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J.J. Matzko

Publications and source records attributed to J.J. Matzko.

8 recordsLinked to original sources
USGS1985

Reconnaissance geochemical exploration of plutons of syenite and shonkinite, southern Asir, Kingdom of Saudi Arabia

Reconnaissance geochemical exploration for rare metals in plutons of syenite and shonkinite disclosed generally less than 20 ppm Nb in rocks, wadi sediments, and concentrates. The sparsity of Nb is accompanied by low values for La, Sn, W, Y, and Zr and relatively high but insignificant values for Be and Mo. Base and precious metals are either below their respective limits of determination in the various sample media or are present at background levels commensurate with average crustal abundances in felsic rocks. Pegmatite dikes associated with the syenite plutons are rare and lack vermiculite. The present investigation disclosed no possible ore deposits in the plutons covered by the field work. Known kyanite-topaz-natroalunite rocks in the vicinity of the surveyed areas should be examined for possible deposits of Cu, Mo, or Au associated with high-alumina hydrothermal deposits.

Open-File Report↗
USGS1985

Reconnaissance geochemical exploration of the plutons of quartz monzonite and granite in the Jabal Lababa and Ar Rayth areas, southern Asir, Kingdom of Saudi Arabia

Geochemical reconnaissance for rare metals in plutons of albite-muscovite granite and quartz monzonite in the vicinity of Jabal Lababa disclosed positive geochemical anomalies for beryllium, tantalum, thorium, lanthanum, niobium, tin, yttrium, and zirconium. The low anomalous values for the rare metals in rocks and the short mechanical dispersion trains, seldom exceeding 4 km in length, of rare-metal-bearing heavy minerals, are interpreted to indicate that primary deposits of these metals are lacking, and any placers would be small and low in tenor. Small positive anomalies for barium were detected at scattered localities in the metasediments adjacent to the plutons in the Jabal Lababa area. Positive anomalies for the precious metals are lacking, and the low values observed for base metals do not indicate the presence of sulfide deposits. The abundant quartz lag gravel in the eastern part of the area is unmineralized. Small books of muscovite are present in some pegmatite, but is of non-commercial volume and quality. A subcircular structure at the coast of the Red Sea near the mouth of Wadi Nahb should be tested to determine if it is a buried salt dome. Three nonmagnetic high-density concentrates containing 1,000 to 15,000 ppm lead were found on the granitic pluton near Ar Rayth. The source of the lead is not galena, and high values for lead appear to be characteristic of the pluton but do not indicate an ore deposit.

Open-File Report↗
USGS1985

Abhurite, a new tin hydroxychloride mineral, and a comparative study with a synthetic basic tin chloride.

Abhurite is a new mineral species found in blister-like protuberances on the surface of tin ingots submerged at a depth of 35 m in the Red Sea. It forms 1.5 mm diameter hexagonal plates bounded by the negative rhombohedron (0115); is colourless, transparent with opalescent lustre, white streak, hackly fracture, with no cleavage, and H.approx 2; D(calc) 4.34, D(meas) 4.29 g/cm3; epsilon approx 2.11, omega 2.06. Chemical analysis gave 73.4 wt.% Sn, 15.7 Cl, 11.0 0 and 0.4 H. leading to the formula Sn3O(OH)2Cl2. DTA shows release of H2O at 235oC and SnCl2 at 525oC. Indexed XRD powder data are tabulated; prominent lines 2.5313(100), 2.8915(70), 4.139(50), 3.404(50), 2.8175(50) A; a 10.0175(3), c 44.014(2) A; space group R3m, R3m or R32; Z = 21. Comparison is made with a hexagonal synthetic dimorph. The name refers to the geographical origin, an arm of the Red Sea known as Sharm Abhur.-L.T.T.

Canadian Mineralogist↗
USGS1977

Black monazite from Taiwan

Two forms of detrital monazite are known in offshore bars in southwestern Taiwan: a yellow-green to colorless form and an unusual but abundant pelletlike form, generally black but also colored gray or brown. These black pellets, which are about 160 by 200 microns in size, are composed of fine-grained monazite crystals from 2 to 20 microns in size. The pellets are associated with highly variable amounts of discrete grains of detrital quartz, rutile, amphibole, tourmaline, and other minerals. Intergrown with the monazite are quartz, a cerium oxide mineral, chlorite, sulfides, and other minerals. Opaqueness of the pelletlike monazite is due principally to the cryptocrystalline nature of part of the monazite; only a small part of the opaqueness can be attributed to opaque inclusions. The black pelletlike monazite lacks thorium and has a high content of europium. In this respect, as in color, shape, size, and inclusions, the pelletlike monazite differs from the yellow-green detrital monazite. Despite the fact that they occur together in the littoral placers, they appear to have had different origins. The yellow-green monazite originated as an accessory mineral in plutonic rocks and has accumulated at the coast through erosion and transport. The origin of the pelletlike monazite is as yet unknown, but it is here inferred that it originated in unconsolidated coastal plain sediments through migration of cerium from the detrital monazite during weathering, and of the intermediate weight mobile rare earths from clay minerals during diagenesis. Possibly these pelletlike grains are detrital particles formed through erosion and transport from originally larger aggregates cemented by diagenetic monazite.

Proceedings of the Geological Society of China↗
USGS1953

Reconnaissance for radioactive deposits in the vicinity of Teller and Cape Nome, Seward Peninsula, Alaska, 1946-47

Placer-mining areas and bedrock exposures near Teller on the Seward Peninsula, Alaska, were investigated in June and July, 1946, for possible sources of radioactive materials. The areas that were investigated are: Dese Creek, southeast of Teller; Bluestone River basin, south and southeast of Teller; Sunset Creek and other small streams flowing south into Grantley Harbor, northeast of Teller; and, also northeast of Teller, Swanson Creek and its tributaries, which flow north into the Agiapuk River basin. No significant amount of radioactive material was found, either in the stream gravels or in the bedrock of any of the areas. A heavy-mineral fraction obtained from a granite boulder probably derived from a bench gravel on Gold Run contains 0. 017 percent equivalent uranium, but the radioactivity is due to allanite and zircon. The types of bedrock tested include schist, slate, and greenstone. Readings on fresh surfaces of rock were the same as, or only slightly above the background count. The maximum radioactivity in stream concentrates is 0. 004 percent equivalent uranium in a sluice concentrate from Sunset Creek.

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