Holocene Reef Research Articles

Holocene reef systems of Eastern Martinique

Holocene reef systems of Eastern Martinique

Holocene sea-level change and coral-reef growth at Huon Peninsula, Papua New Guinea

Research Article| February 01, 1976 Holocene sea-level change and coral-reef growth at Huon Peninsula, Papua New Guinea JOHN CHAPPELL; JOHN CHAPPELL 1Department of Geography, Australian National University, P.O. Box 4, Canberra A.C.T. 2600, Australia Search for other works by this author on: GSW Google Scholar H. A. POLACH H. A. POLACH 2School of Earth Sciences and School of Pacific Studies, P.O. Box 4, Australian National University, Canberra A.C.T. 2600, Australia Search for other works by this author on: GSW Google Scholar Author and Article Information JOHN CHAPPELL 1Department of Geography, Australian National University, P.O. Box 4, Canberra A.C.T. 2600, Australia H. A. POLACH 2School of Earth Sciences and School of Pacific Studies, P.O. Box 4, Australian National University, Canberra A.C.T. 2600, Australia Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (1976) 87 (2): 235–240. https://doi.org/10.1130/0016-7606(1976)87<235:HSCACG>2.0.CO;2 Article history First Online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation JOHN CHAPPELL, H. A. POLACH; Holocene sea-level change and coral-reef growth at Huon Peninsula, Papua New Guinea. GSA Bulletin 1976;; 87 (2): 235–240. doi: https://doi.org/10.1130/0016-7606(1976)87<235:HSCACG>2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract At the tectonically rising terraced coast of Huon Peninsula, Papua New Guinea, a Holocene reef is emerging by as much as 12 m. A clean seacliff section 8 m high provides detailed evidence of the relationship between reef development and early Holocene sea-level changes, relative to the rising coast. The section shows a shallow-water reef-crest facies that grew steadily upward while relative sea level rose approximately 7 m. Reef growth terminated with emplacement of a fluvial gravel cap, which was followed by emergence. Twelve C14 dates and six Th230/U234 dates put the base of the cliff section at 8200 C14 yr B.P. and the crest at 6600 C14 yr B.P. Four Th230/U234 dates from near the base average 9,400 yr old, but C14 ages from the same samples average 7,600 yr old; the cause of the discrepancy is not known. Uplift of the section is known from previous studies of the Pleistocene reefs in the area to be approximately 1.9 m/1,000 yr. If uplift has been at a uniform rate, then the position of sea level at 6,000 C14 yr ago (around northeast Papua New Guinea) was about −4 m; 8,000 yr ago it was about −14 m. Mean upward growth rate of the reef was 4.7 m/1,000 yr, and the maximum rate was about 8 m/1,000 yr. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

Development of Western Canadian Devonian Reefs and Comparison with Holocene Analogues

The complex interplay of basin geometry and tectonic history, subsidence rate, weather conditions, and postdepositional history is the factor determining the ultimate morphology of a reef tract, individual reefs comprising the tract, and the lithologic variations within the reefs. Although the effects of these influences usually can be documented in studies of recent reefs, their determination in fossil settings is commonly obscure. This may preclude the use of recent reefs as explicit analogues of ancient ones. The applicability and limitations of such comparisons with reference to some Devonian reefs of western Canada and various Holocene structures indicate that the variety of reef tracts available for study allows the various causal influences to be isolated to a first order of approximation.

Carbonate Facies and Sedimentation of Patch Reefs off Bermuda

Transportation of skeletal sands from patch reefs on the Bermuda platform down channels in the reef face results in a wedge or apron of reef-flank material. These sediments physically and bathymetrically separate the reef mass from surrounding lagoonal environments. Distance of sediment transport off the reef top is small (on the order of tens of feet), and only minor amounts of reef debris are present at upper limits of the lagoon floor near the base of reefs. Normal wave action and mass wasting caused by storms are believed to be the major mechanisms of sediment transport. Sediment compositions observed in reef-top, reef-flank, and lagoonal environments provide the basis for recognition of their corresponding facies. Smaller sub-environments include sediment pockets, sand channels, reef-face channels, reef flanks, interreef lagoons, and open lagoons. Their microfacies are transitional and, in the order listed, display the following trends: from the reef top lagoonward, the abundance of Homotrema, coral, and red algae in the sediment decreases, and the abundance of Halimeda and Foraminifera (excluding Homotrema) increases. Interreef lagoons are distinguished from open lagoons by a lower mollusk content in the sediment. From the reef top lagoonward, mean grain size generally decreases and sorting progresses from poor to very poor. Sand-size particles dominate sediments of patch-reef facies. The absence of silt and clay is characteristic of the reef top. Except for concentrations of coral sticks in reef-face channels, gravel is distributed nearly evenly in patch-reef environments, in part, because of the high sediment content of Halimeda (25-60 percent), which commonly contributes whole, granule-size plates. Thus, distribution of bioclastic sediments from recent Bermudan patch reefs takes place on a small, local scale to form reef-flank sediments and results in recognizable sedimentary facies. These facies are accounted for by a working model based on substrate control, biofacies development, particle breakdown, and sediment transport by wave action.

Interaction of genetic processes in holocene reefs off North Eleuthera Island, Bahamas

The inner shelf platform off North Eleuthera consists of a series of terraces at 6 m, 8 m, 20 m, and 35 m depth, respectively. The boundary between 6 and 8 m terraces is marked by a near continuous reef ridge, landward and seaward of which isolated reef structures are found. Reefs are aggregates of pillar structures, which in turn are composed of columnar, club-shaped or mushroom-shaped pillars of corals. The dominant primary framebuilder above 3 m depth isAcropora palmata; below corals of the generaMontastrea andDiploria, Porites astreoides andP. porites also contribute to the frame, as does the hydrozoanMillepora. The secondary framebuilders start developing and changing the shape of the frame as soon as they find suitable substrates; most important are coralline red algae, which encrust internal and external surfaces, but also may fuse the components of the frame; other organisms just add to the frame. In contrast boring and rasping organisms destroy the frame. Constructing or destructing organisms were found living on every surface, external or internal, accreting or diminishing.

Ecology, sedimentology, and diagenesis of recent and fossil reefs

At the VIII. International Sedimentological Congress held in Heidelberg in 1971, a symposium with the above title was convened; a selection of the papers presented is assembled in this issue. In the introduction the approaches of the following studies are reviewed to show some trends and problems in reef research.

Reef facies, dolomitization and stratified mineralization

The particularly well developed reef-type cyclical sedimentation seen in the Givetian stage of the Dinant synclinorium (Belgium), is discussed in detail with respect to the various facies, their faunal and physicochemical characteristics and their sequence. More recent (Upper Aptian) reef phenomena in the Province of Santander in northern Spain are similar to the Givetian complex (except for their more marked dolomitization) in that they have the same sequence of identical facies and, generally speaking, the same cyclical sedimentation. A comparative study underscores the similarity of environment between the two stages. This environment, during the Upper Aptian, facilitated the deposition of lead-zinc ores at Reocin, which are limited to certain dolomitized reef levels. A close relationship thus emerges between reefs, the process of dolomitization and stratiform ore deposits.

Submerged Reefs of Eastern Caribbean

Submerged early Holocene or late Pleistocene reefs up to 90 km long and with bottom relief commonly about 20 m were established in relation to preexisting lower sea levels on outer edges of terraces at 30-80-m depths off most islands in the eastern Caribbean Sea. Submerged reefs are far more impressive physiographic features than their modern counterparts and are in depths greater (below about 15-20 m) than those commonly associated with present reef-framework construction by hermatypic corals. Data from echo-sounder profiles, rock dredging, bottom photographs, and in situ observations indicate that off the Virgin Islands, St. Martin, St. Barthelemy, Montserrat, Guadeloupe, Martinique, St. Lucia, and the Grenadine Islands submerged reefs are dead and covered by only a few scattered living corals. Hermatypic corals below 15 m on these reefs cannot cope with skeletal destruction by boring organisms and cannot compete for substrate with other encrusting or attached organisms. Off the west coast of Barbados, however, reef-framework construction is still occurring below about 15 m. The age relations of these reefs are not known, but probably they are no older than late Pleistocene and started to grow no later than 8,000 years ago. Although the eastern Caribbean area is characterized by inner-shelf fringe reefs, the common occurrence of shelf-edge submerged reefs indicates that, during the latter stages of the Holocene transgression, reefs were generally adjacent to deep waters, as are modern Pacific barrier and atoll reefs.

Submerged Reefs of Eastern Caribbean: ABSTRACT

Submerged early Holocene or late Pleistocene reefs up to 90 km long and with bottom relief commonly about 20 m were established in relation to preexisting lower sea levels on outer edges of terraces at depths ranging from 30 to 80 m off most islands in the eastern Caribbean. They are far more impressive physiographic features than their modern counterparts. These reefs are distinguished from modern reefs in that they are present at depths greater (below about 15 to 20 m) than are commonly associated with present reef-framework construction by hermatypic corals. Data from echo-sounder profiles, rock dredging, bottom photographs, and first-hand observations indicate that off the Virgin Islands, St. Martin, St. Barthelemy, Montserrat, Guadeloupe, Martinique, St. Lucia, and t e Grenadine Islands, submerged reefs are dead and covered by only a few scattered living corals. On these reefs, reef corals below 15 m cannot cope with skeletal destruction by boring organisms and cannot compete for substrate with other encrusting or attached organisms. Off the west coast of Barbados, however, reef-framework construction is still occurring below about 15 m. Although the age relations of these reefs are not known, they are probably no older than late Pleistocene, and have a minimum age for initial development of about 8,000 years B.P. The eastern Caribbean is characterized by living inner-shelf fringe reefs; however, the common occurrence of shelf-edge submerged reefs indicates that during the latter stages of the Holocene transgression, reefs in this area were generally adjacent to deep waters similar to the modern Pacific barrier and atoll reefs. End_of_Article - Last_Page 350------------

Calcified Algal Filaments in Reefs: Criterion of Early Diagenesis: ABSTRACT

Calcified algal filaments are a prominent and probably diagnostic feature of the extensive syngenetic submarine cementation in recent Bermudan reefs. The filaments occur within millimeter- to decimeter-size cavities of the reef frame to depths of at least 12 m; they range from 20 to 300µ in diameter and are up to 5 mm long. The filaments are worm-like threads with lateral branching and commonly form an irregular meshwork which lines or fills the cavities; the meshwork commonly incorporates fine sediment that is in turn cemented. SEM photographs show that the original filaments are enveloped by crusts, 5-150µ thick, of bladed to fibrous, outward-growing crystals that bear rhombs at their terminations. The internal casts of the filaments are inward-growing equant and bladed crystals. X-ray diffraction analyses indicate that the crystals are magnesium calcite with 16 mol % MgCO3. The filaments remaining after decalcification are Ostreobium sp., a widely distributed boring green algae characterized by variations in diameter of the filaments from 1-20µ, by a lack of transverse partitions, and by local swellings of the filaments. Individual filaments show both the boring habit and incrustation with magnesium calcite. Whether the outward-growing crust around the filaments is the result of vital activities of the alga, photosynthesis, or boring, and whether the filaments provide an active organic matrix or a passive substratum to localize calcification have not been determined yet. However, it is clear that this type of cementation is submarine and early diagenetic; hence, similar calcified filaments in ancient reefs provide a criterion for and measure of early diagenesis. End_of_Article - Last_Page 364------------

Tectonic Control of Devonian Reef Sedimentation, Alberta: ABSTRACT

Kaybob is one of a group of geologic reefs which underlie west-central Alberta and which comprise the Upper Devonian Swan Hills Formation of the Beaverhill Lake Group. Kaybob is a flat north-south elongate lens, 250 ft thick, 11 mi long, and 3 mi wide, built on the Slave Point Formation, a widespread platform carbonate. Detailed core study of sedimentary structure, texture, and constituents reveals that the carbonate sediments composing the can be grouped into 3 environmentally controlled facies groups: reef-slope, reef-margin, and shelf-lagoon facies. The reef-slope facies is a stromatoporoid-crinoid-brachiopod grainstone. The marginal deposits consist of a groundmass of massive stromatoporoid grainstone containing varied concentrations of different stromatoporoid growth forms (ranging from slender branching to large massive heads). The interior facies includes several rock types arranged in repeated vertical sequences. A basal unit of massive wackestone is overlain by combinations of massive, thin-bedded, and laminated mudstones, mudclast grainstones, and amphiporid carbonate conglomerate. Submarine and subaerial scoured surfaces are present within the upper units. The outer slope sediments intertongue with contemporaneous open-marine deposits seaward and with the reef-marginal facies on the inner side of the reef. This pattern changes laterally in vertical section, as the thickness of the changes from place to place. The upper half of the shows a marked westward displacement. Position of the various facies within the geologic mass, and comparison with Holocene carbonate sediments from several Caribbean localities, together provide a paleoenvironmental interpretation. The interior facies includes most of the sediment types which have been described from recent shallow shelf-lagoon environments. Sequential arrangements are the same and result from similar processes. The marginal realm includes many facies comparable with those observed in Holocene reef tracts, ranging from scattered coral growth on a sand bottom to coral constructed buttresses of ecologic reefs. Circumferential variations in geologic development, the westward displacement of the upper part, and a thick pile of open-marine deposits on the southwest are attributed to prevailing nor h winds during the Devonian. Tectonic control is exhibited at 4 levels. 1. The interior shelf-lagoon sequences are initiated by small-scale pulses of subsidence, perhaps complicated by eustatic sea-level changes. 2. Larger scale subsidence variations account for the thickening and thinning of the geologic body as a whole. 3. An orthogonal pattern of sharp elongate folds trending NE-SW and NW-SE is expressed clearly at the base of the reef. The folds are confined to the area of reefing, where they controlled initiation by forming mud mounds during upper Slave Point deposition. The pattern may reflect Slave Point block faulting. 4. This and others in the region, together with their associated carbonate-shelf deposits, fit into a well-expressed orthogonal tectonic pattern controlled by larger scale ba ement features. The basement features include a family of NE-SW-trending, relatively stable arches revolving about a NW-SE-trending major arch, the West Alberta ridge. They form part of the system of stable arches that provides the tectonic framework of the continent. End_of_Article - Last_Page 854------------

Geophysical Studies of Northern Florida Platform, Gulf of Mexico: ABSTRACT

The western edge of the North Florida platform has been delineated in some detail by seismic-reflection investigations. The platform boundary is not apparent from topographic surveys because of the thick sediment cover. The platform edge appears to coincide with the trend of a probable offshore extension of the Lower Cretaceous (Washita-Fredericksburg) reef trend. The presence of a more recent reef, normal to the lower Cretaceous reef, is indicated from interpretation of additional reflection records. This feature trends almost east-west and crosses the buried edge of the North Florida platform. It can be traced for approximately 30 mi and can be aligned with an old buried shoreline on the east. The top of the Upper Cretaceous has been traced over most of the continental slope south of the Florida Panhandle by seismic-reflection profiling. Studies on the outer slope indicate that this horizon rises near the center of the platform, along long. 86°30^prime, to less than 5,000 ft below sea level. On the west, near the edge of the platform at long. 87°30^prime, the top of the Upper Cretaceous is at 7,000 ft whereas on the east where the Florida escarpment intersects 85°30^prime long., the indicated depth is more than 5,700 ft below sea level. The reflection surveys show that erosion has played a very important role in the formation of the western part of the platform. It is evident that erosional processes have been active at least since the Late Cretaceous. This can be interpreted to indicate that the circulation in the Gulf of Mexico, and the loop current in particular, has been essentially the same during the entire Cenozoic Era. End_of_Article - Last_Page 2031------------

Submarine Lithification of Jamaican Reefs: ABSTRACT

Widespread lithification of recent reef framework is occurring just below the reef-water interface in all zones of the reef to depths of at least 70 m on the north coast of Jamaica. Several different framework-binding End_Page 727------------------------------ processes appear to be involved: (1) crusts of organic origin, commonly concentrically layered deposits of red algae, Foraminifera, and Bryozoa, and (2) thick, laminated, lithified, micrite crusts with a smooth to nodular surface, preferentially accreted upward and not clearly associated with any calcareous taxa. The organic crusts commonly occur just under the reef surface, whereas the hard concretionary crusts are common deeper within the reef, lining the numerous channels and cavities that permeate the framework. Many of the reef pores (both the primary inter- and intra-framework pores and also cavities produced secondarily by boring organisms such as Cliona) are filled with lithified sand, micrite, or acicular crystalline cement. Just beneath the reef surface is extensive lithification of poorly sorted micritic sediments between and within the framework. Sand trapped in interframework cavities is consolidated by drusy cements. In many places, the lithified material is bored by Cliona and the resulting cavities are refilled and relithified, indicating that these processes occur at a rapid rate. Similar features are recognized in Pleistocene reefs on the north coast of Jamaica. This observation suggests that the lithification processes are common in time as well as in space. End_of_Article - Last_Page 728------------

Geochemistry and mineralogy of the Recent reef and lagoonal sediments south of Belize (British Honduras)

A total of 46 bottom grab samples was collected along eight east-west profiles extending from an actively growing reef to shore in an area south of Belize, British Honduras. The Recent calcareous and terrigenous sediments were analyzed for their constituent minerals: quartz, “clay” aragonite, high-Mg calcite, and calcite by X-ray diffractometry. Atomic absorption spectrometric analyses were performed for Ca, Mg, Sr, Fe, Mn, Zn, Na, K, Li, and Rb contents of the 1 N HCl soluble portions of the samples. The sedimentary environments - reef, back-reef, lagoon, and nearshore - may be clearly delineated by almost any of the parameters measured. The relative distribution of the minerals is apparently biologically controlled. Acid-leachable Sr, Mg, and Na concentrations progressively increase toward the reef, their amounts being primarily related to similar increases in aragonite and high-Mg calcite. Contents of acid-leachable Fe, Mn, Zn, and K culminate in the lagoon. The Fe, Mn, and K distributions are a function of the “clay” content of the sediments, with carbonate content exerting a secondary effect. The Zn distribution is almost totally due to the “clay” content. The acid-soluble Li and Rb contents are so small that no systematic trend in their distribution can be discerned.

Terrigenous sedimentation in a shallow water coral reef environment

ABSTRACT Van Veen grab samples were examined to study the environment and history of deposition associated with the coral reefs at Anton Lizardo, Mexico. These are Recent reefs growing on a shallow marine shelf which was emergent until 9,000 to 10,000 years ago. There are eight larger reef structures which rise from depths of less than 25 fathoms. The reefs are elongate and parallel to the shoreline. Although there is some carbonate material in the inter-reef sediments, most of the sediment cover is terrigeneous sand and gravel. Most of these sediments appear to be pre-Wisconsin in age. They were probably deposited while the area was exposed to subaerial processes. The post-Wisconsin coral reefs contribute only a small part of the sedimentary cover, and present deposition from the Rio Jamapa appears to be minor.

Recent Reefs

Recent Reefs