Bureau of Mineral Resources
Bureau of Mineral Resources
Lin Y.,CAS Institute of Remote Sensing |
Jiang M.,Bureau of Mineral Resources
Journal of Applied Remote Sensing | Year: 2017
Tree species information is essential for forest research and management purposes, which in turn require approaches for accurate and precise classification of tree species. One such remote sensing technology, terrestrial laser scanning (TLS), has proved to be capable of characterizing detailed tree structures, such as tree stem geometry. Can TLS further differentiate between broad- and needle-leaves? If the answer is positive, TLS data can be used for classification of taxonomic tree groups by directly examining their differences in leaf morphology. An analysis was proposed to assess TLS-represented broad- and needle-leaf structures, followed by a Bayes classifier to perform the classification. Tests indicated that the proposed method can basically implement the task, with an overall accuracy of 77.78%. This study indicates a way of implementing the classification of the two major broad- and needle-leaf taxonomies measured by TLS in accordance to their literal definitions, and manifests the potential of extending TLS applications in forestry. © 2017 Society of Photo-Optical Instrumentation Engineers (SPIE).
Zhang H.-F.,CAS Institute of Geology and Geophysics |
Ying J.-F.,CAS Institute of Geology and Geophysics |
Tang Y.-J.,CAS Institute of Geology and Geophysics |
Li X.-H.,CAS Institute of Geology and Geophysics |
And 2 more authors.
Gondwana Research | Year: 2011
The Archean lithospheric root of the North China Craton (NCC) has been considerably eroded and modified by Phanerozoic magmatic processes. Here we investigate the decratonization of the NCC through U-Pb and Hf isotopic analyses of zircons from Cenozoic basalts in the Liaodong Peninsula using ion-probe and MC-ICPMS techniques. The U-Pb zircon geochronology identifies three zircon populations: Precambrian, Paleozoic and Mesozoic. The Precambrian zircons yield 207Pb/206Pb ages of 2275-2567Ma with a peak at around 2.5Ga. They define a U-Pb discordia with upper intercept ages of 2447±50Ma to 2556±50Ma and a wide range of Hf TDM ages with a mode at 2.7-2.8Ga. Our results clearly demonstrate the presence of an Archean lower crust in the Liaodong region. The Paleozoic zircons from the Liaodong region lack the clear internal zoning and are subhedral to rounded in shape, and yield a narrow 206Pb/238U concordant ages of 419-487Ma with a weighted mean age of 462±16Ma. The Mesozoic zircons predominantly show crystallization in the early Cretaceous and yield a relatively large range in 206Pb/238U ages from 100 to 138Ma (n=53) with a peak around 120Ma. Three samples give indistinguishable weighted mean 206Pb/238U ages of 120±5Ma, 120±4Ma and 121±2Ma. These early Cretaceous zircons have enriched Hf isotope compositions with εHf(t) values from -26 to -16. Our results provide important constraints on episodic magmatism during the Phanerozoic in the Liaodong region, which led to substantial reactivation of the Archean basement of the North China Craton. © 2010 International Association for Gondwana Research.
Li W.,China University of Geosciences |
Zeng P.,Bureau of Mineral Resources |
Hou Z.,Chinese Academy of Geological Sciences |
White N.C.,University of Tasmania
Economic Geology | Year: 2011
The Pulang porphyry copper deposit recently discovered in northwestern Yunnan province, is located at the south end of the Triassic Yidun island arc. To date, 15 mineralized porphyry deposits have been defined in the Pulang area and the copper resource is estimated to exceed 10 Mt. The Pulang deposit, as currently defined, is made up of five ore-bearing porphyry deposits, covering an area of approximately 9 km2. Intermediate acidic porphyritic intrusions composed of quartz-diorite, monzodiorite, quartz-monzonite, and granodiorite are widespread in the Pulang area. The alteration zones identified with the porphyry deposits include silicic, potassium silicate, quartz-sericite, and propylitic zones. The porphyry deposits have hornfels at the contact with slate, sandstone, and andesite. Re-Os ages of molybdenite, and Ar/Ar and K-Ar dating of biotite indicate that the Pulang porphyry copper deposit formed during the Indosinian tectonic episode, with the main ore formation taking place from 216 to 213 Ma (Late Triassic, Norian); however, the whole process of hydrothermal activity, including overprinting, may have extended from 235 to 182.5 Ma. © 2011 Society of Economic Geologists, Inc.
Hower J.C.,University of Kentucky |
Hoffman G.K.,Bureau of Mineral Resources |
Garrison T.M.,University of Kentucky
International Journal of Coal Geology | Year: 2013
Inertinite macerals in the anthracite-rank Campanian Menefee Formation coal from the Cerrillos coalfield, Santa Fe County, New Mexico, show a range of forms consistent with forms found in lower-rank Mesozoic and younger coals. In particular, funginite is recognized in these anthracites, as is macrinite, and fusinite formed following microbial degradation. The macrinite in the Menefee coal has forms that are consistent with fungal and/or bacterial degradation of wood, followed by the ingestion of the latter material by insects or other animals, the regurgitation or excretion of the partially digested material, and the coprophagous recycling of the latter product. © 2013 Elsevier B.V.
Coleman D.S.,University of North Carolina at Chapel Hill |
Mills R.D.,University of North Carolina at Chapel Hill |
Zimmerer M.J.,Bureau of Mineral Resources
Elements | Year: 2016
Beneath volcanoes are magmas that never erupt but that become frozen into feldspar- and quartz-rich rocks broadly called granite. Where the crystallized magmas form bodies with distinctive textures, they are grouped into named units-plutons. The rate (pace) at which magmas accumulate into plutons is fundamental to understanding both how room is made for the magmas and how unerupted and erupted magmas are connected. Dating plutonic rocks suggests that plutons accumulate slowly. Although the pace of magma accumulation does not preclude direct connections between plutons and small volcanic eruptions, it appears to be far too slow to support connections between most plutons and supereruptions.
McLemore V.T.,Bureau of Mineral Resources
2016 SME Annual Conference and Expo: The Future for Mining in a Data-Driven World | Year: 2016
Production of industrial minerals remains important to the rural economy of New Mexico. In 2014, some 240 mines were registered in New Mexico, including 25 industrial mineral operations and 189 aggregate operations. New Mexico leads domestic production of potash, perlite, zeolite, and travertine. Other production includes aggregate, humate, pumice, gypsum, salt, common and fire clay, scoria, limestone, fly ash, cement, magnetite, silica, and decorative stone. New Mexico has potential for additional production of industrial minerals. One company is exploring for garnet. Cretaceous black sandstones in the San Juan Basin have drawn interest for titanium, rare earth elements (REE), and zircon. Other REE deposits are being explored. REE-Th-U veins are found in the Gallinas, Capitan, and Cornudas Mountains and Laughlin Peak-Chico Hills. Recent exploration has occurred for beryllium in the San Mateo Mountains, Iron Mountain, and Victorio districts. Companies also are examining High-Ca limestone and High-Mg dolomite for potential development. Aggregate continues to be important in urban areas and along highways.
Jiang M.,Bureau of Mineral Resources |
Lin Y.,Finnish Geodetic Institute
IEEE Geoscience and Remote Sensing Letters | Year: 2013
This study proposed and tested a multistep method for the recognition of individual deciduous trees in leaf-off aerial ultrahigh spatial resolution remotely sensed (UHSRRS) imagery. This topic has received limited coverage in previous endeavors, which focused mainly on the detection and delineation of coniferous trees in remotely sensed images with relatively lower spatial resolutions. Thus, the traditional algorithms tend to fail in case of the referred scenario. In order to fill this technical gap, an algorithm that joins mathematical morphological operations and marker-controlled watershed segmentation was first assumed for the extraction of single trees in UHSRRS images. Next, a distribution-free support vector machine (SVM) classifier was applied to distinguish the extracted segments as deciduous or coniferous trees, merely in terms of two newly-derived morphological features. Experimental evaluations indicated that the integral solution plan can extract and classify the deciduous and coniferous trees in the leaf-off aerial UHSRRS images of local dense forest for test with correctness over 92% and 70%, respectively. Overall, the recognition results with >66% correctness have primarily validated the proposed technique. © 2004-2012 IEEE.
Liao Y.-C.,Bureau of Mineral Resources
Geology in China | Year: 2012
In the past, the adding of aluminum and reducing of iron or the separation of aluminum from iron should be adopted as the first step in the application of high iron bauxite, as indicated by most previous literatures. This paper describes physical and chemical characteristics of the diaspore type high iron bauxite in the ore bed of Xianrenyan Rock in Zunyi. The samples of XCK5 and XCK4 of high iron bauxite were collected, the former is characterized by Al 2O3 53.61%,A/S 7.63,and Fe2O3 21.96%, whereas the latter is characterized by Al2O3 51.71%, A/S 7.16,and Fe2O3 24.89%. The Bayer dissolution test shows that the XCK5 has absolute dissolution rate 83.98% and relative dissolution rate 96.65%, chemical alkali consumption 57.9 kg(NaOH)/t(Al 2O3), whereqs the XCK4 shows absolute dissolution rate 80.02%, relative dissolution rate 93.01%, and chemical alkali consumption 34.9 kg (NaOH)/t (Al2O3). The test also reaches good result in red mud settlement. Therefore, the process chain of the application of high iron bauxite can be considerably shortened in that it is not necessary to add aluminum and reduce iron or separate aluminum from iron first before the application. The result obtained by the authors provides a new way for this kind of ore applications and researches.
Zimmerer M.J.,Bureau of Mineral Resources |
McIntosh W.C.,Bureau of Mineral Resources
Bulletin of the Geological Society of America | Year: 2012
Volcanic and plutonic rocks exposed in the Latir volcanic field, northern New Mexico, provide an opportunity to examine the timing of caldera-related magmatic processes. Fifty-five mineral separates were dated using the 40Ar/ 39Ar method. Volcanism began at 28.5 Ma and ended at 22.7 Ma, climaxing with the eruption of the high-SiO2 peralkaline Amalia Tuff from the Questa caldera at 25.39 ± 0.04 Ma. Following caldera collapse, four resurgent plutons were emplaced between 25.4 and 25.0 Ma. Previous geochemical studies suggested that the peralkaline phases of two resurgent plutons and a peralkaline ring dike represent an intrusive equivalent to the Amalia Tuff. A new analysis of K-feldspar from the ring dike yielded a plateau age of 25.38 ± 0.04 Ma, supporting this previous conclusion. Only these small-volume peralkaline intrusions are temporally indistinguishable from syncaldera magmatism. The structurally lower resurgent plutons were emplaced ~100-400 k.y. after the Amalia Tuff eruption and are therefore too young to be the nonerupted, more-mafic parts of Amalia Tuff magma chamber, implying that the Amalia Tuff magma was not generated via in situ differentiation in the upper crust. Following resurgent plutonism, five additional plutons were emplaced between 24.9 and 19.3 Ma along the southern caldera margin and south of the caldera. Thermochronology indicates that most plutons rapidly cooled following emplacement, but that some were subsequently reheated during protracted postcaldera pluton emplacement. The timing of pluton emplacement at the Questa caldera indicates that only small volumes of the intrusive rocks are the same age as the caldera eruption and that most of the intrusive rocks record postcaldera magmatic processes. © 2012 Geological Society of America.
McLemore V.T.,Bureau of Mineral Resources
2015 SME Annual Conference and Expo and CMA 117th National Western Mining Conference - Mining: Navigating the Global Waters | Year: 2015
Lindgren (1933) defined a belt of alkaline-igneous rocks associated with large quantities of gold and rare earth elements (REE) that extends from Alaska and British Columbia southward into New Mexico, Texas and eastern Mexico. The North American Cordilleran alkaline-igneous belt since has been exploited for numerous types of mineral deposits. In New Mexico, Mid-Tertiary alkaline to calc-alkaline rocks are found with seven types of deposits in these districts: (1) polymetallic epithermal/mesothermal veins, (2) gold-bearing breccias/quartz veins, (3) Cu-Au, Au and Mo porphyry deposits, (4) skarns and carbonate-hosted deposits, (5) iron skarns and replacement bodies (with some gold), (6) gold placers, and (7) Th-REE (with some U, Nb) epithermal veins. Some of New Mexico's largest gold and REE deposits are found within this belt. Their origin is not well understood, but a compilation of new data (age dates, isotopic and chemical analyses) allows for a better understanding. The diversity of igneous rocks and associated mineral deposits along this belt suggests that this region is characterized by highly fractionated and differentiated; multiple pulses of magmas and involves both upper mantle and lower crustal sources. Once magmas and metal-rich fluids reached shallow levels, local structures and wall rock compositions determined distribution of and final style of intrusions and resulting mineral deposits. Copyright © 2015 by SME.