南岭及邻区分布一系列与中生代花岗岩有关的锡矿床,这些岩石可以是含角闪石黑云母花岗岩,或是(黄玉)钠长石-(铁)锂云母花岗岩,其岩石化学特征指示它们分别对应于准铝质和过铝质花岗岩.细致的矿物学研究表明它们具有完全不同的矿物学特征.准铝质含锡花岗岩的矿物学特征表现为:(1)角闪石、黑云母、条纹长石等组成特征性的造岩矿物组合:(2)标志性副矿物榍石、磁铁矿等显示其原始岩浆具有较高的氧逸度;(3)含锡矿物为锡石、黑云母、榍石等;(4)锡石的成分比较纯,微量元素含量低.过铝质含锡花岗岩的矿物学特征主要表现为:(1)铁锂云母-锂云母、钾长石、钠长石为典型造岩矿物;(2)富铝矿物黄玉是较常见的副矿物,与花岗岩铝过饱和特征相符;(3)锡石是重要的锡矿物,且富含Nb、Ta.造成两类含锡花岗岩显著矿物学差异的原因可能包括熔体的氧逸度、挥发组分和岩浆分异程度的差异.氧化型准铝质花岗岩熔体中锡以四价为主,这导致锡容易富集在含钛的造岩矿物或副矿物中,在岩浆结晶分异阶段形成富锡矿物;这些富锡矿物可成为含锡花岗岩的标志性矿物.相对还原的过铝质花岗岩熔体中锡以二价为主,不易进入造岩矿物和副矿物,常常在岩浆结晶分异阶段形成岩浆成因的锡石;因此,岩浆成因锡石成为这类花岗岩的重要成矿和找矿标志.岩浆性质和锡在两类花岗岩岩浆中地球化学行为的差异,导致形成的矿床类型有所不同.准铝质花岗岩主要形成岩体浸染型、绿泥石-石英脉型、云英岩型、矽卡岩型等矿床,而过铝质花岗岩除形成云英岩型、矽卡岩型、石英脉型等矿床外,更易形成岩体浸染型锡矿化. A series of tin deposits related to the Mesozoic granites are distributed in Nanling and its adjacent areas. These rocks may be amphibole-bearing biotite granites or (topaz) albite- (iron) lithiated micaceous granites, whose petrochemical characteristics indicate them Which correspond to the quasi-aluminum and peraluminous granites respectively.Micro-mineralogical studies have shown that they have completely different mineralogical characteristics.The mineralogical characteristics of quasi-aluminum tin-bearing granites are as follows: (1) amphibole, biotite, Stripe feldspar and other features of rock-forming mineral assemblage: (2) the iconic secondary minerals such as cristobalite and magnetite show that their original magma has high oxygen fugacity; (3) tin-bearing minerals are cassiterite, black (4) Cassiterite is pure in composition and low in trace elements.The mineralogical characteristics of peraluminous tin-bearing granite are mainly as follows: (1) iron-lithium mica-lepidolite, potassium feldspar and sodium Feldspar is a typical rock-forming mineral; (2) alluvial-rich topaz is the more common accessory mineral that conforms to the supersaturated characteristics of granite; (3) cassiterite is an important tin mineral and is rich in Nb and Ta. The reason for the significant mineralogical differences of tin-bearing granites may include the oxygen fugacity of the melt, And magma differentiation degree.The oxidation of quasi-aluminum granite melt tin is mainly tetravalent, which leads to tin easily enriched in the titaniferous rock mineral or accessory minerals, in the phase of the formation of magma crystallization differentiation rich Tin minerals; these tin-rich minerals can become a landmark of tin-bearing granite minerals.Relatively reduced peridotite granite melt divalent dominated, not easy to enter the rock-forming minerals and minerals, often in the magma crystallization stage Forming cassiterite of magmatic origin.Therefore magmatic cassiterite is the important mineralization and prospecting indicator of such granites.Differences between magmatic properties and geochemical behavior of tin in two types of granite magma lead to different types of deposits formed The quasi - aluminous granites are mainly composed of diagenesis, chlorite - quartz veins, dolomite and skarn - type deposits, while the peridotitic granites not only form dolomite, skarn and quartz Pulse-type deposits, more likely to form rock disseminated tin mineralization.