Primary and Tectonic Folds in the Context of Exploration and Mining

Folds are the most familiar, and commonly the most spectacular, manifestation of bulk heterogeneous deformation in rocks. They occur at all scales from the microscopic to the scale of the whole lithosphere. Folds form under a range of conditions in igneous, sedimentary and metamorphic rocks.



A necessity for identification of folds is the presence of some planar layering that can define the

Pengertian dan Macam-macam Klasifikasi Endapan Placer

Pengertian Endapan Placer (Plaser)

Endapan placer adalah endapan alohton (allochthonous) yang bernilai ekonomis. Endapan alohton sendiri mengandung definisi sebagai endapan yang telah/pernah mengalami transportasi dari lingkungan asalnya menuju ke suatu lingkungan baru di mana kemudian terendapkan bersama-sama dengan kelas-kelas endapan terigen (klastik) dan piroklastik. Kelas-kelas endapan

Types of Nickel Laterite Deposits

Nickel laterite deposits that are exploited for the extraction of nickel, cobalt and related metals generally fall into three distinct types as described below. At places, all three types of deposits may be associated with a single weathering profile occupying different horizons. At most locations, a saprolite zone may underlie an oxide zone.



Oxide Deposits

Consisting essentially of

Limonite and Goethite in the Laterite Profile

Limonite

Limonite is a non-crystalline mineral colloid. It can be found as stalactitic botryoidal or mammillary forms, but most commonly in laterite areas simply as an earthy mass. The colour in its earthy form is brownish yellow to ochre brown.

The term “Limonite” for a specific mineral species is no longer acceptable. At present the term “Limonite” designates various iron hydroxides that

Ekspor Bahan Tambang Mentah Akan Dibuka Lagi, Kemenperin Menolak

Penggodokan draft revisi atas Undang Undang Nomor 4 Tahun 2009 tentang Mineral dan Batubara (UU Minerba) diharapkan oleh Kementerian Perindustrian (Kemenperin) tidak akan memperlonggar larangan ekspor mineral mentah atau barang tambang mentah.




Gambar ilustrasi lesunya industri pertambangan.


Hal tersebut diungkapkan oleh Dirjen Industri Logam, Mesin, dan Alat Transportasi Kemenperin, I

Silicification in the Laterite Profile

Generally speaking, silica is associated with the laterite profile in two distinct ways : a) As massive silica; forming thick silica cap or silcrete, and b) As boxwork; silica sheets and lenses that are emplaced within limonite, saprolite or clay zones.

Massive silica cap or silcrete is generally present in “fossil” laterite deposits that have developed over ultramafic rocks of Precambrian age.

Jenis Batu Permata Ruby dan Safir Berasal Dari Mineral Korundum

Asal Batu Permata Ruby dan Safir

Kebanyakan orang tidak menyadari bahwa ruby dan safir merupakan permata yang berasal dari mineral korundum. Kedua permata ini memiliki komposisi kimia yang sama dan struktur mineral yang sama. Sejumlah jejak unsur "pengotor" menentukan apakah permata korundum akan menjadi ruby merah atau safir biru yang indah. Hal ini cukup mengejutkan karena unsur "pengotor"