Systematic geochemical exploration in the form of a sheet inn scale of 1:100,000

Author Kan Iran Consulting Engineers
Published At 13 July 2004


In the area of map in scale of 1:100,000, Harjand almost complete rows of sedimentary and volcanic rocks are well represented related to different geological periods from Precambrian to the late Cenozoic, that lithostratigrahic units of this row will be discussed respectively from the old to the new constituent.


Introduction Geochemical and heavy mineral exploration in area in scale of 1: 100,000 is regarded as a fundamental exploration operation in each country which its aims is recognizing of areas with mineral potential. To achieve these goals, there are different methods of geophysical, geochemical which are carried out systematically in a sheet of 1:100,000 of  Harjand. This project is designed in two parts. The first part of the operation continues to drawing of geochemical anomaly maps and determining potential areas. The second part consists of controlling the operation of the anomaly which will be pursued by studies of heavy minerals, alteration, mineralization zones and Plunmbing System and ultimately after controlling of the anomalies, each of them are modeled and promising areas will be announced. Goals of geochemical explorations in regional scale Past experiences in different countries and in different weather conditions indicate that the channel sediments can be usefull (generally among 80 - mesh) in small-scale exploration area (1:100,000 to 1:250,000). Results from these exploratory studies can be effective in analyzing the geochemical units and recognition of geochemical patterns and areas where the probability of discovering ore deposits of is more. In addition to direct applications mentioned above, sediment geochemical maps of channel sediments can have role in applications of agriculture and the environment. Obviously, this type of exploratory study are different from  goals such as regional distribution patterns of elements and so for  gaining to any purpose it should be used the appropriate method. In the first case that the purpose is detection of anomaly in the secondary halo we should use statistical techniques which reaches the difference between anomaly values and regional trends to their maximum value and thus through the intensity of the anomaly, we can identify more precisely. In the second case,  because the goal of regional trends is reaching to the statistical techniques that we should use statistical techniques which minimized impression of anomalies on regional trends . Sampling density is an example in this case for several square km which is controlled by the budget limitation. Gathering information (position of a Job Description) At this stage, documents related to the area is covered and were studied by the following preparation. A –topographic maps1:50,000 of region including sheets  Shirin rud River (North East), Dah lou lou (South East), Harjand (South West) and Hojadk (north West) B – 1:100,000 geological map of Harjand C - Map of aerial geophysical (aerial magnetic), Scale of  1:250,000 According to data from the above-mentioned documents, program of field operations became for the foundation were sampled and the parameters of any effective role in planning exploration (especially in the sample) was evaluated in a summary report given on the next section. Geographical and morphology of the area area of geological Harjand map of number in scale of 1:100000, in number of 7451 is located in the north of Kerman, between the lengths of Kerman 57  ̊-  57  ̊ 30 ̒E and 30 ̊ - 30 ̊ 31 ̒ N. large Village of Harjand which is approximately located in the middle range 72 kilometers in north east of Kerman. Ravar to Kerman asphalt road passes through western area. Second degree Soil road is branched from asphalt road and after crossing Harjand Village into the East and South East and continues to Dehran Village. Except to the northeastern part which is relatively smooth plain,  the rest of area forms mountains ranges that their trend is NW - SE. In the eastern parts especially in north-east, due to proximity to Lut Desert the weather is hot dry and the rainfall rate is very low, but in the West and South West, the amount od dryness and warmness of weather is decreased and rate of falling is increased. The annual rainfall in the western area is approximately 158 mm. Nearly all the surface water of the area flow to Lut Desert by rivers such as the Shirin Rud (in north of region), river of Dahane Ghar (in the central part), and Shahdad river (in southern part). In these rivers  the water is often flow to Lut Desert during the year. The Villages have been extended in the western and southern region and  due to be little  agricultural land,  a part of the people are working in coal mines of Hojadk and Bob Nizou that are in close distance and other part have livelihood with pastoralist Carpet sewing. Geology In the area of map in scale of 1:100,000, Harjand almost complete rows of  sedimentary and volcanic rocks are well represented related to different geological periods from Precambrian to the late Cenozoic, that lithostratigrahic units of this row will be discussed respectively from the old to the new constituent. Stratigraphy Desu series (PE - Ed): Late Precambrian – early Cambrian This lithostratigrahic unit is a tangled and tumultuous mix that includes sedimentary section consists of chalk, colorful silty shale, especially by mica – bearing silty shale in color of purple, fine grain purple mica- bearing sandstone, white quartz sandstone arenite, dolomite with and without chert stones and limestones and dark and crystallized gray and igneous part which is composed of the Dyke diabase, small mass of gabbro – diorite and volcanic Dacite - andesite is formed. the existence of Eocene volcanic Dacite – andesitic, related to Dyke in the region and the small mass of basic rocks in the lower Paleozoic series in the region linked to feeding Hungarian volcanis Shemshak.F and Devonian, it seems that part of this igneous rock stratigraphic unit, younger age of host rocks and tectonic stresses Combining cause parts of sedimentary formation Dsv with igneous components has been. This unit act as protean in material because of abundance of gypsum and shale unit and are visible in full pressure tectonical places like anticlines core and thrust faults. Series available Desu series can be compared to Hormuz series in the Zagros region.

tags: KERMAN