نوع مقاله : مقاله پژوهشی
نویسنده
گروه مهندسی معدن، مجتمع آموزش عالی گناباد
چکیده
کلیدواژه‌ها
موضوعات
عنوان مقاله [English]
نویسنده [English]
Summary
Discrimination of the dispersed mineralization zones and the blind mineralization area is an important challenge in minerals exploration. Geochemical Zonality method and alteration models are traditional methods that have been utilized for the exploration of deep ore deposits especially Cu porphyry and Au veiny deposits. In addition to these traditional methods, the situation of deep deposits and dispersed zones can be surveyed using a new method in the frequency domain of geochemical data. In this study, the potential of deep mineralization in one part of the Kashmar Au and Cu mineralization area has been surveyed by frequency coefficients method (FCM) and obtained results have been compared to the Zonality method and deep exploratory boreholes. The results of the newly proposed method have properly been confirmed using the results of deep drillings, unlike the Zonality method.
Introduction
Some researchers used the zonality method and alteration models for discrimination of blind Cu and Au mineralization and dispersed mineralization zones. The Zonality method has been utilized in the spatial domain of geochemical data. Several researchers have applied the Fourier transform for the interpretation of geochemical data in the frequency domain. In this study, the state of the art application of FCM, a new method in the frequency domain, for identification of deep disperse mineralization zone was shown and the results were compared to the traditional methods.
Methodology and Approaches
FCM as an effective technique in the frequency domain of geochemical data was applied for distinguishing of dispersed Au-Cu mineralization zone in this study. There are four-steps for FCM application as bellow:
Step 1: the transformation of geochemical data to the frequency domain
Step 2: application of several filter functions
Step 3: application of PCA method on frequency bands
Step 4: Delineation of frequency coefficients diagram
Results and Conclusions
In this research, the deep Cu-Au mineralization in the Kashmar area is surveyed by performing a novel frequency coefficient method based surface geochemical data and the traditional Zonality method. The Zonality method showed that there are deep Au and Cu mineralization zone in this area. While there is not any frequency anomaly in the FCM diagram. The frequency anomalies on the FCM diagram can be related to a geochemical anomaly in the spatial domain. FCM diagram can show the probability of mineralization at the depth. FCM diagram illustrated there is a non-mineralized zone at the depth. In the next step, drilled exploration boreholes showed there is not notably mineralization and concentration for Au and Cu at the depth. Therefore, these boreholes confirm the results of the proposed FCM approach against the Zonality method.
کلیدواژه‌ها [English]
شناسایی و تمایز بین زونهای کانیسازی عمیق و زونهای کانیسازی فرسایش یافته یکی از مباحث مهم در اکتشافات معدنی است. این موضوع با لحاظ مواردی از قبیل نوع آلتراسیون، نوع کانیسازی و نحوه تهیشدگی و غنی‌شدگی هالههای ژئوشیمیایی مورد تحقیق و بررسی قرار می‌گرفته است [1]. با توجه به اینکه ویژگی‌های ژئوشیمیایی هالههای اولیه ذخایر معدنی قابل استخراج است میتوان با استفاده از آنها اطلاعات اکتشافی مناسبی از ذخایر معدنی به دست آورد [2]. روش زونالیته ژئوشیمیایی که بر اساس توزیع عناصر در هالههای ژئوشیمیایی استوار است به عنوان معیاری جهت شناسایی کانی‌سازی‌های عمیق و کانی‌سازی‌های فرسایش یافته مورد استفاده قرار گرفته است [8-3].
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