|
Bahariya Formation
The Bahariya Formation (also transcribed as Baharija Formation) is a fossiliferous geologic formation dating back to the early Cenomanian, which outcrops within the Bahariya depression in Egypt, and is known from oil exploration drilling across much of the Western Desert where it forms an important oil reservoir.Weishampel, David B; et al (2004). "Dinosaur distribution (Late Cretaceous, Africa)." In: Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. Pp. 604. . Extent The Bahariya Formation forms the base of the depression, the lower part of the enclosing escarpment and all of the small hills within. The type section for the formation is found at Gebel El-Dist, a hill at the northern end of the Bahariya depression. Stratigraphy and sedimentology Four depositional sequences have been recognised in the Bahariya Formation in the Bahariya depression, separated by three sub-aerial unconformities. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geological Formation
A geological formation, or simply formation, is a body of rock having a consistent set of physical characteristics ( lithology) that distinguishes it from adjacent bodies of rock, and which occupies a particular position in the layers of rock exposed in a geographical region (the stratigraphic column). It is the fundamental unit of lithostratigraphy, the study of strata or rock layers. A formation must be large enough that it can be mapped at the surface or traced in the subsurface. Formations are otherwise not defined by the thickness of their rock strata, which can vary widely. They are usually, but not universally, tabular in form. They may consist of a single lithology (rock type), or of alternating beds of two or more lithologies, or even a heterogeneous mixture of lithologies, so long as this distinguishes them from adjacent bodies of rock. The concept of a geologic formation goes back to the beginnings of modern scientific geology. The term was used by Abraham Gottlob Wer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fluvial
In geography and geology, fluvial processes are associated with rivers and streams and the deposits and landforms created by them. When the stream or rivers are associated with glaciers, ice sheets, or ice caps, the term glaciofluvial or fluvioglacial is used. Fluvial processes Fluvial processes include the motion of sediment and erosion or deposition on the river bed. The movement of water across the stream bed exerts a shear stress directly onto the bed. If the cohesive strength of the substrate is lower than the shear exerted, or the bed is composed of loose sediment which can be mobilized by such stresses, then the bed will be lowered purely by clearwater flow. In addition, if the river carries significant quantities of sediment, this material can act as tools to enhance wear of the bed ( abrasion). At the same time the fragments themselves are ground down, becoming smaller and more rounded (attrition). Sediment in rivers is transported as either bedload (the coarser fr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Liriodendrites
''Liriodendrites'' is an extinct genus of plants, known from fossil leaves. These have a forked apex (bifurcate), like those of extant species of ''Liriodendron''. They have been interpreted as transitional between the leaves of the extinct genus '' Liriophyllum'' and ''Liriodendron''. The genus has been placed in the family Magnoliaceae. Five species are known: ''L. aeternus'', ''L. bradacii'', ''L. laramiense'',Kirk R. Johnson; See: Johnson, Kirk R. (1989). A high-resolution megafloral biostratigraphy spanning the Cretaceous-Tertiary boundary in the northern Great Plains. Ph.D Dissertation. Yale University, New Haven. olume=I-II.; Note: "Primary type" of HC166 ''L. occidentalis'' and ''L. sachalinensis''. It has been discovered in the United States (Hell Creek Formation), Egypt (Bahariya Formation) and Russia (Sakhalin and Siberia Siberia ( ; rus, Сибирь, r=Sibir', p=sʲɪˈbʲirʲ, a=Ru-Сибирь.ogg) is an extensive geographical region, constituting all of Nort ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marsileales
The order Salviniales (formerly known as the Hydropteridales and including the former Marsileales) is an order of ferns in the class Polypodiopsida. Description Salviniales are all aquatic and differ from all other ferns in being heterosporous, meaning that they produce two different types of spores (megaspores and microspores) that develop into two different types of gametophytes (female and male gametophytes, respectively), and in that their gametophytes are endosporic, meaning that they never grow outside the spore wall and cannot become larger than the spores that produced them. The megasporangia each produce a single megaspore. In being heterosporus with endosporic gametophytes they are more similar to seed plants than to other ferns. The fertile and sterile leaves are dimorphic, taking on a different shape, and leaves bear anastomosing veins. Aerenchyma is frequently present in roots, shoots, and petioles (leaf stalks). The ferns of this order vary radically in form and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cladophlebis
''Cladophlebis'' is an extinct form genus of fern, used to refer to Paleozoic and Mesozoic fern leaves that have "fern fronds with pinnules that are attached to the rachis, and have a median vein that runs to the apex of the pinnule, and veins from that are curved and dichotomise". By convention this genus is not used to refer to fossil ferns from the Cenozoic. Ferns with this morphology belong to several families, including Osmundaceae, Dicksoniaceae and Schizaeaceae. Ferns with this morphology are common during the Paleozoic and Mesozoic in both the northern and southern hemispheres.''Cladophlebis'' at .org Species There were many species of ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Australasia
Australasia is a region that comprises Australia, New Zealand and some neighbouring islands in the Pacific Ocean. The term is used in a number of different contexts, including geopolitically, physiogeographically, philologically, and ecologically, where the term covers several slightly different, but related regions. Derivation and definitions Charles de Brosses coined the term (as French ''Australasie'') in ''Histoire des navigations aux terres australes'' (1756). He derived it from the Latin for "south of Asia" and differentiated the area from Polynesia (to the east) and the southeast Pacific (Magellanica). In the late 19th century, the term Australasia was used in reference to the "Australasian colonies". In this sense it related specifically to the British colonies south of Asia: New South Wales, Queensland, South Australia, Tasmania, Western Australia, Victoria (i.e., the Australian colonies) and New Zealand. Australasia found continued geopolitical attention in the earl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conifer
Conifers are a group of conifer cone, cone-bearing Spermatophyte, seed plants, a subset of gymnosperms. Scientifically, they make up the phylum, division Pinophyta (), also known as Coniferophyta () or Coniferae. The division contains a single extant class (biology), class, Pinopsida. All Neontology, extant conifers are perennial plant, perennial woody plants with secondary growth. The great majority are trees, though a few are shrubs. Examples include Cedrus, cedars, Pseudotsuga, Douglas-firs, Cupressaceae, cypresses, firs, junipers, Agathis, kauri, larches, pines, Tsuga, hemlocks, Sequoioideae, redwoods, spruces, and Taxaceae, yews.Campbell, Reece, "Phylum Coniferophyta". Biology. 7th. 2005. Print. P. 595 As of 1998, the division Pinophyta was estimated to contain eight families, 68 genera, and 629 living species. Although the total number of species is relatively small, conifers are ecology, ecologically important. They are the dominant plants over large areas of land, most ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Araucariaceae
Araucariaceae – also known as araucarians – is an extremely ancient family of coniferous trees. The family achieved its maximum diversity during the Jurassic and Cretaceous periods and the early Cenozoic, when it was distributed almost worldwide. Most of the Araucariaceae in the Northern Hemisphere vanished in the Cretaceous–Paleogene extinction event, and they are now largely confined to the Southern Hemisphere, except for a few species of ''Agathis'' in Southeast Asia. Description Members of Araucariaceae are typically extremely tall evergreen trees, reaching heights of or more. They can also grow very large stem diameters; a New Zealand kauri tree (''Agathis australis'') named ''Tāne Mahuta'' ("The Lord of the Forest") has been measured at tall with a diameter at breast height of . Its total wood volume is calculated to be , making it the third-largest conifer after '' Sequoia'' and ''Sequoiadendron'' (both from the Cupressaceae subfamily Sequoioideae). The trunks ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Agathis
''Agathis'', commonly known as kauri or dammara, is a genus of 22 species of evergreen tree. The genus is part of the ancient conifer family Araucariaceae, a group once widespread during the Jurassic and Cretaceous periods, but now largely restricted to the Southern Hemisphere except for a number of extant Malesian ''Agathis''.de Laubenfels, David J. 1988. Coniferales. P. 337–453 in Flora Malesiana, Series I, Vol. 10. Dordrecht: Kluwer Academic. Description Mature kauri trees have characteristically large trunks, with little or no branching below the crown. In contrast, young trees are normally conical in shape, forming a more rounded or irregularly shaped crown as they achieve maturity.Whitmore, T.C. 1977. ''A first look at Agathis''. Tropical Forestry Papers No. 11. University of Oxford Commonwealth Forestry Institute. The bark is smooth and light grey to grey-brown, usually peeling into irregular flakes that become thicker on more mature trees. The branch struct ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cladophlebis Retallackii
''Cladophlebis'' is an extinct form genus of fern, used to refer to Paleozoic and Mesozoic fern leaves that have "fern fronds with pinnules that are attached to the rachis, and have a median vein that runs to the apex of the pinnule, and veins from that are curved and dichotomise". By convention this genus is not used to refer to fossil ferns from the Cenozoic. Ferns with this morphology belong to several families, including Osmundaceae, Dicksoniaceae and Schizaeaceae. Ferns with this morphology are common during the Paleozoic and Mesozoic in both the northern and southern hemispheres.''Cladophlebis'' at .org Species There were many species of ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tree Fern
The tree ferns are arborescent (tree-like) ferns that grow with a trunk elevating the fronds above ground level, making them trees. Many extant tree ferns are members of the order Cyatheales, to which belong the families Cyatheaceae (scaly tree ferns), Dicksoniaceae, Metaxyaceae, and Cibotiaceae. It is estimated that Cyatheales originated in the early Jurassic, and is the third group of ferns known to have given rise to tree-like forms. The others are the extinct '' Tempskya'' of uncertain position, and Osmundales where the extinct Guaireaceae and some members of Osmundaceae also grew into trees. In addition there were the Psaroniaceae and Tietea in the Marattiales, which is the sister group to most living ferns including Cyatheales. Other ferns which are also tree ferns, are ''Leptopteris'' and ''Todea'' in the family Osmundaceae, which can achieve short trunks under a metre tall. Fern species with short trunks in the genera ''Blechnum'', '' Cystodium'' and ''Sadleria'' from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xerophytic
A xerophyte (from Greek ξηρός ''xeros'' 'dry' + φυτόν ''phuton'' 'plant') is a species of plant that has adaptations to survive in an environment with little liquid water, such as a desert such as the Sahara or places in the Alps or the Arctic. Popular examples of xerophytes are cacti, pineapple and some Gymnosperm plants. The structural features (morphology) and fundamental chemical processes (physiology) of xerophytes are variously adapted to conserve water, also common to store large quantities of water, during dry periods. Other species are able to survive long periods of extreme dryness or desiccation of their tissues, during which their metabolic activity may effectively shut down. Plants with such morphological and physiological adaptations are .” Xeromorphic”, The Cambridge Illustrated Glossary of Botanical Terms, Michael Hickey, Clive King, Cambridge University Press, 2001 Xerophytes such as cacti are capable of withstanding extended periods of dry con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
