Industrialization affects heavy metal and carbon isotope concentrations in recent Baltic Sea sediments

Oeochimfca et Cosmochimica Acts, 1874, Vol. 38,

pp.823to 842. Pergamon PIWB. Printed in Northern Ireland

affectsheavy c~~en~~o~in recent

IndustrUzation

metal and carbon isotope Baltic Sea ~~en~~

HELMUT ERLENEEUSER, ER~XN SUESS*and HORSTWJXUCOMM Institut fur Reine und Angewandte Kernphysik der Universitiit Kiel, C-14-Labor, 23 Kiel, Olshausenstml3e 40-60, Geb. 32, West Germany (Recei&

30 July 1973; accepted irt revised form 30 November 1973)

Act-Recent sediment cores of the western Baltic Sea were analyzed for heavy metal and carbon isotope contents. The sedimentation rate was determined from mdiocarbon dates to be 1.4 mm/yr. The ‘recent age’ of the sediment was about 850 yr. Within the upper 20 cm of sediment, certain heavy metals became inoreasingly enriched towards the surface; Cd, Pb, Zn and Cu increased 7-, 4-, 3- and 2-fold, respectively, whereas Fe, Mn, Ni and Co remained unchtmged. Simultaneously, the radiocarbon content decreased by about 14 per cent. The enrichment in heavy metals as well as the decrease in the 14C-concentration during the last 130 & 30 yr parallels ~dustri~ growth as reflected in European fossil fuel cons~ption within that same period of time. The near-surface sediments are affected by residues released from fossil fuels at the rate of about 30 g/m* yr for the past two decades. The residues have a pronounced effect on the heavy metal and carbon isotope composition of the most Recent sediments allowing estimates to be made for sedimentation, erosion and heavy metal pollution.

in the most recent geologic deposits can help to determine rates of sedimentation, can aid in stratigraphic correlation and can give an idea of the state of pollution in certain sedimentary environments. For example, MTJROZTJMI et ab. (1969) convincingly demonstrated that the lead concentrations in the annual ice layers of Greenland and of the Antarctica distinctly mark the beginning, the growth, and the present explosive increase in lead in the atmosphere due to increasing industrialization. In the same manner, the gradual development of agricultural activity since prehistoric times has been determined in the stratigraphic record through cereal and weed pollen in bogs and lake sediments (FIRBAS, 1949; NILSSON, 1964; OVERBECP, 1950; AVERDIECK et al., 1972; STBAKA, 1970; SCIFMITZ, 1968; BORTLESON and LEE, 1972). These records were preserved because the rates of accumulation of ice, in the one case, and of lake sediments, in the others, were high. The background ooncentrations of the lead/pollen under investigation were low, and post-depositional changes such as mixing, degradation and mobilization could be excluded. In more common sedimentary en~ronments, however, favorable conditions are rare. Therefore, one generally observes a more or less unspecified or sudden increase of certain elements in sediments which is due to an increased rate of mobilization during the most recent period of deposition. Copper, zinc, lead, cadmium and mercury have been found to be enriched from 5 to 100 times in river sediments in Germany and the Netherlands (BAXAT et al., 1972, DE GROOT, 1971) and in Baltic Sea surface sediments along the ~dustr~hzed west coast of Sweden (O~usso~, INDUSTRXALIZATION effects

* Geologisch-Pal&ontoiogisches Institut und Museum der Universitlit Kiel, 23 Kiel, Olshausenstra6e 40-60, Geb. B 1, West Germany. t Contribution No. 26 of the Sonderforachungsbereich 95 ‘Interaction Se&Sea Bottom’, University of Kiel. 823

824

HELD

ERLENKIJUSER, ERWIN SOESS and HORST WILLKOMM

1970, OLAUSSON et ai., 1972). More recently, CHOW et al. (1973) were able to determine fluxes of ant~opoge~c lead to Southern Californian sedimentary basins. Along with these metals, a large excess of stable carbon isotopes from fossil fuels could as well be deposited locally which strongly dilutes the natural 14C-concentration resulting in abnormally old ages of recent sediments (K&,LE et al., 1972). The time since these more recent anthropogenic effects lirst appeared in the stratigraphic record could at best only be estimated, due to discontinuous sedimentation and erosion-particularly of river sediments. This has been further complicated by analyses of bulk surfabe sediment samples which represent too long a period of depositional history. In the western Baltic Sea, sedimentation is rapid (ZEITSCREL, 1965), the influence of industrial wastes is presumably high, and there is little reworking of the sediment beyond 20 m of water depth (Exow, 1972; SEIBOLD et al., 1971). Therefore, preservation and recognition of such ~d~try-related markers in the sediment was expected. The investigations on the near-surface sediments reported here are part of the joint research programme of ‘Sonderforschungsbereich 95’ Kiel University, for interdisciplinary research on problems of ‘Interaction Sea-Sea Bottom.’ METHODS The locations of the sediment cores are shown in Fig. 1. A gravity piston core with polyvinyl chloride liner of 150 cm length {core A-GC) and a Kastenlot core with zinc plated lining of 200 cm length (core A-KL, = W-Lab.-no.: KI-620) were taken (1971) in 28 m water depth at location A (5P031.0’N La-t, tO”l*l’E Long} in the outer EokernforderBucht. From the 6rst oore, heavy metals were determined, and from the second, carbon isotopes. A single Kastengreifer core with zinc plated lining of 34 cm length (core B-KG, = W-Lab.-no.: KI-483) was taken (1971) at location B (54’463’N Lat, 10°11*3’E Long) southwest of the Danish island of Aero for both analyses. The sediments were black-gray muds and sandy muds and appeared homogeneousexcept for a few quartz sand and organic-richlayers near the top. Radiographs ahowed a weak indistinct stratification throughout with a few filled vertical burrows. In the upper 5 cm of the cores from both locations bioturbation became more obvious, though it appeared to have a negligible effect on msss transport and sediment mixing. Sediment cores A-CC and A-KL were stored at +4% for less than two days and for three weeks, respectively, while sampling was completed; however, core B-KG was stored for 5 months.

From core A-GC, sediments were sampled in 1-3 cm sections at intervals closely spaced near the top and farther apart towards the bottom. Samples for cores A-KL and B-KG were taken from the material used for radiocarbondating. The sediments were washed free of interstitial salts, dried at 50°C, and ground for further analyses. Portions of the sediment samples were digestedin pemhloriojhydrofluoricacid, and iron, manganese, zinc and copper were directly determined by atomic absorption spectroscopy on appropriate diluted aliquots (RAMIREZM~oz, 1968). Before cadmium, lead, oobalt and nickel were measured, however, these elements were concentrated in 6 series of dithizon extracts at pH intervals of 0.5 units ranging between pH 8.5 and pH 11-O. All extracts were combined, the solvents evaporated, the residues digested in perchloricacid, and then the metal contents measuredby atomic absorptionspectrosoopy (KOCHand KOCH-DEDIC, 1964). A piece of coal residue found in core A-GC at 10 cm of depth was ignited at ea. 900°C, digested in hydrofluoric acid, and its metal concentrations determined in the same way as for the sediment samples. Reagent blanks were carried through the entire procedureand appropriatecorrectionsmade on the measuredconcentrations. Organic oarbon was determined voi~et~oa~y as CO, releasedwith ~eh~rnatels~~~ acid t~tment

Industrialization

affects heavy

metal and carbon isotope

concentrations

825

1

Fig. 1. Kicler

Bucht, western Baltic

Sea, bethymetry

and coring locations A and B.

(HARTet al., 1971) and aluminum was determined calorimetrically (RILEY, 1968). All results are listed in Table 1. The reproducibility of the analytical methods can be seen from the average absolute difference of several duplicate determinations for each element on various samples from different depths of the core (number of duplicates in brackets): Cd-O.1 ppm (3), Pb-6ppm (2), Zn-1Oppm (3), C o-3 ppm (3), Cu--8 ppm (3), Ni--50 ppm (6). Fe-O.2 per cent (3), Mn-40 ppm (5), C-org-0.06 per cent (2), Also,0.3 per cent (7). Carbon isotope determinationa The cores were cut into 1 or 2 cm thick slices (about 200-500 g wet weight or 60-120 g dry weight) parallel to the sediment surface. A rim of about 5-15 mm was discarded to avoid contamination by displaced materials adhering to the core liner walls. The final organic carbon yield was about l-2 g, which was suthcient for a gas counter filling. The carbonate mineral fraction, which is generally low in these sediments (&ON, 1972), was removed by hot 2 per cent HCl to exclude dating errors arising from fossil carbonate minerals mobilized by erosion of glacial marl (SEIBOLD et al., 1971). The samples were neutralized by repeated washing, centrifuging and decanting. There seemed to be no age fractionation with this procedure even though a part of the organic carbon might have been dissolved and subsequently discarded. This was confirmed by treating the samples with different HCl concentrations (1-5 per cent) for different lengths of time (05-5 hr) and obtaining identical ages. The sediments were ignited at 900% in a stream of oxygen. The carbon dioxide released underwent different steps of wet purification and was finally distilled from active charcoal (WILLKOMM

E~.ELMUTKnnnrfxnusn~,

826

E~WIX

SUESS and HORST WILLKOMM

Table 1. Trace metals, iron, manganese, organic carbon and ahnninum in sediments and coal ash from Kieler Buoht, Western Baltic Sea Depth

Cd

Pb

Zn

Cu

Co

Ni

Mn

(em)

(ppm)

(ppm)

(ppm)

(ppm)

(ppm)

(ppm)

(ppm)

Core A-GC, 1.87 1.60 1.23 I.85 1.39 1.59 1.00 1.15 1.29 0.80 0.85 0.53 0.33 0.33 0.35 057 0.41 0.30 0.26 0.24 0.26 0.28

82 69 49 68 55 52 51 74 60 65 54 58 22 23 19 28 25 17 23 19 23 20

340 335 260 335 310 250 270 310 290 260 265 220 140 135 140 200 120 115 130 110 115 125

17-019 19-021 22-024 24-026 27-028 31-033 36-038

1.1 06 0.5 0.5 0.3 0.3 0.3

57 56 53 30 36 32 31

(675)t (1500) (2050) (1890) (1520) (2200) (1860)

10

14.5

O-001 l-002 2-003 3-004 4-005 5-006 6-007 7-008 8-009 10-012 12-013 17-018 22-023 24-026 26-027 28-029 32-033 38-039 40-041 60-062 98-100 120-122

71 68 68 57 54 47 51 59 71 45 53 52 47 46 46 70 38 45 37 37 36 35

Core B-KG, 31 31 30 28 28 27 27

Eckernforder 15 15 11 18 16 15 9 12 13 16 16 15 13 15 18 26 14 12 8 14 13 11

Bucht 430 375 535 475 610 625 545 495 455 650 540 700 640 490 510 810 415 415 615 750 460 550

3.12 2-77 3.22 3.25 3.50 3.38 3.25 3.26 3.1% 3.81 3.45 3.73 3.22 3.20 3.47 4.14 2-97 2-97 3.19 3.53 3.18 3.41

5.48 5.29 4,PO 6.87 5.09 4.70 4.50 4.65 (500)* 550 5.54 5.61 4.31 4.50 5.15 5.79 4.54 4.98 5.33 5.13 5.78 6.78

9.25 10.45 8.95 9.60 9.65 9.50 9.40 10.60 9.90 11.40 10.55 9.55 9.90 10.00 10.25 12.40 8-40 9.70 985 10.30 11.55 8.10

42 43 45 40 40 40 40

580 765 730 735 685 580 790

3-75 3.93 4.10 3.84 4.10 3.58 4.01

5.30 5.23 50% 5.22 5.33 5.33 5.18

IO.40 IO.25 9.45 10.60 10.65 10-35 10.50

460

5750

a7 138 87 221 152 96 131 150 133 91 123 107 68 350 480 920 70 60 120 65 77 72

Southwest of Aero :3” 13 12 11 12 13

Coal ash, core A-GC 865

2950

755

177

21.0

nd.

8.70

* Interpolated. t Zn values not included because of possible contamination.

and ERLENXEUSER, 1970) to remove electronegative impurities that wonld disturb the counting procedure. The 14C-activity w&s determined with a proportional counter, the carbon dioxide being used as counting-gas (ERLENKEUSER, 1967). The carbon dioxide was stored for about 3 weeks before measurements were taken. This was long enough for the decay of possible easRn contamination from the sediment samples. The radiocarbon age was calculated with 8 l+Z-half-life of rlfs = 5568 yr (8th Conf. on Radiocarbon Dating); the standard error is based on counting statistics only. The radioc&rbon dates refer to A.D. 1950, the zero-point of the radiocarbon age scale, or B.P. (before present)scale.

Industrialization

affects heavy metal and carbon isotope concentrations

827

Mass spectrometer samples for determination of the stable carbon isotope ratio were taken The carbon-isotopes were measured from the purified gas, not from a separate preparation. against Solnhofen limestone and were corrected to the PDB-scale by &‘C (Solnbofen-PDB) = -1.06% according to CRAIG (1957). The standard error of the 6W detonation is 030/,. not including fractionation effects during the CO, preparation.

RESULTS Elemental distribution The concentrations of iron, m&nganese, cobalt, &lu~urn and orgsnic carbon in core A-GC were more or less constant over the entire length. Cadmium, lead, zinc and copper, however, were constant only below about 33 cm, and gradually increased in concentration from about 22 cm upward towards the sediment surface. Between 26 and 33 cm depth, a general increase of all elements was found, probably due to minerogenic sources. This was parti~~&rly pronounced with nickel which otherwise showed a constant ~st~bution with depth but had larger fluctuations than any of the other elements. The same distribution was found in core B-KG; iron, manganese, organic carbon, aluminum, nickel and cobalt were constant with depth, whereas cadmium, and particularly lead showed an increltse from 25 cm towards the surface. The increase of copper was insignificant and zinc showed far too high a concentration t~oughout, which presumably was due to storage effects from the zinc plated core boxes. It is uncertain to what extent the cadmium and lead contents of this core were also affected, and therefore further discussion on heavy metals is generally restricted to data from core A-GC. The coal ash contained 6-12 times more iron, manganese, cobalt, and nickel; and 13-40 times more zinc, copper, bad and cadmium than the sediment did. Figures 2a-e show for each element the excess, E, with depth as compared to its average concentration below 33 cm, concO, i.e. :

E=

con%e%?ured - COnCO

coq

At 100 per cent increase, B = +I, at 100 per cent decrease E = -1, and at no increase B = 0 for the respective element. Since no analyses of samples below 38 cm for core B-KG were made, those for core A-GC were used for reference. For clarity in each figure, an element without increase in concentration is arbitrarily combined with one that shows an increase towards the surface. Cadmium (Fig. 2a) shows the strongest increase; between 20 cm or 25 cm in the respective cores and the surface, the excess con~ent~tion in both cores gmdually increased, with some fluctuations, from 0 to 600 per cent. An 100 per cent increase in cadmium at 29 cm for core A-GC coincides with a similar increase in all the other elements at that depth, particularly with nickel and cobalt. Cobalt showed no other sign&ant ch&nge throughout both cores. Lead (Fig. 2b) was also excessively con~entr&~d from a depth of 20 cm and from 25 cm in the respective cores and reached an excess of 300 per cent at the surface. Zinc (Fig. 20) increased by 200 per cent between 20 cm of depth and the surface, but the manganese distribution was uniform. Copper (Fig. 2d) reached an excess of

328

HEJXUT

SUESSand HOWT

~~US~,~WIN

Excessconcmtration, 1

0

2

3

W~O~M

102 % 4

6

5

7

20 -

LO -

s

60 -

2

Tz

Lz 60 -

100 -

0

Cadmium

.

Cobalt

120 -

28 0

1

2

3

20

LO

5

60

i 6 d 60

100

I20

2b

2c

Fig. 2 a-e. Excess concentrationsof heavy metals, organic.oarbon, and aluminum in near-surfacesediments as compared to sediments below 33 cm of depth. Solid lines indicate core A-GC, dashed lines core B-KG. l?or clarity, an element without inarease in concentration is associated with one that shows sn increase towards the sediment surface, Fig. 2 cont. next page.

Industrialization affects heavy metal ad carbon isotope concentmtions Excess

concentration,

lO’%

/

v.

II

0

0 copper . oqaric Carbon

.

Fig. caption see previous page.

only 100 per cent at the surface, between 3-9 cm, and between 28-29 cm in core A-GC. A slight but insignificant deficiency of copper was found in core B-KG. Both cores showed uniform organic carbon distributions. Nickel (Fig. 2e) had the largest fluctuations within one core, as well as the largest differences between the two cores; B-KG had a 50 per cent deficiency and core A-GC a very large excess (up to 1000 per cent) in samples between 25-29 cm of depth. These variations are probably due to varying amounts of heavy minerals which also affects concentrations of other metals to a certain extent. No systematic change with depth can be attributed to nickel. Aluminum as a measure for the clay mineral content, was nearly constant in both cores and indicated no major dilution by quartz or carbonate constituents. Carbon isotope composition The 1% age-depth profile of the core A-KL is shown in Fig. 3. The upper parts of cores A-KL and B-KG are presented in Fig. 4a and Fig. 4b, respectively, with an enlarged depth scale. The data of Figs. 3 and 4 are based on the results listed in Tables 2 and 3 but have been normalized to PC (rDB) = -25x0 in order to correct for isotopic fractionation : a decrease of lx0 in PC will increase the ‘%-age by 16 yr (for details see ERLENKEUSER and WILLKOMM,1973a). This correction scheme will be approximately correct, since the major fraction of the organic carbon in these sediments originates from one source, namely the primary production. The minor constituents of different 14C-content as discussed in the present work 2

830

HELD

ERLENKEUSEB,ERWIN SUESS and HORST WILLKO~~~ “C

Age,

y

Fig. 3. Radiocarbon age va depth within the sedimentsof core A-KL (SKI-620). The radiocarbon dates are corrected to S1*C,pBD, = -25x,. The regression line results from a least square fit of the data below 19 cm of depth.

do not affect the stable carbon isotope ratios appreciably with respect to the 14Cdates. The rate of sedimentation is 1.4 mm/yr at greater depth and is rather constant (Fig. 3). At about 20 cm of depth, however, a deviation from the expected trend was found, with radiocarbon age increasing towards the surface (Fig. 3, Fig. 4a). A similar deviation was found in core B-KG (Fig. 4b). Here the inversion starts at somewhat greater depth indicating a sedimentation rate l-2-times higher than that of core A-KL. Normalizing the sample depths with regard to that difference, the 14C-ageregressions were found to coincide for both profiles. At 8 cm depth, a second inversion was found that was not recognized in core A-KL nor in two other cores from the outer Flensburger Bucht (unpublished). The stable carbon isotope ratios for the deeper sediments (i.e. below 30 cm) lie in the range of PCu,ns, about -22 to -23x,. In the upper part they are somewhat lower, about -23 to -24x0 In core B-KG they show a clear relationship to depth within the upper 10 cm layer (Table 3).

Carbon isotope composition

Assuming constant sedimentation, a rate of 1.4 f O-1mm/yr is calculated from the W-dates of core A-KL below 20 cm of depth (Fig. 3). ZEITSCHEL (1965) reports a somewhat higher value for fresh unconsolidated seston at nearly the same location.

Industrialization

af&cts heavy metal and carbon isotope concentrations

-6

-12

-16

E 0

i

-20

f 0

-?I,

-28

-32

-36

Fig. k-b. Radioc~bon age of near-surface sediments ve. depth. (a) Core A-KL ( E KI-620), the dotted line represents the extrapolation of the regression line calculated from the samples between 20 and 150 cm of depth. The statistical uncertainty is indicated by the bars. Radiocarbon values are corrected to G1*Co.nsl = -25x,. (b) Core B-KG (SKI-483), the dotted line starts from a point at the average age of the three samples below 24 cm and proceeds at a rate I-2-times that of core A-KL.

This compares

with the thickness of the Late Pleistocene and Holocene the Kieler Bucht, which are anywhere from 10 to 66 m thick (HINZ et al., 1371). For the upper 20 cm of depth no sedimentation rate can be calculated from the W-dates, It seems only reasonable to assume the same rste for this layer as for greater depths, even if a! small error may be ~t~du~d due to consolidation effects. Then this assumption of a constant sedimentation rate of 1.4 mm/yr indicates for the sediment surface a 14C-age of 850 yr B.P. But, unfortunately, this age of the surface can not be directly measured since it is masked by the anthropogenic effects on the 14C-concentration of recent sediment samples. The sediment surface of core B-KG similsrly shows a 14C-age of about 700 yr, if one extrapolates from 28 cm depth to the surface calculating with a segmentation rate of 1.2~times that of core A-KL (Fig. 4b), the W-dates for depths between 26 and 32 cm are thought to not reflect the industrial effects that contaminate the upper dates. Two cores from the adjacent outer Flensburger Bucht yielded surface W-dates of 760 + 60 and 650 f 100 yr B.P. (unpublished data). The surf&cc!14C-age is the ‘recent age’ of the sedimentary en~ronment-it is the ‘zero-age’ of the sediment age scale. If the 14C-age of any of these samples is compered with 14C-dates of terrestrial samples or with the conventional calendar scale, this ‘recent age’ must be subtracted. sediments

favorably

within

832

HELISUTERLBXKBVSER,ERWIN SVESS and HORST WILLKO~K Table 2, W and 8Y! values of core A-KL ( =KI-6201, age calculationsare unoor~t~ for S’V Kieler Bucht sediments Core A-KL rz HI-620, Eekernforder Buoht

Lab.

no. 620.01 620.02 620-03 620-04 620.05 620.06 620.07 620.08 620.09 620.11 620.20 620.24 620.36 620.37 620.45 620.472* 620.50 620.61 620.74

Depth below surface

(on-d o-5 5-7 7-9 Q-l 1 11-13 13-15 15-17 19-21 23-25 41-43 49-51 73-75 75-77 91-93 93-99 101-103 123-125 149-151

Libby age k.1 u B.P. 1930 2120 1450 1290 1400 1080 1105 935 930 1155 1205 1485 1290 1500 1450 1555 1670 1860

* * & f f f i

85 70 70 55 75 85 40

f + * f f f * * f + &

55 40 60 50 60 40 40 55 40 70 65

PC IPDB , (X1 -23.7 -23.7 -22.6 -21.3 -236 -23.5 - 22.5 -22.1 -239 -22.4 -22.6 -22.4 -21-9 -23.8 -23.4 -23.3 -23.0

* NaOH extracted fraction (humicacids).

A zero-age of zero years could be expected only for samples which derive their carbon exclusively from the atmospheric CO,. For other environments, a higher zero-age may result, e.g. Central European fresh water carbonates have zero-age values of up to 1500 yr (M~~NNICR, 1968). The zero-age reflects the admixture of fossil carbon that is 14Cinactive. Recent investigations on the 14Ccontent of present surface waters and benthonic organisms from the Western Baltic Sea and the Sk~e~ak-Kattegat area suggest that the 14Cconcentration of the bicarbonate in the Baltic surface waters prior to the input of artificial 14Cfrom the atomic bomb tests was in near-equ~ibrium with the 14Ccontent of the atmospheric carbon dioxide. Consequently, the autoehthonous organic carbon of the sediment would yield a surface age of about zero years. Since, however, the real zero-age is considerably higher, fossil organic carbon must presumably be mixed with the sediment. This organic carbon probably is mobilized from glacial marl by erosion of coastal cliffs. The increase in 14C-activity in core B-KG which was observed above 8 cm depth might be caused by artificial 14Cwhich was introduced into the atmosphere after 1954 and especially in the years L962/1963by atomic fusion bomb tests (e.g. VOGEL, 19'72).The atmospheric 1%~level was temporarily raised to 200 per cent of the pre-bomb era and it is now at about 145 per cent of the undisturbed natural I%activity [This activity is 95 per cent of the NBS oxalic acid standard activity; this

Industrializationaffects heavy metal and carbon isotope concentrations

a33

Table 3. W and WC values of core B-KG ( =KI-483), age calculationsare uncorrected for 618C Core B-KG E KIC-483,Southwest of Aero Lab. no.

Depth below surface (cm)

483.01 483.02 483.03 483.04 483.05 483.06 483.07 483.08 483.09 483.10 483.1 I 483.12 483.13 483.14 483.15 483.16 483.17 483.18 483.19 483.20 483.21 483.22

O-2-0 2.0-3-2 3.2-4.4 4.4-5.6 5.6-6.8 6.8-8-O 8.0-9.2 9.2-10.4 104-11.6 11.6-12.8 12.8-14.0 14.0-16.2 X.2-16.4 164-18.8 18.8-21.2 21.2-23.6 23.6-26-O 26.0-28.4 284-30.8 30.8-33.2 33.2-35.6 35-6-38.0

Libby age fl CT B.P. 540 450 680 955 900 1060 1625 1480 1475 1065 1325 1098 1120 1110 1055 920 810

f 46 & 60 & 65 & 55 + 40 f 85 j, 65 & 60 j, 70 f 60 j, 45 & 80 rfi45 f 56 & 55 i. 50 rtr:60

750 & 55 940 Tiz: 60

WC (PDB) (%o) -24.4 -23.6 -23.9 -23.6 -23.0 -22.7 -22.7 -22.2 -22.4 -22.6 -22.2 -23.4 -21.2 -21.2 -21.6 -21.4 -21.8 -22.6 -21.1 -22.6 -23.0 -22.4

figure is adjusted to the 14C-activity of wood from A.D. 1850 (GODWIN, 1962)]. The subsequent increase in open ocean surface waters amounts to 110-120 per cent in the northern hemisphere (GULLIKSEN and NYDAL, 1972). Today in Kieler Bucht surface waters, as well as in benthonic organisms, it is at 135 per cent (ERLENKEUSER and Wagon, 1973b). However, to transport artificial i*C down to a depth of 7 cm of sediment, a strong mixing effect must be assumed. This might be accomplished by burrowing organisms, yet there is little evidence for this from the radiographs as mentioned earlier, or by fishing trawler activity, which is very high in this area. However, the 613C-values that decrease from -22~4%~ at 10 cm depth to -24~4%~ at the surface (Table 3) give some evidence that material of terrestrial origin might be admixed to these surface sediments. In Kieler Bucht sediments the PCPnB values are about -21 to -23%,. That is well within the range found for other marine samples (WILLIAMSand GORDON,1970). Terrestriai plants show 613Cof about -25x, and radiocarbon concentrations near 100 per cent (or higher for the last decade). Thus an admixture of terrestrial material would agree with both the ISC and 14C results. A possible source of terrestrial organic compounds may arise from dumping of sewage sludge just in this part of the Kieler Bucht by some of the coastal cities. Sewage particulates seem to be deposited rather fast thus being restricted mainly to the area of dumping. This is suggested

834

IFIEL~

ERWINSuxss end

blush,

HORST W~.KOXM

by the steep mercury concentration gradients in seawater found in a sludge dumping area in the Irish Sea (&%RlmER and RILEY, 1973). The increasing age in the upper layer gives evidence of an increasing amount of older carbon admixed to the sediment. Assuming the sedimentation rate found in greater depths also to be valid for the surface layers, this effect seems to start at about 150 yr ago (E’ig. 6b). In view of the heavy metal content which is found to increase simultaneously with the increase in radiocarbon age, we think that the change is caused by the admixture of fossil carbon mobilized by industrial activity. If ypc denotes the fossil coal percentage of the total organic carbon content then the l*C-age excess AT is given by AT = -rtimesln -

(1 -$$)

80 times yrc

7 = 8033 yr = 14C-life-time. Thus, an addition of 1 per cent fossil carbon will cause an increase in radiocarbon age of 80 yr. From this relationship, the total organic carbon is calculated to contain up to 14 per cent fossil carbon. If the sedimentation rate in the upper part of the cores is somewhat higher than assumed from the linear se~men~tion model, the calcuIated fossil carbon content will be reduced at the most by 2 per cent. It

M

1950

1900

1050

‘SO0

1750

0

..h

b

i I

c

Fig. Sa-c. Trace metal and carbon isotope stratigraphy of Kieler Bucht sediments. European coal production (a) (A = coal,l3 = lignite) is compared with the increase of radiocarbon age (b) and with the supply of hetEvymetals to the nearsurface sediments (cf. In (b) and (c) the time scale is calculated from the depth scale assuming linear sedimentation of a rate of 1.4 mm@-, M = minerogenic accumulation.

Industrialization a&&s heavy metal and carbon isotopeconcentrations

836

may be even another 1-2 per cent less if one takes into account the dilution of the atmospheric 1%activity by CO, released from fossil fuels (Suess-effect). This effect gradually increased from the end of the last century up to the present time. In detail, the extent to which Kieler Bucht water is affected depends upon the mixing ratio of oceanic and eastern Baltic Sea waters (DIETR~OH,1950), and the estimate of fossil carbon addition given above is an upper limit. The admixture of fossil carbon should be noticed in the stable carbon isotope ratios, since the 8% values of foasil coal are lower by about 3-5x, than those of the undisturbed sediment. A corresponding decrease of 6X! towards the surface is seen from the measured data (Tables 2 and 3). The effect is not very sensitive to the mixing ratio, however, because the 6l9c difference of the components is small and the 81% for the sediments show a large spread due to natural fractionation effeots. Heavy metal content The increased mobilization of heavy metals through burning of fossil fuels (coal and oil) has been discussed by BERRNE and GOLDBERG(1971). Accordingly, the amounts of Cd, Pb, Zn and Cu mobilized through burning of coal is between 70- and 200~times higher than through combustion of oil; therefore, our discussion will be restricted to coal as potentially the more important source of these metals. This assumption is supported by the occurrence of coal pieces and slag fragments in the coarse grain size classes in sediments from the Western Baltic Sea (personal commutation, F. Werner, I%. Hartmann, R. Dold, U~versity of Kiel). But coal ash and coal residue particles of dif?erent origin, e.g. aerosols, may also be preferentially concentrated in the small grain size classes and are thus more difficult to identify. Identification of ooal as the major source of heavy metals depends upon the relative different amounts of Cd, Pb, Zn and Cu in coal and in sediments as listed in Table 4. Line la shows the average metal concentration of the deeper part of oore A-GC which is presumably unaffected by anthropogenic input. The data compare well with those listed as the average values for mobilization of the same eight metals by chemical and physical weathering of rocks (Table 4, lb ; BERTINE and GOLDBERG, 1971; TVIXEXUAX and WEDEPOEL,1961; HJRST, 1962; PIPER, 197X; WEDEPOHL, 1960,1972). A~~or~ngly, normal weathering may cause deposition of these eight metals in the relative amounts in ppm of dry sediment as listed in Table 4, la. The relative amounts of metals presently accumulating at the depositional interface in the Eckernfijrder Bucht are listed in Table 4, le. A ‘pure anthropogenic’ sediment, however, consisting of coal-ash, of aerosol particles (slag), and of residues from oil would contain these metals in far larger and quite different relative amounts, listed in ppm on a carbon- and water-free basis in Table 4,2a. The relative amounts are quite similar to those of coal ash as compiled by BERTINEand GOLDBERQ (1971), if one assumes an ash oontent of 5 per cent (Table 4, 2b), and are therefore believed to be representative for coal ash in general, The en~chment of the eight metals in coal ash is for Cd 54-times, Pb 43-, Zn 25-,

KELP

836

ERLENKEUSER,ERWIN Sums and HORST WILL~OM~~

Table 4. Heavy metals in sediments and coal residuesin ppm of dry weight

la Sediments, below 30 cm, Eckernforder Bucht b Sediments, nearshore marine environment c Sediments, depos. interface EckernforderBucht 2a Coal ash, from EckernforderBucht b Coal ash, 95 %wt. loss on ignition* 3a Enrichment, coal ash over sediment, 2a/la b Enrichment, surface/ deep sediment, lc/la 4

Enrichment, mixture 93 % sediment and 7 % coal ash

Cd

Pb

Zn

cu

Fe

Mn

Ni

Co

0.27

20

117

38

32.000

470

70

13

0.5

21

80

80

50,000

500

100

8

1.9

82

340

71

31,200

430

87

15

14.5

865

2950

755

210,000

5750

460

177

170,000

900

270

90

7

12

7

13

14-600t 440

54

43

600-5000t

270

25

20

6.9

4.1

2.9

1.9

1

1

1

I

4.7

3.9

2.8

2.3

1.4

1.8

1.4

1.8

* Data from BIZRTINEand GOLDBERG,1971. t Data from GLUSKOTERand LIND~L, 1973.

Fe 7-, Mn 12-, Ni 7- and Co lbtimes as great as in unaffected normal sediments (Table 4, 3a). However, the metal enrichment in the surface sediment samples, compared to the deeper sediments, was found to be: Cd 6.9-times, Pb 4-l-, Zn 2*9-, Cu lag-times but remained unaffected for Fe, Mn, Ni and Co (Table 4, 3b). These enrichment figures may be produced by gradually mixing increasing amounts of coal ash into the normal sediment. The maximum amount required is about 7 per cent by weight added to the surface sediment. This amount is so small that the resulting effects on iron, manganese, cobalt and nickel concentrations from normal chemical weathering are difficult to detect; on the other hand, cadmium, lead, zinc and copper become strongly enriched causing the high metal contents for the mixture as a whole (Table 4, 4). If one assumes a water content for the near surface sediments of 350 per cent of its dry weight and a wet density of la’16g/cm3, as reported for similar sediments in the western and central Baltic Sea (K~~GLER, 1967; POUR-NAGHSHBAND, 1972), then the present rates of accumulation of anthropogenically-mobilized heavy metals and fossil carbon are as follows: 80 mg Zn/ma/yr 22 mg Pb/m+ 12 mg Cu/m’/yr 0.58 mg Cd/me& ----2.4 g C/mW. Cu 20-,

~d~t~&~tioR

af%ots heavy metal and carbon isotope concentrations

837

The latter de~aition rate is calculated from the r~ocarbon analyses. The W-age deviation from linear segmentation, that is about 1100 yr in the upper hyer of core A-KL (Fig. 4a) indicates a fossil coal content of about 13 per cent of the total organic carbon or 0*65 per oent of the sediment dry weight. Accumulation rates for the sum of anthropogenically-mobilized Zn, Pb, Cu and Cd from about A.D. 1800 to the present time are shown in Fig. SC,where the distance M represents the minerogenic accumulation of the same four heavy metals. This would place the beginning of industrialization effects at about the year 1820 if no bioturbation had occurred within the sediment. M~LOZUMIet al. (1969) concluded that lead from wind-transported, industry-related particles settled out from the atmosphere on to the Greenland and Antarctic ice sheets around 1850. Technological growth during the past 100 yr was also thought responsible for a 2 to J-fold increase in the mercury of limnic sediments reported by ASTONet al. (1973). The accumulation rates of the metaIs compare well with the total deposition rates of these elements from the air, found by PEIRSONet al. (1973) at a rural station near the western coast of central England. However, these rates depend strongly on the location of the sampling sites in relation to industrial districts as well as on the meteorological conditions (PETRENCHUCK and SELEZNEVA,1970, E~OROVet al., 1970). The accumulation rates above are also comparable to data presented by OLAUSSON(1970) for sediments of the west coast of Sweden which are influenced by industrial waste, and for lead are identical to those recently reported for the Santa Barbara Basin off Southern California (CHOW et al., 1973). If these non-minerogenic metals have toxic effects on marine life and if their concentrations exceed certain limits they are pollutants, and from the foregoing interpretation it is easy to extrapolate when the sediment of the western Baltic Sea may exceed these limits. It should be pointed out that the heavy metal increase observed here is apparently not just an effect of the last 20 or 30 yr as is often the case with other well-publicized cases of pollution. It appears rather to be a long-term effect which probably reflects the state of pollution for a much larger area of the Baltic Sea. The source and supply of coal residue from production figures for coal and lignite during the past 70-80 yr in central Europe are discussed below. Sorption processes and diagenesis, are briefly considered as two al~rnative mechanisms which may, under special conditions, produce a similar enrichment of heavy metals in nearsurface sediments. It should be emphasized that this discussion is intended to show that these figures and the related estimates of fossil carbon and metal input do not contradict our interpretation but in fact support our hypothesis of an interrelation of these two components in the sediments. Xorptiolaand diagenetic processes Organic carbon varies little throughout the core. The clay-mineral composition also shows no change according to aluminum-and X-ray&f&action-analyses. Ill&e, chlorite, rnontrno~o~~ and kaolinite are present in roughly oonstant proportions. Therefore, sorption promses for uadmium, lead, zino tend copper with

838

HELM

ERIJZNKEUSER, ERWINSUESSand HORSTWILLKOMM

organic matter or clay minerals at a constant rate of supply are not responsible for the increase in the metals near the top of the cores (DUURSMA,1970; ASTONand DUURSMA,1973). Also, there was no indication of a major change in redox potential, either during sedimentation or afterwards within the sediment, which could have tied varying amounts of metals as sulfides at different times. HARTMANNand NIELSEN(1969) have shown that the sulfide sulfur content in cores from the western Baltic Sea in general and from location A, in particular, reach rather high values of around 1 per cent right below the water sediment interface (3-4 cm) and increase only slightly with depth. This indicates that a very thin (thinner than 1 cm) oxidizing layer covered the reducing sediment probably during deposition of at least 200 cm of sediment. These strong and permanent reducing conditions near the sedimentrwater interface further exclude any Eh-dependent diagenetic processes having concentrated the heavy metals near the surface. Such a mechanism, known from Atlantic and Pacific Ocean sediments (VANDERWEIJDEN, SCHUILINQ and DAS, 1970; BONATTIet al., 1971), requires a strong Eh gradient within the sediment, so that at low Eh values iron, manganese, copper, nickel and cobalt are mobilized and later, under more positive Eh conditions, reprecipitated. Consequently the increase of certain heavy metals here in Baltic Sea sediments could reflect only an increasing supply from anthropogenic material. Although we did not analyse the isotopic composition of lead, additives to automobile fuel as a source can be eliminated as it has become dominant in sediments dating from only about A.D. 1930 according to CHOWet al. (1973) in their studies of sediments off Southern California, and could not have affected the sediment layers as early as A.D. 1850. Source and supply of coal residue The time dependency of the supply of fossil coal to the sediments as indicated by the increasing radiocarbon age may be compared to the annual coal output of Northwest Europe (Fig. 5a, b). In Fig. 5a, the coal production in lo6 tons/yr of Great Britain, France, Netherlands, Belgium, East and West Germany, Czechoslovakia and Poland are summarized (A), while (B) shows the lignite output of East Germany, Poland, Czechoslovakia and West Germany (HIRZ, 1949 ; UNTERNEHMENSVERBANDRTJXRBERQBAU, 1955; JAHRBUCHBER~BAU, 1972; HILTMANN,1972). The data before 1884 were estimated by assuming a doubling of coal output for every 20 yr. The simultaneous increase in the world coal production is probably reflected best by the dilution of the atmospheric 14C-content by CO, released from fossil fuels (Suess-effect or industry-effect; SUESS, 1955). As has been shown by DE VRIES (1958) and recently by LERMANet al. (1970) in numerous measurements of tree ring samples of known age from different locations throughout the world, the fossil CO, release starts at about 1870-1900 just about the time when fossil coal also becomes recognizable in the sediments. The fossil coal accumulation rate of 2-4 g/ma/yr as found in the Western Baltic Sea sediments is considerably higher (by a factor of lOa) than the estimate by SMITHet al. (1973) for a global average. But industrial waste products are much more likely to be distributed locally near the industrial sites than distributed evenly

~d~t~~lization affeotsheavy metal and carbonisotopecon~ntrationa

839

on a global scale (DEOSDOTA etal.,1970, EGOROVet al., 1970, PEIRSONet al., 1973). ~on~derable amounts of heavy metals and fossil fuel carbon are oarried by aerosols that are released by fuel burning. To estimate the carbon and heavy metal fallout due to this source one might take an area of northwestern Europe roughly between 47” and 55” N Lat and 5” and 22* E Long, representing I.5 x IO*kma. The annual amount of carbon deposition in this area is calculated on the basis of 2.4 g/me/yr to be 3.6 x IO6tonslyr. This is about 3~6%~of the total fossil fuel consumption of about 1000 x lo6 tonsjyr, in the same area. For 1969~70, VESTER (1973)reported 3.2 x IO*tonslyr of aerosols reIeased from fossil fuel burning within the Federal Republic of Germany alone. (The total atmospheric load of dust and gases, not including CO,, is considerably higher; namely 20 x log tonslyr.) The fossil fuel energy consumption at the same time is about 300 x lo6 tons/yr. Thus about 10 to 15 x IO6tons of fuel residues may be injected annually into the atmosphere over northwestern Europe. This is equal to an accumulation rate of 7-10 g~rnz~~. Assuming a residual carbon content of 8 per cent and a combined heavy meta content of 4500 ppm (Zn + Cu + Pb + Cd) one may calculate deposition rates of O-7 g C&Jm*/yr and 40 mg of metals/m2/yr. This is less than the 2.4 g C/m2/yr and 120 mg of metals/m2/yr found in the Baltic Sea surface sediments. These Sgures suggest an ash supply of 30 g~rn2lyr. However, we think that this is a reasonable agreement because deposits from the air might become concentrated in the Baltic Sea basins by runoff from adjacent land areas and by subsequent sedimentation of the fine grained particuIates in the deeper parts of the Kieler Bucht. AclcnowEedgements-We wish to thank H. METZNER for mass-spectrometer analyses, U. TITZ and C. KOWA.LEWSKIfor assistance in traceelementdetermination and preparationof the manuscript, respectively. The counting equipment was operated by FL FINN. We are particularly indebted to F. W’ERNER who arranged for and assisted with sediment sampling procedures and for his helpful comments, as well as to W. HILTMANN who helped make available data on European coal production. The financial support of the Deutsche Forschun~geme~sohaft within the joint research program ‘Sonderforschungsbereich 95’ is gratefully acknowledged. REFERENCES ASTON S. R. and DWR~NA E. K. (1973) Concentration elects of Y%, 062n,*OCo,l@SRusorption by marine sediments with geochemical implications. Neth. J. Sea Res., Radioactivity in the Sea, f&225-240. ASTON S. R., BRUTY D., CHESTER R. and PADGHAM R. C. (1973) Mercury in lake sediments: a possible indicator of technological growth. Nature 241,450-451. A=RDIECK F. R., ERLENKEUSERH. and WILLKOMM H. (1972) Altersbestimmnngen an Sedi_ menten des GroBen Segeberger Sees. ~c~~~f~er~ ~~tz~~~. Ver. ~c~~~g-~o~te~~ 42, 47-57. BANAT K., F~RSTER U. and MUELLERG. (1972) Schwcrmetalle in Sedimenten von Donau, Rhein, Ems, Weser nnd Elbe im Bereich der Bundesrepublik Deutschland. Natecp&@aen_

~~~ft~ 59, 625-528.

BERTINE K. K. and GO~DBERUE. D. (1971) Fossil fuel combustion and the major sedimentary cycle. Science 173, 233-235. BONATTI E., FISHER D. E., JOENSW 0. and RYL)A~L H. S. (1971) Post&positional mobility of some transition elements, phosphors, uranium and thorium in deep-sea sediments. cfeo&m. Cosmochim, Acta 55, 189-201. BORTIXSON G. C. and LEE; G. F. (1972) Recent sedimentary history of Lake Mendot+ Wisconsin. ~~~~~. 6%. ~ec~~o~. 6, 799-808. CHOW T. J., BRYJ~ANDK. W., B~RTINE K., SOUTARA., Kornn M. and GOLDBERGE. D. (1973) Lead pollution: records in Southern California coastal sediments. &‘&ems 181, 551.

840

HELWUT ERLENKEUSER, ERWIN Suxss and HORST WILLKOMM

Csara H. (1957) Isotopic standards for carbon and oxygen and correction factors for mass spectrometric analysis of carbon dioxide. Geochim. Coemochim. Acta 12, 133-149. DIETRICH G. (1950) Die natiirlichen Regionen von Nord- und Ostsee auf hydrographischer Grundlage. Kiel. Meere&rsch. 7, 35-69. DROZDOVA V. M. and MA~HON’KO E. P. (1970) Content of trace elements in precipitation. J. Geophye. Rea. ‘X&3616-3612. Dounsnna E. K. (1970) Organic chelation of “‘Co and OSZnby leucine in relation to sorption by sediments. In Organic Matter in Natural Waters, (editor D. W. Hood), Publication 1, pp. 387-397. Inst. Mar. Science, University of Alaska. EGOROV V. V., ZHIUALOVSKAJAT. N. and MALA~HOV S. G. (1970) Microelement content of surface air above the continent and the ocean. J. Beophys. Res. 75, 3651-3656. ERLEN~EUSER H. (1967) Uber eine Anlage fur Radiocarbon Datierungen mit einem CO, Proportional-Zahlrohr. Forschungsbericht K 67-32 des Bundesministeriums fiir wissenschaftliche Forschung der Bundesrepublik Deutschland, 26 pp. ERLENXEUSER H. and WILLKOMM H. (1973a) Data processing in 14C!measurements II: age calculation. Atomkernenergie 22, 90-94. ERLENKEUSER H. and WILLKOMM H. (1973b) University of Kiel radiocarbon measurements VII. Radiocarbon 15, 113-126. EXON N. (1972) Sedimentation in the outer Flensburg Fjord area (Baltic Sea) since the last glaciation. Meyniana 22, 5-62. FIRBAS F. (1949) iS’p&- und nacheiezeitliche Waldgeachichte Mitteleuropas niirdlich der Alpen, 480 pp. Verlag G. Fischer. GARDNER D. and RILEY J. P. (1973) Distribution of dissolved mercury in the Irish Sea. Nature 241, 526-527. GLUSKOTERH. J. and LINDAHL P. C. (1973) Cadmium: mode of occurrence in Illinois coal. Science 181, 264. GODWIN H. (1962) Radiocarbon Dating Fifth International Conference. Nature 195, 943-945. DE GROOTA. J., DE GOEIJ J. J. M. and ZEQERSC. (1971) Contents and behaviour of mercury as compared with other heavy metals in sediments from the rivers Rhine and Ems. Ueol. Mijnbouw 50,393-398. GULLIKSEN ST. and NYDAL R. (1972) Further calculations on the C-14 exchange between the ocean and the atmosphere. Proc. 8th Int. Conf. Radiocarbon Dating, pp. 282-296. The Royal Society of New Zealand, Wellington. HARTMANN M. and NIELSON H. (1969) G*%-Werte in rezenten Meeressedimenten und ihre Deutung am Beispiel einiger Sedimentprofile aus der westlichen Ostsee. Geol. Rundsch. 58, 621-655. HARTMANNM., LANGE H., SEIBOLDE. and WALGER E. (1971) Oberflachensedimente im Persisthen Golf und Golf von Oman. I. Geologisch-hydrologischer Rahmen und erste sedimentologische Ergebnisse. “Meteo+’ Porschungs Ergebnisse C4, l-76. HILTMANN W. (1972) (personal communication), Lehrstuhl fiir Geologie der festen Brennstoffe, TH Aachen. HINZ K., K~OLER F. C., RICHTER I. and SEIBOLDE. (1971) Reflexionsseismische Untersuchungen mit einer pneumatischen Schallquelle und einem Sedimentecholot in der westlichen Ostse+II. Meyniam 21, 17-24. HIRST D. M. (1962) The geochemistry of modern sediments from the Gulf of Paria-II. The location and distribution of trace elements. Geochim. Cosmochim. Acta 26, 1147-1187. HIRZ H. (1949) Entwicklung und Stand der Technik des Braunkohlentagebaus. Braunkohle, W&me, Energie 1,3-14. KOCH 0. G. and KOCH-DEDIC G. A. (1964) Handbuch der SprenanaZyse, 1232 pp. SpringerVerlag, Berlin. K&+LER F. C. (1967) Geotechnical properties of recent marine sediments from the Arabian Sea and the Baltic Sea. In Marine Beotechnique, (editor A. F. RICHARDS), 327 pp. University of Illinois Press, Urbana. K~LLE W., Rur H. and STIE~LITZ L. (1972) Die Belastung des Rheins mit organischen Schadstoffen. Naturwk8enschoft~ 59, 299-305.

Industrialization affects heavy metal and carbon isotope concentrations

841

J. C., MOOK W. G. and VOUEL J. C. (1970) C 14 in tree rings from different loctxlitiee. In Twelfth Nobel Symposium: Radiocarbon Variutiuns and Absolute Chronology, (titir I. U. Olsson), pp. 275-296.Almquist t Wiksell and Wiley. M~NNICH K. 0. (1968) Isotopen-Datierung von Grundwasser. Natururiseerasclrafteni&168-163. MUROZUIYII M., CHOW T. J. and PATTERSONC. (1969) Chemical concentrations of pollutant lead aerosols, terrestrial dust and sea salts in Greenland and Antarctic snow strata. Ueochim. Cosmochim. Acta 33, 1247-1292. NILSSON T. (1964) Standard Pollendiagramme und Cl’-Datierungen aus dem Agerods Mosse im Mittleren Schonen. Publication 124, 52 pp. Institute of Mineralogy, Paleontology and Quaternary Geology, University of Lund, Sweden. OLAUSSONE. (1970) Water sediment exchange and recycling of pollutants through biogeochemical processes. Medd. Maringeol. Lab. Bijteborg, No. 3, l-8. OLAUSSON E., B;~CEMANE., GUSTAFSSONO., KA~LSSON L. G., SurrnsrnijadB. and SVENSSONR. (1972) Sedimentundersokningar pit Vlistkusten: for&ulringar och konstans. Medd. Maringeol. Lab. Gdteborg, No. 4, l-25. OVERBECKF. (1950) Die Moore Niedersachsens. aeologie und Lagerstiitten Niedersa&revas, Vol. 3.4, II. Aufl., (editor K. BRAVING), 106 pp., Niedersiichsisches Amt fur Landesplanung und Statistik, Hannover. PEIRSON D. H., CAWSEP. A., SALMONL. and CAMBRAYR. S. (1973) Trace elements in the atmospheric environment. Nature 241, 252-256. PETRENCHUCK 0. P. and SELEZNEVA E. S. (1970) Chemical composition of precipitation in regions of the Soviet Union. J. Beophys. Res. 75, 3629-3634. PIPER D. Z. (1971) The distribution of Co, Cr, Cu, Fe, Mn, Ni and Zn in Framvaren, a Norwegian anoxic fjord. Beochim. Cosmochim. Acta 35, 531-550. POUR-NAQHSHBANDG. R. (1972) Bodenmechanische Untersuchungen an zwei Kernen aus dem Bornholm Becken. Diplom-Arbeit, Geol.-Palaont. Institut der Universitlit Kiel, 53 pp. RAMIREZ-MU%OSJ. (1968) Atomic-Absorptim Spectroscopy and Analyses by Atomic-Abso+rption Flame Photometry, 493 pp. Elsevier. REINTGES H. (editor) (1972) Jahrbuch fiir Bergbau, Energie, Mineral61 und Chemie, 1972, pp. 888890. Verlag Ghickauf GmbH. RILEY J. P. (1958) The rapid analyses of silicate rocks and minerals. Anal. China. Acta 18, 413-428. SEIBOLDE., EXON N., HARTMANN M., K~GLER F.-C., Knum~ H., Lazy G. F., NEWTON R. S. and WERXER F. (1971) Marine geology of Kiel Bay. In Sedimentology of Parts of Central Europe. Guide Book, pp. 209-235. VIII Int. Sediment. Congress, Heidelberg. SCHMITZ H. (1968) Der pollenanalytische Nachweis menschlicher EingrifYe in die natiirliche Vegetation in der vor- und friihgeschichtlichen Zeit. In Studien zur Europiiischen Vorund F&hgeschichte, (editors M. CLAUS, W. HAARNAGEL and K. RADDATZ), pp. 409412. K. Wachholtz Verlag. SMITH D. M., GRIFFIN J. J. and GOLDBERGE. D. (1973) Elemental carbon in marine sediments, a baseline for burning. Nature 241, 268-270. S~~AKA H. (1970) Pollenanalyse und Vegetatios.9gmchichte, 109 pp. Ziemsen Verlag. SUESSH. E. (1955) Radiocarbon concentration in modern wood. Science 122, 415417. TUREKIAN K. K. and WEDEPOHL K. H. (1961) Distribution of the elements in some major units of the earth’s crust. Bull. Beol. Sot. Amer. 72, 175-192. UNTERNEHMENSVERBANDRUHRBERGBAU(Ed.) (1955) Die Kohlenwirtschoft der Welt in Zahlen, pp. 15-16. Verlag Ghickauf GmbH. VESTER F. (1972) Dae ~berlebensprogramm, 234 pp. Kindler Verlag. VOGEL J. C. (1972) Radiocarbon in the surface waters of the Atlantic Ocean. Proc. 8th Irat. Conf. Radiocarbon Dating, pp. 267-279. The Royal Society of New Zealand, Wellington. DE VRIES HL. (1958) Variation in concentration of radiocarbon with time and lucation on earth. Koninkl. Ned. Akad. Wetenschap. Proc., Ser. B, 61, 94-102. WEDEPOHL K. H. (1960) Spurenanalytische Untersuchungen an Tiefseetonen aus dem Atlantik. Geochim. Coemochim. Acta 18,200-231. WEDEPOHL K. H. (editor) (1972) In Handbook of geochemistry, Vol. 11-3,30/K-1-13, SpringerVerlag.

LER~

842

HELXUT ERLENKEUSER,ERWIN SUESS and HORST WILLKOMM

VAN DER WEIJDEN C. H., SCHUILIN~R. D. and DAS H. A. (1970) Some geochemical characteristics of sediments from the North Atlantic Ocean. Mar. aeol. 9,81-99. WILLIAMS P. M. and GORDONL. I. (1970) Carbon-13: carbon-12 ratios in dissolved and particulate organic matter in the sea. DeepSea Rea. 17,19-27. WILLEOMM H. and ERLENKEUSER H. (1970) University of Kiel radiocarbon measurements V. Radiocarbon 12, 526-533. ZEITSCE~EL B. (1965) Zur Sedimentation von Seston, eine produktionsbiologische Untersuchung von Sinkstoffen und Sedimenten der westlichen und mittleren O&see. Kiel. Meererrforsch.

91,e-80.