Gold Geological Institute

Langfang, China

Gold Geological Institute

Langfang, China
SEARCH FILTERS
Time filter
Source Type

Qing M.,Gold Geological Institute | Tang M.G.,Gold Geological Institute | Ge L.S.,Gold Geological Institute | Han X.J.,Gold Geological Institute | And 3 more authors.
Acta Petrologica Sinica | Year: 2012

The Bilihe large-scale porphyry gold deposit locates in the Early Paleozoic aeeretionary orogenic belt of the northern margin of North China Craton. The lithology in Bilihe goldfield was the set of volcanic rocks which include andesite, dacite and rhyolite. The andesite belongs to sub-alkaline, high-K calc-alkaline series, with higher content of MgO (2.05% ∼ 10.29% ), low FeOT/MgO ratio and the content of TiO2 (0.21 % ∼ 0.85%) and with high content of Cr (44 × 10-6 -473 × 10-6), Ni (19.3 × 10-6 ∼ 249.4 ×10 -6), depleted Nb, Ta, Ti, P, absence or minor of Eu/Eu* anomalies, which collectively indicated the andesite with the characteristics of volcanic rocks of typical Andean-type active continental margin. The weighted average 206Pb/238U ages of andesite and andesitic tuft were 281 ±4.3Ma and 281 ± 12Ma (the Early Permian), by LA-ICP-MS zircon U-Pb dating respectively, and consistent with the crystallization age (279Ma) of granodiorile porphyry that related to gold mineralization and ore-lorming age (272Ma), which indicated that diagenesis-metallogenesis of mining area was associated with collisional orogeny between the North China plate and the Siberian plate in the Late Paleozoic, and suggesting that it had the great potential to find Late Paleozoic epithermal-porphyry type gold (copper) deposits in northern margin of the North China Craton. U-Pb ages of the ancient inherited zircons presents in the volcanic rocks and intrusive rocks associated with mineralization were 1.8Ga, 2. OGa and 2.4Ga, implying that the mining area was presence of ancient basement of the North China Craton, and as a major factor in generating gold mineralization.


Yang Z.,Chinese Academy of Geological Sciences | Yang Z.,James Cook University | Yang Z.,University of Tasmania | Chang Z.,James Cook University | And 7 more authors.
Economic Geology | Year: 2015

Most known primary Au deposits are produced by hydrothermal processes. In this paper, we report Au mineralization of magmatic origin in the Bilihe deposit, China (8.5 Mt averaging 2.9 g/t Au). At Bilihe, most (>70%) native Au (no detectable Ag) grains are euhedral or subspherical in shape, and occur as trails in dendritic quartz phenocrysts and comb-layered quartz in a moderately reduced, highly fractionated diorite-granite intrusion. The hosting quartz typically has a dendritic core (Q1) and a rim (Q2), with Q1 having concentric zoning and sector zoning in cathodoluminescence (CL) images. Cathodoluminescence petrography and crystallographic modeling reveal that most of the Au trails occur along intersecting crystallographic planes of the host quartz, indicating simultaneous precipitation of both Au and quartz. Abundant melt inclusions are present in Q2 with >950°C homogenization temperatures. Minor Au grains also occur in melt inclusions in quartz. In rare cases, necking of Au melt inclusions is present. Neither Q1 nor Q2 contain primary fluid inclusions; only secondary fluid inclusions were found in healed cracks. The above observations indicate a direct magmatic (quartz phenocryst phase) origin for the Au. This defines a new type of Au deposit, and thereby opens new potential for Au exploration. The magmatic origin of Au at Bilihe also implies that enrichment of Au may occur in a source melt prior to volatile escape, which would enhance the possibility of forming a magmatic-hydrothermal Au deposit. Copyright © 2015 by Economic Geology.


Deng J.,China University of Geosciences | Ge L.S.,Gold Geological Institute | Yang L.Q.,China University of Geosciences
Acta Petrologica Sinica | Year: 2013

The tectonic dynamic system is the base of studying on regional geotectonic evolution and metallogenetic geological environment. As one of the most concentrated regions of the global metal mineral resources and with the best abundant records of the geological tectonic evolution, orogenic belts are the primary objects of studing and explaining different tectonic dynamic system and corresponding metallogenitic environment and mineralization. The plate tectonic derived from the oceans, and it depicts and explains accretion of the continental edge and disappearing of the oceanic plates and corresponding geological phenomena, which are leaded by the plates tectonic mainly in horizontal action, and the geodynamic system named oceanic dynamic system; The continental tectonic depicts and explains the continental substantial accretion and disappearing and corresponding geological phenomena, which mainly happened in intracontinents and not in continental edge and mainly in vertical actions (the crust and the mantle acts each other), and the dynamic system named continental dynamic system; That the transition of from the ocean to the continent is dynamic system of coupling each other and co-action, which mainly moves in vertical active and horizontal action, and it depicts and explains the ocean switched to the continent and corresponding geological phenomena, and it named transitional dynamic systems. On the earth, different tectonic dynamic systems have the features of succeeding conversion in the same areas and coexist in different areas. Each tectonic dynamic systems can produce orogenies, therefore, at the same time there are all kinds of orogeny and orogenic belts on the earth, which can summarized four types of subduction orogeny (or orogenic belts), collision orogeny (or orogenic belts), extensional orogeny (or orogenic belts) and intracontinental orogeny (or orogenic belts) that completely reflect the orogenetic belts evolution processes. The concepts of compoud orogenies scientific explain the complexity of the global orogenetic belts, and it has three means: The first is the like and unlike orogenetic belts compound (or overlaps) in space in different phases, and the second is orogenitic times compound (or stack) of the same orogenetic belts in different geological historical periods and different tectonic dynamic systems, and the third is at the same time with the natures of temporal-spatial compound orogenetic belts. Studing on Sanjian orogeny shows it is a typical compound orogenetic belts with complex temporal-spatial configuration.


Xia R.,China University of Geosciences | Xia R.,Gold Geological Institute | Deng J.,China University of Geosciences | Qing M.,Gold Geological Institute | And 2 more authors.
Acta Petrologica Sinica | Year: 2013

The Dachang gold ore field, one of the super large ore field in the Sichuan-Shanxi-Gansu boundary region, is located in the Kekexili-Songpanganze in Late Palaeozoic-Mesozoic turbidite basin and fold and fault belt. It is controlled by an NW-trending structural and altered belt, and hosted in the Triassic carbonaceous sand stone-slate of flysch deposition. The main ore minerals are pyrite, arsenopyrite and stibnite, and gangue minerals are quartz, feldspar and calcite. The gold occurred as grained gold. Microthermometric measurements show that auriferous quartz veins in the Dachang gold ore field have three types of fluid inclusions: NaCl-H2O inclusions (type W):CO2 brine inclusions (type C) and pure gaseous inclusions (type PC). The salinity values of NaCl-H2O inclusions have a peak of 2% ∼5%NaCleqv, homogenization temperature values with a peak of 180 ∼200°C and metallogenic depths are 1.9 ∼12.3km. The pure gaseous inclusions are dominanted by N2, CO2, O2, H2O, with minor H2S. Liquid phase composition are Ca 2+, Na, Li+, K + and SO4 2-, CI, NO3-, F, with minor Mg2 +. They suggest that the ore-forming fluids of the Dachang gold ore field are characterized by low salinity, low to moderate homogenization temperature. H-0 isotopes analyses show that δD = -62%o ∼-106%o, δOH 2o =3. 1%o ∼10. 5%o, indicating that the ore-forming fluids are composed mainly of devolatilization of organic matter, with meteoric water. Geological and fluild features and metallogenic mechanism suggest that the Dachang gold ore field may be Carlin-like gold deposit.


Ge L.S.,Gold Geological Institute | Deng J.,China University of Geosciences | Wang C.M.,China University of Geosciences
Acta Petrologica Sinica | Year: 2013

Modern mineral geological exploration is changing from single prospecting to systemic prospecting, and the systemic prospecting depends on redefinition of the metallogenetic environment and its confirming for the metallogenetic systems or mineralization along with the building of relationships of spatial-temporal and genesis of the corresponding deposit combination. Tectonic dynamic systems are base of study metallogenetic environment, which evolution decides regional metollagenetic environment spatial framework and its spatial-temporal transition. The metallogenetic environment in every tectonic dynamic system could be divided into extensional and extrusional. In oceanic tectonic dynamic systems, metallogenetic setting and mineralization mainly happened in the plate margins, which include dispersed plate margins and converging plate margins. Oceanic bridge, island arc, continental margin arc, different natures and scale basins developed in arc tectonic setting, which are all important metallogenetic space, and the plate itself features, the changing of process and depths and state about the plates subduction are important factors of deciding metallogenetic setting and mineralization in the plate margins: In continental tectonic dynamic systems, the main geologic setting including deep and giant faults tectonic activity, the mantle plumes or hot spots, the lithosphere increased to scales of delamination, intracontinental orogeny, intracontinental rifts valley etc., and various metallogenetic setting developed peculiar mineralization and deposit types: In transformed tectonic dynamic system, collision-extensional orogeny and developing oceanic rifts are two reverse tectonic processes, in which formed special metallogenetic environment and a lot of kinds of mineralization. The paper takes the Sanjinag compound orogeny as an example, mainly discusses metallogenetic features in all metallogenetic setting and in which deposit-type and corresponding deposit combination developed.

Loading Gold Geological Institute collaborators
Loading Gold Geological Institute collaborators