Geology Reports⌕ Search

Geology topics

Research about Pakistan

Source-linked reports with geographic coverage including Pakistan.

At least 55 records · Page 3Linked to original sources
USGS1976

Exploration for porphyry copper deposits in Pakistan using digital processing of Landsat-1 data

Rock-type classification by digital-computer processing of Landsat-1 (formerly ERTS-1) multispectral scanner data has been used to select 23 prospecting targets in the Chagai District, Pakistan, 5 of which have proved to be large areas of hydrothermally altered porphyry containing pyrite. The known porphyry copper deposit at Saindak was used as a control area. Empirical maximum and minimum apparent reflectance limits were selected for each multispectral scanner band in each rock type classified, and a relatively unrefined classification table was prepared. Where the values for all four bands fitted within the limits designated for a particular class, a symbol for the presumed rock type was printed by the computer at the appropriate location; these symbols formed a classification map. Drainage channels, areas of mineralized quartz diorite, areas of pyrite-rich rock, and the approximate limit of propylitic alteration were very well delineated on the computer-generated map of the test area. The classification method was then used to evaluate 2,100 km 2 in the Mashki Chah region, east of the test area, and a partial check of the results was made in the field. The results of the experiment show that outcrops of hydrothermally altered and mineralized rock can be identified from Landsat-1 data under favorable conditions. The empirical method of digital computer classification of the multispectral scanner data was relatively unrefined and rapid. The five mineralized prospecting sites identified are in locations that I would not have selected as favorable on the basis of geologic knowledge or photogeologic interpretation at the time of the investigation.

Journal of Research of the U.S. Geological Survey↗
USGS1975

Antimony deposits of Quetta-Pishin District, Quetta Division, Pakistan

Vein-type deposits of antimony ore, consisting of stibnite and quartz, are found in the hanging wall of faults cutting slate of probable Miocene age 15 miles northeast of Qila Abdullah in the Quetta-Pishin District. The ore is associated with zones of oxidized slate. Although the known deposits are small, the oxidized zones are found over several square miles, and the prospects for additional ore are encouraging. Deposits of stibnite and oxidized rock are also found in the Qila Viala area, about 25 miles east of the Qila Abdullah deposits. Geologic relationships in the two areas are similar and suggest that deposition of stibnite and quartz, accompanied by alteration of the host rocks, has taken place on a regional scale. This greatly increases the area to be investigated as well as the possibility that deposits of economic value can be found. A program for further geological investigations is recommended.

Quetta-Pishin District, Quetta Division↗
USGS1975

Geochemical prospecting for soluble salts in Kuchakki hamun, Chagai District, Pakistan

The surface soil consisting of clay, silt, sand, and salt crust in Kuchakki hamun (dry lake) contains nitrates, sulfates, salts of boron, magnesium, and widely dispersed traces of potassium. No bromine or iodine salts were detected. Several hundred samples of soil were analyzed by spot-test methods, and the results were given comparative weighted-qualitative values. Isohaline-type geochemical maps, based on weighted-qualitative values, were prepared to show the dispersion patterns of boron, magnesium, potassium, nitrates, and sulfates in Kuchakki hamun. Boron and magnesium salts are concentrated in the southern and southeastern part of the hamun. Nitrates and sulfates are more widely distributed and have higher concentrations in the central area of Kuchakki hamun. More detailed qualitative work and quantitative studies on material collected in Kuchakki hamun are required to appraise the reliability of applied field methods and preliminary analytical data, and to determine the presence, abundance, and grade of economically important salts.

Chagai District↗
USGS1975

Geology of the Khyber Pass, Khyber Agency, Pakistan

The defile of the Khyber Pass is cut in the massive gray recrystallized Khyber Limestone whose thickness exceeds 3,000 feet. Although no fossils have been found in the immediate vicinity of the pass, assemblages collected at the end of the last century from 5 miles south of the pass, and recently collected fossils from Afghanistan, suggest strongly that the limestone is Carboniferous to Permian and perhaps Jurassic in age. The basal contact of the Khyber Limestone in places appears to be conformable upon the quartzites and tuffs of the Ali Masjid Formation; elsewhere it is probably an unconformity or a fault, especially where the limestone lies directly on the Ordovician to Carboniferous Landi Kotal Slate. The Ali Masjid Formation overlies the Shagai Limestone, which, in turn, rests in fault contact on the Landi Kotal Slate. Structurally the area is characterized by at least four major, roughly east-west trending thrust or reverse faults, along which relatively older rocks have moved southward over younger rocks. A north-northeast-trending system of alternating anticlines and synclines has been superimposed on the earlier structures. Elevated terraces and alluvial valleys suggest a very recent uplift of about 600 to 1,000 feet.

Khyber Pass, Khyber Agency↗
USGS1975

Geology of the Gilgit-Hispar area, Gilgit Agency, Pakistan

The Gilgit-Hispar area contains a large variety of igneous and metamorphic rocks, which have been grouped into seven general lithologic units, five composed largely of metamorphic rocks and two of intrusive rocks. The metamorphic units consist of probable correlatives of the Precambrian(?) Salkhala Series; the upper Paleozoic, slightly metamorphosed schists, quartzites, and calcareous rocks of the Chalt Schist; the higher metamorphosed (garnet and staurolite grades) schists, gneisses, and marbles of the Baltit Group; the Pasu Slate; and the Triassic(?) and older(?) greenstone complex consisting in large part of metavolcanic rocks. The metamorphism of the area is due at least in part to the intrusions of two huge silicic to intermediate batholiths of Cretaceous to Tertiary age composed largely of biotite granodiorite. The structural grain is west-northwest throughout the area and represents a part of the structural pattern whose focus is the Hazara-Kashmir syntaxial bend. Although steep faults and isoclinal folds are present, no large thrust faults were seen. The area apparently is structurally less complicated than comparable parts of the Hindu Kush mountains farther west in Chitral State. Deeply incised streams and elevated terraces indicate very recent uplift of considerable magnitude. Although traces of potential ore minerals are common in the Gilgit-Hispar area, deposits of possible commercial value were not seen. Heavy-mineral samples of stream sands contain fairly high concentration of scheelite. The radioactivity of the stream sands is in large part due to the thorium and uranium content of zircon. Radiometric traverses showed slightly higher radioactivity over gneisses and quartzites than over other rocks, but no unusually high values were recorded.

Open-File Report↗
USGS1975

Stratigraphy and paleontology of coal beds in the Ghazij Shale, Sor Range-Daghari Coal Field, Quetta Division, Pakistan

Coal mine tunnels and surface sections in the Ghazij Shale of early Eocene age in the coal field near Quetta, Pakistan, were sampled in detail in order to make a foraminiferal analysis. This analysis and consequent correlations suggest that the coal seams are lenticular and have little lateral continuity. The planktonic Foraminifera date the geologic age of the coal-bearing sequences as early Eocene. Other Foraminifera indicate the shallow-water environment of deposition of the coal. Evidence is presented to show that coal was deposited in a series of unconnected swamps or marshes.

Quetta↗
USGS1975

Barite deposits near Khuzdar, Kalat Division, Pakistan

Important deposits of barite are about 6 miles southwest of Khuzdar in a folded belt of Jurassic limestone and shale. The deposits are lenses distributed along a narrow stratigraphic zone more than 4,600 feet long. Wallrocks have been altered by silicification, leaching, and by the introduction and oxidation of iron. Alteration appears to be partly related to barite deposition, and the deposits are tentatively classified as hydrothermal. Mime deposits are of economic interest. The largest is 30 to 80 feet thick and 1,200 feet long. Smaller deposits are 270 to 460 feet long and average about 15 feet in thickness. Preliminary estimates indicate that the deposits contain 1,280,000 short tons of barite. Most of the ore can be mined by openpit methods.

Khuzdar↗
USGS1975

Heavy mineral prospecting in Pakistan

Heavy-mineral prospecting is a method of tracing potential ore minerals to their source by systematically examining the heavy minerals of stream sands. The heavy minerals are partially concentrated in the field by panning. In the laboratory the heavy minerals are further concentrated by floating off the quartz and feldspar in a heavy liquid, such as bromoform, having a specific gravity of 2.89. Magnetite is separated magnetically and scheelite is identified under short-wave ultraviolet light. To obtain quantitative results on the minerals present, the sample is reduced by coning and quartering, mounted on a slide in oil, and a count of a minimum of 250 grains made. The chi square test applied to the splitting and counting techniques shows them to be statistically valid. The properties of some heavy minerals most useful for their rapid identification are listed. Methods here described are those utilizing a minimum of field and laboratory equipment and may be appropriate for application in many areas of the world.

Open-File Report↗
USGS1975

Heavy minerals in stream sands of the southern Hazara District, Pakistan

The areal distribution of heavy minerals in 99 samples from stream sands in the southern Hazara District, West Pakistan, indicates that the metamorphic grade of the rocks in the area increases toward the northwest. Minerals of potential economic value in the heavy-mineral samples include scheelite from the Oghi-Batgram-Battal area and hematite from the Galdanian area. The total weight of magnetite sand grains transported down the Indus River past Darband is calculated to be about 200,000 tons per year, a quantity which may be of economic value. Radioactive minerals are not present in any of the samples in sufficient quantity to be of economic importance.

Hazara District↗
USGS1975

Results of core drilling for coal at Lakhra Anticline, Pakistan, from December 1961 to May 1965

High-quality lignite has been mined in small quantity from rocks of early Tertiary age in the Lakhra anticline area for at least 20 years, but because coal outcrops are poor or nonexistent, the extent of the field was not known. However, between 1953 and 1958, five oil test holes penetrated the coal and revealed that coal underlies a large part of the Lakhra anticline. The Geological Survey of Pakistan began core drilling in 1961 to determine the extent and thickness of the shallower coal beds. By May 19630 25 borings had been completed. The Lailian coal bed was penetrated in borings over a distance of 5 miles from east to west and 11 miles from north to south, commonly at depths of less than 150 feet. The Lailian bed ranges in thickness from 2.6 to 8.4 feet; total reserves are estimated to be 130,000,000 tons. Coal below the Lailian bed appears to be lenticular, although present information is fragmentary.

Open-File Report↗
USGS1975

Sulfur, fluorspar, magnesite, and aluminous chromite in Pakistan

Reports and analyses on elemental sulfur, fluorspar, magnesite, and aluminous chromite were reviewed for the purpose of identifying and categorizing the known deposits, and to indicate those which seem to merit further study on the basis of available information. General conclusions drawn from the study are: (1) Although aluminous chromite deposits exist, no minable deposits of refractory-grade material have been made found to date; (2) small but minable reserves of elemental sulfur, fluorspar, and magnesite are available; (3) detailed mapping, prospecting, and sampling are required to fully assess the ore reserves in known deposits, and (4) field examination of some of the other deposits described herein may call for additional exploration which may eliminate them from further consideration as minable deposits. The sulfur deposits at Koh-i-Sultan volcano in the Chagai District of Quetta Division are the only assured source of elemental sulfur in Pakistan. Indicated reserves are 85,000 tons of less than 50 percent sulfur ore of solfataric origin. The deposits are currently being mined.

Open-File Report↗
USGS1975

Stratigraphy and mineralogy of laterite beds near Ziarat, Quetta Division, Pakistan

Ferruginous aluminous laterite beds crop out in the Ziarat-Loralai area east of Quetta for a strike length of about 60 miles. The beds are steeply dipping, sometimes overturned and faulted, and have an average thickness of 8 feet. Detailed mineralogical and chemical analyses were made on chip-channel samples from four sections of the laterite in the vicinity of the village of Ziarat. One of the sections, 9 1/2 miles southeast of Ziarat, is 21 feet thick and has an average content of 42 percent available alumina, 3.6 percent silica, and 31 percent Fe 2 0 3 . The other sections have an average available alumina content of less than 32 percent. The alumina minerals present are mostly boehmite and diaspore, with minor amounts of kaolinite. The laterite beds, which are between the Dunghan Formation of Paleocene age and the Parh Limestone of Cretaceous age, appear to mark the Cretaceous-Tertiary boundary; if this relationship is confirmed by further work, it would be of considerable assistance in prospecting for aluminous rocks in this and other parts of Pakistan.

Ziarat↗
USGS1973

Sampling and milling tests of chromite ore in the Hindubagh mining district, Quetta Division, Pakistan

Milling tests on chromite ores and analyses of cleaned chromite from the Hindubagh mining district show that gravity concentration methods can raise the grade of subcommercial ores to 48 percent Cr 2 0 3 or more. The Cr:Fe ratio in concentrates from the Nasai subdistrict, however, will be less than the conventional commercial standard of 3:1. A Cr:Fe ratio of 3:1 could be produced by blending low-grade and high-grade ores, but for the district as a whole, concentrates averaging 50-52 percent Cr 2 0 3 and 2.8:1 Cr:Fe ratio probably would yield the largest economic returns. Although not readily marketable now, ores and concentrates of this grade will be used increasingly in the near future.

Open-File Report↗