REE and Nd-Sr isotope provenance signatures in clastic sedimentary terranes and geological evolution of the Asia-Pacific margin

本州、北海道和韩国主要地体中的砂岩-泥岩套在全岩地球化学成分上表现出明显的对比。在本州，岛户-田边、Sambagawa和黑河组具主要、微量和稀土元素特征，这是相对演化的CIA或ACM沉积物的典型特征。球粒陨石标准化的稀土配分模式为分馏，平均La_N/Yb_N为10.4~10.9，平均为8.2和9.2，Gd_N/Yb_N分别为1.72~1.33，1.45和1.71。较低的Gd_N/Yb_N比值指示了锆石和石榴石的集中。所有三个套间均出现负Eu异常(平均Eu/Eu^*分别为0.77-0.73、0.63和0.79)。大岛硅质地体(北海道)具有较高的La_N/Yb_N比值(平均11.00)和较大的Eu/Eu负异常(0.64)，表明物源相对成熟。下部Yezo群-Idonnappu带岩石的La_N/Yb_N和Eu/Eu^*(平均值分别为9.74和0.69)在上部进一步降低(6.76和0.78)，反映出较大的镁铁质成分。AV…韩国庆生超群的La_N/Yb_N平均值(13.5)大于相关Kanmon群的La_N/Yb_N比值(8.8)，但Eu/Eu*平均值相近(0.78~0.79)。And模型(时代来自岛户，Sambagawa。大岛和耶佐-伊多纳普地体形成了鲜明的对比。Shimanto模式年龄在0.74~1.6Ga之间，但大多数在1.0~1.4Ga之间，介于潜在的Ryoke地体和Higo Ryoke地体之间。两个Sambagawa片岩产生了1.04和1.2Ga的可比模式年龄，为Shimanto原岩提供了支持。大岛地体模型年龄明显偏老(1.44-1.85Ga)，与扬子克拉通的年龄相当，扬子克拉通是其可能的来源。下部Yezo-Idonnappu套的模式年龄始终较年轻(1.05-1.31Ga)，而上部Yezo-Idonnappu岩石的模式年龄更年轻(0.71-0.93Ga)，这可能反映了洋壳在增生杂岩中循环的贡献。元素丰度与平均日本造山带上地壳弧(JOAUC)的归一化结果显示，某些组合的某些元素(如Fe、Mn、Mg、Ca、P、Sc、V、Cr和Ni)出现负异常，尽管REE和HFSE总体上比较好。与泥岩相比，大岛、耶佐-伊顿纳普和岛托地体的枯竭最为明显。这些异常情况表明，JOAUC平均值可能会对某些元素进行修正。较少

Sandstone-mudstone suites from major terranes in Honshu, Hokkaido and Korea show significant contrasts in whole rock geochemical compositions. In Honshu, the Shimanto-Tanabe, Sambagawa, and Kurosegawa suites show major, trace, and rare earth element signatures typical of relatively evolved CIA or ACM sediments. Chondrite-normalized REE patterns are fractionated, with average La_N/Yb_N of 10.4-10.9,8.2, and 9.2, and Gd_N/Yb_N ratios of 1.72-1.33,1.45, and 1.71, respectively. The lower Gd_N/Yb_N ratios suggest concentration of zircon and garnet. Negative Eu anomalies occur in all three suites (average Eu/Eu^* 0.77-0.73,0.63, and 0.79, respectively). High La_N/Yb_N ratios (average 11.00) and larger negative Eu/Eu anomalies (0.64) in the silicic Oshima terrane (Hokkaido) indicate a relatively mature source. Lower La_N/Yb_N and Eu/Eu^* (average 9.74 and 0.69) in lower Yezo Group-Idonnappu Zone rocks decrease further in the upper part (6.76 and 0.78), reflecting a greater mafic component. Av … More erage La_N/Yb_N ratio (13.5) in the Gyeongsang Supergroup (Korea) is greater than in the correlative Kanmon Group (8.8), but average Eu/Eu* values are comparable (0.78-0.79). Nd model (ages from the Shimanto, Sambagawa. Oshima and Yezo-Idonnappu terranes contrast significantly. Shimanto model ages range from 0.74 to 1.6 Ga, although most lie between 1.0-1.4 Ga, intermediate between potential Ryoke and Higo Ryoke terrane sources. Two Sambagawa schists yield comparable model ages of 1.04 and 1.2 Ga, lending support to a Shimanto protolith. Oshima terrane model ages are significantly older (1.44-1.85 Ga), comparable with values for the Yangtze craton, their probable source. Model ages in the lower Yezo-Idonnappu suite are consistently younger (1.05-1.31 Ga), and are younger still (0.71-0.93 Ga) in upper Yezo-Idonnappu rocks, possibly reflecting contributions from oceanic crust recycled within the accretionary complex. Normalization of elemental abundances against average Japan Orogenic are upper crust(JOAUC) shows negative anomalies for some elements (e.g.Fe,Mn,Mg,Ca,P,Sc,V,Cr and Ni) in some suites, although the REE and HFSE generally compare well. Depletion is most marked in the Oshima, Yezo-Idonnappu, and Shimanto terranes, and in sandstones compared to mudstones. The anomalies suggest the JOAUC average could be amended for some elements. Less