نتایج جستجو برای: sedimentary structures

تعداد نتایج: 464979  

سلطانی, افسانه , فردوست, فرج الله , مصدق, مهدیه ,

Halalan Manganese ore deposit is located in Torud-Chah Shirin volcano-sedimentary band and the northern part of Central Iran structural-sedimentary zone. The outcropped rocks in the area include metamorphic complex with lithology composition of slate, phyllite, schist, marble, limestone, dolomite and slightly metamorphed sandstone with Early Jurassic age. Manganese mineralization has occurred i...

2016
Walter Prochaska

A consanguineous origin of the sparry siderite and magnesite mineralizations of the Eastern Alps has been repeatedly discussed in the past, often without the back-up of sound scientific arguments. Here, it is shown that the characteristics of these mineralizations including structures, fluid parameters, timing etc. are amazingly similar suggesting in fact the genetic linkage of these deposits. ...

2009

Mud volcanoes can be large and long lived geological structures that morphologically resemble magmatic volcanoes. Because of their capricious behaviour and their spectacular morphology and landscapes, mud volcanoes have attracted attention since antiquity. More recently, mud volcanoes have become the focus of extensive studies for natural science research, including geologists and biologists. M...

2004
J. Nussbaumer

Introduction: Cold temperatures on Mars [1] and a thin atmosphere prevent the occurrence of water in liquid form on the planet. However, sedimentary rocks at Meridiani Terrae show aqueous sedimentation. Catastrophic outgassing due to the Tharsis rise would result in increasing temperature and pressure, enabling water to exist on the surface for short periods of time. Magma–ice interactions duri...

2014
Amany G. Taher

The coastal sabkha in Ras Gemsa, Red Sea coast with its colonizing microbial mats and biofilms was investigated. The sabkha sediments consist mainly of terrigenous siliciclastic material accompanied by the development of evaporites. Halite serves as a good conduit for light and reduces the effect of intensive harmful solar radiation, which allows microbial mats to survive and flourish. The micr...

Nigel P. Mountney Shahid Ghazi

Deposits of the Warchha Sandstone in the Salt Range, Pakistan are characterised by a range of fluvial facies and architectural elements that together preserve a record of both the proximal and distal parts of a meandering river system that drained the northern margin of Gondwanaland. Several fining-upward cycles are recognised and completely preserved cycles can be divided in to three parts; a ...

Journal: :Science 1977
A H Knoll E S Barghoorn

A newly discovered population of organic walled microstructures from the Swaziland System, South Africa, is considered to be biological on the following grounds: (i) the structures are carbonaceous and occasionally have internal organic contents; (ii) the population has a narrow unimodal size frequency distribution (average diameter, 2.5 micrometers; range, 1 to 4 micrometers); (iii) the struct...

2009
F. MENEGHINI M. MARRONI J. C. MOORE L. PANDOLFI C. D. ROWE

Existing studies on active subduction margins have documented the wide diversity in structural style between accretionary prisms, both in space and time. Together with physical boundary conditions of the margins, the thickness of sedimentary successions carried by the lower plate seems to play a key role in controlling the deformation and fluid flow during accretion. We have tested the influenc...

Journal: :رخساره های رسوبی 0

two polygonal biogenic sedimentary rare structures of koilosoma (hitchcock 1858) have been found due to neoichnology of the abhar-rud river fluvial sediments, northwest iran. one of them is polygon holes, with about one square meter area. polygons are same in size and depth, and are hexagonal in shape. they have distinct boundaries like the honeycomb. this sample is like the reported specimens ...

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