id	author	title	date	pages	extension	mime	words	sentence	flesch	summary	cache	txt
esrj-33840	Hernández Pardo, Orlando; Gretta, C; Alexander, E; Iraida, M; Pintor, B	Geophysical exploration of disseminated and stockwork deposits associated with plutonic intrusive rock: a case study on the eastern flank of Colombia’s western cordillera	2012	13	.pdf	application/pdf	5931	70	-22	These deposits are normally associated with intermediate to acid plutonic intrusive rocks and all are characterized by intense, extensive hydrothermal alteration of host rocks Disseminated deposit exploration in the tropics suffers from difficult geological mapping due to dense vegetation, lack of rock out- crops and extensive but variable saprolytic weathering Geophysical exploration of these deposits normally includes magnetic, induced polarization and gamma ray spectrometry surveys The largest RTP total mag- netic field anomaly highs are usually associated with diorite porphyry intrusive bodies Diorites are usually less magnetic than basaltic rocks; thus when magnetic anomaly highs are related to intrusions they can be explained by basic metals’ intensive mineralization (including magnetite) associated with porphyry intru- sions Magnetic anomaly gradients regularly help delineate local discontinuities which can be interpreted as local faults and joints that can be mineralized Gamma ray spectrometry is useful for determining anomalous potassium, uranium and thorium concentration as it can map alteration halos and linear discontinuities Statistical analysis of the data also can determine the intermediate intrusive / extrusive nature of porphyry intrusions Gamma ray spectrometry can help to determine elemental potassium concentration, regardless of the associated potassium mineral species, thereby enabling alteration mapping in a geological setting related to volcanic-associated massive sulphide base metal and gold deposits An induced polarization survey is use- ful in outlining disseminated sulphide distribution in porphyry deposits related to chargeability anomaly highs The results of the Quinchía project’s geophysical exploration program are discussed RESUMEN Los depósitos de sulfuros diseminados son depósitos de bajo tenor y alto tonelaje, los cuales son impor- tantes fuentes en la explotación de oro, cobre, molibdeno y zinc Estos depósitos están asociados a rocas plutónicas intermedias a acidas y se caracterizan por una intensa y extensa alteración de la roca huésped o encajante La exploración de estos depósitos en las zonas tropicales presenta una gran dificultad debido a la densa vegetación, escasez de afloramientos y alteración saprolítica variable The highest mean chargeability val- ues and most associated mineralized areas were located at 170m depth The resistivity lows had values from 7 ohm-m to 300 ohm-m related to sulphur mineralization and altered igneous rocks It was concluded that about 40% of the studied area covered by the induced polarization survey had the potential to host porphyry style alteration areas and sulphide areas which might be mineralized with base and precious metals in the porphyry intrusion of La Cumbre, Matecaña, la Lenguita, el Cedral, Mandeval, San Luis and Dos Quebradas	cache/esrj-33840.pdf	txt/esrj-33840.txt