High pressure minerals and the origin of the Tertiary breccia pipe, Ballogie Gem Mine, near Proston, Queensland
High pressure minerals and the origin of the Tertiary breccia pipe, Ballogie Gem Mine, near Proston, Queensland
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昆士兰州普罗斯顿附近的巴洛吉宝石矿高压矿物和第三纪角砾岩管的起源
DOI：
10.3853/j.0067-1975.35.1983.317
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发表时间：
1983
期刊：
影响因子：
--
通讯作者：
R. Pogson
中科院分区：
文献类型：
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作者：
J. D. Hollis;F. Sutherland;R. Pogson
在巴洛吉中新世玄武质火山岩中发现的高压矿物包括大型石榴石、铝质单斜辉石和正辉石、橄榄石、钾长石角闪石、斜长石和不透明氧化物;它们与少量黑云母、锆石和锆石一起出现。石榴石、某些辉石和斜长石可具有宝石品质。这些矿物伴随着火山岩中丰富的二辉橄榄岩捕虏体，类似于东南昆士兰州的一些其他产状。对该遗址的磁力测量表明，该地区主要由侵入小型玄武岩体的角砾岩组成。石榴子石（Mg_（62）66Fe_（21）-24Ca_（12）_1_4）、单斜辉石（Mg_（49）_56Ca_（34）-39Fe_（13），6.7 - 8.50/0AbO_3）和正辉石（Mg_（81）-84Fe_（15）Ca_（34），4.8 - 5.8%AbO_3）可能代表石榴辉石岩和伟晶榴辉岩与尖晶石橄榄岩地幔互层的捕虏晶。这些矿物的组成表明，它们是在14 - 15千巴和1000 - 1100 ℃的压温条件下结晶的。钛含量的钾霞石，使用一种新的地质压力计，给出近似的结晶压力主要在12 kb和14 kb之间。大部分的巴洛吉矿物样品来自含挥发分的上地幔，相对富含Ti，但Cr贫乏。为复合底辟（如巴洛吉管）的就位而调用的模型涉及到上升底辟上方通过裂纹扩展而发生的突然释气。由此产生的上升阻力还提供了从金刚石稳定区输送非常深的材料的可能性。霍利斯，J.D.，F.L. Sutherland & R.E. POGSON，1983年。昆士兰州普罗斯顿附近巴洛吉宝石矿高压矿物和第三纪角砾岩筒的成因。澳大利亚博物馆记录35（4）：181 - 194。181. 1981年，E.A.先生来自昆士兰州布恩杜马的汤姆森要求澳大利亚博物馆的矿物学和岩石学系调查他在普罗斯顿西南偏西17公里处（151 ° 31.5 'E，26 ° 18.0'S）的Coverty Creek的宝石租赁。小溪东侧的巴洛吉宝石矿产出宝石级红石榴石，可与布里古达以西10公里处的石榴石沟前景相媲美（昆士兰州地质调查，1981年）。这些碎片来自花岗岩围岩中的一小块碱性玄武岩。(Fig. 1.）的人。玄武岩中的斜长岩巨晶给出的K-Ar年龄为16.0 ± 0.2百万年，解释为喷发年龄（Sutherland & Wellman，准备中）。玄武岩中的其他主要矿物包括橄榄石、辉石和氧化物，这些矿物是在澳大利亚东部发现的高压巨晶套中的典型矿物（Wass &欧文，1976年）。昆士兰州（Murphy等人，1976年）。它属于比这些玄武岩的主体更年轻的一段，
High pressure minerals found in Miocene basaltic volcanics at Ballogie include large garnets, aluminous clinopyroxenes and orthopyroxenes, olivine, kaersutitic amphibole, anorthoclase and opaque oxides; they occur together with minor amounts of biotite, corundum and zircon. The garnet, some pyroxenes and anorthoclase can be of gem quality. The minerals accompany abundant lherzolite xenoliths in the volcanics and resemble some other occurrences in SE Queensland. A magnetic survey of the site suggests a diatreme composed largely of breccia intruded by small basaltic bodies. The garnet (Mg62 66 Fe2i-24 Ca12 _i4), clinopyroxenes (Mg49_s6 Ca34-39 FelO-13, with 6.7-8.50/0 Ab03) and orthopyroxenes (Mg8i-84 Fell_iS Ca3_4, with 4.8-5.8% Ab03) probably represent xenocrysts derived from garnet pyroxenites and pegmatitic garnetites interlayered with spinellherzolite mantle. The compositions suggest that these minerals crystallized under pressuretemperature conditions around 14-15 kb and l000-1100°C. The Ti content of the kaersutites, using a new geobarometer, gives approximate pressures of crystallization mostly between 12 kb and 14 kb. The bulk of the Ballogie minerals were sampled from a volatile-bearing upper mantle, relatively rich in Ti, but poor in Cr. The model invoked for the emplacement of a composite diatreme such as the Ballogie pipe involves sudden outgassing above a rising diapir by crack propagation. The resultant updrag also provides the potential to transport very deep material from the diamond stability zone. HOLLIS, J.D., F.L. SUTHERLAND & R.E. POGSON, 1983. High pressure minerals and the origin of the Tertiary breccia pipe, Ballogie Gem Mine, near Proston, Queensland. Records of the Australian Museum 35(4): 181-194. 181 In 1981 Mr E.A. Thomson of Boondooma, Queensland asked the Department of Mineralogy and Petrology at the Australian Museum to investigate his gemstone lease at Coverty Creek, 17 km SSW of Proston (151 °31.5' E, 26° 18.0' S). The Ballogie Gem Mine, on the east side of the creek, yields gem-quality red garnet, comparable with the Garnet Gully prospect 10 km west at Brigooda (Queensland Geological Survey, 1981). The fragments come from a small alkali basalt exposure within granite country rock. (Fig. 1.) An anorthoclase megacryst from the basalt gave a K-Ar age of 16.0 ± 0.2 Myr, interpreted as the age of eruption (Sutherland & Wellman, in prep.). Other prominent minerals brought up by the basalt include olivine, pyroxenes and oxides, typical of high pressure megacryst suites found in eastern Australia (Wass & Irving, 1976). Queensland (Murphy et al., 1976). It belongs to a younger episode than the bulk of these basalts and is