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Tarney, J; Saunders, Andrew D; Bougault, Henri; Joron, Jean Louis; Treuil, M; Cann, Joe R (1979): Major and trace element content of the 17 lithostratigraphic units recovered during DSDP Leg 49 (Table 1) [dataset]. PANGAEA, https://doi.org/10.1594/PANGAEA.710759, Supplement to: Wood, D A; Tarney, J; Varet, J; Saunders, Andrew D; Bougault, Henri; Joron, Jean Louis; Treuil, M; Cann, Joe R (1979): Geochemistry of basalts drilled in the North Atlantic by IPOD Leg 49: implications for mantel heterogeneity. Earth and Planetary Science Letters, 42(1), 77-97, https://doi.org/10.1016/0012-821X(79)90192-4

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Abstract:
IPOD Leg 49 recovered basalts from 9 holes at 7 sites along 3 transects across the Mid-Atlantic Ridge: 63°N (Reykjanes), 45°N and 36°N (FAMOUS area). This has provided further information on the nature of mantle heterogeneity in the North Atlantic by enabling studies to be made of the variation of basalt composition with depth and with time near critical areas (Iceland and the Azores) where deep mantle plumes are thought to exist. Over 150 samples have been analysed for up to 40 major and trace elements and the results used to place constraints on the petrogenesis of the erupted basalts and hence on the geochemical nature of their source regions.
It is apparent that few of the recovered basalts have the geochemical characteristics of typical "depleted" midocean ridge basalts (MORB). An unusually wide range of basalt compositions may be erupted at a single site: the range of rare earth patterns within the short section cored at Site 413, for instance, encompasses the total variation of REE patterns previously reported from the FAMOUS area. Nevertheless it is possible to account for most of the compositional variation at a single site by partial melting processes (including dynamic melting) and fractional crystallization. Partial melting mechanisms seem to be the dominant processes relating basalt compositions, particularly at 36°N and 45°N, suggesting that long-lived sub-axial magma chambers may not be a consistent feature of the slow-spreading Mid-Atlantic Ridge.
Comparisons of basalts erupted at the same ridge segment for periods of the order of 35 m.y. (now lying along the same mantle flow line) do show some significant inter-site differences in Rb/Sr, Ce/Yb, 87Sr/86Sr, etc., which cannot be accounted for by fractionation mechanisms and which must reflect heterogeneities in the mantle source. However when hygromagmatophile (HYG) trace element levels and ratios are considered, it is the constancy or consistency of these HYG ratios which is the more remarkable, implying that the mantle source feeding a particular ridge segment was uniform with respect to these elements for periods of the order of 35 m.y. and probably since the opening of the Atlantic. Yet these HYG element ratios at 63°N are very different from those at 45°N and 36°N and significantly different from the values at 22°N and in "MORB".
The observed variations are difficult to reconcile with current concepts of mantle plumes and binary mixing models. The mantle is certainly heterogeneous, but there is not simply an "enriched" and a "depleted" source, but rather a range of sources heterogeneous on different scales for different elements - to an extent and volume depending on previous depletion/enrichment events. HYG element ratios offer the best method of defining compositionally different mantle segments since they are little modified by the fractionation processes associated with basalt generation.
Project(s):
Coverage:
Median Latitude: 48.852688 * Median Longitude: -30.515238 * South-bound Latitude: 36.543200 * West-bound Longitude: -33.388300 * North-bound Latitude: 63.938700 * East-bound Longitude: -25.952800
Date/Time Start: 1976-07-23T00:00:00 * Date/Time End: 1976-08-28T00:00:00
Minimum Elevation: -2977.0 m * Maximum Elevation: -832.0 m
Event(s):
49-407 * Latitude: 63.938700 * Longitude: -30.576000 * Date/Time: 1976-07-23T00:00:00 * Elevation: -2472.0 m * Penetration: 458.5 m * Recovery: 171.6 m * Location: North Atlantic/RIDGE * Campaign: Leg49 * Basis: Glomar Challenger * Method/Device: Drilling/drill rig (DRILL) * Comment: 40 cores; 382.5 m cored; 57 m drilled; 44.9 % recovery
49-408 * Latitude: 63.377200 * Longitude: -28.911800 * Date/Time: 1976-07-29T00:00:00 * Elevation: -1624.0 m * Penetration: 361 m * Recovery: 218.4 m * Location: North Atlantic/RIDGE * Campaign: Leg49 * Basis: Glomar Challenger * Method/Device: Drilling/drill rig (DRILL) * Comment: 37 cores; 351.5 m cored; 9.5 m drilled; 62.1 % recovery
49-409 * Latitude: 62.616300 * Longitude: -25.952800 * Date/Time: 1976-08-02T00:00:00 * Elevation: -832.0 m * Penetration: 319 m * Recovery: 86.2 m * Location: North Atlantic/RIDGE * Campaign: Leg49 * Basis: Glomar Challenger * Method/Device: Drilling/drill rig (DRILL) * Comment: 28 cores; 266 m cored; 20 m drilled; 32.4 % recovery
Comment:
Trace elements were analysed by several investigators. Further relevant data see Tarney et al. (1979) data sets: doi:10.1594/PANGAEA.710816
Parameter(s):
#NameShort NameUnitPrincipal InvestigatorMethod/DeviceComment
1Event labelEvent
2Latitude of eventLatitude
3Longitude of eventLongitude
4Elevation of eventElevationm
5Sample code/labelSample labelWood, D ADSDP/ODP/IODP sample designation
6Sample code/label 2Sample label 2Wood, D ADSDP/ODP/IODP sample designation
7Silicon dioxideSiO2%Wood, D AX-ray fluorescence (XRF)
8Titanium dioxideTiO2%Wood, D AX-ray fluorescence (XRF)
9Aluminium oxideAl2O3%Wood, D AX-ray fluorescence (XRF)
10Iron oxide, Fe2O3Fe2O3%Wood, D AX-ray fluorescence (XRF)
11Iron oxide, FeOFeO%Wood, D AX-ray fluorescence (XRF)
12Iron oxide, FeOFeO%Wood, D A
13Manganese oxideMnO%Wood, D AX-ray fluorescence (XRF)
14Magnesium oxideMgO%Wood, D AX-ray fluorescence (XRF)
15Calcium oxideCaO%Wood, D AX-ray fluorescence (XRF)
16Sodium oxideNa2O%Wood, D AX-ray fluorescence (XRF)
17Potassium oxideK2O%Wood, D AX-ray fluorescence (XRF)
18Phosphorus pentoxideP2O5%Wood, D AX-ray fluorescence (XRF)
19Water in rockH2O%Wood, D AX-ray fluorescence (XRF)
20Carbon dioxideCO2%Wood, D AX-ray fluorescence (XRF)
21Magnesium numberMg#Wood, D A
22ScandiumScmg/kgJoron, Jean LouisInstrumental neutron activation analysis (INAA) (Reimann et al., 1998)
23VanadiumVmg/kgBougault, HenriX-ray fluorescence (XRF)
24ChromiumCrmg/kgBougault, HenriX-ray fluorescence (XRF)
25CobaltComg/kgBougault, HenriX-ray fluorescence (XRF)measurement 1
26CobaltComg/kgJoron, Jean LouisX-ray fluorescence (XRF)measurement 2
27NickelNimg/kgBougault, HenriX-ray fluorescence (XRF)
28RubidiumRbmg/kgBougault, HenriX-ray fluorescence (XRF)
29StrontiumSrmg/kgBougault, HenriX-ray fluorescence (XRF)
30YttriumYmg/kgBougault, HenriX-ray fluorescence (XRF)
31ZirconiumZrmg/kgBougault, HenriX-ray fluorescence (XRF)
32NiobiumNbmg/kgBougault, HenriX-ray fluorescence (XRF)
33CaesiumCsmg/kgJoron, Jean LouisX-ray fluorescence (XRF)
34LanthanumLamg/kgJoron, Jean LouisInstrumental neutron activation analysis (INAA) (Reimann et al., 1998)
35CeriumCemg/kgWood, D AInstrumental neutron activation analysis (INAA) (Reimann et al., 1998)
36NeodymiumNdmg/kgWood, D AInstrumental neutron activation analysis (INAA) (Reimann et al., 1998)
37SamariumSmmg/kgWood, D AInstrumental neutron activation analysis (INAA) (Reimann et al., 1998)
38EuropiumEumg/kgWood, D AInstrumental neutron activation analysis (INAA) (Reimann et al., 1998)measurement 1
39EuropiumEumg/kgJoron, Jean LouisInstrumental neutron activation analysis (INAA) (Reimann et al., 1998)measurement 2
40GadoliniumGdmg/kgWood, D AInstrumental neutron activation analysis (INAA) (Reimann et al., 1998)
41TerbiumTbmg/kgWood, D AInstrumental neutron activation analysis (INAA) (Reimann et al., 1998)measurement 1
42TerbiumTbmg/kgJoron, Jean LouisInstrumental neutron activation analysis (INAA) (Reimann et al., 1998)measurement 2
43ThuliumTmmg/kgWood, D AInstrumental neutron activation analysis (INAA) (Reimann et al., 1998)
44YtterbiumYbmg/kgWood, D AInstrumental neutron activation analysis (INAA) (Reimann et al., 1998)
45LutetiumLumg/kgWood, D AInstrumental neutron activation analysis (INAA) (Reimann et al., 1998)
46HafniumHfmg/kgWood, D AInstrumental neutron activation analysis (INAA) (Reimann et al., 1998)measurement 1
47HafniumHfmg/kgJoron, Jean LouisInstrumental neutron activation analysis (INAA) (Reimann et al., 1998)measurement 2
48TantalumTamg/kgJoron, Jean LouisInstrumental neutron activation analysis (INAA) (Reimann et al., 1998)
49ThoriumThmg/kgWood, D AInstrumental neutron activation analysis (INAA) (Reimann et al., 1998)measurement 1
50ThoriumThmg/kgJoron, Jean LouisInstrumental neutron activation analysis (INAA) (Reimann et al., 1998)measurement 2
51UraniumUmg/kgJoron, Jean LouisInstrumental neutron activation analysis (INAA) (Reimann et al., 1998)
Size:
722 data points

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