概括性地介绍了聚敛型板块边缘大地构造环境中的岩浆活动及其所形成的火成岩岩石构造组合类型，并以此为线索，将板块构造、岩石圈运动与沉积盆地的形成有机地结合起来，简要地分析和介绍了聚敛型板块边缘的主要沉积盆地类型及其沉降机理。指出盆地形成是板块构造、岩石圈运动在地壳浅部的一种表现形式，岩石圈板块运动直接受深部作用过程的制约，火山喷发或侵入是上地幔、深部地壳对流在地表或浅部地壳的表现。因此，对火成岩岩石组合或系列的研究，将为沉积盆地的形成与演化提出重要的深部动力学约束。

利用岩石地球化学的方法，研究了北羌塘新生代火山岩。结果表明，北羌塘第三纪火山岩可区分为碱性（钾玄岩质）和高钾钙碱两套不同的火山岩组合，它们分别起源干一个特殊的、不均一的富集型上地帽和一个加厚陆壳的榴辉岩质下地壳。由于青藏之下软流层物质的上涌而形成帽源碱性岩浆活动，而慢源岩浆在Moho面的底侵作用又为下地壳中酸性高钾钙碱系列火山岩的起源提供了热动力条件。该区两套不同糸列和源区类型的火山岩正是在这种特殊的构造环境中彤成。

Ultrabasic rocks in the Mianxian-Lueyang ophiolitic melange zone include harzbur-gite and dunite which exhibit LREE depletion with remarkable positive Eu anomaly. The dia-base dike swarm shows LREE enrichment but slightly negative Eu anomaly. Metamorphosed volcanic rocks can be divided into two groups in terms of their REE geochemistry and trace ele-ment ratios of Ti/V, Th/Ta, Th/Yb and Ta/ Yb. One is the MORB-type basalt with LREE depletion, representing the fragments of oceanic crust and implying an association of the MORB-type ophiolite and an ancient ocean basin between the Qinling and Yangtze plates dur-ing the Middle Paleozoic-Early Mesozoic era. The other comprises the island-arc volcanic rocks including tholeiitic basalt and a large amount of calc-alkaline intermediate-acid volcanic rock, which could not be the component of the ancient oceanic crust but the result of magmatism at the continental margin. This indicates that the Mianxian-Lueyang limited ocean basin had un-dergone a whole process of development, evolution and vanishing from Devonian-Cretaceous to Permian. And the Qinling area had become an independent lithospheric microplate, on the southern side of which there were exhibited the tectonic characteristics of active continental margins during the Late Paleozoic-Early Mesozoic. That is to say, the Qinling cannot be sim-ply considered as a result of collision between the Yangtze and North China plates.

利用电子探针和激光探针剥蚀系统（LA-IEP-MS）对北羌塘新第三纪高钾钙碱岩系英安岩中角闪石的主元素和微量、稀土元素进行了分析。结果表明，本区角闪石均属钙质角闪石亚类，主元素特征指示该套火山岩为陆壳局部熔融岩浆系列。角闪石强烈富集Sc、Ti、V、Cr、Co、Ni等弱不相容亲铁元素，而相对亏损Th、U、Pb、Rb等强不相容的大离子亲石元素。稀土元素丰度高，且无.Eu异常，指示北羌塘这套高钾钙碱岩系火山岩可能是青藏高原加厚的相当于榴辉岩相物质组成的下部陆壳脱水熔融的产物。

Volcanic units with ages in the range 4.27-44.60 Ma in the Zhentouya area south to Ulan Ul Lake, Hoh Xil region, are mainly lava, predominantly dacite in composition, together with lesser amounts of andesite. The high-potassium calc-alkaline dacite series is characterized by enriched LIL elements such as Rb, Ba, Th, U, and K, and depleted HFSE such as Ti, Nb, Ta, and Sr, whereas the andesite series containing high-potassium calc-alkaline and shoshonitic components is enriched in the LIL elements Cs, Rb, Ba, Th, U, and Sr, and depleted in the HFSE Ti, Nb, and Ta. La/Sm-La and Zr/Sm-Zr discrimination diagrams indicate that both the dacite and the andesite series, with their contrasting evolutionary trends, were generated from partial melting of the continental crust rather than by fractional crystallization of a primary basaltic magma derived from the mantle. Nd, Sr, and Pb isotopic compositions of the dacite (radiogenic 87Sr/86Sr=0.709227-0.709578, 208Pb/204Pb=39.1356-39.2622, 207Pb/204Pb=15.6675-15.7063, 206Pb/204Pb=18.7635-18.7970 and nonradiogenic 143Nd/144Nd=0.512287-0.512591, εNd=-0.92 to -6.85) provide evidence that crustal anatexis in the Tibetan Plateau played an important role in petrogenesis of the dacite series Moreover, the presence of granulite xenoliths in the dacite series places P-T constraints on the magma source at a temperature range of 780-820℃ and pressure of 0.86 GPa (equal to a depth of 28km). Combined with P-T conditions inferred from the granulite-facies xenoliths, the geochemistry of the dacite and the isotopic signature of crustal anatexis suggest that partial melting of the middle part of thickened Tibetan crust could have produced the primary dacite magma series. The andesite, to some degree, shows an adakitic compositional signature involving high Sr>1000ppm, Sr/Y ratios>50, and low Yb contents<2ppm. Evidently plagioclase broke down in the andesitic magma source region under the P-T conditions of partial melting. Compared with the dacite series, it appears that partial melting of the lower part of the thickened, eclogite-facies Tibetan crust was responsible for generation of the andesitic magma.

Detailed studies indicate that the main rock type of the Neogene high-potassium calc-alkaline volcanic rock association from north Qiangtang is andesite, dacite and rhyolite. They belong to typical crust-generation magmatic system and originate from the special thickened crust of the Tibetan Plateau by dehydration melting. This group of rocks exhibits LREE enrichment but no remarkable Eu anomaly that shows their source region should be a thickened deep crust consisting of eclogitic mass group, implying that the crust had been thickened and an eclogitic deep crust had been formed during the Neogene period in Qiangtang area. This understanding is important and significant to making further discussion on the uplift mechanism and continental dynamics of the Tibetan Plateau.

详细的地球化学解析表明，西乡群火山岩系具有Nb、Ta亏损等弧岩浆系列特征，其中白勉峡组火山岩与一个部分亏损的地幔源区有关，形成于洋内岛弧（或初始岛弧）的大地构造环境&而局限于柳树店K孙家河-三郎铺一带分布的孙家河组、三郎铺组和大石沟组火山-沉积岩系可能为一外来构造移置体，形成于泥盆-石炭纪，与一个活动大陆边缘及加积增生岛弧型地壳裂陷形成的初始弧间盆地环境有关，并在区域上与勉略缝合带相关联，原应为该缝合带的一个组成部分。

Major and trace elements and Sr-Nd-Pb isotope data are presented for adakitic andesite-dacite-rhyolite association from Tibetan Plateau with ages in the range of 9.4～26. 94 Ma. All of the rocks ex-hibit characteristics of adakites derived by partial melting of an eclogitic lower crust. Such as w(SiO2)) 58%, low Y and Yb, high La/Yb values, LREE enrichment but no remarkable Eu depletion with a steep REE pattern. They are highly enriched in some mobile trace elements (w(Sr))340X 10-e). Iso-topic compositions exhibit radiogenic Sr and Pb (N(87Sr)/N(86Sr)=0.706 365～0.708 156; N(208Pb)/N(204pb)=38.955 5～39.052 5; N(207Pb)/N(204Pb)=15.651 2～15.672 7; N(206Pb)/N(204Pb)=18.679 2～18.839 7) and unradiogenic Nd (N(143Nd)/N(144Nd)=0.512 411～0.512 535; ε(Nd)=-2.01 to -4.43). Constancy of Sr and Nd isotopic values contrasts with variations in Pb isotopes and negative ε(Nd), and highlights the importance of crustal anatexis in their genesis. Their adakitic geo-chemical features and crustal anatexis isotopic signature suggest a primitive magma generation process responsible for the partial melting of an eclogitic lower crust of the Tibetan Plateau, implying that the crust had been thickened and an eclogitic lower crust had been formed during the Neogene period in north Tibet area. This understanding is important and significant to making further discussion on the uplift mechanism and continental dynamics of the Tibetan Plateau.

In northern Qinghai-Tibet plateau there are developed Cenozoic volcanic rocks. They constitute a trachybasalt-shoshonite-latite-trachydacite assemblage. According to the forming ages, three Cenozoic volcanic rock lithozones can be distinguished in the northern part of the plateau. Cenozoic volcanic rocks and muscovite/two-mica granites forming the three belts in pairs represent the northern and southern margins of the plateau in different periods. In fact, the tectonic setting of the northern part of the Qinghai-Tibet plateau is significantly different from that of the southern part -Himalayas. The southern part has experienced subduction and continent-continent collision. There are developed the Cenozoic S-type granites (muscovite/two-mica granites) there. But the northern part is characterized by Cenozoic basaltic magma-tism which obviously comes from the upper mantle. Slight doming of the upper mantle is recog-nized underneath the northern part of the plateau, which is the result of resistance of the Tarim plate to the north direction-sense movement of the Tibetan plate. And at the same time, the u-plift machanism shows that the formation of the Qinghai-Tibet plateau involved three orogenic stages (35-23 Ma, 23-10 Ma and<2Ma) of uplift in the vertical direction and extension in the horizontal direction with the Gangdise-Qiangtang orogenic belt as its core.

分析了北羌塘半岛湖新第三纪玻基粗面安山岩中黑云母的常量、微量及稀土元素特征。结果表明，黑云母均属钛铁黑云母类，富集大离子亲石元素B3以及Sc，Ti，V，Cr，Co，Ni等铁族元素，而相对亏损Th，U，Pb等亲石元素$轻稀土强烈富集，轻重稀土分异显著，但Eu亏损并不严重，暗示原始岩浆来源于一个基性岩质的、相当于榴辉岩矿物相（斜长石相缺失）的源区类型。