What is Paragenesis and zoning?
Paragenesis – sequence of deposition of ore and gangue minerals. Determined from both. microscopic and megascopic studies. Zoning – distribution of ore minerals in space laterally and vertically.
What is a Paragenesis in mineralogy?
Paragenesis, the sequence in which the minerals are formed in an ore deposit. Variations in the pressure and temperature and in the chemical constituents of a hydrothermal solution will result in the precipitation of various minerals at different times within the same ore deposit.
What is meant by Paragenesis?
Paragenesis is a petrologic concept meaning an equilibrium sequence of mineral phases. It is used in studies of igneous and metamorphic rock genesis and importantly in studies of the hydrothermal deposition of ore minerals and the rock alteration (vein metasomatism) associated with ore mineral deposits.
What is Paragenetic sequence?
The chronological order of crystallization of minerals in a rock or ore deposit.
What is Orthogneiss geology?
Definition: A gneiss with mineralogy and texture indicating derivation from a phaneritic igneous rock protolith. Typically consists of abundant feldspar, with quartz, and variable hornblende, biotite, and muscovite, with a relatively homogeneous character.
How are metamorphic facies related to temperatures and pressures?
The different metamorphic facies are defined by the mineralogical composition of a rock. When the temperature or pressure in a rock body change, the rock can cross into a different facies and some minerals become stable while others become unstable or metastable.
What is the meaning of Polygenetic?
1 : polyphyletic. 2 : having many distinct sources.
What is wall rock alteration?
wall-rock alteration A reaction of hydrothermal fluids with enclosing rocks, causing changes in mineralogy that are most marked adjacent to the vein and become less distinct further away.
What term describes the retrograde metamorphism?
Retrograde metamorphism (diaphthoresis, retrogressive metamorphism) is the mineralogical adjustment of relatively high-grade metamorphic rocks to temperatures lower than those of their initial metamorphism.
At what temperature does diagenesis end and metamorphism begin?
Metamorphism typically occurs between diagenesis (maximum 200°C), and melting (~850°C).
What are the requirements for a generalized zoning code?
GENERALIZED SUMMARY OF ZONING REGULATIONS Updated March 2020 Table 1 – General Development Standards Zone Use Maximum Height Required Yards Minimum Area Min. Lot Width Parking Stories Feet Front Side Rear Per Lot Per Dwelling Required Unit Agricultural A1 Agriculture One-Family Dwellings, Parks, Playgrounds, Community Centers,
How is zoning defined in Pasadena, CA?
Pasadena’s zoning designation are divided between residential (R) districts and commercial districts (C or I). A land use regulation designator (i.e. RS, RM, CG, etc.), indicating the principal land uses permitted or conditionally permitted in each district, is a component of all zoning designations.
How many boarding homes are allowed in a zoning district?
Zoning Codes. A maximum number of six (6) residents are allowed for a boarding home in a single family zoning district There is a required minimum 1/2 mile separation between boarding homes Boarding homes must comply with the Minimum Property Maintenance Code requirements Find additional information on City Zoning.
When does the Prince George’s County zoning ordinance go into effect?
The County Council of Prince George’s County has initated a Countywide Sectional Map Amendment (CMA) to reclassify properties in the County to the new zones included in the County’s upcoming Zoning Ordinance, adopted on October 23, 2018 as part of the ongoing Zoning Ordinance and Subdivision Regulations Update.