scholarly journals Type deposits of primary gold mineralization in the Central Belt of Peninsular Malaysia

2002 ◽  
Vol 45 ◽  
pp. 111-116 ◽  
Author(s):  
Wan Fuad Wan Hassan ◽  
◽  
Heru Sigit Purwanto
Keyword(s):  
Gold Mineralization ◽  
Peninsular Malaysia ◽  
Central Belt ◽  
Primary Gold

Genesis of Shear Zone Hosted Primary Gold Mineralization in Wyanad Gold Field, South India

1999 ◽  
Vol 2 (4) ◽  
pp. 671-672
Author(s):  
S.S. Binu-Lal ◽  
H. Wada ◽  
M. Santosh
Keyword(s):  
Shear Zone ◽  
South India ◽  
Gold Mineralization ◽  
Primary Gold

scholarly journals Evolution of Pyrite Compositions at the Sizhuang Gold Deposit, Jiaodong Peninsula, Eastern China: Implications for the Genesis of Jiaodong-Type Orogenic Gold Mineralization

Minerals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 344
Author(s):  
Zhankun Liu ◽  
Xiancheng Mao ◽  
Andrew Jedemann ◽  
Richard C. Bayless ◽  
Hao Deng ◽  
...  
Keyword(s):  
Trace Elements ◽  
Phase Separation ◽  
Gold Deposit ◽  
Gold Mineralization ◽  
Structural Deformation ◽  
Fault System ◽  
Magmatic Fluid ◽  
Jiaodong Peninsula ◽  
Stage 1 ◽  
Primary Gold

Gold deposits in the Jiaodong Peninsula represent a primary gold resource in China and mostly exhibit similar ore-forming features related to sericite-quartz-pyrite alteration and other controls from (micro-)structural deformation. This study investigates the pyrite textures and trace elements in the Sizhuang gold deposit (>100 t Au) to document the key factors impacting on the genesis of the Jiaodong-type orogenic deposits. Three main types of pyrite are identified: (1) the first generation of pyrite (Py1) occurs as disseminated euhedral to subhedral grains in K-feldspar-albite-rutile-hematite and sericite alteration (stage 1), (2) Py2 as aggregates in quartz-sericite-pyrite altered rocks or quartz-pyrite veins (stage 2) can be subdivided into Py2a as irregular cores, Py2b as a zoned overgrowth on Py2a, and Py2c as overgrowth on early pyrite, and (3) Py3 as fine-grained crystals in siderite-polymetallic veins (stage 3). Primary gold at the Sizhuang deposit is coevally or slightly later deposited with Py2b, Py2c, and Py3. Laser ablation–inductively coupled plasma mass spectrometry (LA–ICP–MS) analyses show that the highest Co and Ni contents in Py1 and high but variable Co in Py2b favors the involvement of deep high-temperature magmatic waters at stage 1 and middle stage 2. The elevated As contents from Py2a to Py2c and depletion of trace elements (e.g., Co, Ni, As and Te) and high Au/Co, Cu/Ni, and As/Ni values in Py2a and Py3, combined with published H-O isotope data, imply a meteoric water ingress during stage 2–3. Thus, the fluid evolution at Sizhuang is a consequence of pulsed deep magmatic fluid release plus progressive meteoric fluid ingress. The rhythmic Co–As–Ni–Au bands of Py2b additionally suggest episodic changes in the composition of ore-forming fluids. Moreover, the sharp textural features (e.g., pyrite overgrowth on previously cataclastic crystals) of Py2 and As-Cu-rich and Co-poor bands in zoned Py2b probably also reflect rapid metal deposition and self-organization and subsequent mineral crystal growth due to the pressure release during phase separation in the Sizhuang deposit. Considering the significantly concentrated gold (>1300 t) in the regional Jiaojia fault zone and Au-bearing mineral formation related to phase separation (boiling) in the Sizhuang deposit, gold mineralization in the Sizhuang deposit was interpreted to be controlled by the pressure-driver owing to the seismic activities in the Jiaojia fault system.

scholarly journals KETERDAPATAN EMAS DAN PERAK DALAM SEDIMEN PERMUKAAN DASAR LAUT DI PERAIRAN BAYAH DAN CIHARA, BANTEN SELATAN

2016 ◽  
Vol 5 (3) ◽  
Author(s):  
Maman Surachman ◽  
Yudi Darlan
Keyword(s):  
Grain Size ◽  
Gold Mineralization ◽  
Fine Sand ◽  
Silty Sand ◽  
Surficial Sediments ◽  
Grain Sizes ◽  
Investigation Area ◽  
Gold Silver ◽  
Block Area ◽  
Primary Gold

Sedimen permukaan dasar laut di daerah penyelidikan lebih dari 95 % terdiri atas material sedimen klastik hasil rombakan dari batuan di daratan (terrigenous sediment). Berdasarkan teksturnya, sedimen daerah telitian dapat diklasifikasikan menjadi 4 jenis : pasir lanaun, pasir, lanau pasiran, dan pasir sedikit kerikilan. Secara lateral, pasir lanauan merupakan sedimen yang paling luas sebarannya. Berdasarkan ukuran butirannya, komposisi sedimen di daerah telitian didominasi oleh ukuran pasir halus, pasir sangat halus dan lanau. Di blok timur, kadar emas dalam sedimen berkisar antara 0,1 – 0,54 ppm, namun umumnya < 0,3 ppm. Kadar perak berkisar antara 5,62 -30,85 ppm, umumnya < 15 ppm. Di blok barat, kadar emas berkisar antara 0,11 – 0,57 ppm, namun umumnya >0,3 ppm. Kadar perak antara 7,43 – 28,35 ppm, namun umumnya > 15 ppm. Emas dan perak dalam sedimen terutama diperkirakan berasal dari mineralisasi primer yang terdapat di daerah hulu S. Cimadur dan daerah hulu S. Cihara. Kata Kunci : Emas, perak, sedimen, Bayah & Cihara. Submarine surficial sediments of the investigated area consist of more than 95 % land derived sediments. Based on textural classification the sediments are divided into 4 units: silty sand, sand, sandy slit and slightly gravelly sand. Laterally silty sand are the widest distribution. Based on grain size analyses, the composition of the sediment consists of fine sand, very fine sand and silt grain sizes. The Gold (Au) content within the sediment of the east block area ranges beetwen 0,1 – 0,54 ppm, but generally less than 0.3 ppm. The Silver (Ag) content ranges between 5,62 - 30,85 ppm, but generally less than 15 ppm. In west block area, Au content within sediment ranges between 0,11 – 0,57 ppm, but generally > 0,3 ppm. The Ag content ranges between 7,43 – 28,35 ppm, but generally > 15 ppm. The occurrence of Au and Ag within sediments of the investigation area are mainly estimated from primary gold mineralization areas which are located in upstream areas of Cimadur and Cihara Rivers. Keyword : Gold, silver, sedimen, Bayah & Cihara

scholarly journals Placer gold occurrences along the major rivers of Nepal Himalaya and their possible primary sources

1996 ◽  
Vol 13 ◽  
Author(s):  
K. P. Kaphle ◽  
P. R. Joshi ◽  
H. R. Khan
Keyword(s):  
Gold Mineralization ◽  
Gold Deposits ◽  
Primary Sources ◽  
Gold Content ◽  
Lower Paleozoic ◽  
Nepal Himalaya ◽  
Placer Gold ◽  
Flood Plains ◽  
River Flood ◽  
Primary Gold

Recent exploration in Lungri Khola area, Rolpa district, midwestern Nepal helped to delineate a discontinuous 1.5 to 40 m thick and about 30 km long primary gold mineralization zone in the Precambrian greenschists and Lower Paleozoic micaceous marbles of the Lesser Himalaya. The gold content in these lodes vary from 0.01 to 6.7 ppm. In eastern Nepal occurrences of primary gold is recorded in quartz-biotiteschist, amphibolite and pegmatite bodies in Sunmai and Bering Khola of Ilam district. Fine flakes of gold also occur in the pyritiferous quartz beds/lenses in chlorite-sericite phyllite and quartzite of Bamangaon polymetallic prospect, Dadeldhura district, far western Nepal. In this prospect the gold content is from 0.2 to 0.8 ppm, and one sample showed up to 14 ppm. Primary gold occurrences are also detected in few irregular quartz-pyrite veins and iron-copper sulphide bearing quartzite lying close to the amphibolite bodies. Some pyrite bearing radioactive quartzite beds in Banku Quartzite of Purchauni Crystalline Complex exposed at Boregad, Bangabagar, Baggoth and Jamari Gad area in Darchula and Baitadi districts, far western Nepal also contain gold. The gold content in the radioactive quartzite varies from 0.2 to 1.2 ppm and in some pyritiferous radioactive quartzite floats it reaches up to 5.06 ppm. The primary gold appears to be of synsedimentary, hydrothermal and possibly volcanogenic in origin. Placer gold is derived from primary sources and deposited at favourable locations along the river flood plains. Further investigations in similar geological terrain may help to identify economically viable primary as well as placer gold deposits in the Nepal Himalaya.

Sign in / Sign up

Export Citation Format

Share Document