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亚利桑那州北部高原和峡谷地带出露有数千个溶蚀塌陷角砾岩筒。这些岩筒从密西西比纪红墙灰岩(Mississipian Redwall Limestoile)开始,一直到晚古生代岩层中都有分布,部分延伸到三叠系莫因科皮和钦纳尔组(Moenkopi and Chinle Formation)。一些高品位铀矿的岩筒还伴随有潜在经济价值的Ag、Pb、Zn、Cu、Co和Ni,一直刺激着亚利桑那州北部的采矿活动,尽管其中有些元素的市场需求下降。已经验证的和尚未验证的共900多个角砾岩筒,本次研究了一部分,在过去的六年期间进行了地质填图工作。在填图过程中,找到了许多探测矿化角砾岩筒的勘探判据。1983年在默豪克峡谷(Mohdwk Canyon)西部发现了一个岩筒,由于它具有以下的勘探判据,因此,在1984年进行了钻探。 1.有同心内倾的地层; 2.沿一封闭圆环产生侵蚀; 3.有放射性异常。 4.针铁矿假象和黄铁矿印模; 5.胶状的染色石玉髓; 6.有表生Cu矿化; 7.角砾化; 8.在地表露头上微量元素Ag、As、Cd、Co、Cr、Cu、Mo、Ni、Pb、Se、U、V、Zn的丰度高。在这个岩筒上打了5个岩心钻,在岩筒的30英尺高的溶洞中由于套管失落、漏失循环液及水的消耗量太大等钻探问题,使钻探结果受到限制。由于岩筒中心的钻孔中采集的岩芯说明1010英尺的整个深度都已角砾化,黄铁矿的丰度高,并有少量的方铅矿。钻孔γ的测井在1335英尺处(低于1000英尺没有得到粉样),发现在1191英尺处有一个1厚英尺含0.52％eU_3O_8的区段和一个平均含0.04％U_3O_8的20英尺的矿带。这些都与被凯伯布灰岩(Kaibab Limestone)的哈里斯伯格吉普西费勒斯段(Harrisburg Gypsiferous Member)覆盖的高原相似,其矿体的顶部位于相同的地层。默豪克峡谷岩筒(Mohawk Canyon Pipe) 的矿化已经得到充分验证,为了评价其经济潜力有必要进行进一步的钻探工作。
Thousands of corrosion-collapsed breccia tubes are revealed in the highlands and valleys of northern Arizona. These rock formations, beginning with the Mississipian Redwall Limestoile, have been distributed throughout the Late Paleozoic strata and partly to the Triassic Moenkopi and Chinle Formation. Some of the high-grade uranium rock drums are also accompanied by potentially economic values of Ag, Pb, Zn, Cu, Co and Ni, which have stimulated mining activity in Northern Arizona, despite the drop in market demand for some of these elements. A total of over 900 brecciated basins that have been verified and unverified, part of this study, have been geo-mapped during the past six years. During the mapping process, many exploration criteria for detecting mineralized breccia tubes were found. A rock was discovered in 1983 in the western part of the Mohdwk Canyon and was drilled in 1984 due to its following exploration criteria. 1. There are concentric levelers; 2. Erosion along a closed ring; 3. Abnormal radioactivity. 4. Goethite illusion and pyrite impression; 5. Colloid stained stone chalcedony; 6. Cu surface mineralization; 7. Corundum; 8. In the outcrops of trace elements Ag, As, The abundances of Cd, Co, Cr, Cu, Mo, Ni, Pb, Se, U, V and Zn are high. Five core drills were struck on this rock tube and the drilling results were limited by drilling problems such as the loss of casing, loss of circulation fluid and water consumption in a 30-foot-tall cave. As the core collected from the borehole in the center of the rock barrel shows that the entire depth of 1010 feet has been brecciated, the abundance of pyrite is high, and a small amount of galena is present. Logging of borehole γ at 1335 feet (less than 1000 feet did not yield a powder sample) revealed a 1-ft thick section containing 0.52% eU_3O_8 at 1191 ft and a 20-ft mine containing 0.04% U_3O_8 on average band. These are similar to the plateaus covered by the Harrisburg Gypsiferous Member in Kaibab Limestone, with the top of the orebody in the same formation. The mineralization of the Mohawk Canyon Pipe has been fully validated and further drilling is needed to assess its economic potential.