User:DBoyd13/AricleSandbox

=Xiong'er Volcanic Belt=

The Xiong'er Volcanic Belt which is also known as the Xiong'er Group is a 1.8 billion year old group of volcanic rocks located on the southern edge of the North China craton. It covers an area of approximately 60,000 km2 and ranges in thickness from 3000ft to 7000ft. It is bound on the.....The volcanic belt formed at a time in the earths history when the all of the continents were joined together forming the Supercontinent Columbia which is the earliest known supercontinent. The Xiong'er volcanic belt is very important because it can provide valuable information to help piece together the history of the supercontinent Columbia and the position of North China craton within it.

Geologic Formations
The Xiong'er Volcanic Belt is made up of four geologic formations, one sedimentary and three volcanic. Starting at the bottom and going up they include the Daguish, Xushan, Jidanping, and Majiahe formations. They are uncomformibly overlie Tietonggou Group and lie uncomformibly below the Ruyang Group.

Daguish Formation
The Daguish formation is bottom most formation and is composed of sedimentary rocks such as breccia,  conglomerate, and  mudstone.

Xushan Formation
The Xushan formation is the second formation from the bottom and is dominantly composed of the volcanic rocks basalt andesite and andesite.

Jidanping Formation
The Jidanping formation is the third formation from the bottom and is a mixture of volcanic rocks which include dacite, rhyolite, basalt andesites, and andesites.

Majiahe Formation
The Majiahe formation is the top formation and is dominatly basalt andesite and andesite but also contains pyroclastic and sedimentary rocks as well.

Tectonic Setting
Currently there are two proposed hypothesis for the tectonic setting in which Xiong'er Volcanic Belt was formed. One is in a continetal rift setting and the other is in an Andean type continetal margin where an oceanic plate is subducting underneath a continental plate.