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幔源尖晶石橄榄岩的结构变化过去常被认为是软流圈地幔底辟存在的证据,并指示大范围(几公里～几十公里)内变形的非均一性.但许多火山口都挟带有变形及未变形的捕虏体,同时橄榄岩体中所呈现的野外关系表明:因为大量的岩石圈剪切带的存在,变形与未变形橄榄岩的蚀变规模较小(几厘米～几米).极少数捕虏体既含变形的、又含未变形的橄榄岩.在变形与交代矿物生长之间也存在明显关系,角闪石通常富集在强烈变形带、橄榄岩体和变形捕虏体中,有时也出现于交切状脉及其周围的接触变质带中.人们还可以看到在变形作用和地球化学富集作用标志之间存在一定的关系.许多变形尖晶石橄榄岩中的单斜辉石显示出轻稀土元素富集的特点,而未变形尖晶石橄榄岩中的单斜辉石通常具有洋中脊玄武岩(MORB)型轻稀土元素亏损模型.未变形橄榄岩的Sr和Nd放射性同位素组成通常与MORB的相似.并且有低ε_(Sr)值和高ε_(Nd)值.相反,含或不含角闪石的变形橄榄岩常具高ε_(Sr)电和低ε_(Nd)值.这表明了富大离子亲石元素和富轻稀土元素的流体或熔体的地球化学富集作用,从上所述可推断:在浅部地幔内有岩石圈韧性剪切带存在,角闪石和单斜辉石在这些剪切带的交代流体中发生沉淀.
Structural changes in the mantle-derived spinel peridotites have historically been considered as evidence of asthenospheric mantle emplacement and indicate heterogeneity of deformation over a wide range (a few kilometers to tens of kilometers), but many crater threats With the deformed and undeformed xenoliths, the field relationships in peridotite indicate that due to the large lithospheric shear bands, the alteration and undeformed peridotites are relatively small in scale (a few centimeters ~ A few meters.) A handful of xenoliths contain both deformed and undeformed peridotites, and there is a clear relationship between deformation and replacement mineralogy. Amphiboles are generally enriched in intense deformation zones, peridotite and deformation Xenopus, sometimes found in the contact veins and the surrounding metamorphic belt, one can see there is a certain relationship between the deformation and the signs of geochemical enrichment Many deformed spinel olives The clinopyroxene in the rocks shows the enrichment of light rare earth elements, whereas the clinopyroxenes in the undistorted spinel peridotites usually have the MORB depletion model of light rare earth elements. Rock Sr and Nd radioisotopes It is generally similar to MORB and has low and high ε_ (Nd) values. In contrast, peridotites with or without amphibole are often characterized by high ε Sr and low ε Nd, This shows the geochemical enrichment of a large ion-lithophile and a light-rare earth-rich fluid or melt, from which it can be deduced that there is a lithospheric ductile shear zone in the shallow mantle Amphibole and clinopyroxene precipitate in the substitutive fluids of these shear zones.