573 * South-bound Latitude: 48.175600 * West-bound Longitude: -126.678667 * North-bound Latitude: 48.789583 * East-bound Longitude: -126.065100
Minimum DEPTH, sediment/rock: 0.00 m * Maximum DEPTH, sediment/rock: 187.80 m
Event(s):
311-U1329C  * Latitude: 48.789583 * Longitude: -126.678667 * Elevation: -946.4 m * Recovery: 186.16 m * Campaign: Exp311 (Cascadia Margin Gas Hydrates) * Basis: Joides Resolution * Method/Device: Drilling/drill rig (DRILL) * Comment: 23 cores; 187.5 m cored; 99.3 % recovered; 2 m drilled; 189.5 m penetrated
DR59  * Latitude: 48.178200 * Longitude: -126.065200 * Elevation: -850.0 m * Method/Device: Dredge (DRG)
DR271  * Latitude: 48.175600 * Longitude: -126.097300 * Elevation: -850.0 m * Method/Device: Dredge (DRG)
Parameter(s):
#NameShort NameUnitPrincipal InvestigatorMethod/DeviceComment
Event labelEvent
Latitude of eventLatitude
Longitude of eventLongitude
Elevation of eventElevationm
Sample code/labelSample labelJoseph, CraigDSDP/ODP/IODP sample designation
Sample code/label 2Sample label 2Joseph, Craig
DEPTH, sediment/rockDepth sedmGeocode – mbsf
Magnesium/Calcium ratioMg/Cammol/molJoseph, Craig
Manganese/Calcium ratioMn/Cammol/molJoseph, Craig
10 Strontium/Calcium ratioSr/Cammol/molJoseph, Craig
11 Barium/Calcium ratioBa/Caµmol/molJoseph, Craig
12 δ13Cδ13C‰ PDBJoseph, Craig
13 δ18Oδ18OJoseph, Craig
14 Ageprofile Datum DescriptionAgeprof dat desJoseph, Craig
Size:
216 data points

Data

Download dataset as tab-delimited text — use the following character encoding:


Event

Latitude

Longitude

Elevation [m]

Sample label

Sample label 2

Depth sed [m]

Mg/Ca [mmol/mol]

Mn/Ca [mmol/mol]
10 
Sr/Ca [mmol/mol]
11 
Ba/Ca [µmol/mol]
12 
δ13C [‰ PDB]
13 
δ18O []
14 
Ageprof dat des
311-U1329C 48.790-126.679-946311-U1329C-4H-3,92-94U1329-131.00804.35.901.10900-21.37.10.70917
311-U1329C48.790-126.679-946311-U1329C-4H-3,140-142U1329-231.50790.23.201.20900-22.97.30.70917
311-U1329C48.790-126.679-946311-U1329C-8H-2,63-65U1329-359.70208.31.001.80600-29.35.10.70916
311-U1329C48.790-126.679-946311-U1329C-8H-2,71-73U1329-459.80173.40.602.10800-30.24.80.70921
311-U1329C48.790-126.679-946311-U1329C-17H-1U1329-5135.60172.91.201.701200-12.04.90.70897
311-U1329C48.790-126.679-946311-U1329C-18X-2,8-10U1329-6141.80661.44.601.5019005.26.50.70862
311-U1329C48.790-126.679-946311-U1329C-18X-5U1329-7146.60139.70.902.101300-20.34.00.70898
311-U1329C48.790-126.679-946311-U1329C-20X-3,35-37U1329-8163.00169.90.501.90800-20.94.30.70892
311-U1329C48.790-126.679-946311-U1329C-21X-3,63-65U1329-9172.90110.45.002.101900-13.03.60.70819
311-U1329C48.790-126.679-946311-U1329C-22X-CC,44-46U1329-10187.5071.217.900.702005.4-10.80.70542
311-U1329C48.790-126.679-946311-U1329C-22X-CC,70-72U1329-11187.8048.416.400.702005.8-10.10.70539
PGC-C23 48.311-126.067-850PGC C23 AB 110-120cmBC11.16229.70.701.59160-24.94.70.70918
PGC-C2348.311-126.067-850PGC C23 AB 150 cmBC20.76221.10.471.56230-19.64.90.70913
PGC-C2348.311-126.067-850PGC C23 AB 170 cmBC30.56207.50.591.80400-24.04.30.70918
PGC-C2348.311-126.067-850PGC C23 AB 200 cmBC40.26233.80.801.73160-21.34.80.70915
DR59 48.178-126.065-850DR59 PsC 46BC50.08107.78.502.40150-4.6-8.60.70652
DR5948.178-126.065-850DR59 PsC 44BC60.2254.00.7512.14220-20.53.90.70916
DR271 48.176-126.097-850DR271 - R1BC70.0050.00.4510.6650-47.64.10.70917
DR27148.176-126.097-850DR271 - R2BC80.009.20.0910.4140-45.44.10.70915
DR27148.176-126.097-850DR271 - R3BC90.008.40.059.6130-43.44.10.70916
DR27148.176-126.097-850DR271 - PC41 4 cmBC1O0.04255.60.681.58100-50.953.00.70865
DR273 48.311-126.065-850DR273 - PC41 10 cmBC110.105.80.0312.84250-22.23.90.70916
DR27348.311-126.065-850DR273 - PC41 5 cmBC120.05317.713.351.90490-4.9-9.30.70574
DR27348.311-126.065-850DR273 - PC66 18 cmBC130.18187.80.511.65100-11.44.90.70897