The new biotite activity model and standard-state thermodynamic properties of Ann, Phl, and Eas presented in part-I were used to make pseudosections of bulk compositions representing experimental Fe–Mg exchange equilibria and (model) pelitic bulk rock compositions in the system K₂O–FeO–MgO–Al₂O₃–SiO₂–H₂O (KFMASH), using mainly the software Perple_X. These pseudosection calculations (termed ‘our calculation(s)’ in the following) were compared to analogous ones performed with the solution model of biotite and thermodynamic data cited in White et al. (J Metamorph Geol 32:261–286, 2014, 10.1111/jmg.12071), termed ‘W14 calculation’. Our calculations with the experimental bulk composition used by Zhou (Ti–Mg–Fe biotites: formation, substitution, and thermodynamic properties at 650 to 900 °C and 1.1 Kb with fO₂ defined by the CH₄–graphite buffer. PhD thesis, State University of New York, 1994) in his experimental study of the Fe–Mg exchange between biotite (Bt) and olivine (Ol) confirm that biotite had no or only minimal octahedral Al (Al^VI) in these experiments. The experimental data of Ferry and Spear (—FS78, Contrib Mineral Petrol 66:113–117, 1978, 10.1007/BF00372150) on the Fe–Mg distribution between biotite and garnet (Grt) are well reproduced by our calculations. The computed composition of biotite (X_Fe) in equilibrium with garnet of Alm₉₀Py₁₀ composition and the resulting lnK_D values as a function of temperature are in good agreement with the experimental brackets. An analogous W14 calculation on the same Fe-rich bulk composition predicts too high X_Fe^Bt in order of 0.1 mol fraction. The Al^VI contents of biotite of about 0.3–0.45 apfu, as measured by Gessman et al. (Am Mineral 82:1225–1240, 1997, 10.2138/am-1997-11-1218) in similar biotite–garnet exchange experiments performed with Alm₈₀Py₂₀ and Alm₇₀Py₃₀ garnets, are well reproduced by our, as well as by W14 calculations. The extent of Tschermak substitution in biotite in the FS78 experiments, which had Fe-richer bulk compositions, has not been measured. Comparing the FS78 biotites with the ones from Gessman et al. (Am Mineral 82:1225–1240, 1997, 10.2138/am-1997-11-1218), it is very likely that the biotites reported in FS78 contained Al^VI in the same order of ca. 0.3–0.4 apfu. A T–X_Fe (= molar FeO/(FeO + MgO) pseudosection demonstrates the bulk composition dependence of lnK_D of the Mg/Fe^Grt/Bt exchange reaction in high-variance fields. Further comparisons, demonstrating the application of the new biotite solution model in the KFMASH system, are presented in pseudosections constructed for an average model pelite, as well as for a natural high-T/low-P and a natural high-P metapelite. The pseudosections show that biotite according to our biotite model breaks down at lower temperatures and pressures than predicted from the W14 biotite model in the KFMASH system. This means that KFMASH biotite can break down before the wet solidus is reached, which can explain the existence of dry high-T/low-P metapelites. At higher pressures, biotite according to our calculations breaks down at lower pressures than computed with the W14 biotite model. Before biotite breaks down, however, its Al^VI content based on our calculations could potentially be used for pseudosection barometry, similarly as the Si-in-phengite barometer. These trends need to be confirmed by a future extension of our model which incorporates Ti, Fe³⁺ and a di–tri-octahedral substitution.

第一部分中介绍的新黑云母活性模型和Ann，Phl和Eas的标准态热力学性质被用来制作代表实验中Fe-Mg交换平衡的块状组成的假剖面和系统K中的（模型）胶状块状块状组成。₂ O–FeO–MgO–Al ₂ O ₃ –SiO ₂ –H ₂ O（KFMASH），主要使用软件Perple_X。这些拟断面计算（称为“我们的计算（小号在下面）”）进行比较，以类似的那些与黑云母的溶液模型来执行并在White等人的热力学数据引用。（J Metamorph Geol 32：261–286，2014，10.1111 / jmg.12071），称为“W14计算'。我们使用周（Ti–Mg–Fe黑云母：在650至900°C和1.1 Kb下由CH _{4 –}石墨缓冲液定义的fO _2的形成，取代和热力学性质）进行的实验计算。纽约大学（1994）在他对黑云母（Bt）和橄榄石（Ol）之间的Fe-Mg交换的实验研究中证实，在这些实验中，黑云母没有或只有极少的八面体Al（Al ^VI）。通过我们的计算可以很好地再现费里和矛（-FS78，Contrib Mineral Petrol 66：113–117，1978，10.1007 / BF00372150）关于黑云母与石榴石（Grt）之间的Fe-Mg分布的实验数据。计算出的黑云母成分（与Alm ₉₀ Py ₁₀组成的石榴石平衡的X _Fe）和所得的ln K _D值随温度的变化与实验范围非常吻合。对相同的富铁本体组成进行的类似W14计算可预测X _Fe ^Bt太高，仅为0.1 mol分数。根据Gessman等人的测量，黑云母的Al ^VI含量约为0.3–0.45 apfu。（Am Mineral 82：1225-1240，1997，10.2138 / am-1997-11-1218）在使用Alm ₈₀ Py ₂₀和Alm ₇₀ Py ₃₀进行的类似黑云母-石榴石交换实验中我们的以及W14的计算都很好地再现了石榴石。在FS78实验中，黑铁矿中Tschermak取代的程度没有测定，该实验具有富铁的大块成分。将FS78黑云母与Gessman等人的黑云母进行比较。（Am Mineral 82：1225-1240，1997，10.2138 / am-1997-11-1218），在FS78中报道的黑云母很可能以大约相同的顺序含有Al ^VI。0.3–0.4 apfu。甲Ť - X_铁（=摩尔的FeO /（FeO的+ MgO）的拟断面演示的LN主体组成依赖ķ _d中，Mg /铁^{石榴石/ BT}高变场中的交换反应。进一步的比较证明了新黑云母溶液模型在KFMASH系统中的应用，在为普通模型磷灰石以及天然高T / low- P和天然高P变云母构造的假剖面中进行了介绍。伪剖面显示，根据我们的黑云母模型，黑云母在比KFMASH系统中W14黑云母模型预测的温度和压力低的情况下分解。这意味着KFMASH黑云母可以在达到湿固相线之前分解，这可以解释干高T /低P变质岩的存在。在更高的压力下，黑云母我们的计算在比W14黑云母模型低的压力下分解。然而，在黑云母分解之前，根据我们的计算得出的Al ^VI含量可能与伪硅Si气压计类似，可用于伪剖面气压计。这些趋势需要在我们的模型的未来扩展中得到证实，该模型包括Ti，Fe ³⁺和二-三八面体取代。