3. 1. Major and Trace Elements Geochemistry
Beach sand collected along the coasts of Southwest Japan, on the coastlines of Northern Kyushu, Yamaguchi, Shimane, Tottori, Tango Peninsula and Noto Peninsula comprise siliciclastic (quartz and feldspar) and biogenic deposits. The sands are representative of the characteristics of their constituent materials. These materials originate from a variety of sources and processes – some are transported to the beaches by marine currents from external sources or by rivers from nearby land, some are produced by erosion of the shoreline in the vicinity of the beach, some are created in situ by living organisms while others are related to human activity. The abundance of the major elements determined from the beach sand samples from the six coastal sites under investigation are summarized in Table 8. The corresponding LOI values are included in each Table for each location. The average geochemical composition of 15 local river sediments from AIST & GSJ (2013a), 15 near-shore marine sediments along the San’in district from AIST & GSJ (2013b), UCC (Rudnick & Gao, 2005) and UCJA (Togashi & Imai, 2000) estimated from the representative surface rocks and the means of major elements and trace elements are included in Table 8 for comparison.
3. 1. 1. Northern Kyushu
XRF major and trace element analyses of the beach sands from Northern Kyushu, Japan, are listed in Table 2 and Table 8. The beach sands had moderate to high SiO2 contents, with abundances ranging from 54.43wt% to 91.23wt% (mean 77.24wt%); this is well above the 66.62 wt% present in the average Upper Continental Crust (UCC) reported by Rudnick and Gao (1995). The higher values in the beach sands reflected their quartz content. The next most abundant element, Al2O3, ranges from 4.71wt% to 18.35wt%, averaging (10.62wt%), less than in UCC (15.40wt%). In most samples, CaO contents are low (< 5wt%) and less than UCC (4.76wt%), reflecting low shell contents. Samples from Ashia and Munakata-1 are exceptions, with higher CaO contents of 13.47wt% and 28.43wt%, respectively. Among the remaining major elements K2O (average 2.97wt%, range 1.63 - 4.64wt%), Na2O (2.17wt%, range 0.87 - 3.63wt%) and Fe2O3* (1.35wt%, range 0.31 - 3.97wt%) are the next most abundant.
Other major elements (MgO, TiO2, MnO, and P2O5) are less abundant, and average values for all are less than in UCC.
Loss on ignition (LOI) data are presented in Table 2 to indicate variations in organic matter and calcium carbonate content of the beach sand sediment.
Average LOI was low, averaging only 3.45wt%. However, the very high CaO contents at Ashiya and Munakata-1 identified in the XRF analysis was reflected in two the LOI readings for these two sites, which were significantly higher that this average figure, at 10.87wt% and 18.78wt% respectively. Table 2 also shows the concentration of trace elements in the beach sands. The two elements with
the highest contents were chlorine (average concentration 2920ppm (range 44 to 10660ppm)) and sulphur (average concentration 871ppm (range 405 to 2260ppm)). The strontium content was significant, averaging 382ppm (range 76ppm to 989ppm), whereas iodine content varied from 3ppm to 3630ppm, averaging 145ppm. Fluorine content ranged from 11ppm to 340ppm, and zirconium from 8ppm to 67ppm. With average concentrations of 27ppm and 20ppm respectively, the vanadium and chromium contents were considerably lower than those seen in the UCC (97ppm and 92ppm respectively).
Concentrations of other trace elements such as As, Pb, Zn, Cu, Ni, Y, Th, Sc, and Br were less than 20ppm on average, and below the abundances in UCC.
3. 1. 2. Yamaguchi Prefecture
Yamaguchi coastal beach sand samples had low to high SiO2 contents, with abundances ranging from 4.72wt% to 92.16wt%, and averaging 61.20wt%, the high values reflecting their quartz content (Table 3 and Table 8). CaO was the next most abundant, the average value being 28.18wt% with a range of 0.77wt% to 87.37wt% (low values corresponding to high SiO2 content and vice versa). The wide range of these values represented two situations – those samples with higher values were indicative of a significant biogenic CaCO3
presence, but a low shell content was suggested by those with lower CaO values.
Al2O3 was the next abundant element with (4.63wt%) average and ranges from 0.65wt% to 9.50wt%. Among the remaining major elements, K2O (average 1.76wt%, range 0.34 - 4.40wt%), MgO (average 1.46wt%, range 0.10 - 4.93wt%), Na2O (average 1.31wt%, range 0.30-1.99wt%), and Fe2O3*
(1.18wt%, range 0.01-2.66wt%) were the next most abundant. Other major elements (TiO2, P2O5, and MnO) were less abundant.
The Yamaguchi coastal beach sand samples demonstrated relatively low to high LOI contents with CaO contents (averaging 28.18wt%, ranging from 0.77 to 87.37wt%). Among the analysed trace elements, Cl had the highest content as a result of contaminations from seawater, averaging 12602ppm, and ranging from 40ppm to 54231ppm, followed by total sulphur (TS) averaging 2263ppm, with a range from 30ppm to 5557ppm. Sr contents were significant, averaging 695ppm and ranging from 44ppm to 1358ppm, whereas F contents varied from 11ppm to 274ppm, averaging 11ppm. Zr contents ranged from 41ppm to 144ppm and V from 3ppm to 43ppm. The average contents of I and Sc were 28ppm and 20ppm, respectively. Concentrations of other trace elements were less than 20ppm on average. The Yamaguchi beach sands contained small amounts of SiO2, Al2O3, and Fe2O3*, whereas CaO and LOI accounted for over 65% and 35% respectively and were relatively rich in organic matter. Of particular note were the samples from three beaches – Doigahama, Hinaka and Akada. These beaches’ samples comprise carbonate or biogenic sands, composed primarily of foraminifera, ostracod, shells and sea urchins, the primary constituent of which is CaCO3. The high LOI results were demonstrated by XRF analysis, confirming the high CaCO3 content of the sands.
3. 1. 3. Shimane Prefecture
As expected, SiO2 was the most abundant from the Shimane coastal beach sand samples, averaging 82.27wt%, with a range of 54.38-89.50wt%, followed by
Al2O3 (average 8.77wt%, range 4.54-16.46wt%) (Table 4 and Table 8).
Among the remainder, CaO (2.70wt%, range 0.45-35.35wt%), K2O (2.16wt%, range 0.88-4.44wt%), Fe2O3* (1.66wt%, range 0.42-3.14wt%) and Na2O (1.65wt%, range 0.87-2.97wt%), were the next most abundant on average.
MgO (average 0.49wt%) and TiO2 (average 0.24wt%) were present in small amounts, whereas MnO and P2O5 (both averaging 0.48 and 0.03wt%) were present only in trace amounts. In these samples, overall, LOI contents ranged from 0.42-22.59wt%, averaging 2.18wt%. Cl was the most abundant trace element (again a result of seawater contamination), with an average value of 2995ppm, and a maximum of 9959ppm. The TS values were significant, ranging from 275ppm to 3398ppm, with a mean value of 621ppm. Sr was the next most abundant, with a maximum of 1126ppm, a minimum of 77ppm, and an average value of 209ppm. Among the remaining trace elements, only F, Zr, Zn, Cr, V, As, and I contents were present in moderate concentrations, other trace elements, Pb, Cu, Ni, Y, Nb, Th, Sc and Br showing very low concentrations.
3. 1. 4. Tottori Prefecture
The samples from the Tottori coastal beach sands generally comprised silicate materials (for example, feldspar and quartz), the high quartz content being reflected in their high SiO2 content (mean value 72.05wt%, range 66.30-82.23wt%). (See Tables 5 and 8.) There were also relatively high levels of Al2O3 present, albeit only in the order of one-fifth the level of SiO2 (average 14.71wt%, range 10.05-17.35wt%). A relatively wide range of values about the average of 3.86wt% was seen for CaO content (0.84-7.49wt%), with a
significant shell material content being indicated by similar values from the LOI analysis (a range of 0.05-5.50wt%, average 1.81wt%). Na2O and K2O, also likely to be contained within feldspar, was less abundant, averaging 2.91wt%
and 2.62wt%, respectively. Three major elements (Fe2O3*, MgO and TiO2), were present only in minor amounts (averages 2.48wt%, 1.02wt%, and 0.26wt%
respectively), and P2O5 and MnO were present only in trace amounts (both averaging 0.05wt%). Iodine (I) was the most abundant trace element averaging 3698ppm, with a maximum of 7394ppm. It was followed by total Chlorine (Cl), which averaged 578ppm (range 342-1007ppm), and Sr (average 384ppm, range 131-598ppm). Average concentrations of all other trace elements except TS (152ppm) were less than 100ppm, reflecting the high SiO2 content and marked quartz dilution in this suite of sediments.
3. 1. 5. Tango Peninsula
Results showed that SiO2, dominated the analysed sand samples averaging 78.02wt% (Eastern San’in coast sands), 81.02wt% (Tango Peninsula sands) and 84.83wt% (Wakasa Bay sands) (Tables 6 and 8). The other sites’ samples showed relatively high SiO2 content, with three exceptions. These three sites were Kirihama (average 69.06wt%), Shibayama (66.82wt%) and Takeno (41.89wt%) and, as would be expected given their high SiO2 content, they exhibited high CaO contents of 13.77wt%, 11.21wt% and 43.35wt%
respectively, as shown in Table 6. The high SiO2 concentrations resulted in low contents of other elements, with Al2O3 contents of between 5.30 and 11.86wt%
in the Eastern San’in coast sands, 7.60 to 12.44wt% in the Tango Peninsula
and 5.55 to 10.27wt% Wakasa Bay sands (Table 6). Average Al2O3 contents were 8.45wt% in the Eastern San’in coast sands, 9.92wt% for the Tango Peninsula sands and 7.95wt% in the Wakasa Bay sands (Table 8). Seven other elements were present in significant quantities; these were TiO2, Fe2O3*, MnO, MgO, Na2O, K2O and P2O5. As shown in Table 6, their concentrations were, in the most part, less than 5wt% and, in some cases, less than 1wt%. Among the trace elements, the contents of ferromagnesian elements (Ni, Cr, V and Sc) and large cations (Y, Nb, Zr, Th and Sr) tended to be less abundant than they were in the UCC and the JAUC (Table 8).
3. 1. 6. Noto peninsula
Generally, beach sands from the Noto Peninsula were characterized by moderate contents of SiO2 (75.44-83.43wt%, average 79.00wt%) and Al2O3
(8.13-13.02wt%, 11.39%). Furthermore, the Fe2O3* content was low (1.79-5.27wt%), as were those both of MgO (0.37-1.85wt%) and of TiO2
(0.20-0.66wt%, 0.31wt%). These can be accounted for by the presence of a high level of quartz and a low level of mafic components (see Tables 7 and 8).
The low CaO contents (0.57-1.83wt%, 1.27wt%) indicated that all the beach sand samples had very low carbonate components. The contents of Cr, Ni and Sc showed a wide range from 3 to 45ppm, detection limits to 9ppm, and 1 to 9ppm respectively, suggesting a contribution from more mafic components. Contents of the high field strength elements Th, Y, Nb, showed similarly wide ranges from 6 to 9ppm, 15 to 22ppm, and 5 to 8ppm respectively.
2. XRF major (wt%) and trace (ppm) element analyses of beach sands from northern Kyushu, Japan. LOI, oven-dried loss on ignition; and indices of Chemical Index of Alteration (PIA) and Chemical Index of Weathering (CIW). SiO2TiO2Al2O3Fe2O3＊MnO MgOCaONa2OK2OP2O5LOI CIAPIACIWAs Pb Zn Cu Ni Cr V Sr Y Nb Zr Th Sc TS F Br I Cl efecture (n=26) 67.120.299.643.110.081.4513.472.092.700.0610.872419262314263.114155616337130172410111116197 88.250.106.210.990.020.361.500.941.630.015.585151592013214.313642314246221153549122310660 75.170.189.982.210.040.916.492.202.770.041.873531391512142.23141811124626674355361007 54.430.198.281.730.041.8428.431.963.000.0818.78138131111186.51798914..2462260.935232 85.390.095.760.920.010.324.621.031.810.033.583227361712132.783379146213724206326. 89.250.105.810.720.010.250.611.162.070.010.98535466812132.21.115103533.74211303630. 80.870.139.341.130.020.393.531.962.610.022.584340491213162..1636513254311665227424. 77.560.169.251.460.030.656.132.012.700.045.023531391312196.7244331324731810171727192239 84.030.139.110.980.020.371.021.642.670.020.93555867101518513026241154552656989536. 81.410.169.671.180.020.521.591.823.610.021.225050621016173.2515247153542553061527. 82.320.0910.980.720.010.310.961.812.790.011.2559637011161761251730016245288021319323962 ajiro91.230.094.710.500.010.260.290.872.050.000.82535671812122221.7993461.7636011334021 86.740.037.400.410.010.110.681.173.440.010.55525470318120.2.183132561.405131328. 82.400.0410.670.310.010.130.601.973.860.010.58566071319151.11.231162531.564217341984 76.670.0913.380.760.020.311.152.974.640.020.91535566321202.2.27417360135981049271895 68.120.1713.651.330.030.908.993.143.640.055.92353139613188.13196541412522295514361844 74.480.1612.921.300.030.914.042.883.260.042.4545445261317615382646414239113704348232730 72.930.1510.191.330.030.769.042.153.390.046.49302534713166.1919557142382271182486251817 79.660.1110.560.850.020.443.701.792.850.023.92454452915165.3323434163452181151898294777 77.840.1010.100.810.020.484.791.853.970.033.70393346916134.9241015245312805.8222397 75.720.2712.472.290.051.142.902.652.460.041.13515157413237154262316145582136873409232812 71.230.2915.392.340.041.193.363.192.940.021.285252584152491443623861444821258634821288 81.010.1111.050.910.020.471.472.262.670.020.84545664417155414102231335526652.10293005 75.720.1613.211.280.020.612.922.553.490.041.34505058815166320133541434916503.528. 79.200.0911.580.730.010.322.642.233.170.022.26494958817154219123651634129662.530693 76.500.1712.541.420.030.742.732.693.160.021.2950495741520792631359154442856831623380 efecture (n=4) 64.770.5218.353.970.061.634.033.543.090.032.73535358515452072410941915654214788598142737 73.960.2314.311.700.040.692.713.083.250.021.40525259816226321383691344929561103626. est 174.690.1414.101.140.020.462.513.683.240.031.50505057815192.17143821335628665.7351685 est 268.460.228.002.020.031.3015.911.702.290.0711.771915201311202.203481612183432081.8153674 !1
Table 3. XRF major (wt%) and trace (ppm) element analyses of beach sands from Yamaguchi Prefecture, Japan. LOI, oven-dried loss on ignition; and indices of CIA, PIA and CIW. SAMPLESiO2TiO2Al2O3Fe2O3＊MnO MgOCaONa2OK2OP2O5LOI CIAPIACIWAs Pb Zn Cu Ni Cr V Sr Y Nb Zr Th Sc TS F Br I Cl Toyoura 184.520.056.840.520.010.213.041.513.270.022.80372946717122618.1551815531745.11323480 Toyoura 284.000.037.790.360.010.132.271.114.290.022.1542355771851510.1102405031499235530. Kawatana73.730.099.500.770.020.469.021.974.400.037.18281933518163111.38623273581113.11214804 Kogushi84.420.097.140.010.200.203.141.393.390.012.75383047417151318.1502016353735.112610049 Doigahama4.720.060.650.450.034.9387.371.310.350.1241.12...1714.5.13487...3955576215.18114 Arata57.400.235.731.640.031.4729.851.771.810.0919.35...711233.10.95412..12425177814.11784 Kanda31.390.142.730.990.022.7659.351.401.050.1623.66...4883.10.13548...37410614514.13222 Tunoshima 146.620.112.010.670.021.2347.690.860.650.1226.44...2854.8.12545..1333817249.8941 Tunoshima 237.300.243.031.350.031.4654.860.970.630.1328.82...2785.13.13165..13536451819.6715 Agawa48.290.195.011.770.031.8339.921.331.510.1224.08...99196.9.114311..2302789.10.5094 Hinaka18.900.183.431.790.054.1168.691.890.830.1435.49...57165.8.133610..13540238913.54231 Akada21.360.112.620.980.033.5068.711.690.850.1435.01...4864.16.13588...3846939615.180 Ushirohama A 84.680.047.250.380.010.172.431.243.790.012.6841335351781518.120211533198011514306568 Ushirohama B89.280.035.630.330.010.110.770.942.880.011.5648466651471515.85191513.422114431. Narabimatsu87.890.055.940.360.010.101.740.833.070.011.30433757316813813.4418.414.744116123540 Yasuoka 81.640.224.851.250.020.608.161.441.780.056.52201522714325532.335121772101414.92226640 Ayaragi88.900.114.280.790.020.292.950.901.730.022.93332639612182919.14211155241010.14367541 Yoshimi A87.240.323.411.420.030.445.620.860.620.044.67221923412274840325572792610617612276361 Yoshimi B87.070.313.721.390.030.455.380.970.640.044.592421255112629373258827828103113711285297 Yoshimi C80.540.904.492.660.040.668.860.940.850.056.79....11345659433839514431312121248163748 Yoshimi D76.950.764.902.510.040.8311.871.140.930.068.96....123447502847710410321415771111196211 Yoshimo42.390.203.831.400.042.3147.171.511.010.1326.23....9203616.12139..1333652558.8016 Arata A32.290.183.901.660.043.1455.411.941.330.1329.15....10206.20.119713..237473527412.9163 Arata B43.880.184.391.530.042.4744.251.691.450.1126.21....9205.12.108312..2333917.18.17912 Arata C28.290.163.711.690.043.5959.231.991.160.1432.35....9206.7.123812..23745188920.46472 Arata D56.580.195.941.680.031.5530.471.631.830.1019.39....10244.16.97012..226301416.21873 Fukue92.160.382.271.610.030.292.600.300.340.021.862927314111535321497627321561128534. !1
able 4. XRF major (wt%) and trace (ppm) element analyses of beach sands from Shimane Prefecture, Japan. LOI, oven-dried loss on ignition; and CIA, PIA and CIW. SAMPLESiO2TiO2Al2O3Fe2O3＊MnO MgOCaONa2OK2OP2O5LOI CIAPIACIWAs Pb Zn Cu Ni Cr V Sr Y Nb Zr Th Sc TS F Br I Cl Shizuma 77.710.3511.293.100.130.902.432.141.900.050.645354591454856928383271348735373.617. Uozu 76.950.1912.521.850.060.633.092.422.240.051.2851525716335556209395132783451019452911 Isotake 81.510.1510.751.300.040.471.702.051.970.041.245657631425515718730314280316885010244234 Ohura75.560.1713.421.590.050.523.052.632.960.051.465151582026454715.4021527922502164922492 Nima76.630.3012.162.680.090.772.992.371.960.051.015252571343606422274011338138407240617. Kotogahama 183.490.079.220.700.010.161.771.712.840.021.355051612013122511.22514.64.1439271618. Kotogahama 289.500.056.440.420.010.100.741.201.540.010.75575966161382615.15711.5621421102631. Kotogahama 384.230.218.321.910.050.441.161.632.000.051.085557641913102421.15012.5511482.731785 Yusato81.050.1810.741.620.030.392.212.401.320.050.9954545871543552095558.683150849252018 Iwamifukumitsu71.070.2616.462.130.040.641.952.974.440.042.3556586617205955141223122381465211161015789 Kuromatsu 180.020.1711.841.260.030.341.012.173.130.021.125861691219433617141571927722480168928898 Kuromatsu 282.630.169.891.240.030.321.021.912.780.020.865558671016343519.1391627642428116729648 Kuromatsu 380.460.539.612.930.080.521.371.802.660.030.8054566481747652969143184935437626523. Asari 184.080.318.541.800.050.391.101.532.180.020.64565866816393632291271638344329185431. Asari 283.580.209.111.310.040.260.951.702.830.020.51555767616283624.1201627131275142329. Asari 382.700.129.910.920.030.210.861.953.270.020.71545768616243519.124171653.40962824119 Gohtsu87.110.088.010.580.020.160.451.502.080.010.97596471314163725.87141573.7992213377591 Tunozu88.820.276.381.250.040.260.561.111.310.010.73606469515294723401011437535581898313236 Okinohama87.740.705.802.640.080.290.690.871.170.020.42606369513314533103801359743349168424. Hashi 186.870.127.620.850.030.240.771.561.940.020.89565866614266822.1171316631588310323841 Hashi 286.860.117.540.840.030.210.771.472.160.020.57555867713233416.1191416433374146629. Hashi 384.250.099.220.740.020.180.771.812.890.021.02555868615192615.124161652.3709626. Hashi 480.600.1511.141.050.030.341.062.423.190.021.27545765818314618116218272328313614307493 Shimokou77.590.1712.731.360.040.431.532.523.610.031.275456651017363715.216192773258816811272984 Nishihamada70.660.407.402.870.051.2414.361.681.220.1111.4420182114105556251964213256220116231952512 Orii 1 80.170.418.113.140.071.283.651.531.600.052.034341471116331210251822614.9841562076723241 Orii 276.490.259.722.160.050.976.231.912.180.054.65373440101533108252632815.97511108816612216208 Tanoura 186.550.645.263.060.070.751.730.881.020.031.434848548134191446951031247341243838422. Tanoura 284.960.395.882.570.070.833.021.081.190.042.454139458133581538491681227839582283627980 Kitahama87.290.214.541.160.030.334.610.920.880.035.05302732101020232593099.82281179.9295371 Araiso54.380.154.801.410.041.5735.351.211.000.1022.59757118153.11.11268..219339815911.9959 Iwamitsuda 182.070.209.461.830.040.451.601.522.790.042.0853556422154348256125223685448462723. Iwamitsuda 282.520.188.621.720.030.452.291.582.580.042.844847562114397821515620269647027511213124 Mochiishi 183.870.208.681.830.040.450.961.632.280.051.495659672314345102759621373726032747291599 Mochiishi 285.010.198.031.680.040.400.871.452.270.041.4556596721143051126128620369715991137352028 Mochiishi 385.370.117.771.210.020.291.201.322.670.021.725253641814234725.1012125952510155730583 Mochiishi 485.060.197.961.820.040.400.961.482.040.051.2556596623142951128795193757.42689435. Mochiishi 585.550.197.631.790.040.401.061.401.900.051.3655586523152641024890193727.500.633921 Mochiishi 686.300.157.061.500.030.341.091.422.060.041.625253632213234922.911826751628.10353642 Mochiishi 787.450.067.010.640.010.141.211.342.120.021.455152622314325132941061937971427140530. Nakasu 187.050.266.931.640.040.390.871.221.580.031.645760661514406104130851958162809.9356416 Nakasu 287.040.297.381.670.040.370.800.931.450.031.53626772181451610445185206745437289334. Nakasu 85.070.417.632.240.060.490.981.171.920.041.315761681813436114528771967273415.627. Kohama 85.910.187.451.200.030.271.751.162.030.022.60515160181427252351412047752754309295145 !1
Table 5. XRF major (wt%) and trace (ppm) element analyses of beach sands from Tottori Prefecture, Japan. LOI, oven-dried loss on ignition; and CIA, PIA and CIW. SAMPLESiO2TiO2Al2O3Fe2O3＊MnO MgOCaONa2OK2OP2O5LOI CIAPIACIWAs Pb Zn Cu Ni Cr V Sr Y Nb Zr Th Sc TS F Br I Cl Houzyou 166.200.3817.313.770.081.985.323.281.600.070.90515154715154724.2391927334198631293447 Houzyou 282.230.1110.050.890.020.240.841.833.770.020.5054576961391423.131201593.162525.355 Tomari73.570.2014.621.870.040.662.783.073.150.040.905253591413223719537117279376210264064621 Ishiwaki68.520.3616.693.210.061.153.683.392.890.061.20525358141432582332455173804103509223404613 Anedomari68.610.2317.352.280.040.874.303.502.770.051.8051525616143048229506142733715710202753580 Anedomari66.200.3817.313.770.081.985.323.281.600.070.90515154111140512244359812361315115315.355 Hamamura 78.030.1412.391.460.030.422.222.612.680.031.305353601713194618.287151752215610284505679 Hamamura76.560.1613.431.700.030.582.522.582.390.030.80545561161222272433421427824131326.342 Hakuto77.430.2811.122.840.061.262.522.342.110.031.305151571511295123424277153773520010233766598 Karo70.720.4814.463.910.081.673.592.902.150.051.50525256151241414364939616489310.9102951576 Sakyuuhigashi 77.170.2512.362.300.050.861.842.442.690.041.4055576316142931336182271737846.10242651549 Makitani 68.580.2214.792.090.040.867.492.912.960.055.50413945161330492395261726931117012175198996 Makitani69.880.2516.432.450.051.004.403.042.450.051.90515256171336611312248616373311102322.432 Higashihama68.160.2516.032.400.040.905.713.313.140.064.1046455121143768241748016376410140141873941007 Higashihama 68.890.2416.262.290.040.805.343.122.960.053.2048475221143749229480162753737418.517 !1
able 6. XRF major (wt%) and trace (ppm) element analyses of beach sands from the Eastern San’in coast, Tango Peninsula and Wakasa Bay, Japan. LOI, oven-dried loss on Alteration (CIA), Plagioclase Index of Alteration (PIA) and Chemical Index of Weathering (CIW). SAMPLESiO2TiO2Al2O3Fe2O3＊MnO MgOCaONa2OK2OP2O5LOI CIAPIACIWAs Pb Zn Cu Ni Cr V Sr Y Nb Zr Th Sc TS F Br I Cl East San'in coasts (n=17) Kasumi84.670.247.421.700.040.542.081.421.870.0448.0048475531595.291721724511530897231520 Shibayama66.820.3411.863.310.041.2711.212.502.560.0851.353027334138322721157153481433860226. Sazu87.860.116.830.750.020.170.331.252.670.0155.2955607281416459055181154532105671046191435 Yasugi80.110.1410.311.020.020.251.701.654.780.0248.5449476431333.3.117153442.390208427. Kirihama69.060.278.761.990.030.9013.771.623.550.0648.482215242211202834212221336335513164227. Takeno41.890.315.302.450.062.2243.351.532.780.1039.65636161283220.142122483.514118531. Kumihama 174.350.249.742.220.051.007.451.633.270.0451.73332838121112414535012251213936169204118 Kumihama 272.580.699.783.890.081.357.341.442.820.0455.18343039261434417333847319255315881367131717 Kumihama 383.530.127.641.180.020.412.771.352.940.0249.4542385127154562113989472195914147657558. Kumihama 481.070.188.501.720.030.643.531.492.810.0251.04423849191317171292211736626731489242452 Hachohama84.240.096.350.850.020.314.791.142.190.0250.3133273822142821431282661736637698.7201282 Kotobikihama88.190.076.170.650.010.161.510.992.250.0147.6248465999254.319131516..246257613110.6414 Sunakata83.800.197.271.730.030.563.171.162.060.0253.974240491512245.219826191764251551140934356 Taiza86.040.077.920.430.020.140.611.343.420.0153.115356711116172..9168264714252847418. Hei 181.090.1210.460.970.020.321.302.053.650.0252.00525365414161..366184613353104219. Hei 282.380.169.271.430.030.471.551.922.780.0250.90515161131868103154367017239524118638621132 Hei 378.640.2610.062.510.041.162.662.072.580.0347.90484755513205314271861238434399103216. Tango peninsula Kyoto (n=14) Iwagahana78.130.1212.441.040.020.341.232.893.780.0253.0053556441521311015170192672272013110324018 Satonami81.010.0610.850.540.010.201.172.453.700.0151.70525364315851112.149182471.6301758312939 Hioki81.190.0911.540.780.020.280.872.542.670.0157.205760674141721922151173643.7931711306891 Ejiri82.000.0910.070.700.020.381.432.502.800.0150.9051516031310211562153153523279328110355756 Amanohashidate80.930.1111.180.850.020.271.112.393.120.0154.605557654151733291153163582.37889235. Ryuguhama83.210.039.060.360.010.172.211.783.170.0148.6047455761271.18.1981824525906.10326062 Kobashi74.280.0511.290.630.020.307.202.423.790.0247.6035304071213..8.45618241212813230424. Nojiri73.160.2112.112.180.041.185.162.753.180.0348.40413947101335552227313581737241110194510225072 Tangoyura a77.191.469.095.350.121.482.941.111.210.0452.00525256141260133322019316516912761549374413472 Tangoyura b84.600.358.032.720.050.800.741.201.470.0362.4062667112114811266873881468343557104630995 Kunnda a86.610.127.650.780.020.290.641.442.450.0155.4055596931216433681021546531712.10325110 Kunnda b84.140.099.210.720.020.180.771.533.340.0155.105559702151980222117163593.3117237. Tango Kanzaki a82.530.458.713.420.061.050.911.331.510.0461.80626570181258123166112931579347712.9274544 Tango Kanzaki b85.260.317.602.530.050.730.701.291.490.0360.606164702011428234162871357933644619312393 Wakasa bay (n=7) Matubara 84.170.437.583.200.060.880.861.081.650.0960.706165717124214204459611857757365145324. Sakajiri82.150.319.582.070.060.521.041.612.590.0657.1057616991750612392611821596837971276301297 Diamondo90.310.025.550.250.010.040.120.633.060.0054.90556482.................. Suishou87.810.036.790.440.010.050.170.963.740.0153.5053607891651742.18284414.49189433. Sugehama80.750.1310.271.310.030.220.791.465.020.0252.70535673719424826.63358626.925112244988 Sada83.240.187.711.460.040.362.991.392.590.0450.60423950111633383221851938755849768282922 Kehinomatubara85.360.098.180.960.030.170.261.513.420.0255.305560744171831128.39284548.5491308281533 !1
Table 7. XRF major (wt%) and trace (ppm) element analyses of beach sands from Noto Peninsula, Japan. LOI, oven-dried loss on ignition; and CIA, PIA and CIW. SAMPLESiO2TiO2Al2O3Fe2O3＊MnO MgOCaONa2OK2OP2O5LOI CIAPIACIWAs Pb Zn Cu Ni Cr V Sr Y Nb Zr Th Sc TS F Br I Cl Sanrihama-A75.440.4912.593.840.071.061.702.202.510.102.2358606620155610929962811961178862889 9193727 Sanrihama-B76.120.4712.523.630.070.941.572.122.450.101.7659626719165297269728220611899446131424. Awara-A80.360.2611.112.300.050.390.681.882.930.041.306065722312325.33317722715191430.221. Awara-B81.790.2410.222.160.060.380.621.902.600.041.235964712413294..33 16819613381413173324. Awara-C83.000.229.432.110.050.370.661.752.370.031.195963702413261.9361621861328243074324. Kaga-A81.520.2410.492.110.050.410.611.892.640.041.476065722814314.1334 176195 1257 246613428. Kaga-B82.080.2210.162.040.050.390.571.842.590.041.406065722814283.1033 172185 12481451.327. Katayamada82.780.308.133.190.071.041.251.381.800.051.025658651612394.2648 166156 12073417118 227. Komatsu-A83.430.209.031.790.030.501.051.862.070.041.455658651211272.824186165 10782108311810275078 Komatsu-B78.170.668.785.270.111.851.831.581.660.071.115455601011555245114203168161696471755141476 Komatsu-C80.570.399.163.410.071.121.471.771.980.061.175556631011416214592041661257661232620510 Komatsu-D80.480.2710.942.060.030.581.282.072.220.051.58586066101240511847 231175101657932759334227 Komatsu-E80.300.2711.132.090.030.581.242.012.270.061.4959616791340311653233176107857601478272047 Komaiko79.140.3211.362.510.040.741.462.022.340.061.8258606611144352185223218610986726619293093 Mikawa-A79.580.2911.422.150.040.591.212.132.530.061.415861671013385.840 22719611374623.7191414 Mikawa-B79.170.3011.492.390.040.681.402.112.350.061.78586066111643752155 23918610375 813.11275392 Hakusan-A78.400.3211.862.540.040.691.372.162.550.071.635861671515466.1256 23819612095 7571498272823 Hakusan-B77.950.3312.112.600.040.761.482.182.490.071.815861661315475123652481961068788913110266019 Kanazawa77.290.3312.652.590.040.731.452.172.680.071.83596268131654521566255196110877461808203110 Hahoku76.370.3313.022.740.050.641.362.363.050.081.415861682315383.1450 261216123954998932339 Shiroo-B77.710.2712.612.340.040.601.232.382.780.061.855861681916404.2152 257185106748145910275187 Shiroo-A78.000.2912.292.460.040.651.292.292.650.061.855861671915404.2549 25518510785 84916010275808 Takamatsu-C78.850.2811.752.450.040.661.352.162.410.061.8358616720133942245824518510168881.10276273 Takamatsu-B77.050.2812.932.340.040.601.252.512.950.061.87586167201539331855 2641951087583213011245998 Takamatsu-A77.550.2912.562.500.040.661.312.352.680.061.93586167201642411952257185102758826012286730 Imahama77.990.2912.172.600.040.681.412.242.520.061.95586167221539321355258186 100767433410243734 Senrihama-A77.210.3012.602.630.040.701.442.352.670.072.075861672214393.1451264185 100867803012215081 Senrihama-B77.620.3212.162.800.040.791.502.222.490.072.075860662115415.176025618610077832.11236044 Senrihama-C77.410.3212.272.810.040.801.522.282.480.062.01586066221443721961260186101778048912235078 Hakui76.640.3212.772.870.040.751.512.272.750.072.02586167231544411861259195 1048577447 9203994 !1
8. Summary statistics of major element abundances in beach sands from the coasts of South West Japan, on the coastline of Northern Kyushu Yamaguchi, Shimane, Tottori, Tango Wakasa Bay, and Noto Peninsula. LOI, oven-dried loss on ignition; and CIA, PIA and CIW. Average geochemical compositions of local river sediments from the Geological of Japan and National Institute of Advanced Industrial Science and Technology (AIST 2013a), near-shore marine sediments around Yamaguchi (AIST 2013b), average Upper Crust Archipelago (UCJA), according to (Togashi et al. 2000), and average Upper Continental Crust (UCC) (Rudnick & Gao, 2005). SiO2TiO2Al2O3Fe2O3＊MnO MgOCaONa2OK2OP2O5LOI CIAPIACIWAs Pb Zn Cu Ni Cr V Sr Y Nb Zr Th Sc TS F Br I Cl thern Kyushu (n=30) verage77.240.1610.621.350.030.674.762.172.970.033.4545445391418562027382143472158719981452920 54.430.034.710.310.010.110.290.871.630.000.55238133111201227991813405113344 91.230.5218.353.970.081.8428.433.684.640.0818.7859637123214520154310998917660346226034030363010660 verage61.200.214.631.180.031.4628.181.311.720.0815.7018152251117461918695122712202263108112812602 4.720.030.650.010.010.100.770.300.340.011.30...171115344504111301141640 92.160.909.502.660.204.9387.371.994.400.1641.1248466691834139594313582451445395557274203654231 verage82.270.238.771.660.040.482.701.652.160.032.1851536013173557242520916374456211158272995 54.380.054.540.420.010.100.450.870.880.010.42757388231117781551127533511 89.500.7016.463.140.131.5735.352.974.440.1122.59626772235485121546103112622698720339828314379959 verage72.050.2614.712.480.051.023.862.912.620.051.8151515715132949262038716274381528223698578 66.200.1110.050.890.020.240.841.831.600.020.50413945611914183131121592237310293342 82.230.4817.353.910.081.987.493.503.770.075.50555769211541614364959820489415350143173941007 verage78.020.218.451.690.030.706.421.562.880.0350.2741394913132248292635316360313792936192714 41.890.075.300.430.010.140.330.991.870.0139.65636393112366121391133816221132 88.190.6911.863.890.082.2243.352.504.780.1055.29556072271868102113989131526591546257620810316414 verage81.020.259.921.610.030.551.931.972.690.0254.2453546281327618594717416468366551208294023 73.160.037.600.360.010.170.641.111.210.0147.6035304021171081871324111317213472 86.611.4612.445.350.121.487.202.893.790.0462.406266712015601352227193456199127615101928111376891 akasa bay (n=7) verage84.830.177.951.380.030.320.891.243.150.0354.97545871816325113529812557065663957282685 80.750.025.550.250.010.040.120.631.650.0050.6042395041251726218183414336513241297 90.310.4310.273.200.060.882.991.615.020.0960.7061658211195014204459185358968792514512334988 verage79.000.3111.392.640.050.711.272.082.480.061.65586167181440521855230186114856941078244038 75.440.208.131.790.030.370.571.381.660.031.025455609112610324162155100614131321439 83.430.6613.025.270.111.851.832.513.050.102.236065722816561094511428222816199108327512336730 74.720.6111.704.830.121.591.792.422.090.13.5658632050172431743892041485279..... 73.720.298.403.170.061.998.072.431.780.09.292631172272111227434961043056..... verage Upper crust of the Japanese archipelago, according to (Togashi et al. 2000), and average Upper Continental Crust (UCC) (Rudnick & Gao, 2005). 67.530.6214.675.390.112.533.902.722.420.12.51525771774253884110225269135816..... 66.620.6415.405.040.102.483.593.272.800.15.515257517672847929732021121931010..... !1
3. 2. UCJA and UCC – Normalized compositions
As has been seen, there were many differences between the geochemical compositions of the coastal sand samples taken from the six coastal regions. These variations in composition are the result of a number of factors, including differential weathering, differences in the relative proportions of the quartz, feldspar and biogenic content of the sands in the locations and differences in the origins of the constituent substances. To compare the compositions of the beach sand in the individual sites, average values were normalized against the average UCJA, according to (Togashi et al. 2000), and against the average UCC (Rudnick & Gao, 2005). Both the UCJA-normalized and the UCC-normalized patterns for five of the six study regions’ beach sands compositions had very similar shapes. These regions were: Northern Kyushu, Shimane, Tottori, Tango Peninsula, and Noto Peninsula. Normalization revealed that, with the exception of SiO2, elements were depleted relative both to UCJA and UCC, as shown in Figure 9. The depletion was particularly marked for the ferromagnesian elements (MgO, Fe2O3*, TiO2, Ni, Cr, V) which are typically strongly depleted in felsic volcanic rocks such as granites and for mobile elements CaO, Na2O and Sr, all of which are liable to loss during weathering (Nesbitt & Young, 1984). In contrast, the UCJA-normalized as well the UCC-normalized diagrams for the Yamaguchi beach sand samples, for most of major and trace elements were less than 1 (Figure 9), exceptions being CaO, Sr, and Th.
Figure 9. Average major and trace elements diagrams of beach sands collected along the coasts of South West Japan, on the coastline of Northern Kyushu, Yamaguchi, Shimane, Tottori, Tango Peninsula, and Noto Peninsula, normalised to average Upper Crust of the Japanese Archipelago (UCJA), according to (Togashi et al. 2000), and average Upper Continental Crust (UCC) (Rudnick & Gao, 2005).
0.01 0.1 1 10 100
Si Ti
Al Fe
Mn Mg
Ca Na
K P
As Pb
Zn Cu
Ni Cr
V Sr
Y Nb
Zr Th
Sample/Japan upper crust
Northern Kyushu
Tango Peninsula Shimane Prefecture
Yamaguchi Prefecture
Noto Peninsula Tottori Prefecture
Sc
Sample/Upper continental crust
Northern Kyushu
Tango Peninsula Shimane Prefecture
Yamaguchi Prefecture
Noto Peninsula Tottori Prefecture
0.01 0.1 1 10 100
Si Ti
Al Fe
Mn Mg
Ca Na
K P
Pb Ni
Cr V
Sr Y
Nb Zr
Th Sc
A
3. 3. Inter-Element Relationship
Figure 10 illustrates Harker variation diagrams for selected elements in the beach sand samples, in each case the major element content being plotted against the SiO2 content. The increase of SiO2 reflects a greater geochemical maturity. All of the major elements plotted show general trends towards decreased abundance with increased silica content. The significant SiO2, Al2O3 and Na2O contents of beach sands form northern Kyushu, silica rich sands form Yamaguchi, Shimane, Tottori, Noto Peninsula and Tango Peninsula, indicate that quartz and feldspar are the main constituents. The overall depletion of CaO and MgO suggests that the carbonate content of the beach sand sediments is generally low, in the majority of samples. Silicate or siliciclastic sands – those sands comprising grains originating from clasts, or fragments of silicate rocks – generally consist of feldspars, micas, quartz and other silicate substances. While the majority of the components are quartz and plagioclase feldspar, as indicated by the high SiO2
content and significant CaO, Na2O and Al2O3 contents, relatively high K2O contents suggested significant K-feldspar and K-bearing micas contents were also present. CaO showed a well-defined decrease with increasing SiO2, except for higher values in a small group of Yamaguchi beach sands with lower SiO2
contents. These samples also had higher LOI values, and hence were likely to contain a biogenic CaCO3 component, such as shell material.
To better understand the major element composition, the samples were broadly subdivided as follows: silica, aluminium, and calcium (Figures 11 and 12). The geochemical compositions of these three subgroups (represented by SiO2, Al2O3, and CaO) for the six study areas’ coastlines were displayed on a modified map
of the Geological Survey of Japan (GSJ) and National Institute of Advanced Industrial Science and Technology (AIST). As expected, SiO2 contents were greater in samples from the silica-rich sands from the Yamaguchi and Shimane pocket beaches due to their abundance of quartz; these account over 80% of silica. The maximum SiO2 concentration was observed in the silica-rich sands from Yamaguchi, Shimane, Kotogahama and Kotobikihama, which may be due to the input of sediments supplied through major river systems from the Chūgoku Mountains to the Japan seacoast (the Takasu, Gono Hii, Hino, Tenjin and Sendai rivers). The Al2O3 contents varied from approximately 5wt% to over 10wt% in some samples; this variation can be attributed to the contribution of fine grains and feldspars. The maximum Al2O3 contents were seen in the northern Kyushu and Tottori beach sand. Beach sand samples from Tottori typically consisted of silicate minerals with little quartz but a significant quantity of feldspar.
Furthermore, the presence of considerable CaO in the Yamaguchi beach sand samples indicated a significant biogenic CaCO3 component; in this case, the likely constituents were Foraminifera, shells or animal skeletons, which – like sea urchin and ostracod – primarily comprise the compound (Figure 13). Biogenic carbonate sands found in the coastal zone and shallow water consist of porous or hollow particles with a rough texture.
Figure 10. Harker diagrams for selected major elements of beach sands collected along the coasts of South West Japan, on the coastline of Northern Kyushu, Yamaguchi, Shimane, Tottori, Tango Peninsula, and Noto Peninsula.
0 1 2 3 4 5 6 7
c) Fe2O3* (wt%)
0 1 2 3 4 5
d) MgO (wt%)
0 20 40 60 80 100
e) CaO (wt%)
0 1 2 3 4
f) Na2O (wt%)
0 2 4 6
0 20 40 60 80 100
SiO2 (wt%) g) K2O (wt%)
0 0.1 0.2
0 20 40 60 80 100
SiO2 (wt%) h) P2O5 (wt%)
Northern Kyushu Shimane Prefecture Tango Peninsula Yamaguchi Prefecture Tottori Prefecture Noto Peninsula
Marine Sediment River Sediment
0 5 10 15 20
b) Al2O3 (wt%)
0 0.5
1 1.5
a) TiO2 (wt%)
Figure 11. Geological map of South West Japan, showing the geochemical composition of SiO2 and Al2O3 elements, and location of beaches sampled along the coastline of Northern Kyushu, Yamaguchi, Shimane, Tottori, Tango Peninsula, Wakasa Bay, and Noto Peninsula. Modified from the Geological Survey of Japan (GSJ) and National Institute of Advanced Industrial Science and Technology (AIST), 2016.
Tottori Prefecture 80 wt% 10 wt% 5 wt%
Al O2 3
SiO2 Houzyou 1 Houzyou 2 Tomari Ishiwaki
ed An ar om i 1
ed An ar om i 2
m Ha ur am a 1
m Ha ur am
a 2 ku Ha
toro uuKa ky Sa
h. i 1 i 2 anan kitkit MaMa
ga Hi
iha sh
a 1 m ga Hi
iha sh
a 2 m
80 wt% 10 wt% 5 wt%
Al O2 3 SiO2 Fukue Arata D Arata C Arata B Arata A Yoshimo
sh Yo
imiD YoshimiC Yoshimi B
sh Yo
imi A Ayarag
i Yasuok
a ra Na bim u ats
hir Us am oh a B
hir Us am oh
a A ad Ak
aka awna HiAg
a no Tu
im sh
a 2 no Tu
im sh
a 1 nd Ka
a ata Ar
iga Do
m ha
a sh gu Ko
i
wa Ka a tan
yo To
a 2 urur yo To
a 1
Yamaguchi Prefecture s
s
ss s s
s s AA
A A
A
A A AA A
A
A A
A A
AA A
AA v v
vv
vvv
v
v
v v
v
v v
vv vv p p p
p p
p p p p
p p M
M
M
M
M M
MM
M M
M
MM
M s sss vv
Shimane Prefecture 80 wt% 10 wt% 5 wt%
Al O2 3
SiO2 Kohama Nakasu Nakasu 2
oc M sh hii
i 7
am Iw
itsud
1 a ta Ki m ha
aa ur no Ta
2 no Ta a ur
1 ii 1 Or
im Sh
ou oksh Ha
i 3
ino Ok
m ha
azusui 2nohtar TuGo As
ro Ku at m 2 su
am Iw
ifuku
. to sa Yu
to Ko ha ga a m
2 m Ni
a ur Oh
akezum taUo izuIso Sh
a
0
10 wt%
80 wt%SiO 5 wt%
2 Al O2 3
Fukui - Ishikawa Prefecture 80 wt% 10 wt% 5 wt%
Al O2 3 SiO2
nr Sa
iham
a ar Aw
aga Ka
ta Ka m ya a ad
m Ko
sukow ataiikam M Ko
an sa ku Ha
na Ka w za
akuiroho Sh Ha
o ka Ta at m
su am ah Im
a nr Se
iham
a ku Ha
i Wakasa Bay
Tango peninsula
East San'in coastTango peninsulaWakasa bay
ag Iw an ah
aiokm Hina to Sa
i Ejiri Amano.
ug Ry am uh
a sh ba Ko
i Nojiri
ng Ta ur oy
a da nn Ku
ng Ta Ka o ak nz
i
su Ka
im
iba Sh
m ya
azugi amsuSa rihYa Ki
ano ke Ta
m Ku
iham
a ch Ha am oh
ai. bik to Ko
na Su
ta Taizka
a He
i
at M ar ub
ia jir ka Sa
am Di
doou onish Su
ge Su m ha
a da Sa
hi Ke m no ub at a ar
80 wt% 10 wt% 5 wt%
Al O2 3
SiO2 Northern Kyushu
San'in coast
80 wt% 10 wt% 5 wt%
Al O2 3
SiO2 Northern Kyushu
ra Ka W tsu 2
ra Ka W tsu
1 2 1kajo tsutsuikaNi raraSh KaKa
5 jo Ni
4 jo Ni
3 jo Ni
2 jo Ni
1 sh Ito
ima 3 Itoshim
a 2a 1 im sh Ito
ga Na m ha a 2
ga Na m ha
a 1ku aju Im
2 1m kuno Ikiaju Im
.jirogau 1u 2yaajiKongngWMi SiSi
uy Ts ak az
i
tsu Ka ah ur am a
na Mu ta ka 2
na Mu ta ka
1a u 2u 1 hiyitsitsAsmm NaNa
Sedimentary rocks Accretionary complexes Volcanic rocks Plutonic rocks Metamorphic rocks
Geology M
A v p
s 0100 Km
Silica - Alumin um
Sea of Japan https://gbank.gsj.jp/seamless/seamless2015/2d/index.html?lang=en
Southw est Ja pan
Tottori PrefectureShimane ef Pr ectur e
Yamaguchi Prefecture
Fukui Prefecture Ishik
a aw ef Pr ectur e
Fukuoka Prefecture Saga Prefecture Hyōgo Prefecture
Kyoto PrefectureTottori Prefecture
Shimane ef Pr ectur e
Yamaguchi Prefecture
Fukui Prefecture Ishik
a aw ef Pr ectur e
Fukuoka Prefecture Saga Prefecture Hyōgo Prefecture
Kyoto Prefecture Noto peninsula
Figure 12. Geological map of South West Japan, showing the geochemical composition of SiO2 and CaO elements, and location of beaches sampled along the coastline of Northern Kyushu, Yamaguchi, Shimane, Tottori, Tango Peninsula, Wakasa Bay, and Noto Peninsula. Modified from the Geological Survey of Japan (GSJ) and National Institute of Advanced Industrial Science and Technology (AIST), 2016.
80 wt% 10 wt% 5 wt%
CaO
SiO2Tottori Prefecture
uz Ho
u 1 yoyo uz Ho
u 2 m To
iarak iw Ish
i
ed An ar om i 1
ed An ar om i 2
m Ha ur am a 1
m Ha ur am
a 2 ku Ha
toh.ro uuKa ky Sa
kit Ma
i 1 anan kit Ma
i 2 ga Hi
iha sh
a 1 m ga Hi
iha sh
a 2 m
80 wt% 10 wt% 5 wt%
CaO
SiO2 Fukue Arata D Arata C Arata B Arata A Yoshimo sh Yo
imiD YoshimiC Yoshimi B
sh Yo
imi A Ayarag
i Yasuok
a ra Na bim u ats
hir Us am oh a B
hir Us am oh
a Aad Ak
aka awna HiAg
a no Tu
im sh
a 2 no Tu
im sh
a 1 nd Ka
a ata Ar
iga Do
m ha
a sh gu Ko
i
wa Ka a tan
yo To
a 2 urur yo To
a 1
Yamaguchi Prefecture s
s
ss s s
s s AA
A A
A
A A AA A
A
A A
A A
AA A
AA v v
vv
vvv
v
v
v v
v
v v
vv vv p p p
p p
p p p p
p p M
M
M
M
M M
MM
M M
M
MM
M s sss vv 0
10 wt%
80 wt%SiO 5 wt%
2 CaO
East San'in coast 80 wt% 10 wt% 5 wt%
CaO
SiO2Tango peninsulaWakasa bay
ag Iw an ah
aiokm Hina to Sa
i Ejiri Amano.
ug Ry am uh
a sh ba Ko
i Nojiri
ng Ta ur oy
a da nn Ku
ng Ta Ka o ak nz
i
su Ka
im
iba Sh
m ya
azugi amsuSa rihYa Ki
ano ke Ta
m Ku
iham
a ch Ha am oh
ai. bik to Ko
na Su
ta Taizka
a He
i
at M ar ub
ia jir ka Sa
am Di
doou onish Su
ge Su m ha
a da Sa
hi Ke m no . at
80 wt% 10 wt% 5 wt%
CaO
SiO2Fukui - Ishikawa Prefecture
nr Sa
iham
a ar Aw
aga Ka
ta Ka m ya a ad
m Ko
sukow ataiikam M Ko
an sa ku Ha
na Ka w za
akuiroho Sh Ha
o ka Ta at m
su am ah Im
a nr Se
iham
a ku Ha
i Wakasa Bay Northern Kyushu
Tango peninsula
San'in coast
Shimane Prefecture 80 wt% 10 wt% 5 wt%
CaO
SiO2 Kohama Nakasu Nakasu 2
oc M sh hii
i 7
am Iw
itsud
1 a ta Ki m ha
aa ur no Ta
2 no Ta a ur
1 ii 1 Or
im Sh
ou oksh Ha
i 3
ino Ok
m ha
azusui 2nohtar TuGoAs
ro Ku at m 2 su
am Iw
ifuku
. to sa Yu
to Ko ha ga a m
2 m Ni
a ur Oh
aa kezum taUoizuIso Sh
80 wt% 10 wt% 5 wt%
CaO
SiO2 Northern Kyushu
ra Ka W tsu 2
ra Ka W tsu
1 2 1kajo tsutsuikaNi raraSh KaKa
5 jo Ni
4 jo Ni
3 jo Ni
2 jo Ni
1 sh Ito
ima 3 Itoshim
a 2a 1 im sh Ito
ga Na m ha a 2
ga Na m ha
a 1ku aju Im
2 1m kuno Ikiaju Im
.jirogau 1u 2yaajiKongngWMi SiSi
uy Ts ak az
i
tsu Ka ah ur a am
na Mu ta ka 2
na Mu ta ka
1au 2u 1 hiyitsitsAsmm NaNa
Silica - Calcium
Sedimentary rocks Accretionary complexes Volcanic rocks Plutonic rocks Metamorphic rocks
Geology M
A v p
s 0100 Km
Sea of Japan https://gbank.gsj.jp/seamless/seamless2015/2d/index.html?lang=en
Southw est Ja pan
Tottori PrefectureShimane ef Pr ectur e
Yamaguchi Prefecture
Fukui Prefecture Ishik
a aw ef Pr ectur e
Fukuoka Prefecture Saga Prefecture Hyōgo Prefecture
Kyoto PrefectureTottori Prefecture
Shimane ef Pr ectur e
Yamaguchi Prefecture
Fukui Prefecture Ishik
a aw ef Pr ectur e
Fukuoka Prefecture Saga Prefecture Hyōgo Prefecture
Kyoto Prefecture
Noto peninsula
Figure 13. Selected microscopic photographs biogenic carbonate sands from the Tsunoshima, Akada, Hinaka, Arata, and Doigahama Beaches, Yamaguchi Prefecture, South West Japan. The identified species are Foraminifera, ostracod, shells, and sea urchin, made primarily of CaCO3.
The variations of ecosystem and geography of marine condition in Hinaka and Arata beach are shown in figure 14. Typical small-scale pocket beach, and inlet of beach shape characteristic. Rocky points of both sides of the Hinaka beach, Zostera marina and other sea weed are exposed on the shore of the Hinaka beach suggesting the existence of under-water sea plant field. On the left side of the Hinaka beach, Zostera marina are found on the shore (Figures 15a, 15b and 15c. Doigahama beach is more strait than Arata beach (Figure 16), but sea plant habit is suggestive. Under-water structure may make a variety of geography for ecosystem.
<RTMNRGHL
J C 1HM J
Q S
-NHF G L
<RTMNRGHL
J C
1HM J
Q S
-NHF G L % LL
Identification: Foraminifera, ostracod, shells, sea urchin, made primarily of CaCO3.