Mark Your Calendar! Next Meeting – 16 November 2017 at 6:00 PM
Next Monthly Meeting
Thursday, 16 November 2017
Sponsor: Clear Creek Associates
Speaker: Jeff Geier, Project Manager, Avrupa Minerals
Program: The Slivovo, Republic of Kosovo, Gold – Silver Project
Program Details: The Slivovo gold occurrence, located along the highly productive, base metal-dominant Vardar Trend in the central-eastern portion of the Republic of Kosovo, consists of intrusive-related, stratiform massive to disseminated gold-bearing and base-metal mineralogy hosted in Cretaceous-aged calcareous sediments. The discovery outcrop was identified by Avrupa Minerals (AVU: Toronto Stock Exchange) in 2012 following a regional exploration program. The project has been advanced through to a Pre-Feasibility Study and beyond, in conjunction with their joint-venture partner, Byrnecut International, based in Australia. Ore-grade mineralization, associated with pyrite, pyrrohtite, arsenopyrite, and base-metal sulfides, occurs as disseminated to massive replacement of steeply dipping, calcareous sandstone to pebble conglomerate and minor replacement of limestone. Alteration is dominated by early silicification, pyritization, and sericitization, after matrix decalcification. It is concentrated in the immature flysch sediments and is followed by three stages of dolomitization. Lithologic control played a major role in focusing the alteration and mineralization, which is bounded by a series of high-angle, post mineral faults and is decapitated by a low-angle thrust fault. Overprinting alteration styles and mineral paragenesis indicate syn-mineralization telescoping of the deposit. The ore body plunges to the northeast and remains open at depth. Further exploration has been designed to identify the offset portions of the mineralization and to search for the roots of the potentially larger system.
Within the claim, the outcropping Main Gossan prospect has been defined measuring 200 by 100 by 100 meters, approximating 760,000 tones at an average grade of 8.9 ppm gold and 9.8 ppm silver with a 1 ppm cutoff. Initial resource estimates designate 152,500 ounces of indicated gold with 167,500 ounces of silver and 46,000 ounces of inferred gold with 37,000 ounces of silver. Two zones of lower grade gold mineralization have been identified within and adjacent to the Main Gossan.
Drilling revealed large intercepts of gold grades ranging from one to three ppm with high grade zones ranging in the tens of grams of gold per ton for five to seven meters. Individual high-grade samples in drill core include a 165 ppm gold intercept with 33.79 ppm over seven meters and a 211 ppm with a 19.18 ppm intercept over 25 meters. One surface rock chip sample assayed at 389 ppm gold. Silver to gold ratios are 53.8 silver to gold within 3261 drill core samples and 6.01 silver to gold in all gold grades greater than 1 ppm. Gold ranges from micron-to-two millimeter free grains associated with base metal sulfides, arsenides, as gold tellurides, and gold bismuthides. Minor amounts of disseminated to semi-massive base metal sulfides contribute up to 0.26% copper, 0.8% lead, and 1.0% zinc.
Mineralization and alteration are spatially and temporally related to intrusive dikes and sills consisting of hornblende-biotite porphyry (basaltic trachyandesite var. shoshonite). The hydrous dikes are variably altered and mineralized; dominated by quartz – sericite – pyrite veins and silicification. Regional core- complex formation during the Early Tertiary, and the related magmatism appear to have been the driver for crustal extension, dike emplacement and mineralization in Slivovo and throughout the region.
Speaker Bio: Jeff Geier graduated from Arizona State University with a B.S (2008) and M.S (2010) in Geological Sciences under the guidance of Dr. Stephen Reynolds. Jeff focused on structural geology as it applied to base and precious metal deposits in the southwestern United States and northern Mexico. In 2007 he began an employed master’s study of the Santa Gertrudis, Sonora, Mexico gold occurrence focusing on the structural control and timing of mineralization, along with planning and drilling three phases of exploration holes.
Immediately following graduation Jeff co-founded Metal Resource Development (MRD), an exploration consulting group focusing on field-based structural and geochemical relationships to mineral deposits. MRD has been contracted in Mexico, Portugal, Spain, the U.S. and Kosovo and has worked on a variety of deposit types including VMS, porphyry, mesothermal, epithermal and IOCG, focusing primarily on gold and copper. Two potential economic discoveries and several sub-economic discoveries have been attributed to MRD.
Jeff is a classically-trained field geologist with a long pedigree of mapping legends as mentors. As a consultant, he has been able to maintain a close relationship within the Canadian exploration sphere, while being exposed to a large variety of deposit types in many regions of the world. He has lived in Mexico for most of the last ten years and is currently based out of Hermosillo, Sonora.
Change in Dinner Pricing Structure
Our new dinner fee pricing structure is as follows:
Members and Guests of Members: $30
As before, dinner includes two drink tickets thanks to our generous sponsors. Annual membership is still $25. Memberships from other local sections will be recognized as qualifying for the member dinner price.
2016–2017 Maricopa Section Officers
Program / Chair
Immediate Past Chair
Vice Chair & Treasurer
480 831-0310 x 272
Secretary & Communications
Donald M. Burt,Ph.D.
Arizona State University