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Kober, developing geosyncline theory, posited that stable blocks known as forelands move toward each other forcing the sediments of the intervening geosynclinal region to move over the forelands and forming marginal mountain ranges known as Randketten, while leaving an intervening median mass known as the Zwischengebirge. [3]
Development of a mountain range by sedimentation of a geosyncline and isostatic uplifting. This is the "collapse" of the geosyncline. A geosyncline (originally called a geosynclinal) is an obsolete geological concept to explain orogens, which was developed in the late 19th and early 20th centuries, before the theory of plate tectonics was envisaged.
From the late 18th century until its replacement by plate tectonics in the 1960s, geosyncline theory was used to explain much mountain-building. [4] The understanding of specific landscape features in terms of the underlying tectonic processes is called tectonic geomorphology , and the study of geologically young or ongoing processes is called ...
In 1933 Stille would shorten Leopold Kober's concept of kratogen, that was used to describe those portions of the continental crust that were old and stable, into kraton (English: craton). [6] The Geotectonic Research journal was founded in 1937 by Hans Stille and Franz Lotze .
Orogeny (/ ɒ ˈ r ɒ dʒ ə n i /) is a mountain-building process that takes place at a convergent plate margin when plate motion compresses the margin. An orogenic belt or orogen develops as the compressed plate crumples and is uplifted to form one or more mountain ranges.
The earliest evidence for life on Earth includes: 3.8 billion-year-old biogenic hematite in a banded iron formation of the Nuvvuagittuq Greenstone Belt in Canada; [30] graphite in 3.7 billion-year-old metasedimentary rocks in western Greenland; [31] and microbial mat fossils in 3.48 billion-year-old sandstone in Western Australia. [32] [33 ...
The Origin and Nature of Life on Earth: The Emergence of the Fourth Geosphere (2016) is a book by Eric Smith and biophysicist Harold J. Morowitz which provides an introduction to origins of life research via a review of perspectives from a variety of fields active in this research area, including geochemistry, biochemistry, ecology, and microbiology.
The history of life on Earth traces the processes by which living and extinct organisms evolved, from the earliest emergence of life to the present day. Earth formed about 4.5 billion years ago (abbreviated as Ga, for gigaannum) and evidence suggests that life emerged prior to 3.7 Ga. [1] [2] [3] The similarities among all known present-day species indicate that they have diverged through the ...