Marble Bar Chert Member
Marble bar has a hot desert climate köppen bwh with sweltering summers and warm winters.
Marble bar chert member. Here we interpret the finely laminated thin bedded cherts mixed conglomeratic beds. The archean biosphere drilling project abdp drilled a continuous 270 m long oriented core from the towers formation which includes the marble bar chert member 3456 1 3476 0 ma in the pilbara craton northwestern australia. The town set a world record of most consecutive days of 100 f 37 8 c or above during a period of 160 days from 31 october 1923 to 7 april 1924. A paleomagnetic study of 261 discrete specimens collected from a 158 5 to 182 0 m section of the marble bar chert member revealed two distinct magnetic components lt.
The 3 46 ga marble bar chert member of the east pilbara craton western australia is one of the earliest and best preserved sedimentary successions on earth. The marble bar chert of the archean proterozoic sedimentary sequence is only slightly metamorphosed. Another specimen is marble bar chert of 3 5 ga warrawoona group member which is distributed at pilbara craton in western australia. 1 a well bedded evenly and finely flat laminated lower section characterized by a conspicuous red white dark blue banded facies and prominent brecciated beds locally referred to as.
It is composed of two very distinctive sub units. Gunflint chert specimens were collected from the locality of kakabeka falls near lake superior. Red and white banded chert at marble bar pool in the east pilbara. The layers of red chert jasper contain up to 10.
Most of the annual rainfall occurs in the summer. Initial magnetic measurements of the whole core revealed that the black or red layers in the marble bar chert member display strong natural remanence magnetization. These yellowy rocks are the volcanic rocks that underly the marble bar chert and the black is the chert. Sedimentological evidence indicates water depths exceeding 200 m.
The marble bar chert member dated between 3463 to 3454 ma thorpe et al 1992 is a world famous early archean unit with little metamorphism. Marble bar chert member is located at chinaman pool. Here we report new evidence to suggest that haematite crystals in the jasper chert unit of the 3 46 gyr marble bar chert member mbc in the pilbara craton western australia probably nucleated. The marble bar chert member represents brecciation of the chert cut by fault with the breccia material showing disruption of the original structure.
We re right at the bottom. You can see the nice layering all through here right up over. Geological mapping reveals that the 3460 million year old marble bar chert was deposited in a caldera setting across an area of at least 50 km x 30 km.