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Waitemata Group
The Waitemata Group is an Early Miocene geologic group that is exposed in and around the Auckland Region of New Zealand, between the Whangarei Harbour in the North and the Raglan Harbour in the South. The Group is predominantly composed of deep water sandstone and mudstone (flysch). The sandstone dominated units form the cliffs around the Waitemata Harbour and rare more resistant conglomerates underlie some of Auckland's prominent ridges. Sub-units and deposition The Waitemata Group was deposited within fault controlled basins. These were bounded to the North and South by up faulted Mesozoic basement sedimentary rocks and volcanic rocks to the East and West. The sedimentary source for the Group's sandstone is a mix of these basement sediments of the Waipapa Terrane and the mostly intermediate volcanic rocks. The maximum water depth of the Waitemata Group basin was 2,000 m. The basal strata (Kawau Subgroup) are from the early Miocene ( Otaian) and range in thickness from 10 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Early Miocene
The Early Miocene (also known as Lower Miocene) is a sub-epoch of the Miocene Epoch made up of two stages: the Aquitanian and Burdigalian stages. The sub-epoch lasted from 23.03 ± 0.05 Ma to 15.97 ± 0.05 Ma (million years ago). It was preceded by the Oligocene epoch. As the climate started to get cooler, the landscape started to change. New mammals evolved to replace the extinct animals of the Oligocene epoch. The first members of the hyena and weasel family started to evolve to replace the extinct ''Hyaenodon'', entelodonts and bear-dogs. The chalicotheres survived the Oligocene epoch. A new genus of entelodont called ''Daeodon'' evolved in order to adapt to the new habitats and hunt the new prey animals of the Early Miocene epoch; it quickly became the top predator of North America. But it became extinct due to competition from '' Amphicyon'', a newcomer from Eurasia. ''Amphicyon'' bested ''Daeodon'' because the bear-dog Amphicyonidae is an extinct family of terrestr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stratigraphy Of New Zealand
This is a list of the units into which the rock succession of New Zealand is formally divided. As new geological relationships have been discovered new names have been proposed and others are made obsolete. Not all these changes have been universally adopted. This table is based on the 2014 New Zealand Stratigraphic Lexicon (Litho2014). However, obsolete names that are still in use and names postdating the lexicon are included if it aids in understanding. Names for particular rock units have two parts, a proper name which is almost always a geographic location where the rock is found and a hierarchical rank (e.g. Waitematā Group). This ranking system starts with individual 'beds' of rock which can be grouped into 'members', members are grouped into 'formations', formations into 'subgroups' then 'groups'. In New Zealand, groups are further combined into 'supergroups' or for basement rocks into terranes. Not all of these hierarchical layers are necessarily present within a part ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geologic Groups Of Oceania
Geology () is a branch of natural science concerned with Earth and other astronomical objects, the features or rocks of which it is composed, and the processes by which they change over time. Modern geology significantly overlaps all other Earth sciences, including hydrology, and so is treated as one major aspect of integrated Earth system science and planetary science. Geology describes the structure of the Earth on and beneath its surface, and the processes that have shaped that structure. It also provides tools to determine the relative and absolute ages of rocks found in a given location, and also to describe the histories of those rocks. By combining these tools, geologists are able to chronicle the geological history of the Earth as a whole, and also to demonstrate the age of the Earth. Geology provides the primary evidence for plate tectonics, the evolutionary history of life, and the Earth's past climates. Geologists broadly study the properties and processes of Earth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
