新疆萨热克铜矿床绿泥石化蚀变相与构造-岩浆-古地热事件的热通量恢复

发布时间：2018-09-13 15:17

【摘要】：据新疆萨热克铜矿区内绿泥石化蚀变相的产状可划分为A型、B型、C型和D型4期。采用绿泥石矿物温度计和地球化学岩相学研究,认为4种绿泥石蚀变相为陆内红层盆地中紫红色铁质碎屑岩系发生褪色化蚀变机制之一。A型和B型绿泥石相为中-晚侏罗世—早白垩世构造-热事件所形成,A型自生粒间状绿泥石在侏罗系-下白垩统中总体顺层分布,形成温度在163~217℃,与辉铜矿共生且形成于埋藏-压实成岩期,热流密度为40.39~48.43 Jm-2s-1,热通量较小。B型微细脉型绿泥石化蚀变相形成于盆地流体改造期,总体沿切层裂隙和显微裂隙分布,与辉铜矿和斑铜矿等共生,形成温度为188~219℃,热流密度较大,在116.90~330.49 Jm-2s-1。斑铜矿+辉铜矿型(196~237℃)和斑铜矿型(203~226℃)铜矿石带指示了盆地流体改造富集成矿的中心部位,热流密度在330.49~878.78 Jm-2s-1,其热流密度明显较大。B型绿泥石相与碎裂岩化相和沥青化蚀变相具有多重耦合结构,形成温度越高,裂隙渗透率越高,可达30×10-6 cm2/211~227℃,推测存在热启裂隙作用。C型和D型绿泥石相为构造-岩浆-热事件所形成,C型团斑状-细脉状绿泥石化蚀变相分布在辉绿辉长岩脉群边部和外接触带含铜漂白-褪色化蚀变带中,含铜蚀变辉绿岩发生绿泥石化相蚀变温度为平均为175℃,平均热流密度321.46 Jm-2s-1,在克孜勒苏群褪色化杂砾岩中其绿泥石形成温度较高(236~238℃),热流密度高达442.86~922.63 Jm-2s-1;而D型绿泥石化蚀变相分布在碎裂岩化蚀变辉绿辉长岩脉群中,揭示遭受构造热事件的古地温在121~185℃,平均热流密度为239.59 Jm-2s-1。四种类型绿泥石蚀变相揭示萨热克铜矿区经历了异常古地场演化和古热事件。
[Abstract]:According to the occurrence of greenstone alteration in Sajek copper deposit, Xinjiang, it can be divided into four stages: type A, type B, type C, and type D, respectively. Using chlorite mineral thermometers and geochemical lithofacies studies, It is considered that the four types of chlorite alteration are one of the mechanisms of fading and alteration of reddish iron clastic rock series in the continental red bed basin. Type A and B type chlorite facies are formed by tectonic-thermal events of Middle-Late Jurassic-early Cretaceous. The distribution of authigenic intergranular chlorite in the Jurassic-Lower Cretaceous is as a whole. The formation temperature is at 163 ~ 217 鈩，

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