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68-654: In 1875, Gilbert recognized and named the Redwall Limestone for the red coloration of its escarpment on either side of Grand Canyon. As originally defined by him, it included some strata younger and older than as it is currently defined. Later in 1910, Darton selected a canyon that he named the Redwall Canyon in the Shinumo drainage basin, on north side of the Grand Canyon, as the type section of

136-571: A and b . Their chloroplasts are surrounded by four and three membranes, respectively, and were probably retained from ingested green algae. Chlorarachniophytes , which belong to the phylum Cercozoa , contain a small nucleomorph , which is a relict of the algae's nucleus . Euglenids , which belong to the phylum Euglenozoa , live primarily in fresh water and have chloroplasts with only three membranes. The endosymbiotic green algae may have been acquired through myzocytosis rather than phagocytosis . (Another group with green algae endosymbionts

204-408: A and c , and phycobilins. The shape can vary; they may be of discoid, plate-like, reticulate, cup-shaped, spiral, or ribbon shaped. They have one or more pyrenoids to preserve protein and starch. The latter chlorophyll type is not known from any prokaryotes or primary chloroplasts, but genetic similarities with red algae suggest a relationship there. In the first three of these groups ( Chromista ),

272-460: A fault displaces the ground surface so that one side is higher than the other, a fault scarp is created. This can occur in dip-slip faults , or when a strike-slip fault brings a piece of high ground adjacent to an area of lower ground. Earth is not the only planet where escarpments occur. They are believed to occur on other planets when the crust contracts , as a result of cooling. On other Solar System bodies such as Mercury , Mars , and

340-480: A few places, this member exhibits conspicuous medium-scale crossbedding . In the Grand Canyon, the Whitmore Wash Member varies in thickness from about 9 m (30 ft) in the eastern Grand Canyon to nearly 30 m (98 ft) at Iceberg Ridge, 8 km (5.0 mi) beyond the western end of Grand Canyon. The overlying Thunder Springs Member lies conformably on Whitmore Wash Member and its base

408-539: A form and capabilities not possessed by the symbiont species alone (they can be experimentally isolated). The photobiont possibly triggers otherwise latent genes in the mycobiont. Trentepohlia is an example of a common green alga genus worldwide that can grow on its own or be lichenised. Lichen thus share some of the habitat and often similar appearance with specialized species of algae ( aerophytes ) growing on exposed surfaces such as tree trunks and rocks and sometimes discoloring them. Coral reefs are accumulated from

476-643: A high, resistant cliff standing on a narrow bench or series of ledges typical of underlying strata . This member consists of nearly pure limestone and dolomite, which contains less than 2 percent insoluble gypsum and iron oxides . This member is predominately composed of thick-bedded, ranging from 0.6 to 1.22 m (2.0 to 4.0 ft) and locally thicker, limestone in western Grand Canyon and changes to mostly very thick-bedded 1.2 to 4.5 m (3.9 to 14.8 ft), fine-grained dolomite in central and eastern Grand Canyon. The limestones are composed mostly of pelletal, skeletal or oolitic wackestones and packstones . In

544-425: A lateral distance of 30 to 61 m (98 to 200 ft). The duration of geologic time represented by this unconformity increases eastward across the Grand Canyon and the rest of northern Arizona. The upper contact of the Redwall Limestone is a disconformity that represents a buried, irregular and karstified paleosurface that contains many contemporaeous caves and collapse structures. Eroded into this paleosurafce are

612-598: A lineage that eventually led to the higher land plants. The innovation that defines these nonalgal plants is the presence of female reproductive organs with protective cell layers that protect the zygote and developing embryo. Hence, the land plants are referred to as the Embryophytes . The term algal turf is commonly used but poorly defined. Algal turfs are thick, carpet-like beds of seaweed that retain sediment and compete with foundation species like corals and kelps , and they are usually less than 15 cm tall. Such

680-498: A major part of the high, sheer escarpment for which the Redwall Limestone is named. It consists predominantly of pure limestone, except locally where it is dolomitized. It contains less than 0.5 percent insoluble residue. These limestones consist of oolites, pellets, and a variety of skeletal fragments dominated by crinoid plates. In its upper part near its contact with the overlying Horseshoe Mesa Member, one or two zones containing thin beds or lenses of chert occur. The Mooney Falls Member

748-423: A prominent examples of algae that have primary chloroplasts derived from endosymbiont cyanobacteria. Diatoms and brown algae are examples of algae with secondary chloroplasts derived from endosymbiotic red algae , which they acquired via phagocytosis . Algae exhibit a wide range of reproductive strategies, from simple asexual cell division to complex forms of sexual reproduction via spores . Algae lack

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816-483: A red dye derived from it. The Latinization, fūcus , meant primarily the cosmetic rouge. The etymology is uncertain, but a strong candidate has long been some word related to the Biblical פוך ( pūk ), 'paint' (if not that word itself), a cosmetic eye-shadow used by the ancient Egyptians and other inhabitants of the eastern Mediterranean. It could be any color: black, red, green, or blue. The study of algae

884-468: A turf may consist of one or more species, and will generally cover an area in the order of a square metre or more. Some common characteristics are listed: Many algae, particularly species of the Characeae , have served as model experimental organisms to understand the mechanisms of the water permeability of membranes, osmoregulation , turgor regulation , salt tolerance , cytoplasmic streaming , and

952-516: Is easily recognized by the lowest appearance of thin, dark, chert beds alternating with thin beds of lighter gray limestone or dolomite. The Thunder Springs Member is the most distinctive member of the Redwall Limestone, because it forms cliffs that exhibit prominent black and light-brown banding. Its light and dark banded appearance is imparted by thin beds of either light gray limestone or light gray dolomite alternating with thin beds of dark reddish brown or dark gray beds or lenses of chert. Most of

1020-625: Is locally derived from either the underlying Temple Butte Formation or Muav Limestone . In the eastern Grand Canyon, the Temple Butte Formation consists of a thin, discontinuous layer of Devonian strata that fills paleovalleys cut into the underlying Cambrian Muav Limestone. Westward, the Temple Butte Formation thickens until it becomes a continuous, westward thickening, layer underlying the Redwall Limestone. In western Grand Canyon, this contact consist of an irregular erosional surface having up to 3 m (9.8 ft) of relief in

1088-550: Is most commonly called phycology (from Greek phykos  'seaweed'); the term algology is falling out of use. One definition of algae is that they "have chlorophyll as their primary photosynthetic pigment and lack a sterile covering of cells around their reproductive cells ". On the other hand, the colorless Prototheca under Chlorophyta are all devoid of any chlorophyll. Although cyanobacteria are often referred to as "blue-green algae", most authorities exclude all prokaryotes , including cyanobacteria, from

1156-502: Is normally thick-bedded and looks massive in outcrop. The upper third of this member at several localities in central and eastern Grand Canyon reportedly exhibits large-scale, tabular-planar cross-bedding. The Mooney Falls Member is the thickest member of the Redwall, ranging from about 61 m (200 ft) in eastern Grand Canyon to nearly 120 m (390 ft) at the western end. The overlying Horseshoe Mesa Member lies conformably on

1224-544: Is quite different from those of reds and browns, because they have distinct nodes, separated by internode 'stems'; whorls of branches reminiscent of the horsetails occur at the nodes. Conceptacles are another polyphyletic trait; they appear in the coralline algae and the Hildenbrandiales , as well as the browns. Most of the simpler algae are unicellular flagellates or amoeboids , but colonial and nonmotile forms have developed independently among several of

1292-528: Is the Latin word for 'seaweed' and retains that meaning in English. The etymology is obscure. Although some speculate that it is related to Latin algēre , 'be cold', no reason is known to associate seaweed with temperature. A more likely source is alliga , 'binding, entwining'. The Ancient Greek word for 'seaweed' was φῦκος ( phŷkos ), which could mean either the seaweed (probably red algae) or

1360-423: Is the dinoflagellate genus Lepidodinium , which has replaced its original endosymbiont of red algal origin with one of green algal origin. A nucleomorph is present, and the host genome still have several red algal genes acquired through endosymbiotic gene transfer. Also the euglenid and chlorarachniophyte genome contain genes of apparent red algal ancestry) These groups have chloroplasts containing chlorophylls

1428-526: The Charophyta , a division of green algae which includes, for example, Spirogyra and stoneworts . Algae that are carried passively by water are plankton , specifically phytoplankton . Algae constitute a polyphyletic group since they do not include a common ancestor , and although their chlorophyll -bearing plastids seem to have a single origin (from symbiogenesis with cyanobacteria ), they were acquired in different ways. Green algae are

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1496-751: The Calymmian period , early in Boring Billion , but it is difficult to track the key events because of so much time gap. Primary symbiogenesis gave rise to three divisions of archaeplastids , namely the Viridiplantae ( green algae and later plants ), Rhodophyta ( red algae ) and Glaucophyta ("grey algae"), whose plastids further spread into other protist lineages through eukaryote-eukaryote predation , engulfments and subsequent endosymbioses (secondary and tertiary symbiogenesis). This process of serial cell "capture" and "enslavement" explains

1564-614: The Infusoria (microscopic organisms). Unlike macroalgae , which were clearly viewed as plants, microalgae were frequently considered animals because they are often motile. Even the nonmotile (coccoid) microalgae were sometimes merely seen as stages of the lifecycle of plants, macroalgae, or animals. Although used as a taxonomic category in some pre-Darwinian classifications, e.g., Linnaeus (1753), de Jussieu (1789), Lamouroux (1813), Harvey (1836), Horaninow (1843), Agassiz (1859), Wilson & Cassin (1864), in further classifications,

1632-612: The International Association for Lichenology to be "an association of a fungus and a photosynthetic symbiont resulting in a stable vegetative body having a specific structure". The fungi, or mycobionts, are mainly from the Ascomycota with a few from the Basidiomycota . In nature, they do not occur separate from lichens. It is unknown when they began to associate. One or more mycobiont associates with

1700-589: The Late Cambrian / Early Ordovician period, from sessile shallow freshwater charophyte algae much like Chara , which likely got stranded ashore when riverine / lacustrine water levels dropped during dry seasons . These charophyte algae probably already developed filamentous thalli and holdfasts that superficially resembled plant stems and roots , and probably had an isomorphic alternation of generations . They perhaps evolved some 850 mya and might even be as early as 1  Gya during

1768-525: The Moon , the Latin term rupes is used for an escarpment. When sedimentary beds are tilted and exposed to the surface, erosion and weathering may occur. Escarpments erode gradually and over geological time . The mélange tendencies of escarpments results in varying contacts between a multitude of rock types. These different rock types weather at different speeds, according to Goldich dissolution series so different stages of deformation can often be seen in

1836-986: The Vindhya basin have been dated to 1.6 to 1.7 billion years ago. Because of the wide range of algae types, they have increasingly different industrial and traditional applications in human society. Traditional seaweed farming practices have existed for thousands of years and have strong traditions in East Asia food cultures. More modern algaculture applications extend the food traditions for other applications, including cattle feed, using algae for bioremediation or pollution control, transforming sunlight into algae fuels or other chemicals used in industrial processes, and in medical and scientific applications. A 2020 review found that these applications of algae could play an important role in carbon sequestration to mitigate climate change while providing lucrative value-added products for global economies. The singular alga

1904-601: The apicomplexans are also parasites derived from ancestors that possessed plastids, but are not included in any group traditionally seen as algae. Algae are polyphyletic thus their origin cannot be traced back to single hypothetical common ancestor . It is thought that they came into existence when photosynthetic coccoid cyanobacteria got phagocytized by a unicellular heterotrophic eukaryote (a protist ), giving rise to double-membranous primary plastids . Such symbiogenic events (primary symbiogenesis) are believed to have occurred more than 1.5 billion years ago during

1972-435: The apicomplexans , are also derived from cells whose ancestors possessed chlorophyllic plastids, but are not traditionally considered as algae. Algae have photosynthetic machinery ultimately derived from cyanobacteria that produce oxygen as a byproduct of splitting water molecules , unlike other organisms that conduct anoxygenic photosynthesis such as purple and green sulfur bacteria . Fossilized filamentous algae from

2040-545: The calcareous exoskeletons of marine invertebrates of the order Scleractinia (stony corals ). These animals metabolize sugar and oxygen to obtain energy for their cell-building processes, including secretion of the exoskeleton, with water and carbon dioxide as byproducts. Dinoflagellates (algal protists) are often endosymbionts in the cells of the coral-forming marine invertebrates, where they accelerate host-cell metabolism by generating sugar and oxygen immediately available through photosynthesis using incident light and

2108-424: The diatoms , to multicellular macroalgae such as the giant kelp , a large brown alga which may grow up to 50 metres (160 ft) in length. Most algae are aquatic organisms and lack many of the distinct cell and tissue types, such as stomata , xylem and phloem that are found in land plants . The largest and most complex marine algae are called seaweeds . In contrast, the most complex freshwater forms are

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2176-720: The "algae" are seen as an artificial, polyphyletic group. Throughout the 20th century, most classifications treated the following groups as divisions or classes of algae: cyanophytes , rhodophytes , chrysophytes , xanthophytes , bacillariophytes , phaeophytes , pyrrhophytes ( cryptophytes and dinophytes ), euglenophytes , and chlorophytes . Later, many new groups were discovered (e.g., Bolidophyceae ), and others were splintered from older groups: charophytes and glaucophytes (from chlorophytes), many heterokontophytes (e.g., synurophytes from chrysophytes, or eustigmatophytes from xanthophytes), haptophytes (from chrysophytes), and chlorarachniophytes (from xanthophytes). With

2244-478: The Mooney Falls Member and its contact can be difficult to define in outcrops. Typically, the boundary is located at the change from vertical, cliff-forming, medium- and coarse-grained, and thick- or massive-bedded limestone to a receding-ledge-forming, fine-grained, and relatively thin-bedded, limestone. The Horseshoe Mesa Member is the youngest, thinnest, and of the least areal extensive member of

2312-626: The Mooney Falls Member. The Horseshoe Mesa Member accumulated during early Late Mississippian time as the shoreline retreated westward and back into Nevada. The age of the Redwall Limestone indicates that it accumulated during the same period of time as the Escabrosa Limestone of southeastern Arizona, the Leadville Limestone of southwestern Colorado, and the Monte Cristo Group of southeastern Nevada. Four of

2380-510: The Redwall Limestone are both unconformities. The lower contact of the Redwall Limestone is a disconformity that rests either on upon the Devonian Temple Butte Formation or, where it is missing in the eastern Grand Canyon, strata of Cambrian Tonto Group . Often, the Redwall Limestone immediately overlying this disconformity contains a basal conglomerate . Normally, this basal conglomerate is composed of gravel that

2448-497: The Redwall Limestone is divided into the Whitmore Wash , Thunder Springs , Mooney Falls , and Horseshoe Mesa members. All four member have their type locality in the Grand Canyon or its tributaries. They are recognized throughout the Grand Canyon area, northern Arizona, and southern Utah. They are all Mississippian in age. The Whitmore Wash Member is the basal, oldest, member of the Redwall Limestone. It typically forms

2516-587: The Redwall Limestone is the History of the Redwall Limestone of northern Arizona by McKee and Gutschick. Redwall Limestone consists predominantly of light-olive-gray to light-gray, fine- to coarse-grained, thin- to thick-bedded, often cherty, limestone. Its lower part consists of brownish-gray, interbedded with finely crystalline dolomite and fine- to coarse-grained limestone with layers of white chert lenses and yellowish-gray and brownish-gray, cliff-forming, thick-bedded, fine-grained dolomite. In ascending order,

2584-539: The Redwall Limestone. At this location, it consists mostly of the usual heavily bedded massive limestone and is circa 244 m (801 ft) thick. Noble subsequently redefined the Redwall Limestone in its present definition, which includes all strata of Mississippian age. As a result of studies in Yavapai County, Arizona , Gutschick recognized four informal members within the Redwall Limestone and McKee later formally named them. The most comprehensive study of

2652-411: The Redwall Limestone. This member is normally composed of thin-bedded, light gray, fine-grained, limestone, typically a mudstone to wackestone that commonly contains encrusting and sediment-binding algal structures. It contains some chert lenses in its lower part. Also, crossbedding, ripple marks, and oolite beds occur locally. The Horseshoe Mesa Member typically forms weak receding ledges in contrast to

2720-547: The Whitmore Wash Member at Nautiloid Canyon. The chert beds of the Thunder Springs Member contain an abundance invertebrate marine fossils. The fossils found in these cherts are corals (particularly the colonial coral, Syringapara ), bryozoans, brachiopods, crinoids, and a few gastropods , blastoids, and cephalopods. Similar fossils and conodonts occur in the carbonate beds of the Thunder Springs Member. They are less abundant and not at well preserved, likely as

2788-675: The abandonment of plant-animal dichotomous classification, most groups of algae (sometimes all) were included in Protista , later also abandoned in favour of Eukaryota . However, as a legacy of the older plant life scheme, some groups that were also treated as protozoans in the past still have duplicated classifications (see ambiregnal protists ). Some parasitic algae (e.g., the green algae Prototheca and Helicosporidium , parasites of metazoans, or Cephaleuros , parasites of plants) were originally classified as fungi , sporozoans , or protistans of incertae sedis , while others (e.g.,

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2856-472: The base of the plateau . Scarps are generally formed by one of two processes: either by differential erosion of sedimentary rocks , or by movement of the Earth's crust at a geologic fault . The first process is the more common type: the escarpment is a transition from one series of sedimentary rocks to another series of a different age and composition. Escarpments are also frequently formed by faults. When

2924-451: The carbon dioxide produced by the host. Reef-building stony corals ( hermatypic corals ) require endosymbiotic algae from the genus Symbiodinium to be in a healthy condition. The loss of Symbiodinium from the host is known as coral bleaching , a condition which leads to the deterioration of a reef. Endosymbiontic green algae live close to the surface of some sponges, for example, breadcrumb sponges ( Halichondria panicea ). The alga

2992-420: The chloroplast has four membranes, retaining a nucleomorph in cryptomonads , and they likely share a common pigmented ancestor, although other evidence casts doubt on whether the heterokonts , Haptophyta , and cryptomonads are in fact more closely related to each other than to other groups. The typical dinoflagellate chloroplast has three membranes, but considerable diversity exists in chloroplasts within

3060-624: The composition of the three major groups of algae. Their lineage relationships are shown in the figure in the upper right. Many of these groups contain some members that are no longer photosynthetic. Some retain plastids, but not chloroplasts, while others have lost plastids entirely. Phylogeny based on plastid not nucleocytoplasmic genealogy: Cyanobacteria Glaucophytes Rhodophytes Stramenopiles Cryptophytes Haptophytes Euglenophytes Chlorarachniophytes Chlorophytes Charophytes Land plants (Embryophyta) These groups have green chloroplasts containing chlorophylls

3128-436: The definition of algae. The algae contain chloroplasts that are similar in structure to cyanobacteria. Chloroplasts contain circular DNA like that in cyanobacteria and are interpreted as representing reduced endosymbiotic cyanobacteria . However, the exact origin of the chloroplasts is different among separate lineages of algae, reflecting their acquisition during different endosymbiotic events. The table below describes

3196-425: The diversity of photosynthetic eukaryotes. Recent genomic and phylogenomic approaches have significantly clarified plastid genome evolution , the horizontal movement of endosymbiont genes to the "host" nuclear genome , and plastid spread throughout the eukaryotic tree of life . Fossils of isolated spores suggest land plants may have been around as long as 475  million years ago (mya) during

3264-432: The first to divide macroscopic algae into four divisions based on their pigmentation. This is the first use of a biochemical criterion in plant systematics. Harvey's four divisions are: red algae (Rhodospermae), brown algae (Melanospermae), green algae (Chlorospermae), and Diatomaceae. At this time, microscopic algae were discovered and reported by a different group of workers (e.g., O. F. Müller and Ehrenberg ) studying

3332-657: The five formations in the Monte Cristo share nearly identical lithologic characteristics and stratigraphic position with the four members of the Redwall Limestone in northern Arizona. It is likely that the Redwall Limestone deposits were laterally continuous with all the above unit. Escarpment An escarpment is a steep slope or long cliff that forms as a result of faulting or erosion and separates two relatively level areas having different elevations . The terms scarp and scarp face are often used interchangeably with escarpment . Some sources differentiate

3400-480: The fossils of blastoids , trilobites , ostracods , fish teeth, and algal remains. Microfossils of foraminifers and conodonts have also been found. The members of the Redwall Limestone vary greatly in the abundance and presevation of fossils that they contain. As the result of the extensive alteration of the original sediments and bioclasts by dolomitization , fossils are rare in the Whitmore Wash Member. However, nautiloid fossils are found in abundance at in

3468-538: The genera Volvox and Corallina , and a species of Acetabularia (as Madrepora ), among the animals. In 1768, Samuel Gottlieb Gmelin (1744–1774) published the Historia Fucorum , the first work dedicated to marine algae and the first book on marine biology to use the then new binomial nomenclature of Linnaeus. It included elaborate illustrations of seaweed and marine algae on folded leaves. W. H. Harvey (1811–1866) and Lamouroux (1813) were

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3536-446: The generation of action potentials . Plant hormones are found not only in higher plants, but in algae, too. Some species of algae form symbiotic relationships with other organisms. In these symbioses, the algae supply photosynthates (organic substances) to the host organism providing protection to the algal cells. The host organism derives some or all of its energy requirements from the algae. Examples are: Lichens are defined by

3604-538: The green algae Phyllosiphon and Rhodochytrium , parasites of plants, or the red algae Pterocladiophila and Gelidiocolax mammillatus , parasites of other red algae, or the dinoflagellates Oodinium , parasites of fish) had their relationship with algae conjectured early. In other cases, some groups were originally characterized as parasitic algae (e.g., Chlorochytrium ), but later were seen as endophytic algae. Some filamentous bacteria (e.g., Beggiatoa ) were originally seen as algae. Furthermore, groups like

3672-571: The group, and a number of endosymbiotic events apparently occurred. The Apicomplexa , a group of closely related parasites, also have plastids called apicoplasts , which are not photosynthetic, but appear to have a common origin with dinoflagellate chloroplasts. Linnaeus , in Species Plantarum (1753), the starting point for modern botanical nomenclature , recognized 14 genera of algae, of which only four are currently considered among algae. In Systema Naturae , Linnaeus described

3740-453: The groups. Some of the more common organizational levels, more than one of which may occur in the lifecycle of a species, are In three lines, even higher levels of organization have been reached, with full tissue differentiation. These are the brown algae, —some of which may reach 50 m in length ( kelps ) —the red algae, and the green algae. The most complex forms are found among the charophyte algae (see Charales and Charophyta ), in

3808-408: The it. The initial accumulation of the basal Whitmore Wash Member in western Grand Canyon occurred during early Early Mississippian time. The basal strata of the Redwall Limestone become progressively younger as the sea transgressed eastward across northern Arizona and submerged it under a shallow epiric sea. Thus, they are no older than late Early Mississippian age in eastern Grand Canyon. Subsequently,

3876-417: The late phase of the Boring Billion . A range of algal morphologies is exhibited, and convergence of features in unrelated groups is common. The only groups to exhibit three-dimensional multicellular thalli are the reds and browns , and some chlorophytes . Apical growth is constrained to subsets of these groups: the florideophyte reds, various browns, and the charophytes. The form of charophytes

3944-506: The layers where the escarpments have been exposed to the elements. Algal Algae ( UK : / ˈ æ l ɡ iː / AL -ghee , US : / ˈ æ l dʒ iː / AL -jee ; sg. : alga / ˈ æ l ɡ ə / AL -gə ) is an informal term for any organisms of a large and diverse group of photosynthetic eukaryotes , which include species from multiple distinct clades . Such organisms range from unicellular microalgae such as Chlorella , Prototheca and

4012-485: The limestone is fine to very coarse, thin-bedded, crinoidal grainstone or packstone. The carbonate beds vary from being predominately limestone in the western Grand Canyon and to predominately dolomite in the eastern Grand Canyon. The thin chert beds in this member consist of silicified bryozoan wackestones and lime mudstones . The Thunder Springs Member gradually increases in thickness from 30 m (98 ft) in eastern Grand Canyon to about 46 m (151 ft) in

4080-483: The massive cliff that characterizes the Mooney Falls below. Within the Grand Canyon it varies from 14 to 38 m (46 to 125 ft). It normally thinnest in the eastern Grand Canyon. Because of erosion, this member wedges out 48 to 64 km (30 to 40 mi) south of the Grand Canyon. The Horseshoe Mesa Member is also absent from the Redwall Limestone in most of central Arizona. The upper and lower contacts of

4148-603: The remnants of a westward-draining network of coastal paleovalleys and paleochannels. Filling these buried paleovalleys, paleochannels, caves, and collapse structures are sedimentary strata of the Surprise Canyon Formation. Overlying the Surprise Canyon Formation and adjacent protruding paleosurface of the Redwall Limestone are marine, fluvial , and aeolian deposits of the Supai Group. The paleovalleys are incised as much as 122 m (400 ft) through

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4216-699: The result of alteration of the original sediments by dolomitization. Invertebrate marine fossils are abundant throughout the Mooney Falls Member. They include solitary and colonial corals, spiriferid brachiopods , crinoids, foraminifers, and conodonts. Finally, although rare, well-preserved, invertebrate, marine fossils are present throughout the Horseshoe Mesa Member. Among the most abundant fossils found in it are spiriferid brachiopods, bivalves, and corals. In addition, at least 16 species of foraminifers occur in it. The Redwall Limestone has yielded index fossils that constrain time of accumulation of most of

4284-405: The same phycobiont species, from the green algae, except that alternatively, the mycobiont may associate with a species of cyanobacteria (hence "photobiont" is the more accurate term). A photobiont may be associated with many different mycobionts or may live independently; accordingly, lichens are named and classified as fungal species. The association is termed a morphogenesis because the lichen has

4352-494: The shallow marine sediments comprising the Thunder Springs Member accumulated as the sea regressed back towards the west leaving northern as dry land. Terrestrial weathering, erosion, and lack of sediment accumulation formed an unconfortmity separating the Thunder Springs and Mooney Falls members. A second marine transgression submerged northern Arizona and permitted the accumulation of shallow marine sediments that comprise

4420-439: The two terms, with escarpment referring to the margin between two landforms , and scarp referring to a cliff or a steep slope. In this usage an escarpment is a ridge which has a gentle slope on one side and a steep scarp on the other side. More loosely, the term scarp also describes a zone between a coastal lowland and a continental plateau which shows a marked, abrupt change in elevation caused by coastal erosion at

4488-465: The underlying Horseshoe Mesa and Mooney Falls members and into the Thunder Springs Member. Overall, the strata of the Redwall Limestone commonly contain the fossils of shallow marine animals. The analysis of data collected by McKee and Gutschick found that the most abundant macrofossils are brachiopods and corals . they are followed in abundance by bryozoans , crinoids , bivalves , invertebrate burrows and trails, and cephalopods . Less common are

4556-842: The various structures that characterize plants (which evolved from freshwater green algae), such as the phyllids (leaf-like structures) and rhizoids of bryophytes ( non-vascular plants ), and the roots , leaves and other xylemic / phloemic organs found in tracheophytes ( vascular plants ). Most algae are autotrophic , although some are mixotrophic , deriving energy both from photosynthesis and uptake of organic carbon either by osmotrophy , myzotrophy or phagotrophy . Some unicellular species of green algae, many golden algae , euglenids , dinoflagellates , and other algae have become heterotrophs (also called colorless or apochlorotic algae), sometimes parasitic , relying entirely on external energy sources and have limited or no photosynthetic apparatus. Some other heterotrophic organisms, such as

4624-427: The western Grand Canyon. The contact of the overlying Mooney Falls Member with the underlying Thunder Springs Member is disconformable except in the extreme western end of Grand Canyon. Locally, this contact is a low-angle unconformity. This is indicative of a period of emergence, minor tectonic activity, and erosion between the deposition of the Thunder Springs and Mooney Falls members. The Mooney Falls Member forms

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