Report on systematic geochemical exploration in 1:100000 sheet of Abriz area
The study area (1:100000 sheet of Abriz or Rizab) is located in Yazd province, Central Iran. It marks the region between 55? to 55?30' eastern longitudes and 32? to 32?30' northern latitudes.
The Chapedouni and Bonehshouro igneous and metamorphic complexes are oldest exposed rock units in the area. Sedimentary and metamorphic units of Natk and Tatk, low-grate metavolcanic rocks and volcano-sedimentary and sedimentary rocks (carbonate, shale and chert) are the younger units. Following outcropping units in the Abriz sheet include Cretaceous carbonates, sandstones, and marly conglomerate, Eocene sedimentary, volcanic and volcano-sedimentary units, Miocene sedimentary units and felsic to basic volcanics, and finally Quaternary alluvial terraces, sand dunes, clay and salt flats and playas. Stream sediment deposits were used for geochemical exploration with consideration of lithology and fault contact. Totally 560 samples were analyzed for 22 elements that involve Sn, Mo, Ni, Pb, Cu, W, Hg, Bi, Sb, As, Au, Co, Cr, Sr, Ba, Sc, Te, Cd, V and Y.
Thompson control diagram and relative error calculation were used for controlling the accuracy of analysis. For deletion of lithology effect on enrichment index calculation, the values were normalized relative to the proportion of each one of variables to median of same class; the classification was done based on lithology. Multi- and uni-variable statistical analyses such as calculation of correlation coefficient, cluster analysis and factor analysis were conducted for enrichment index data. This leads to identification of elemental paragenesis.
The control phase was carried out by field study. 86 heavy mineral and 99 mineralized samples were selected to be analyzed. Univariable estimation maps were produced by analysis data of heavy minerals.
Also univariable maps drawn by application of network estimation program for enrichment index data, through which preliminary anomaly regions were identified.
Finally, anomalous regions indicated from the compilation of geochemical data and heavy minerals were objected to modeling. The geochemical information was presented in 37 maps. Important anomalies include:
1- Southern area of Saghand desert in 1:50000 sheet of Saghand
2- Southeastern area of Darreh Anjir mountain located in 1:50000 sheet of Darreh Anjir
3- Northeastern area of 1:50000 sheet of Abriz
4- Southern area of Darreh Anjir mountain and western part of no. 5 anomaly in Darreh Anjir sheet
In addition, four anomalies were ranked as second priorities and seven as third priorities.