Petrological evidence of an anhydrous carbonatitic peridotite source for the Xiaogulihe ultrapotassic volcanic rocks, northeastern China
Petrological evidence of an anhydrous carbonatitic peridotite source for the Xiaogulihe ultrapotassic volcanic rocks, northeastern China
复制标题
中国东北小古里河超钾质火山岩无水碳酸盐岩橄榄岩来源的岩石学证据
DOI：
10.1016/j.lithos.2022.106776
复制
发表时间：
2022
期刊：
影响因子：
3.5
通讯作者：
Pengli He
中科院分区：
文献类型：
--
作者：
Boyin Weng;L. Hong;Yinhui Zhang;Le Zhang;Yigang Xu;C. Yuan;Pengli He
本文提供了东北地区小古里河超钾质火山岩的橄榄石和全岩地球化学新资料。这些资料为研究二克山-五大连池-科罗-小古里河钾质-超钾质火山岩带的岩石成因提供了新的认识。小古力河火山岩的岩石学和全岩地球化学组成表明，形成于岩浆，主要经历了橄榄石+单斜辉石分馏与轻微的地壳混染和岩浆后蚀变。小古力河火山岩中高Fo（87-90）橄榄石具有高Ni（2050-3800 ppm）和Mn（1190-1750 ppm），高10000 Zn/Fe值（12-15），低Ca（1310-1800 ppm），低Fe/Mn（56-72）和Mn/Zn（10-14）的特征。它们的高Mn含量和低Fe/Mn值以及低FC 3 MS（<0.65; FC3MS = FeO/CaO - 3MgO/SiO2），低FCKANTMS（<0.37; FCKANTMS = ln（FeO/CaO）− 0.08ln（K2O/Al2O3）− 0.052ln（TiO2/Na2O）− 0.036ln（Na2O/K2O）ln（Na2O/TiO2）− 0.062（ln（MgO/SiO2））3-0.641（ln（MgO/SiO2））2-1.871ln（MgO/SiO2）− 1.473）和低CaO-Al 2 O3-Fe 2 O3总值表明其来源于含耐火橄榄岩的地幔源。小古里河橄榄石有略高的Zn/Fe和较低的Mn/Zn值比预期的橄榄石形成的典型的橄榄岩衍生的熔体，这表明这些熔岩的来源是以前交代富锌沉积碳酸盐熔体的相互作用。小古力河熔岩的低岩浆水含量（用橄榄石中钙地质湿度计测定<1wt%）也表明其来源于无水地幔。这些数据表明，小古力河超钾质熔岩代表了无水难熔的陆下岩石圈地幔橄榄岩的部分熔融。这些火山岩的富钾性质是来自地幔富钾储层的指示，这与碳酸盐交代作用密切相关，表明这一过程在富钾EWKX火山岩的生成中的作用。
This study presents new olivine and whole-rock geochemical data for the Xiaogulihe ultrapotassic volcanic rocks of northeastern China. These data provide insights into the petrogenesis of the rocks of the Erkeshan–Wudalianchi–Keluo–Xiaogulihe (EWKX) potassic–ultrapotassic volcanic belt. The petrography and whole-rock geochemical compositions of the Xiaogulihe volcanic rocks are indicative of formation from magmas that primarily underwent olivine + clinopyroxene fractionation with insignificant crustal contamination and post-magmatic alteration. The high-Fo (87–90) olivine within the Xiaogulihe volcanic rocks has high Ni (2050–3800 ppm) and Mn (1190–1750 ppm) contents, high 10000Zn/Fe values (12–15), low Ca (1310–1800 ppm) contents, and low Fe/Mn (56–72) and Mn/Zn (10–14) values. Their high Mn contents and low Fe/Mn values together with their low FC3MS (<0.65; FC3MS = FeO/CaO – 3MgO/SiO2), low FCKANTMS (<0.37; FCKANTMS = ln(FeO/CaO) − 0.08ln(K2O/Al2O3) − 0.052ln(TiO2/Na2O) − 0.036ln(Na2O/K2O) ln(Na2O/TiO2) − 0.062(ln(MgO/SiO2))3–0.641(ln(MgO/SiO2))2–1.871ln(MgO/SiO2) − 1.473) and low CaO–Al2O3–Fe2O3Totalvalues are indicative of derivation from a mantle source containing refractory peridotite. The Xiaogulihe olivines have slightly higher Zn/Fe and lower Mn/Zn values than expected for olivines formed from typical peridotite-derived melts, suggesting that the source for these lavas was previously metasomatized by interaction with Zn-rich sedimentary carbonatitic melts. The low magmatic water contents of the Xiaogulihe lavas (<1 wt% determined by use of the Ca-in-olivine geohygrometer) is also indicative of derivation from an anhydrous mantle source. These data suggest that the Xiaogulihe ultrapotassic lavas represent partial melts of anhydrous refractory subcontinental lithospheric mantle peridotite. The K-rich nature of these volcanic rocks is indicative of derivation from the K-rich reservoir of the mantle, which is closely associated with carbonatitic metasomatism, indicating the role of this process in the generation of the K-rich EWKX volcanics.