piton de la franc

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JOURNAL OF PETROLOGY VOLUME 38 NUMBER 2 PAGES 171201 1997

The Geochemical Regimes of Piton de la

Fournaise Volcano (Re union) During theLast 530 000 Years

F. ALBARE` DE 1, B. LUAIS 1, G. FITTON 2, M. SEMET 3, E. KAMINSKI 1,B. G. J. UPTON 2, P. BACHE ` LERY 4 AND J.-L. CHEMINE E31LABORATOIRE DES SCIENCES DE LA TERRE, ECOLE NORMALE SUPE RIEURE DE LYON,

46 ALLE E DITALIE, 69364 LYON CEDEX 7, FRANCE2DEPARTMENT OF GEOLOGY AND GEOPHYSICS, GRANT INSTITUTE, UNIVERSITY OF EDINBURGH, WEST MAINS ROAD,

EDINBURGH EH9 3JW, UK3INSTITUT DE PHYSIQUE DU GLOBE DE PARIS, 75252 PARIS CEDEX 05, FRANCE4UNIVERSITE DE LA RE UNION ET OBSERVATOIRE, 97418 LA PLAINE DES CAFFRES, RE UNION

RECEIVED APRIL 30, 1996 REVISED TYPESCRIPT ACCEPTED SEPTEMBER 13, 1996

Piton de la Fournaise (Re union, Indian Ocean) is a large active crystallization on cold dyke walls during times of lower magma volcano which shares many features with the Hawaiian volcanoes.uxes. The total lifetime of a Re union volcano ( [ 21 my) includes Its particularly simple elemental and isotopic geochemistry suggests,early and waning stages with alkalic activity bracketing a steady-

however, a rather homogeneous mantle source and makes this volcanostate stage of tholeiitic activity. We estimate that Re union volcanismideally suited for petrogenetic studies. We report mineralogical results from the impingement on the base of lithosphere of a solitarydescriptions, major element, trace element and Sr isotope compositions wave of hotspot material with a radius of 100130 km and a of four volcanic sequences spanning the 530 ka of the knownvelocity of 59 cm/yr.lifetime of the volcano. The lavas change with time from mildlyalkalic to mildly tholeiitic. This change is due to crystal fractionationbecoming shallower with time as olivine replaces clinopyroxene as the liquidus phase at lower pressure. Fractionation of an

KEY WORDS: Re union; alkalinity; bu ff ered di ff erentiation; hotspot dy-olivineclinopyroxene assemblage at lithosphericmantle pressure namics; assimilationdrives tholeiitic basalts into the eld of alkali basalts and puts some

limitation on trace-element modelling of the melting process. Most Fournaise lavas are basalts with a narrow compositional range (steady-state basalts) and picrites containing common plastically

INTRODUCTIONdeformed phenocrysts. The bu ff ering of the compatible element Most mature shield volcanoes from ocean islands eruptcompositions indicates that the lavas last equilibrated in solid-lavas with nearly constant compositions, and little under-dominant conditions which are incompatible with magma chamber standing of the volcanic processes is to be expected from processes and may have resulted from the ascent of liquid-rich zones the repetitive analysis of nearly similar lavas. In contrast,through dykes lled with a slurry of olivine clinopyroxene crystals.the knowledge of the products emitted during the early A quantitative model describing mass balance during the displacement and most variable stages of volcanic activity could po-of a solitary porosity wave leaving behind cumulates with residual tentially shed some light on how the melting regime and porosity accounts for the major and trace element distributions.The magma transfer through the oceanic lithosphere changedykes are ushed during major magma surges forming picritic slurries

( = oceanites). The transient alkalic lavas are products of dynamic while the plate carrying the volcanic edice moves above

Corresponding author.UMR CNRS 5570.URA CNRS 1758. Oxford University Press 1997


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JOURNAL OF PETROLOGY VOLUME 38 NUMBER 2 FEBRUARY 1997

the hotspot. The early studies of the waning stage in the Gondwanaland (Duncan et al ., 1989). The age of thelithosphere under the island is 60 Ma (Bonneville et al .,life of a volcano (Macdonald & Katsura, 1964) and the

discovery of a seamount representing a juvenile Hawaiian 1988) and the absolute plate velocity above the hotspotis 015 deg/my or 17 cm/yr (Gripp & Gordon, 1990). volcano at Loihi have identied a succession of volcanic

regimes (Frey & Clague, 1983; Clague, 1987; Garcia et The island, which is elongated in a northwestsoutheastdirection and forms an oval 50 km by 70 km, representsal ., 1995). Alkalic lavas both precede and follow the main

tholeiitic stage of shield building. The dynamic causes of the aerial part of a much larger volcanic cone, 350 kmin diameter (Lenat & Labazuy, 1990).such a pattern are not yet entirely elucidated but both the

extent of melting (Feigenson et al .,1983) andinteraction of Re union is composed of two large volcanic edices,plume-derived magmas with the lithosphere (Chen & Piton des Neiges, to the northwest, and Piton de laFrey, 1983) are commonly perceived as major factors Fournaise, to the southeast. Piton des Neiges has beenaccounting for the dual character of ocean island vol- active since at least 21 Ma (McDougall, 1971) andcanism. became extinct 1020 ka ago (Deniel, 1990; Kie ff er,

Because of its long-standing isotopic homogeneity 1990). The oldest lavas exposed on Piton de la Fournaise(McDougall & Compston, 1965; Fisk et al ., 1988), the are found at the bottom of the deep canyons of RiviereRe union hotspot is ideally suited for a geochemical des Remparts and Riviere de lEst and have been datedinvestigation of the dynamics of volcanic processes as- at 527 ka (Gillot et al ., 1990). The volcano erupts, onsociated with intraplate volcanoes. Piton de la Fournaise average, once every 18 months. Stieltjes & Moutou (1989) volcano has been active since at least 530 ka (Gillot et reported a productivity of 001 km 3/yr (03 m 3/s) overal ., 1990) and major source heterogeneity that can confuse the period 19311985.petrogenetic modelling has been ruled out by the re- The geology and the petrology of Piton de la Fournaisemarkable Sr and He isotopic homogeneity over the last have been described in numerous papers. Recent activity320 ka of its history (Graham et al ., 1990). Modern lavas is largely conned within a caldera ~8 km in diameter,are exclusively basaltic with a chemical composition open to the southwest as a result of gravitational collapsetransitional between tholeiitic and alkali basalts (Lacroix, and known as lEnclos. Radiocarbon dating suggests the1936; Upton & Wadsworth, 1972 a ; Ludden, 1978; Cloc- caldera was formed 4745 yr ago (Bache `lery & Mairine,chiatti et al ., 1979). 1990). The mean elevation at the bottom western part

The present investigation is an attempt to assess both of the caldera is relatively constant at ~2000 m. In theshort-term and long-term variations in the geochemical centre of lEnclos, a cone rises to an altitude of ~2700 m.dynamics of the volcano. The short-term variability of

Two small craters (Dolomieu and Bory) formed at theincompatible element ratios has been shown to be in- top of the cone in the early 1930s. Rivers have deeplyconsistent with the presence of a large magma reservoir dissected the western part of the volcano and two prom-(Albare de, 1993; Albare de & Tamagnan, 1988) and inent canyons (Rivie`re de lEst and Rivie`re Langevin)supports short transfer times in agreement with the appear to have been eroded along the fault bounding ndings of UThRa disequilibria (Condomines et al ., the old caldera which limits the Plaine des Sables to the1988; Sigmarsson et al ., 1995). A new concept of bu ff ered west. The impressive canyon of Riviere des Remparts,diff erentiation will be o ff ered as an explanation of the west of Riviere Langevin, seems to utilize some oldstriking compositional homogeneityof most basaltic lavas. morpho-tectonic features (Bachelery & Mairine, 1990).We report extensive mineralogical, major and trace ele- Some 150 ka ago, the volcanic centre moved eastwardment data, complemented by 87Sr/ 86Sr measurements, by 610 km from a position next to the Plaine des Sableson both prehistoric and modern lavas. Particular em- to its present position. The seismic structure of thephasis will be placed on the interaction of lavas with volcano has recently been investigated (A. Hirn, personalolder magmatic products (cannibalism). These data will

communication, 1995). A high-velocity plug 15 kmbe shown to constrain the evolution of the volcano and in diameter underlies the Dolomieu crater down to sea-the rate of ascent of the parent hotspot material. level and is rimmed by a low-velocity sheath which is

thought to represent the outlet of the e ff usive products.No unambiguous seismic evidence of a magma reservoirwas found.GEOLOGICAL OVERVIEW OF PITON The two Reunion volcanoes have strong petrological

DE LA FOURNAISE similarities (Lacroix, 1936; Upton & Wadsworth, 1966,1972 a ; Ludden, 1978; Clocchiatti et al ., 1979; Nativel et Re union (Fig. 1) is located in the Indian Ocean atal ., 1979; Albare de & Tamagnan, 1988; Fisk et al ., 1988;2110 S, 5530 W. Its position at the southern end of aSobolev & Nikogosian, 1994). The products of the twowell-dened hotspot track associates the Reunion vol- volcanoes are predominantly basalts, referred to as ol-canoes with the Deccan ood basalts whose eruption

65 my ago accompanied the separation of India from ivine, transitional or cotectic basalts, and hawaiites. For

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ALBARE DE et al. PITON DE LA FOURNAISE GEOCHEMISTRY

Fig. 1. Map of Re union island. The now extinct Piton des Neiges volcano forms the northwestern part of the island and the active Piton de laFournaise makes up the southeastern part. The major cli ff s are outlined. Symbols indicate sampling sites.

the olivine-rich basalts, Lacroix coined the term ocean- emphasized what turned out to be a remarkable periodof volcanic quiescence. The KAr data of Gillot et al .ite, but, although we feel a need to discriminate MgO-

rich melts from olivine-rich basalts, we will adhere to a (1990) dated that period between 290 and 220 ka whereasBache lery & Mairine (1990) described a deep canyonmore common usage and subsequently refer to theselavas as picritic basalts or, simply, picrites. Albare `de & eroded in this interval at nearly the same location as the

modern Rivie`re des Remparts and lled with ~100-ka-Tamagnan (1988) found evidence of up to three distinctphases of plastic deformation in picritic olivine, which old lavas (Nez-de-Boeuf series). The oldest rocks, found

in the Rivie re des Remparts and Rivie `re de lEst, arethey interpreted as xenocrysts. The waning stages of thePiton des Neiges abound in di ff erentiated rocks, which plagioclase-phyric basalts (Bachelery & Mairine, 1990)

and other di ff erentiated lavas. Younger ows are almostwere investigated in detail by Upton & Wadsworth(1972a ) and Ludden (1978). exclusively olivine, picritic and occasional aphyric basalts.

Fisk et al . (1988) presented some phase relationships for A recent account of the petrological diversity of thePiton de la Fournaise products has been given by Ba- pressures up to 10 kbar in basalts and oceanites from the

Piton des Neiges. Crystallization temperature determinedche lery & Mairine (1990). Making a distinction betweenan Old Shield and a Recent Shield, Ludden (1978) from melt inclusion homogenization or chemical

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thermometers (Sobolev et al ., 1983; Sobolev &Nikogosian, 1994; H. Bureau, personal communication,1996) generally fall in the range 11601230 C.

Mantle xenoliths are absent. Babkine et al . (1966)and Upton & Wadsworth (1972 b ) described nodules of wehrlite and dunite cumulates from Piton de Chisny, asmall cone 4 km west of the summit which last eruptedin AD 800 (F. Albare de & M. Semet, unpublished ra-diocarbon dating). The cuttings recovered from theGrand Bru le drill hole bored in the Remparts caldera atnear sea-level indicated the presence of gabbros, wehrlite and dunite with traces of hydrothermalalteration at depths >1000 m (Auge et al ., 1989; Lerebour

Fig. 2. Calculation of the return time between two lava ows at theet al ., 1989; Rancon et al ., 1989). same locality of lEnclos caldera. The surface ages of the lava owsMajor and trace element modelling of Reunion lava younger than 1920 obey an exponential distribution: the fraction F of

lavas erupted at year t before the year t 0 = 1986 shown on thecompositions by Upton & Wadsworth (1972 a ), Luddenhorizontal axis varies as F = exp( t t 0 )/ , where is the return time.(1978) and Albare`de & Tamagnan (1988) focused onThe linearity of this plot suggests that lava covers pre-existing ows atfractional crystallization and partial melting. Albare `de & random(Poisson distribution). A lava ow is expected to remain exposed

for 22 yr before it is covered by a younger ow.Tamagnan (1988) showed that fractionation takes placebelow the plagioclaseclinopyroxene cross-over, i.e. atpressures >4 kbar, in disagreement with the concept of based on old maps and interpretation of informal reports.a shallow magma chamber inferred from seismic and In contrast to the older series, the elevations at whichmagnetic observations. Melting of a source enriched in the samples were taken are not reported because of aincompatible elements leaving a harzburgitic residue was broadly dispersed sampling, not necessarily carried outa successful, although standard, result of inverting trace in vent areas. The modern samples tend to be com-element melting equations. positionally bimodal. Basaltic samples with few to com-

mon (


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(4) Thirty-two samples of the oldest series from the were redissolved in HCl and Sr was separated on a strong cation-exchange resin upon elution by HCl and citric7001700 m western rim of the Rivie `re des Remparts

canyon were cored by climbers. The oldest lavas in the acid according to the method of Birck & Alle `gre (1978).The Sr fraction was loaded on an oxidized Ta lamentcanyon have been dated by KAr at 527 ka (Gillot et al .,

1990) whereas one lava ow sampled at 1390 m gave a andrun on a double collector Micromass-30 in Clermont-Ferrand. The unweighted average 87Sr/ 86Sr value of theKAr age of 395 ka (P.-Y. Gillot, unpublished data,

1991). The age of the ows at the top of the cli ff (1700 NBS 987 standard over the period when the presentmeasurements were carried out is 0710207 24. Them) is estimated, by interpolating the age of neighbouring

samples, at 290 ka (Gillot et al ., 1990). Again, these ages entire chemical processing of the samples was carriedout in Lyon.are indicative of a very large proportion of stratigraphic

hiatuses (>90% with reference to the eruption frequencyin lEnclos caldera). The bottom and the top of this seriesare very di ff erent. Above ~1300 m, the series is dominated

MINERALOGYby basaltic and picritic samples similar to those of recentMean values of mineral compositions are given in Tableeruptions. In the lower part, several samples (RP18,1. The Fe 3+ contents have been calculated with theRP25, RP31, RP32) contain 3050% plagioclase phe-assumption of stoichiometric oxygen/cation proportions.nocrysts and occasional irregular clusters of plagioclase

clinopyroxene crystals representing dismantled gabbroicfragments. Much more di ff erentiated lavas, with com-positions extending to mugearite and largely aphyric, are Olivine (97 microprobe analyses)observed higher up in the series, most notably between

Cr-spinel inclusions are frequent and devitried glass1150 and 1340 m (RP14, RP15, RP17, RP19, RP28).inclusions are common. Although rare phenocrysts maycontain up to 89% forsterite, a strong frequency max-imum is observed at 8384% (Fig. 3), which correspondsto the literature descriptions and to the olivine com-ANALYTICAL TECHNIQUESposition in equilibrium with the FeO and MgO con-

All the samples were examined in thin sections and then centrations in common basalts. Iron-rich olivine isminerals were analysed with a Cameca SX-50 electron frequently observed as microphenocrysts. The CaO con-probe in Paris. The cores of lavas were rinsed in acetone tent of the olivine peaks at ~03% (Fig. 3), which is

and deionized water before crushing in an agate mortar. typical of basalt phenocrysts ( Jurewicz & Watson, 1988a).The whole rocks were analysed for major elements, and Many olivine crystals seem to have a complicated history.a selected set of trace elements in Edinburgh by X-ray Dislocations in olivine decorated by heating at 900 Cuorescence (XRF) according to the method described for 1 h (Fig. 4ac) following the technique of Kohlstedtby Fitton et al . (1996) (see Table 2, below). A 100 mg et al . (1976) and mantled olivines (Fig. 4d) have beenaliquot of lava rock was dissolved in mixed HF observed. As discussed below, no di ff erence could beHNO 3 HClO 4 and analysed in Montpellier by in- found in the chemistry of plastically deformed and un-ductively coupled plasma mass spectrometry (ICP-MS) deformed crystals.according to the external calibration technique. Themeasurement of each series of 10 samples and onestandard rock is preceded and followed by the analysis

Clinopyroxene (101 analyses)of a set of standard solutions. Interference corrections,reproducibility, precision, and data for standards have The pyroxenes are typical augites with Ca/

been reported by Albare `de (1996). Accuracy with respect (Ca+ Fe+ Mn + Mg) values of 045 001. The chemicalto the BE-N standard is generally better than 2% except trends appear to reect the extent of di ff erentiation. Infor Th and U (4%). Typical 2 reproducibility is 25% the Remparts series, high iron contents are associatedfor most elements except for Yb, Lu, Th, U and Pb, for with the most di ff erentiated rocks. Principal componentwhich it is 68%. A correction for blanks is routinely analysis (PCA) is a standard brute-force technique thatapplied, which is invariably less than a few per cent. extracts the direction of the most signicant variationsIsotopic spikes of Sr, Ba, Nd and Yb were added to the from a large data set with insu ffi cient readability (e.g.samples from the Rivie`re des Remparts series to monitor Strang, 1988; Johnson & Winchern, 1992; Albare `de,the sensitivity drift. Except for Nb, for which the solutions 1995). Some directions or components that are com-are unstable, overall excellent agreement was observed binations of the initial variables account for a muchwith the data obtained by XRF. For Sr isotopes, a 50100 larger fraction of the total variance than others and PCAmg aliquot was dissolved in a similar mixture of acids provides an optimal selection of these directions. PCA

amounts to the search of the eigenvalues and eigenvectorsand the solution evaporated to dryness. The samples

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Table 1: Average composition (with standard deviation given in parentheses) of the phenocrysts observed in the Piton de la Fournaise lavas

Olivine Clinopyroxene Plagioclase Spinel Ti-magnetite 1 Ti-magnetite 2 Ilmenite

n 97 101 98 50 50 50 50

SiO 2 3920 (052) 4957 (095) 4812 (156) 006 (002) 010 (005) 040 (083) 004 (004)

TiO 2 003 (001) 167 (044) 008 (004) 343 (073) 2193 (320) 3442 (107) 4919 (111)

Al2O 3 004 (005) 419 (065) 3245 (090) 1615 (070) 221 (151) 141 (061) 011 (008)

FeO 1790 (228) 707 (084) 064 (006) 3199 (084) 6761 (225) 6364 (156) 4524 (053)

MnO 026 (005) 015 (006) 001 (002) 025 (006) 054 (013) 075 (008) 059 (016)

MgO 4255 (196) 1457 (065) 011 (003) 1042 (030) 276 (133) 194 (043) 270 (100)

CaO 030 (004) 2139 (066) 1602 (108) 001 (001) 008 (012) 022 (026) 017 (007)

Na 2O 001 (002) 035 (007) 230 (076) 001 (001) 002 (001) 003 (002) 001 (001)

K2O 001 (001) 001 (001) 010 (006) 000 (001) 001 (001) 002 (002) 002 (002)

NiO 021 (006) 003 (002) 007 (006) 003 (003)

Cr 2O 3 3584 (080) 005 (003) 015 (011) 006 (006)

Total 10030 9897 9983 9837 9534 10305 9816

of either the covariance matrix or the correlation matrix 1994). Using the calibration of Fe 2+ Fe3+ equilibriumbetween spinel and liquid of Maurel & Maurel (1982),of the data. In the present case, no large variations in

the analytical uncertainties on the data are expected and the average Fe 2+ /Fe 3+ ratio in the spinel indicates that13 1% of the iron in the basaltic liquid is ferric. ThePCA has therefore been carried out on the correlation

matrix [see Albarede (1995) for a discussion]. Calculation composition of the Ti-magnetite is clearly distinct fromthat of the Cr-spinel and much more variable. Theof components on the clinopyroxene correlation matrix

shows that 62% of the variance is associated with one occurrence of ilmenite is restricted to a few samples(LGV1, 16, RP1) and does not seem to be related tocomponent which correlates negatively the group of Si

and Mg with the group Ti, Al, ferric Fe, and Na. A particular chemical characters.second component accounting for 21% of the varianceopposes ferrous Fe to Ca.

Amphibole (3 analyses)Only one crystal of hornblende was observed, in samplePlagioclase (98 analyses) RP1.

The maximum on the distribution of anorthite contentsin the plagioclase phenocrysts from the Remparts seriesis at 84%. Phenocrysts from di ff erentiated lavas andmicrophenocrysts are signicantly more sodic (6070%). GEOCHEMICAL RESULTSFerric iron enters the plagioclase molecule in the pro- Overviewportion of 0025 atoms for 8 oxygens. As the large number of samples and elements analysed

(Table 2) raises the suspicion that some major re-lationships may escape scrutiny through the reading of Oxides (50 analyses) simple binary plots, we resorted once more to principal

component analysis. The usual way of reporting PCAThey are mostly Cr-spinel and Ti-magnetite with oc-casional ilmenite (Fig. 5). The composition of the Cr- results is to plot the individual data points and the unit

vector in the direction of each initial observation (e.g. Srspinel, frequently included in olivine phenocrysts, is ratherconstant with an average proportion of 45% chromite, or Yb) in the component space with the unit circle

being the trace of the 1 ellipsoid. About 835% of the32% spinel and 21% magnetite components. The meanratios Cr/(Cr + Al) = 0593, Mg/(Mg + Fe2+ ) = 048, variability is accounted for by two components (Fig. 6).

Each component of higher order accounts for 35% atFe3+ /(Fe 3+ + Cr + Al) = 014, Fe 2+ /Fe 3+ = 19 placethe Reunion and Hawaii Cr-spinel in the same eld, at most, which may not be signicant. Many binary dia-

grams show an L-shaped spread of data: one arm of theoxygen fugacity about two orders of magnitude abovethe quartzfayalitemagnetite (QFM) bu ff er (Horn et al ., L is made by the picritic basalts, the other by the

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8/31


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T a b l e 2 b : M a j o r a n d t r a c e e l e m e n t d a t a

S a m p

l e :

L G V 0 1

L G V 0 2

L G V 0 3 L G V 0 4

L G V 0 6

L G V 0 7

L G V 0 9 L G V 1 2 L G V 1 3

L G V 1 4

L G V 1 5

L G V 1 6

L G V 1 7

L G V 1 8

L G V 2 0

L G V 2 1

L G V 2 2

L G V 2 3

L G V 2 5 L G V 2 6

E l e v

( m ) :

2 3 0 0

2 2 8 0

2 2 6 0

2 2 4 0

2 2 0 0

2 1 9 0

2 1 6 0

2 1 0 0

2 0 8 0

2 0 6 0

2 0 4 0

1 9 9 0

1 9 8 0

1 9 8 5

1 9 6 0

1 9 3 0

1 9 1 0

1 9 0 5

1 8 7 0

1 8 5 0

X R F

S i O

2

4 8 4

4

4 4 2

6

4 7 8 4

4 8 3

8

4 8 6

6

4 4 7

3

4 9 1

6

4 7 9 3

4 7 3

8

4 2 7

2

4 8 0

8

4 6 7

3

4 6 0

6

4 6 4 1

4 8 6

8

4 8 2

7

4 7 9

0

4 5 7

7

4 7 5

7

4 8 2

1

A l 2 O

3

1 4 5

2

9 7 6

1 4 6 5

1 5 4

7

1 5 0

4

1 0 1

7

1 4 9

4

1 4 2 2

1 4 2

5

6 6 8

1 4 4

9

1 2 9

1

1 2 2

6

1 2 1 2

1 4 8

8

1 5 1

2

1 4 5

7

1 1 2

5

1 2 8

8

1 3 0

9

F e O

1 1 4

6

1 2 1

5

1 1 1

4

1 1 3

9

1 1 2

0

1 3 0

3

1 1 8

1

1 0 6

0

1 1 5

8

1 2 5

2

1 1 4

5

1 1 5

6

1 1 9

2

1 1 9 8

1 0 9

2

1 1 3

4

1 1 7

0

1 2 3

8

1 2 1

1

1 1 7

0

M g

O

6 4

0

1 9 2

2

6 5 5

4 9 6

5 9 6

1 9 1

9

5 3 4

8 2 1

6 5

9

2 6 6

7

6 9 2

1 0 6

5

1 2 4

4

1 2 9 9

6 8 5

6 1 1

6 5 9

1 6 3

4

9 7

6

9 4 4

C a O

1 1 1

0

8 2

3

1 1 3

5

9 9 5

1 0 7

5

7 0 0

9 7 8

1 1 0

9

1 1 0

8

5 9 7

1 1 2

7

1 0 4

8

9 8 8

9 8

1

1 1 5

0

1 1 0

8

1 0 5 4

8 4 1

9 6

8

1 0 2

6

N a 2

O

2 7

7

1 4 6

2 7 8

3 1 5

2 9 6

1 8 1

3 2 2

2 4 6

2 3

4

0 9 7

2 6 3

2 2 5

2 1 0

2 1 7

2 6 6

2 8 9

2 8 8

1 9 4

2 4

6

2 3 2

K 2

O

0 6 9

0 4 3

0 8 9

0 9 8

0 9 0

0 5 3

0 9 8

0 6 1

0 5

5

0 2 2

0 7 2

0 8 1

0 7 7

0 7 7

0 7 4

0 9 1

0 9 2

0 6 0

0 7

3

0 5 3

T i O

2

2 6 8

1 7 8

2 9 2

3 2 0

2 9 9

1 8 8

3 1 7

2 4 9

2 6

0

1 2 0

2 6 1

2 5 3

2 4 4

2 4 4

2 6 5

3 0 4

3 0 1

1 9 2

2 8

8

2 4 1

M n

O

0 1 7

0 1 8

0 1 6

0 1 7

0 1 7

0 1 8

0 1 8

0 1 7

0 1

7

0 1 8

0 1 8

0 1 8

0 1 7

0 1 8

0 1 7

0 1 7

0 1 8

0 1 8

0 1

8

0 1 8

P 2 O

5

0 3 1

0 2 1

0 3 7

0 3 9

0 3 7

0 2 5

0 4 2

0 2 9

0 2

8

0 1 2

0 3 1

0 3 1

0 2 9

0 2 9

0 3 1

0 3 8

0 3 7

0 2 3

0 3

6

0 2 6

S u m

9 8 5

3

9 7 6

7

9 8 6 5

9 8 0

3

9 8 9

9

9 8 7

7

9 8 9

9

9 8 0 7

9 6 8

2

9 7 2

4

9 8 6

5

9 8 4

0

9 8 3

4

9 9 1 4

9 9 3

5

9 9 3

0

9 8 6

5

9 9 0

1

9 8 6

1

9 8 4

0

N b

2 6 8

1 8 4

3 2 4

3 3 3

3 1 0

2 0 4

3 4 7

2 3 2

2 3 2

1 1 3

2 5 7

2 6 8

2 6 3

2 5 9

2 6 1

3 0 9

n . d .

1 9 8

2 7 4

2 3 8

Z r

2 0 2

9

1 3 8

5

2 3 8

0

2 5 3 0

2 4 0 5

1 5 2 0

2 6 6 8

1 8 6 4

1 8 0 1

8 2 2

1 9 5 6

1 8 7 4

1 7 8 7

1 7 7 9

1 9 4 4

2 3 4 8

n . d .

1 4 7 1

2 1 5 2

1 6 5 4

Y

2 8 9

1 7 5

2 8 6

3 3 7

3 2 1

1 9 8

3 6 2

2 5 9

2 8 3

1 1 9

2 8 1

2 5 4

2 2 9

2 3 3

2 7 4

2 9 3

n . d .

1 9 4

2 8 7

2 7 5

S r

4 0 0

2 7 3

4 7 0

4 5 5

4 3 4

2 9 1

4 3 7

3 7 8

3 4 7

1 7 1

4 0 8

4 0 6

3 8 5

3 9 9

4 0 8

4 6 0

n . d .

3 0 8

3 6 1

3 1 7

R b

1 5 1

7 3

2 1 0

2 2 7

2 1 2

1 0 6

2 0 7

1 3 4

1 2 3

3 9

1 7 4

2 0 8

2 0 0

2 0 0

1 4 9

1 8 8

n . d .

1 5 7

1 5 9

1 1 8

Z n

1 0 3

7

1 0 0

8

1 0 1 4

1 1 0 4

1 0 2 5

1 0 7 5

1 1 1 7

9 8 2

1 0 1 7

1 0 1 3

1 0 1 0

9 6 5

1 0 7 5

1 0 1 3

9 7 0

1 0 1 4

n . d .

1 0 3 8

1 0 4 3

1 0 7 9

C u

8 2 3

8 4 8

7 0 4

5 6 0

7 8 9

5 6 0

7 9 4

8 9 1

9 0 0

6 5 2

1 0 3 4

9 3 7

9 1 4

7 3 3

1 0 8 5

7 9 2

n . d .

7 6 6

1 0 2

1

9 2 8

N i

6 3 2

7 1 0 0

7 7 3

3 6 0

5 9 9

6 7 8 6

4 5 9

1 6 8 6

6 7 2

1 1 6 5

2

8 8 0

2 6 6 1

3 6 9

3

3 8 0

2

9 6 3

6 3 8

n . d .

5 5 5 6

2 8 7 0

1 9 5 8

C r

1 2 2

1 2 7 1

1 5 1

5 4

1 1 9

1 0 1 3

5 9

3 1 5

1 4 4

1 6 9 7

1 6 2

5 6 1

7 1 4

6 8 9

1 7 4

5 5

n . d .

8 1 4

3 3 7

4 8 1

V

3 0 0

7

2 0 3

1

3 0 2

0

3 3 1

2

3 0 3 7

1 9 0 5

3 0 5 5

2 6 8 4

2 9 8 6

1 6 1 1

2 9 0 4

2 7 6 7

2 6 6

5

2 5 7 2

2 9 3 9

3 0 8 8

n . d .

2 1 7 2

2 9 4 7

2 6 2 8

B a

1 5 8 6

1 2 4

3

2 0 6

9

2 1 8 0

1 9 2 5

1 3 0 2

2 0 1 7

1 4 4 2

1 4 5 5

7 4 0

1 6 6 6

1 9 1 9

1 8 1

5

1 8 5 2

1 6 7 1

1 9 7 4

n . d .

1 3 9 9

1 6 1 8

1 4 3 8

S c

3 1 8

2 6 6

3 7 1

2 7 6

2 6 5

2 1 7

2 8 3

3 1 1

3 2 1

2 1 4

2 9 8

2 8 3

2 6 1

2 5 2

3 0 1

3 0 9

n . d .

2 5 2

2 9 2

2 7 1

179


10/31


T a b l e 2 b : c o n t i n u e d

S a m p

l e :

L G V 0 1

L G V 0 2

L G V 0 3 L G V 0 4

L G V 0 6

L G V 0 7

L G V 0 9 L G V 1 2 L G V 1 3

L G V 1 4

L G V 1 5

L G V 1 6

L G V 1 7

L G V 1 8

L G V 2 0

L G V 2 1

L G V 2 2

L G V 2 3

L G V 2 5

L G V 2 6

E l e v

( m ) :

2 3 0 0

2 2 8 0

2 2 6 0

2 2 4 0

2 2 0 0

2 1 9 0

2 1 6 0

2 1 0 0

2 0 8 0

2 0 6 0

2 0 4 0

1 9 9 0

1 9 8 0

1 9 8 5

1 9 6 0

1 9 3 0

1 9 1 0

1 9 0 5

1 8 7 0

1 8 5 0

I C P - M S

R b

1 3 0

6 6

9

1 9 3

2 1 3

2 0 1

1 0 1

1 9 7

1 2 2

1 1 8

3 6 6

1 5 8

1 8 1

1 9 1

1 8 9

1 4 4

1 8 4

2 1 5

1 4 6

1 5 4

1 2 1

S r

3 5 8

2 5 3

4 4 1

4 2 9

4 0 8

2 7 8

4 0 8

3 3 5

3 2 9

1 6 0

3 7 6

3 9 1

3 7 3

3 6 9

3 9 9

4 5 5

4 2 2

2 9 3

3 5 3

3 1 4

Y

2 8 9

1 7 5

2 8 6

3 3 7

3 2 1

1 9 8

3 6 2

2 5 9

2 8 3

1 1 9

2 8 1

2 5 4

2 2 9

2 3 3

2 7 4

2 9 3

n . d .

1 9 4

2 8 7

2 7 5

N b

2 4 2

1 7 0

3 0 8

3 1 1

2 8 9

1 9 2

3 2 4

2 0 3

1 9 2

8 9

2 0 7

2 3 6

2 2 9

2 1 7

2 2 0

2 6 9

2 6 9

1 6 6

2 3 5

2 0 3

C s

0 1 8 2

0 0 8 9

0 1 1 3

0 2 9 0

0 1 8 0

0 1

2 1

0 2 3 2

0 1 9 5

0 1 8 8

0 0 6 6

0 2 7 2

0 2 8 2

0 2 0 9

0 2 9 6

0 1 3 2

0 0

9 8

0 1 0 0

0 0 9 7

0 2 5 9

0 2 2 3

B a

1 4 4

1 0 7

1 8 9

2 0 6

1 8 4

1 1 7

2 0 5

1 2 3

1 3 3

6 0

1 5 6

1 7 9

1 6 8

1 6 1

1 5 6

1 9 4

1 9 2

1 2 9

1 5 2

1 3 8

L a

2 0 5

1 4 5

2 5 5

2 5 8

2 3 9

1 6 3

2 7 2

1 7 5

1 8 2

8 7

1 9 9

2 1 7

2 0 5

1 9 8

2 0 5

2 5 4

2 5 3

1 5 6

2 3 1

1 9 5

C e

4 7 7

3 4 2

5 8 9

5 9 6

5 5 9

3 7 4

6 2 5

4 1 1

4 3 5

2 0 7

4 7 0

5 0 7

4 8 0

4 5 9

4 7 9

5 8 8

5 7 2

3 5 8

5 2 5

4 2 8

P r

6 0 7

4 4 1

7 3 0

7 5 0

7 1 1

4 7 1

7 8 6

5 2 6

5 5 7

2 6 6

6 0

3

6 3 5

6 0 5

5 7 8

6 0 8

7 4 5

7 3

6

4 6 7

6 7 7

5 4 3

N d

2 6 9

1 9 4

3 1 7

3 2 9

3 1 2

2 0 7

3 4 4

2 3 5

2 5 2

1 2 0

2 6 7

2 8 1

2 6 4

2 5 1

2 7 0

3 2 9

3 2 1

2 0 4

3 0 0

2 3 9

S m

6 2 1

4 2 8

6 9 7

7 3 7

7 1 9

4 6 5

7 8 2

5 4 2

6 0 8

2 8 1

6 2

9

6 2 3

5 9 6

5 6 4

6 2 5

7 3 8

7 2 5

4 7 4

6 8 0

5 6 2

E u

2 1 5

1 4 4

2 3 7

2 5 1

2 4 4

1 5 5

2 6 5

1 8 8

2 0 7

0 9 5

2 1

4

2 0 8

1 9 9

1 8 9

2 1 3

2 5 0

2 3 8

1 5 5

2 2 3

1 9 4

G d

6 3 9

4 6 0

7 0 4

7 5 7

7 3 7

4 8 2

8 1 6

5 7 0

6 3 4

2 9 2

6 4

0

6 2 2

5 9 0

5 6 7

6 4 1

7 3 6

7 3 9

4 9 3

7 1 6

6 4 4

T b

1 0 1

0 6 5

1 0 6

1 1 5

1 1 4

0 7 3

1 2 4

0 8 7

1 0 1

0 4 6

1 0

0

0 9 4

0 8 9

0 8 6

0 9 8

1 1 2

1 1 0

0 7 4

1 0 8

0 9 9

D y

5 6 7

3 5 9

5 7 4

6 4 1

6 3 2

4 1 0

7 0 0

4 8 6

5 8 0

2 6 0

5 6

4

5 3 1

4 9 9

4 8 2

5 5 4

6 2 5

6 0 8

4 1 2

6 0 0

5 6 8

H o

1 0 3

0 6 5

1 0 3

1 1 8

1 1 6

0 7 4

1 2 8

0 8 8

1 0 7

0 4 8

1 0

3

0 9 6

0 9 1

0 8 8

1 0 0

1 1 2

1 1 3

0 7 6

1 1 3

1 0 8

E r

2 6 5

1 6 5

2 5 6

2 9 8

2 9 1

1 9 1

3 2 6

2 2 1

2 7 4

1 2 7

2 6

1

2 4 4

2 3 1

2 2 0

2 5 6

2 7 7

2 8 4

1 9 3

2 8 6

2 7 7

Y b

2 1 2

1 3 1

2 0 2

2 4 4

2 3 5

1 5 5

2 6 6

1 7 7

2 1 5

0 9 7

2 0

5

1 8 6

1 7 3

1 6 7

2 0 0

2 1 3

2 1 7

1 4 7

2 1 9

2 1 9

L u

0 3 2

0 2 0

0 3 1

0 3 6

0 3 6

0 2 3

0 3 9

0 2 7

0 3 4

0 1 6

0 3

1

0 2 9

0 2 7

0 2 6

0 3 1

0 3 2

0 3 4

0 2 3

0 3 5

0 3 4

H f

5 0 0

3 3 9

5 6 7

5 8 6

5 7 1

3 7 6

6 1 8

4 2 1

4 8 3

2 0 7

4 8

7

4 9 2

4 6 7

4 4 1

4 8 5

5 7 2

5 7 9

3 7 9

5 5 5

4 4 6

P b

1 8 0

1 2 6

2 2 3

2 1 9

2 0 1

1 4 0

2 2 3

1 4 2

1 6 4

0 7 4

1 7

4

1 7 6

1 6 0

1 6 4

1 7 6

2 0 6

2 1 5

1 4 1

2 2 4

1 6 0

T h

2 6 0

1 7 4

3 2 8

3 2 4

2 8 7

1 9 4

3 3 1

2 0 5

2 3 9

0 7 3

2 5

1

2 6 8

2 5 6

2 4 5

2 5 5

3 0 7

3 3 3

2 0 2

2 9 3

2 6 3

U

0 6 6 7

0 4 7 3

0 8 7 0

0 8 3 2

0 7 7 1

0 5 0 8

0 8 5 7

0 5 2 9

0 6 0 3

0 2 7 4

0 6 4 8

0 6 7 8

0 6 7 0

0 5 9 1

0 6 2 9

0 7 5 6

0 8 1 7

0 5 0 9

0 7 1 9

0 6 0 1

a l k

0 0

3 4

0 0

6 1

0 3 9 8

0 6 6 3

0 2 8 2

0 2 1 9

0 4 4 2

0 2

2 9

0 2 1 4

0 1

8 8

0 0

0 5

0 2 0 0

0 2 6 2

0 1 9 6

0 1

8 1

0 3 7 1

0 5 0 7

0 0 3 2

0 0 2 0

0 5

5 6

E u

/ E u

1 0 4

0 9 9

1 0 3

1 0 3

1 0 2

1 0 0

1 0 1

1 0 3

1 0 2

1 0 1

1 0

3

1 0 2

1 0 3

1 0 2

1 0 3

1 0 4

0 9 9

1 0 2

0 9 8

0 9 9

8 7 S r /

8 6 S r

0 7 0 4 1 1 8

0 7 0 4 1 6 1

0 7 0 4 1 3 8

0 7 0 4 1 0 1

0 7 0 4 1 0 4

0 7 0 4 1 0 3

0 7 0 4 0 6 5

0 7 0 4 0 9

0 7 0 4 0 9

0 7 0 4 2 1 1

0 7 0 4 0 5 8

0 7 0 4 2 0 9

0 7 0 4 2 0 8

0 7 0 4 2 2 7

0 7 0 4 1 2 6

0 7 0 4 1 1 9

0 7 0 4 1 0 2

0 7 0 4 1 6 3

0 7 0 4 1 6 6

0 7 0 4 0 4 2

180


11/31


S a m p

l e :

L G V 2 7

L G V 2 8

L G V 2 9

R 0 1

R 0 2

R 0 7

R 0 3

R 0 4

R 0 5

R 0 6

R 0 8

R 0 9

R 1 0

R 1 1

R 1 2

R 1 3

R P 0 1

R P 0 2

R P 0 3

R P 0 4

E l e v

( m ) : 1 8 3 0

1 8 2 0

1 8 1 5

1 8 5 0

1 8 4 5

1 8 0 0

1 7 5 0

1 7 3 0

1 7 2 0

1 7 1 0

1 7 0 5

1 6 9 5

1 6 9 0

1 6 7 5

1 6 7 0

1 6 6 5

1 6 9 0

1 6 7 0

1 6 3 0

1 6 0 5

X R F

S i O

2

4 7 6

8

4 7 4

5

4 5 8

4

4 7 5

5

4 7 1

1

4 7 5

8

4 6 7

9

4 7 2

4

4 7 2

7

4 7 7

2

4 8 4

3

4 7 8

3

4 8 5

1

4 5 9

5

4 6 5

9

4 7 0

5

4 7 2

7

4 4 6

9

4 7 5

2

4 7 4

3

A l 2 O

3

1 4 1

4

1 3 4

8

1 1 0

1

1 4 5

2

1 4 1

7

1 3 4

6

1 3 9

2

1 4 5

6

1 3 9

6

1 4 3

5

1 5 8

3

1 5 6

8

1 6 0

8

1 3 5

9

1 4 1

7

1 3 7

4

1 3 9

7

9 2 3

1 4 2

2

1 4 4

0

F e O

1 1 3

9

1 1 4

5

1 3 7

6

1 1 4

1

1 2 0

5

1 2 1

1

1 2 2

9

1 2 3

1

1 1 3

9

1 1 3

9

1 1 2

8

1 1 2

7

1 1 0

9

1 2 0

1

1 1 9

8

1 2 2

0

1 2 2

5

1 3 1

6

1 2 9

7

1 3 1

2

M g

O

7 1 2

1 0 3

7

1 6 0

3

6 8

9

9 9 6

9 1 7

9 2 8

9 1 4

8 7 7

8 2 0

6 3 4

6 2 3

5 7 9

1 0 3

5

9 8 3

1 0 2

8

8 0 4

2 1 1

1

7 0 0

6 9 0

C a O

1 0 9

7

1 0 3

4

8 3 3

1 1 3

1

8 6 0

9 4 1

9 6 2

8 8 8

1 0 1

5

1 0 0

5

9 1 0

9 1 0

8 9 0

1 0 1

3

9 1 7

9 3 1

1 1 2

1

8 0 7

9 8 2

1 0 0

3

N a 2

O

2 4 4

2 4 8

1 9 8

2 8

2

2 9 9

2 7 3

2 7 0

2 9 3

2 6 0

2 8 8

3 3 6

3 2 3

3 4 8

2 4 0

2 8 0

2 7 7

2 5 2

1 5 1

3 1 5

2 9 7

K 2

O

0 5 2

0 7 2

0 6 4

0 9

8

0 9 2

0 8 9

0 7 4

0 7 3

0 8 5

0 9 4

1 0 7

1 0 6

1 1 3

0 5 5

0 9 5

0 7 8

0 8 1

0 4 5

1 1 0

0 9 9

T i O

2

2 5 1

2 3 5

2 0 5

3 0

8

2 7 7

2 8 1

2 8 6

2 6 5

2 7 2

2 7 8

3 2 6

3 2 9

3 3 4

2 7 7

2 5 7

2 5 3

2 6 4

1 6 0

3 2 0

3 1 3

M n

O

0 1 7

0 1 7

0 1 8

0 1

7

0 1 8

0 1 7

0 1 7

0 1 8

0 1 7

0 1 8

0 1 7

0 1 7

0 1 7

0 1 8

0 1 8

0 1 8

0 1 7

0 1 8

0 1 7

0 1 8

P 2 O

5

0 2 8

0 2 8

0 2 6

0 3

8

0 3 9

0 3 9

0 3 4

0 3 5

0 3 6

0 3 7

0 4 3

0 4 3

0 4 5

0 3 4

0 3 6

0 3 3

0 3 8

0 2 2

0 4 9

0 4 3

S u m

9 7 2

2

9 9 0

8

1 0 0 0 7

9 9 1

2

9 9 1

3

9 8 7

1

9 8 7

1

9 8 9

7

9 8 2

3

9 8 8

5

9 9 2

7

9 8 2

9

9 8 9

4

9 8 2

6

9 8 6

0

9 9 1

7

9 9 2

6

1 0 0 2 1

9 9 6

4

9 9 5

8

N b

2 2 2

2 4 7

2 1 4

3 1 9

3 0 9

3 1 0

2 5 4

2 5 1

2 8 6

2 8 9

3 5 2

3 5 1

3 7 6

2 7 7

2 9 4

2 6 5

2 7 3

1 4 9

3 6 6

3 4 3

Z r

1 8 2 1

1 7 6 0

1 5 7 9

2 3 4 5

2 3 4 9

2 3 4 4

2 2 0 9

2 1 7 4

2 1 6 3

2 2 0 7

2 5 8 4

2 5 8 5

2 7 4 6

2 1 7 8

2 1 4 7

1 9 9 2

2 0 2 4

1 1 9 9

2 6 9 8

2 5 2 5

Y

2 7 4

2 3 9

2 1 3

2 9 6

2 9 6

3 2 3

3 2 8

2 9 5

3 0 0

3 0 9

3 4 6

3 5 0

3 6 2

3 0 5

2 8 0

2 7 0

2 7 4

1 6 5

3 3 3

3 3 8

S r

3 5 6

3 8 7

3 1 2

4 5 2

4 3 8

3 7 7

3 9 5

3 9 4

4 1 9

4 2 6

4 7 7

4 7 7

4 8 6

3 9 2

4 2 4

3 9 2

3 6 4

2 3 5

4 5 1

4 2 8

R b

1 1 5

1 7 5

1 5 9

2 2 9

2 2 0

2 3 2

1 1 1

1 8 0

2 1 4

2 4 0

2 6 9

2 6 3

2 8 0

4 3

2 4 2

1 8 3

1 6 0

8 8

2 6 3

1 7 7

Z n

1 0 8 9

1 0 0 1

1 0 3 8

1 1 2

1

1 1 0 9

1 1 7 7

1 1 6 0

1 1 6 1

1 0 7 7

1 0 4 9

1 0 9 2

1 0 9 7

1 1 2 6

1 1 6 0

1 1 3 0

1 0 7 9

9 9 2

9 4 9

1 1 3 3

1 1 8 8

C u

1 0 7 9

7 1 7

7 3 0

8 9 3

5 6 0

4 5 6

6 6 3

6 5 6

6 4 4

7 5 8

4 1 8

3 9 4

5 5 2

8 8 0

6 7 3

6 9 5

1 0 2 1

6 0 5

8 8 7

9 0 9

N i

9 1 7

2 2 4 7

5 4 0 7

9 3 2

2 4 8 4

2 1 7 0

2 2 8 1

2 0 5 8

1 8 2 7

1 4 6 5

7 9 2

7 6 3

6 0 7

2 7 1 0

2 4 7 1

2 5 7 8

1 6 5 4

8 1 9 3

1 2 3 6

1 3 1 5

C r

2 8 0

4 3 6

8 0 7

2 1 2

3 7 1

3 5 5

3 6 6

3 3 7

4 1 3

3 4 9

1 3 5

1 3 2

8 3

4 9 0

4 0 1

4 1 5

3 6 7

1 4 4 9

1 9 2

1 9 5

V

2 7 3 9

2 5 2 7

2 0 3 3

3 1 7 4

2 4 4 6

2 8 2 5

2 6 1 4

2 4 1 2

2 7 8 3

2 7 7 5

2 9 1 9

2 8 8 6

3 0 9 9

2 9 1 1

2 7 2 0

2 5 0 5

2 7 2 7

1 6 4 8

2 8 0 6

2 7 4 9

B a

1 3 1 3

1 7 4 6

1 5 6 1

2 0 4 9

1 9 1 5

1 7 0 3

1 4 5 9

1 4 6 2

1 9 2 4

1 9 6 4

2 2 1 3

2 2 6 1

2 2 2 6

1 6 5 6

2 0 0 0

1 6 6 1

1 1 5 3

7 1 5

1 5 5 8

1 4 4 1

S c

2 6 6

2 4 2

2 2 5

3 3 5

2 2 2

2 6 2

2 6 2

2 2 4

2 7 0

2 7 2

2 1 5

2 1 6

2 1 3

2 9 3

2 6 1

2 2 9

3 5 7

2 6 4

2 1 3

3 0 0

181


12/31


T a b l e 2 b : c o n t i n u e d

S a m p

l e :

L G V 2 7

L G V 2 8

L G V 2 9

R 0 1

R 0 2

R 0 7

R 0 3

R 0 4

R 0 5

R 0 6

R 0 8

R 0 9

R 1 0

R 1 1

R 1 2

R 1 3

R P 0 1

R P 0 2

R P 0 3

R P 0 4

I C P - M S

R b

1 0 5

1 5 8

1 5 2

2 1 0

1 6 0

1 9 4

1 0 2

1 4 8

2 0 4

1 7 8

2 5 9

2 4 5

2 4 9

4 6 9

2 0 4

1 6 7

1 6 9

9 2 3

2 7 1

1 8 5

S r

3 3 4

3 6 3

2 9 2

4 3 5

3 8 4

3 5 2

3 7 0

3 6 3

4 0 1

3 8 9

4 5 9

4 5 7

4 5 6

3 7 3

3 8 9

3 6 8

3 6 6

2 2 8

4 4 2

4 2 7

Y

2 7 4

2 3 9

2 1 3

2 4 6

2 2 5

2 5 4

2 5 9

2 3 3

2 4 8

2 3 9

2 9 0

2 9 0

2 9 2

2 5 0

2 2 4

2 2 4

1 7 . 2

3 2 5

3 3 5

N b

1 7 6

2 0 6

1 8 3

3 2 8

3 1 2

3 1 3

2 5 4

2 4 9

3 2 0

2 9 8

3 4 9

3 4 7

3 6 8

2 8 0

2 8 2

2 6 4

3 7 3

1 7 8

4 6 5

3 2 7

C s

0 1 7 8

0 1 4 2

0 0 9 8

0 2 2 0

0 1 0 4

0 2 1 4

0 0 6 8

0 1 9 8

0 1 8 8

0 1 4 3

0 1 6 7

0 1 8 6

0 1 6 6

0 0 5 5

0 1 0 4

0 3 4 1

0 1 8 5

0 0 8 3

0 1 6 0

0 0 7 3

B a

1 2 3

1 5 8

1 4 1

1 9 6

1 7 4

1 6 5

1 4 8

1 4 1

1 8 4

1 8 4

2 1 7

2 1 5

2 2 1

1 6 2

1 9 6

1 5 0

1 6 7

9 1

2 1 9

2 1 1

L a

1 7 7

1 9 2

1 7 3

2 3 4

2 3 6

2 3 3

1 9 8

2 0 3

2 1 7

2 1 9

2 6 3

2 6 3

2 7 2

2 0 8

2 1 3

2 0 7

2 1 1

1 1 3

2 6 5

2 5 1

C e

4 1 2

4 3 9

3 9 2

5 4 3

5 4 1

5 3 9

4 6 8

4 7 7

4 9 8

5 0 5

6 0 9

6 0 2

6 2 2

4 8 3

4 9 4

4 7 5

4 9 3

2 6 8

6 1 8

5 9 4

P r

5 5 5

5 6 6

5 1 3

6 9 9

6 7 8

6 9 4

6 1 2

6 2 7

6 4 3

6 5 0

7 7 2

7 6 8

7 8 7

6 2 2

6 1 6

6 0 1

6 4 5

3 5 7

8 0 4

7 6

8

N d

2 4 6

2 5 1

2 2 3

3 1 4

2 9 7

3 0 8

2 7 9

2 8 1

2 8 6

2 9 0

3 4 2

3 4 1

3 4 8

2 8 0

2 7 8

2 6 7

2 7 8

1 5 7

3 4 2

3 2 9

S m

5 8 7

5 7 2

5 0 4

7 0 2

6 4 8

7 0 2

6 5 8

6 4 8

6 4 4

6 5 5

7 6 3

7 6 0

7 8 1

6 3 4

6 0 0

5 8 5

6 1 6

3 6 4

7 5 1

7 3

3

E u

2 0 0

1 9 5

1 7 4

2 3 5

2 2 1

2 3 1

2 2 5

2 2 0

2 2 2

2 2 4

2 6 1

2 5 8

2 6 7

2 2 1

2 1 0

2 0 6

2 0 9

1 2 3

2 4 4

2 3

9

G d

6 3 6

6 4 0

5 2 3

7 0 7

6 6 9

7 3 1

7 0 7

6 6 7

6 8 7

6 8 8

8 0 6

7 9 3

8 1 7

6 9 2

6 4 1

6 3 2

6 2 8

3 7 8

7 4 3

7 2

5

T b

0 9 6

0 9 0

2 6 9

1 0 8

1 0 0

1 1 1

1 0 8

1 0 2

1 0 4

1 0 5

1 2 1

1 2 1

1 2 6

1 0 6

0 9 6

0 9 6

1 0 1

0 6 0

1 1 1

1 1

2

D y

5 4 6

5 0 2

4 4 6

5 9 2

5 5 6

6 2 3

6 1 7

5 6 7

5 8 9

5 8 1

6 7 6

6 8 0

6 9 3

5 9 1

5 3 4

5 4 1

5 4 4

3 2 9

6 2 5

6 2

5

H o

1 0 1

0 9 3

0 8 0

1 0 8

1 0 1

1 1 3

1 1 3

1 0 4

1 1 0

1 0 8

1 2 6

1 2 5

1 2 9

1 1 0

0 9 9

1 0 0

1 0 6

0 6 2

1 1 6

1 1

6

E r

2 5 9

2 3 6

1 9 8

2 6 9

2 5 8

2 8 4

2 8 9

2 6 0

2 7 8

2 7 2

3 2 0

3 1 9

3 2 3

2 7 5

2 4 8

2 4 5

2 6 7

1 5 8

3 0 0

3 0

4

Y b

2 0 0

1 7 7

1 6 1

2 1 1

2 0 3

2 2 8

2 3 4

2 0 7

2 2 7

2 2 2

2 5 7

2 5 9

2 6 0

2 2 2

2 0 3

1 9 6

2 2 2

1 3 5

2 4 6

2 4

8

L u

0 3 1

0 2 7

0 2 4

0 3 1

0 3 1

0 3 4

0 3 4

0 3 1

0 3 4

0 3 3

0 3 9

0 3 9

0 4 0

0 3 3

0 3 0

0 3 0

0 3 8

0 2 2

0 3 6

0 3

6

H f

4 6 7

4 5 6

4 1 9

6 8 9

6 3 8

6 5 2

6 0 3

5 9 4

6 0 7

6 0 9

7 1 2

7 1 0

7 2 8

5 7 9

5 6 1

5 3 9

5 5 9

3 3 0

6 4 2

5 9

7

P b

1 5 4

1 7 9

1 5 0

2 3 4

1 8 9

1 8 1

1 8 1

1 6 9

2 0 7

1 9 8

2 1 8

2 4 2

2 2 5

1 8 9

2 0 2

1 7 7

n . d .

n . d .

n . d .

n . d .

T h

2 1 6

2 4 3

2 1 7

2 9 6

2 8 6

2 8 2

2 3 9

2 3 5

2 7 0

2 5 6

3 3 1

3 2 7

3 4 5

2 6 1

2 6 5

2 6 2

3 1 3

1 6 0

3 4 6

3 3

2

U

0 5 2 6

0 3 3 2

0 5 7 4

0 7 1 4

0 6 7 1

0 7 3 0

0 5 4 0

0 6 5 0

0 6 9 0

0 6 8 9

0 8 2 7

0 8 2 7

0 8 8 3

0 6 5 2

0 6 5 8

0 6 2 1

0 8 0 4

0 4 3 2

0 9 4 0

0 4 4 9

a l k

0 2

4 6

0 0 7 5

0 0 8 6

0 6 3 7

0 9 0 4

0 4 4 4

0 5 6 0

0 6 1 2

0 3 8 5

0 5 9 4

0 9 4 2

1 0 2 4

1 0 9 4

0 3 7 5

0 9 4 4

0 5 7 0

0 2 6 6

0 1

4 6

1 0 9 5

0 8 4 3

E u

/ E u

1 0 0

0 9 9

1 0 4

1 0 2

1 0 3

0 9 9

1 0 1

1 0 2

1 0 2

1 0 2

1 0 2

1 0 2

1 0 2

1 0 2

1 0 4

1 0 4

0 9 7

0 9 9

1 0 0

1 0

0

8 7 S r /

8 6 S r

0 7 0 4 0 4 7

0 7 0 4 0 9 1

0 7 0 4 1 0 6 n . d .

n . d .

n . d .

n . d .

n . d .

n . d .

n . d .

n . d .

n . d .

n . d .

n . d .

n . d .

n . d .

0 7 0 4 1 7 9

0 7 0 4 1 2 2

0 7 0 4 1 3 6

0 7 0 4 0 8 3

182


13/31


14/31


Table 2b: continued

Sample: RP27 RP28 RP29 RP30 RP31 RP32 Steady-state

Elev (m): 810 790 760 750 740 720

XRFSiO 2 4770 4907 4736 4660 4704 4605 476Al2O 3 1495 1480 1418 1438 1667 1727 146FeO 1348 1289 1536 1451 1171 1294 121MgO 516 408 505 546 527 462 71CaO 1045 820 1007 962 1179 1116 106Na 2O 304 401 319 302 267 278 28K2O 092 148 084 103 053 073 08TiO 2 306 335 337 337 252 292 29MnO 018 019 021 019 016 019 02P2O 5 048 081 048 048 037 034 04Sum 9942 9889 10011 9865 9872 9899Nb 317 520 308 322 200 219 289

Zr 2018 2987 2289 2212 1478 1486 214Y 305 403 364 314 231 234 298Sr 450 497 429 403 462 458 414Rb 259 387 126 253 69 129 191Zn 1126 1204 1248 1156 889 944 107Cu 650 185 904 738 665 519 84Ni 362 33 244 334 372 235 114Cr 53 5 19 34 46 32 216V 3135 1988 3508 3449 2806 3222 288Ba 1573 2615 1273 1406 984 1070 159Sc 286 210 337 321 241 259 293ICP-MS

Rb 266 395 136 253 76 147 179Sr 456 506 438 402 473 483 399Y 305 395 359 315 238 246 276

Nb 415 664 441 419 265 301 315Cs 0440 0277 0416 0320 0166 0276 02Ba 217 328 212 199 142 165 179La 237 370 276 234 168 173 221Ce 542 843 576 549 399 406 510Pr 703 1062 816 719 530 542 66Nd 308 455 352 315 237 238 290Sm 661 918 759 678 516 533 65Eu 230 305 266 229 183 192 22Gd 634 881 738 665 494 518 67Tb 097 129 123 101 075 084 103Dy 566 734 670 590 451 474 58Ho 104 136 131 109 083 090 107Er 274 356 334 287 215 235 27Yb 227 287 275 234 176 190 22

Lu 033 043 050 035 027 032 034Hf 586 767 662 628 462 490 57Pb 224 279 250 208 150 180Th 314 498 326 303 195 225 28U 0729 1091 0764 0718 0402 0320 0684alk 0739 1766 0941 1237 0229 0900 044Eu/Eu 092 096 092 096 090 089 10387Sr/ 86Sr 0704074 0704086 0704129 0704123 0704117 0704065

Sample provenance: RPXX, Remparts; RXX, Nez-de-Buf; LGVXX, Langevin. Alkalinity index = (Na 2O + K2O) 037(SiO 2 39). Eu = 0327 8 (Sm Gd). Steady-state: mean value of basalts with 5% < MgO < 10%.

184


15/31


Fig. 5. The three oxide phases present in the Piton de la Fournaiselavas in a Fe 2+ vs Ti plot.

extremely similar to that described for the Mauna Loalava compositions by Rhodes (1988).

Fig. 3. Olivine compositions: histogramsof forsterite (bottom)and CaO Major elements(top) contents. The smallest rectangles correspond to one measurement. The mean value and standard deviation of selected

concentrations and elemental ratios in the whole-rock samples are given in Table 3. For many of thesediff erentiated lava ows from the Remparts series. The

common basalts cluster at the apex. This pattern is parameters, a smooth pattern of temporal evolution is

Fig. 4. Microphotographs of various dislocation patterns ind

piton de la franc

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