Carbonate Sedimentology

Carbonate eolianites areabundant in the lower Chesterian Upper Mississippian succession in the Appalachian and Illinois
Basins The eolianites arequartz peloid grainstones composed of well rounded very fine to fine sand size peloids wholeooids broken
ooids that have been re rounded skeletal fragments and generally finer grained subangular frosted quartz Eolian deposits are I to 8
m thick and tens of meters to many kilometers wide They have wedge sets of planar and tangential sharply defined inverse graded
laminae with dips of up to 20 degrees
A high resolution sequence stratigraphic framework was generated using the available biostratigraphy and closely spaced strati
graphic sections and core and tracing regional disconformities marked by breccia calcrete and soil horizons between the sections
EolianiIe units backstep within the transgressive part of the Chesterian supersequence and are absent from the highstand part which is
dominated by siliciclasticsand likely formed in a more humid setting Withinthird order and fourth order sequences the eolianites occur
updip in disconformity bounded parasequences In the transgressive and early highstand systems tracts of sequences eolianiIes overlie
exposure surfaces and are preserved in the transgressive parts of the parasequences In the late highstand parts of sequences eolianites
are preserved in the regressive parts of parasequences and are capped by sequence bounding disconformities marked by breccia and
calcrete
The abundance of carbonaIe eolianiIes in the Upper Mississippian is likely due to seasonal semiarid climate and moderate amplitude
fourth order eustatic sea level changes The reservoir potential of the eolianites is limited by tight packing and calcite cementation
However recognition of the eolianites is critical to understanding the vertical and lateral distribution of reservoir facies within the
sequence stratigraphic framework because they indicate subaerial conditions and commonly mark subtle sequence boundaries

This study focusses on aspects related to carbonate build-ups in an upper Paleozoic succession in the south central Norwegian Barents Sea. Seismic and well data are used to map and characterize the protozoan and heterozoan carbonate build-ups in order to assess the factors that control their distribution within the Gipsdalen- and Bjarmeland Groups. The main objectives are (1) to describe, compare, and contrast geomorphological characteristics of the carbonate succession on the Bjarmeland and Finnmark Platforms, (2) to determine the controlling factors on the distribution of the carbonate build-up development, and lastly (3) examine the impact of evaporites on the distribution and development of the carbonate build-ups.

The upper section of the Gipsdalen Group consists of protozoan carbonates and evaporites with occasional carbonate build-ups that were deposited in an arid-warm marine environment in a global icehouse period. The Bjarmeland Group consists of heterozoan carbonates with build-ups deposited in post-glacial environment. Previous studies have suggested that faults play a role in the distribution of carbonate build-ups in the Norwegian Barents Sea.

The two areas on the Finnmark Platform (north and south) have been used in order to compare against two areas on Bjarmeland Platform (east and west). The carbonate build-up sequence observed on the eastern Bjarmeland Platform is comparable with the build-up sequence on the northern Finnmark Platform. The two areas share similarities as both are located on footwall uplifts. The geomorphology of these carbonate units are characterized as large build-up complexes. In contrast, the geomorphology of the western Bjarmeland Platform and the southern Finnmark Platform differs significantly. These units consist of polygonal build-up morphologies of reticulated arrangement with cellular structures of various scales; this depositional pattern is similar in architecture to modern patch and pinnacle reef systems observed in Holocene carbonate systems (e.g. Abrolhos Islands in Western Australia). The similarities defining these elements are that carbonate build-ups stack vertically above the layered evaporite sequence of the Gipsdalen Group. The layered evaporite sequences are observed on both platforms where salt pillows are a main characteristic. The carbonate build-ups deposit vertically above thin units of evaporites, opposed to laterally absent where the salt pillows are present, suggesting that salt has been displaced by the weight of the growing build-up. The result supports antecedent topography as a dominant component affecting the carbonate build-up succession in the eastern Bjarmeland Platform and the northern Finnmark Platform. Furthermore, the build-up development in the two areas on western Bjarmeland Platform, and southern Finnmark Platform, has been controlled by physical conditions influenced by a combination of biotic self-organization, fossil reef growth and karst-induced structures caused by dissolution of the underlying carbonate strata. The current geomorphology of the carbonate build-up succession has been enhanced due to remobilization of the mobile evaporite unit as a result of differential loading by the carbonate build-ups.

The Upper Mississippian Chesterian Ste Genevieve and Paoli Formations of the Illinois basin are composed of five carbonate and
mixed carbonate siliciclastic fourth order 100500 k y sequences Interpretive cross sections based on detailed measured sections of 57 closely
spaced outcrops and cores show that sequence bounding carbonate and siliciclastic paleosol horizonsand distinctive marker beds canbe correlated
basin wide within the available biostratigraphic framework Each sequence is composed of as many as nine regionally developed parasequences
Carbonate parasequences have patchy updip carbonate eolianites at the base overlain by laterally discontinuous ooid tidal ridge and skeletal bank
facies and laterally extensive muddy carbonate caps Mixed carbonate siliciclastic parasequences are composed of skeletal limestone capped by fos
siliferous shale Carbonate tidal flat facies are rare in the succession
The sequences were produced by moderate amplitude fourth order 100500 k y glacio eustatic sea level changes whereas the parasequences
were likely produced by fifth order 10100 k y glacio eustatic sea level changes during atime of transition from the greenhouse conditions of the
Early Mississippian to the icehouse conditions of the late Paleozoic This transition is reflected in upward change from carbonate dominated dis
conformity bounded sequences with little lowstand erosion at thebase to mixed carbonate clastic sequences with significant lowstand erosion at the
top of the study interval and in overlying sequences These changes were likely caused by an increase in the magnitude of sea level fluctuations cou
pled with increasingly humid wet dry seasonal climate The sequences may be stacked into one ortwo third order 0 5 5 m y composite sequences
that are bounded by relatively well developed unconformities However the magnitude of lhe fourth order signal makes third order bundling less
clear than in strata deposited during greenhouse times of lower amplitude fourth and fifth order sea level fluctuations The dominance of fourth
order disconformity bounded sequences and the lack of regional tidal flat facies reflect moderate amplitude eustasy associated with the transition
from global greenhouse climates of the Early Mississippian to times of abundant global ice in thelate Paleozoic

Reservoir characterization and structural mapping using integration of well logs and 3-D seismic data was carried out to determine the prolificacy of OVU field, onshore Niger delta. The distribution of reservoir physical parameters (porosity, permeability etc.) and availability of traps that favour hydrocarbon accumulation in the field were evaluated. Four hydrocarbon bearing reservoirs were delineated out of several identified sands in the field out of which three horizons were mapped. Two major growth faults, an antithetic fault and five synthetic faults were delineated. Structural closures were identified as rollover anticlines with the trapping mechanism delineated as a Fault assisted anticlinal structure. The computed range of values for gross thickness, volume of shale, net to gross, water saturation, hydrocarbon saturation, total porosity and absolute permeability with respect to each reservoir are: 18-125m, 9-17%, 83-92%, 18-28%, 62-82%, 21-23%, and 736-3965mD respectively. Hydrocarbon reserves calculations reveals a total reserve of 30.9 billion stock tank barrels of oil. With the very good to excellent calculated values of petrophysical parameters and high hydrocarbon reserve together with the suitable trapping mechanisms makes the study field prolific. Few wells exist in the southwestern corner of the field where a closure is identified in this study. The area should therefore be subjected to further evaluation with a view to increasing the number of wells there.

Strontium isotope data indicate that sediments of the Norwest Bend Formation were deposited within a large estuarine system during the Latest Miocene to Early Pliocene (probably N 5 Ma). The Norwest Bend Formation is divisible into two members; a lower sand-dominated member and an upper oyster coquina member. These two units are separated by an irregular, erosion surface that has no correlative within the adjacent Loxton-Parilla Sands. Tectonism in the western Murray Basin adjacent to the Adelaide Foldbelt has exerted a considerable control over the formation of these estuarine sediments. The Lower Norwest Bend Formation occupies a paleodrainage system that was restricted to a region west of the Hamley Fault and was presumably incised following uplift of this western block. Flooding of this paleodrainage system produced the Lower Norwest Bend estuarine system. Later tectonism on the Hamley Fault resulted in the formation of the erosion surface within the Norwest Bend Formation. We suggest that the Norwest Bend estuarine system owes its existence to marginal tectonism associated with the young uplift of the Mt. Lofty-Flinders Ranges. The paleodrainage system incised prior to deposition of the Norwest Bend Formation differs markedly in geometry from the present Murray River-gorge system. This suggests that the modern Murray River system developed after deposition of the Late Miocene-Pliocene Norwest Bend Formation.

Shallow marine mixed siliciclastic-carbonate shoals, a carbonate platform, and the subsequent development of a reefal buildup occur in sequence from the late Chattian to the Aquitanian in the Niah area of Sarawak. They document the transition from larger foraminifera-dominated, calcitic environments to scleractinian coral-dominated, aragonitic environments in SE Asia, which correspond to a significant increase in biodiversity. A late Chattian to early Aquitanian phase of carbonate sedimentation was initiated by larger foraminifera on shallow marine argillaceous shoals raising from the seabed at about 60 m in water depth occasionally up to near sea level. Carbonate production is almost entirely the result of the accumulation of larger foraminiferal shells dominated by Eulepidina dilatata, a species that could thrive thanks to its photosymbiosis with microalgae. Such mixed carbonate-clastic shoals formed repeatedly on a muddy shelf during a period stretching from about 23.5 Ma to 22.3 Ma. Following a period of siliciclastic deposition, a roughly circular carbonate platform with an area of some 25 km 2 was formed at around 21.2 Ma in stratigraphic continuity with the underlying shallow marine sandstones of the Nyalau Formation. Known as the Subis Limestone, it consists at first of bedded carbonates characterized by the presence of red algae, a high diversity of free benthic and sessile endosymbiotic sessile foraminifera, and a variety of organisms typical for reefal environments, including colonial corals. A reefal buildup started forming on the carbonate platform as early as 21.1 Ma. This phase of growth was likely initiated by low-relief patch reefs, 150 to 200 m in diameter and 60 to 80 m in height, such as those exposed in a southern quarry. Analogous with same-age reefal development models from the Java Sea, it is proposed that the patch reefs coalesced through time to form a larger isolated carbonate buildup that grew up at least until the end of the Aquitanian at 20.4 Ma. This Subis buildup reached an area of 16 km 2 ; it has a preserved thickness of 260 to 280 m and had a paleo-relief of about 100 m above the surrounding sea floor. It is asymmetrical, with a reef wall forming high, west-facing cliffs and another reef wall likely extending on the NE edge of the buildup, beyond the Niah Great Cave. A further increase in faunal and floral diversity occurred during this phase, concomitant with the diversification of ecological niches within the buildup. Reefal and peri-reefal environments are dominated by red algae; solitary and colonial corals (domal, branching, and platy), with subordinate foraminifera (large and small benthic); and associations of foraminifera and algae forming laminar foralgal binding tissues, sponges, hydrozoans, bryozoan, bivalves, echinoderms, and serpulids. The reef rim consists of coral framestone and algal-foraminiferal bindstone. The backreef facies is characterized by rudstones and floatstone with coral debris, and the lagoon facies includes microbial crusts, green algae, articulated and nonarticulated red algae, benthic foraminifera (Miliolids), ostracods, gastropods, and up to 4-m-high platy corals pillars. Forereef deposits include grain-and mud-supported reef debris; a debris apron present some 2.5 km away from the western edge of the buildup consists of debris flows and calciturbidites embedded in outer neritic shales. The upper part of the buildup is missing as a result of recent subaerial erosion. Three successive steps in the development of carbonate ecosystems are identified, which are linked to a series of innovative symbiotic relationships established during the late Chattian and the Aquitanian. During an early phase (23.5-22.3 Ma), monospecific populations of endosymbiotic larger benthic foraminifera thrived on shallow marine muddy shoals. At around 21.2 to 21.1 Ma, new species of endosymbiotic larger benthic foraminifera, sessile-encrusting foraminifera, and coralline algae colonized shallow marine grounds and created a carbonate platform. From about 21.1 to at least 20.4 Ma endosymbiotic scleractinian corals, red algae, and a diverse association of organisms created patch reefs and a buildup.

Origin of Permeability in Carbonate Rocks
Carbonate reservoirs, which are typically dual or triple porosity systems, produce a major portion of the world’s oil and gas and hold more than half of the world’s largest crude oil and natural gas reserves. The best known Jurassic carbonate reservoirs are the Arab-D and Arab-C systems, Hanifa and Hadriya. These reservoirs account for large quantities of crude oil production in Saudi Arabia. The Permo-Triassic Khuff formation holds the world’s largest known natural gas reserves in five Arabian Gulf countries. Some of the world’s best quality crude oil is located in two Cretaceous carbonate reservoirs: the Shuaiba and Tharmama reservoirs. Many of these carbonate reservoirs are naturally fractured and/or have an extensive and extremely complex secondary porosity system. Accurately predicting amounts and types of porosity, locally for field development and regionally for stratigraphic traps, is a major challenge. Three methods are used to estimate fracture porosity: well-test analysis, well logging, and core analysis.

A natural fracture is a planar discontinuity in reservoir rock due to deformation or physical diagenesis. Diagenesis—chemical and physical changes after deposition—strongly modifies the reservoir properties possessed at the time of deposition. The dominant diagenetic process consists of early cementation, selective dissolution of aragonite and reprecipitation as calcite, burial cementation, dolomitization, and compaction-driven microfracturing [2]. Cementation and compaction forces completely eradicate any porosity available at the time of deposition. However, chemical changes, usually dissolution, especially in carbonate rocks, modify the initial porosity and recover it partially. Depositional facies, their architecture, systems, and tracts are predominant driving factors in the distribution and quality of current reservoir properties, which are completely different from the properties at the time of deposition.

High-permeability vugs, molds, natural fractures, and caverns in carbonate rocks are the result of intense dissolution, which took place before burial as a result of nonreservoir or seal units. Dissolution is also caused by meteoric diagenesis, which is related to subaerial exposure of carbonate rocks and is explained by the general aggressiveness of meteoric water toward sedimentary carbonate minerals. Aragonite is metastable, which dissolves and precipitates into cement, whereas calcite is stable and less affected by dissolution. Such a type of dissolution causes significant variation in the distribution of porosity and permeability in the reservoirs, thereby defining reservoir quality.

Shallow-marine carbonates and siliciclastics of the Corallian Formation (Oxfordian-Early Kimmeridgian) accumulated on and around an intrabasinal high in the extensional Wessex Basin. Four sequences can be recognized. Sequences 1-3 accumulated under conditions of thermal subsidence on a ramp-type margin. The initial sequence was siliciclastic. Highstand sedimentation in this sequence reflects the supply of sandy mud from a recently emergent intrabasinal high. During transgression and regression this muddy sediment was reworked into cleaner sandstone bodies by landward or basinward migrating zones of shoreface erosion. Carbonates dominate the second and third sequences when rising sea level increased the area of carbonate production and reduced siliciclastic input. Oolite bodies developed as both transgressive barrier bars and highstand sheets. The forth sequence formed during the activation of major normal faults. This caused the breakdown of the ramp system, and patterns of sediment accumulation were strongly controlled by tectonic subsidence patterns.

The Vaca Muerta Formation in the Cerro Domuyo area shows an interesting intercalation of facies with opposite paleocurrents. The unit is represented by outer ramp to basinal facies with a westward direction of progradation. However, in its middle section, slope deposits correlatable with the Huncal Member, intercalate with slumped strata verging northeast. This interval is composed of carbonate facies and it is probably associated with the development of a slope related to a carbonate platform or a distally steepened carbonate ramp. Based on the ammonoid fauna, the age of the Vaca Muerta Formation ranges from the early Tithonian to the late Berriasian, but it could also reach the early Valanginian. The Huncal Member yields representatives of the Substeueroceras koeneni Biozone (Upper Tithonian), hence its age is older than that proposed in its type locality allowing its correlation with units exposed in the Chilean territory.

May, A. (1995b): Verwitterungsbeständigkeit und Verwitterung von Kalkstein-Naturbausteinen. - Münstersche Forschungen zur Geologie und Paläontologie, 77: 229-243, 6 figs., 2 tabs.; Münster.

Abstract: Weathering durability and weathering process of natural building stones from the Lower Muschelkalk, the Upper Muschelkalk, and the Devonian have been investigated. Various properties of each building stone and its limestone material are measured (microscopy, SEM, porosity, ultrasonic velocity, geochemical methods). Defined microfacies types show clear differences in their weathering durability. The quantities of the cold water absorption, the Schurecht ratio (= ratio cold/boiling water absorption), and the residue insoluble by hydrocloric acid strongly affect the weathering durability. Together with the investigation of thin-sections, these properties enable prognoses about the weathering durability. The limestones are mainly damaged by fissures which harm the unity of the stone. Probably these fissures are mainly based on frost phenomena. Connections between the sedimentary environment and the weathering durability are recognizable: generally limestones of the agitated (shallow) marine are more durable than other limestones.

Kurzfassung: Es wird die Verwitterungsbeständigkeit und Verwitterung von Naturbausteinen aus dem Unteren und Oberen Muschelkalk sowie dem Devon untersucht. Definierte Mikrofaziestypen zeigen deutliche Unterschiede in der Verwitterungsbeständigkeit. Die Größe der freiwilligen Wasseraufnahme, der Schurecht-Ratio und des Gehalts an salzsäureunlöslichem Rückstand beeinflussen die Verwitterungsbeständigkeit dieser Kalksteine stark. Der hauptsächliche Schaden an den Kalksteinen sind Risse, die wahrscheinlich durch Frostverwitterung entstehen. Es lassen sich Zusammenhänge zwischen dem sedimentären Environment und der Verwitterungsbeständigkeit erkennen.

This paper covers the famous Cambrian section at Camp Creek, Montana. The paper describes the section, the depositional environments, the processes that produced the grand cycles and their boundaries, and the Cambrian mass extinction or biomere boundaries.

This paper examines the geology of the Lagrasse area, southern France. The stratigraphy in the area ranges in age from 72ma-52ma with recent Quaternary superficial deposits noted. All the strata in the region are calcite bearing, this along with tectonic influences in the area forms the rugged valley filled landscape around Lagrasse. The area is located in the Pyrenean foothills and has noticeable deformation throughout many units especially the Ribaute Limestone, likely deformed during the Eocene. The tectonic processes before the Eocene that led to the formation of the Pyrenees are also responsible for the depositional environments of the strata. The depositional settings are controlled by related processes such as foreland basin formation. The rugged landscape created makes the region prone to flooding with narrow valleys that have to share waterways and roads making natural disasters ever present in the area such as disastrous floods in 1999 and 2014.

Two giant fields composing of the Oligo-Miocene carbonates and reefs have been discovered recently in the East Java Basin. They are the Bukit Tua-Jenggolo (Gulf/ConocoPhillips Ketapang,
2001) and the Banyu Urip (ExxonMobil Cepu, 2001). These two fields represent the Kujung-
Prupuh carbonate sedimentation on the land-attached platform and the offshore isolated platform, respectively. Geologic factors leading to the formation of giant field is presented and general lessons are outlined. It is obvious that geology and petroleum system’s elements should be crossrelated
for giant field to form. We should be encouraged and comforted in the knowledge that giant fields do exist in the East Java Basin and there are more remain to be found.

Keywords:

Canning Basin;
Devonian;
Famennian;
Frasnian;
palaeokarst;
reefs

The Frasnian–Famennian boundary in the Canning Basin has long been associated with a shelf-wide, short-lived fall in relative sea-level. A near-planar palaeokarst surface, separating Frasnian proximal forereef and Famennian backreef facies, locally marks the boundary in the northwestern Lennard Shelf (Chedda Cliffs area, northern Napier Range). Surface and subsurface relationships between the Frasnian and Famennian strata suggest that a major episode of normal faulting and associated tilting in the latest Frasnian uplifted the platform margin to subaerially expose and erode all of the margin and uppermost forereef facies. Tectonic control on the development of this Frasnian–Famennian palaeokarst surface questions the interpretation of a simple, shelf-wide eustatically driven relative sea-level fall. Instead, a tectonic event affecting the northwestern Lennard Shelf, coupled with widespread recognition of a reduction in carbonate production at or very near the Frasnian–Famennian boundary elsewhere on the shelf, supports earlier interpretations of a major phase of basin-margin uplift related to extension along basin-bounding faults.

Echinoderms represent a major ecological component and contribute considerably to Oligocene–Miocene carbonate sediments, both as macrofossils and as skeletal grains. The skeletal morphology of all five extant echinoderm classes (echinoids, asteroids, ophiuroids, crinoids, holothuroids) is reviewed. Disarticulated skeletal elements are much morecommonin sediments than articulated specimens for all echinoderm classes except for echinoids; studies relying on complete specimens alone may be severely biased. The reproduction and growth of echinoderms, the composition of the skeleton, and the crystallography and diagenesis of echinoderm ossicles are reviewed. The echinoderm skeleton consists of high-Mg calcite with 3–18.5 wt% Mg. The skeleton exhibits strong interlacing of microcrystalline calcite with organic material and nonrandom orientation of crystals, achieving considerable hardness and durability. Echinoderm biostratinomy and the identification of disarticulated material are considered. The echinoderm origin of sediment particles can usually be recognised by their characteristic microstructure. Due to the high degree of specialisation, disarticulated remains can often be identified to family or genus level, leading to a more accurate picture of spatial and temporal echinoderm distributions.
  Echinoderm geochemistry is reviewed with respect to the Mg-content of the skeleton as a palaeotemperature proxy, and the Mg/Ca ratio as a monitor of ancient seawater composition; Sr/Ca ratios and carbon and oxygen stable-isotopes are considered. The echinoderm skeleton is altered during diagenesis and is transformed to low-Mg calcite. The microstructure of the skeleton is largely unaffected by this process, but changes in the isotopic signature and minor/trace-element contents may occur. These factors, together with physiological effects of isotope intake, hamper geochemical applications. However, echinoderms have been used successfully in studies of Phanerozoic seawater chemistry: theMgand Sr contents of echinoderm skeletons apparently strongly correlate with temperature. Asteroids and ophiuroids are probably best suited for palaeotemperature reconstructions because of the lack of known fractionation within the skeleton and because genetic effects are less pronounced than in echinoids. Controlled laboratory experiments are needed to establish calibrations. 
Echinoderm remains may account for 5–30% of the particles within specific Oligocene and Miocene carbonate facies. They seem to be more abundant in temperate shelf carbonates than in tropical settings. Diagenetic changes associated with echinoderm ossicles strongly affect the embedding sediment and promote lithification. Bioerosion by grazing echinoids is important for carbonate budgets in coral reefs and influences the modal size-distribution of sediments by the production of carbonate mud. Burrowing echinoderms may cause intensive bioturbation and reworking of sediments. Echinoderms provide valuable evidence for palaeoenvironmental reconstructions. Ecological information can both be gained by actualistic comparisons with modern echinoderms and by a functional morphological approach, allowing the detailed assessment of general life habits, substrate conditions, nutrient availability and hydrodynamic regimes
"

The Saint-Triphon Formation is a new formally established Early Middle Triassic lithological unit of the Prealps and the Western Alps. The type locality occurs in the vicinity of the village of Saint-Triphon in the Rhône Valley of Western Switzerland. Subdivided in 3 Members and 19 levels, this Forma t ion, 2 20 m thick in the type a r e a, consists of 5 ma in shalowing upward carbonate séquences. Appearing as the base of the internai part of the Prealpes Médianes Nappe ("Prealpes médianes rigides"), the Saint-Triphon Formation is also present ail along the Briançonnais domain of the Western Alps, from the Barrhorn area (N of the Matterhorn) to the Ligurian Alps in the S.
The palinspastical reconstruction of the Middle Triassic marine area shows that the shallow marine carbonate sédimentation occurs in an intracratonical subsident half-graben of estima-ted 500 km length and 100 to 150 km width. Its orientation was to the NE and E in relation to the actual alpine trend. During the time of the Saint-Triphon Formation déposition, the more subsident area was emplaced in the original position of the Prealpes médianes and the calculated rate of sédimen¬tation is 100 Bubnoffs. This rate decreases from a 2/3 ratio in the direction of the Ligurian Alps with an average there of about 30 Bubnoffs.
The original aragonitic sédiment with high Sx content is now màde of dolomite and low Mg calcite. Accessory minerais con-sist of detrital and authigenic quartz, chalcedony (quartzine), clays with illite, chlorite and smectite, authigenic silicate with K feldspath, albite and tourmaline, fluorite and sulfate (celestite). More than 40 samples are analysed in respect to the clay and silicate contents. The interprétation of the illite cristallinity shows that in the Prealps the internai part is affected by a lower greenschist metamorphic faciès (about 300°). The adjacent external part (Rigides externes) shows an anchimetamorphic faciès.
Diagenetic fluorite, celestite and quartzine spherulite attests a fluctuating diagenetic from restricted marine to meteoric environment.
The évolution of the flora and the fauna communities is pré-sentée!. Attention is given to the underestimated rôle of the siliceous sponge with respect to biosedimentary (sponge mats) and diagenetical (chert) processes. The expression "crypto-spongial" is introduced for the spicule rich micritic texture of vanished siliceous sponges. The Schizophytes (Cyanophytes and Bacterias) are the main lime mud producer and act also as raound builders in the upper part of the Formation (Andonce

-3-
Member).
Also an important feature are the deformational structures that appear in the shallow ramp to lagoonal rythmicaly layered lime sédiments. Vertical, "en chevron" and sigmoidal slab joints, pseudo-folding, crumpled beds and pseudobre.ccia or conglome-rate are illustrated and 2 processes of the synsedimentary déformations are analysed. Thèse processes are influenced by reversed viscosity gradients and by the "soft" and "hard" layers thic"kness ratio.
The dynamic aspect of the sédimentation and the faciès models are presented through the 3 main stages of shallow water car-bonate platform development*
1. the birth and initial developpment stage occurs during the
end of the Early Triassic (T") and the beginning of the
Anisian and is characterised by a multiphased transgression
of the peritidal dolomites followed by the shallow ramp
to lagoonal vermicular. limestone?
2. after an important eustatic régression and emersion of the platform, the juvénile stage (Early to Middle Anisian) is represented by a complète tidal fiât succession;
3. during the mature stage of the carbonate platform (Middle to Early Late Anisian), the depositional model consist of 4 main paleoenvironnments: - the peritidal flat, - the proper tidal flat, - the "barrier" consisting in lime sand shoals and patch algal-sponge mounds (lithoherme), - the ramp and shallow basin.
The quick overlapping of the shallow basin faciès by the peritidal dolomites indicate a lowering of the sea level and corresponds to the end of a 3rd. order -eustatic cycle. A tentative eustatic curve for the Anisian is given. Paleo-geographical and geodynamical trends are under the influence of the tardi-variscan structural directions and of a régional tentional activity. To the S (Southern Alps area) strike slip movments better explain the observed features

The basal unit of the succession in the Illela borehole belongs to the Dange Formation comprising thick calcareous and variably coloured dark-greyish shale of 36.30 m thick which is overlain by a 31.44 m thick limestone of Kalambaina Formation with 1.7 m thick shaly-limestone inclusive. The uppermost part of the section belongs to the Gwandu Formation which has intercalation of silty-clay, muddy siltstones with well lithified ironstone capping the borehole section. The limestone/carbonate microfacie as deduced from their salient lithologic, sedimentologic and paleontologic features are comparable to standard microfacie (SMF) types 9 and 10, i.e. bioclastic wackestone/bioclastic micrite and packstone-wackestone respectively. Diagenetically, syndepositional and early diagenesis have taken place particularly cemen-tation and replacement in the carbonate rocks and these have greatly affected the reservoir potential negatively. The matrix/grain relationships indicate a shallow marine environment of deposition. The borehole section is delineated into upper foraminifera and lower ostracod biostratigraphic units as no formal biostratigraphic zonation could be attempted due to low diversity of both benthic foraminifera, marine ostracods and the absence of planktonic foraminifera. The similarity of the ostracod assemblages between this study area, Illela borehole, West Africa, North Africa (Libya), Mali and Niger Republic) and SouthWestern Nigeria (West Africa) suggests that a marine connection exists between the Gulf of Guinea and the Sokoto Basin via the area occupied by the River Niger during the Paleocene.

It appears that the tectonism throughout early middle Miocene played an important role in the variations and distribution of facies zones within Jeribe basin. Although, the domination of the lagoonal influences within the most studied exposed succession; microfacies analysis revealed the influences of many other shallow environmental zones. Intermittent tectonic uplifts in basement blocks are reflected by successive secondary marine regressions toward the center of the basin in Sheikh-Ibrahim area. However, this regression had led to the termination of the Jeribe successions at studied area. This is represented at study area by a thick development of tidal flat facies overlain by a fresh lake facies at eastern parts; however it is exclusively represented by a thin bed of tidal flat facies at the western parts.

Siklus batuan : seluruh proses pembentukan batuan, dimodifikasi, ditransportasikan, mengalami dekomposisi, dan dibentuk kembali sebagai hasil dari proses internal dan eksternal Bumi terjadi di kerak benua (geosfer) yang berinteraksi dengan atmosfer, hidrosfer, dan biosfer dan digerakkan oleh energi panas internal Bumi dan energi panas yang datang dari Matahari.

: ‫ﻋﻤﺎﻥ‬ ‫ﺒﺴﻠﻁﻨﺔ‬ ‫ﺍﻟﺨﻭﺽ‬ ‫ﻤﻨﻁﻘﺔ‬ ‫ﻓﻲ‬ ‫ﺍﻟﺴﻴﺏ‬ ‫ﺘﻜﻭﻴﻥ‬ ‫ﺩﺭﺍﺴﺔ‬ ‫ﺍﻟﻜﺭﺒﻭﻨﺎﺘﻲ‬ ‫ﺍﻟﻨﻅﺎﻡ‬ ‫ﻟﻬﺫﺍ‬ ‫ﻜﻤﺜﺎل‬ ‫ﺍﻟﺤﺎﺭﺜﻲ‬ ‫ﻋﺒﺩﺍﻟﺭﺤﻤﻥ‬ ‫ﻭ‬ ‫ﺤﺭﺯﻱ‬ ‫ﺼﻼﺩ‬ ‫ﻋﺜﻤﺎﻥ‬ ‫ﺨﻼﺼﺔ‬ : ‫ﺘﺒﻠﻎ‬ ‫ﺣﻮاﻟﻲ‬ ‫اﻟﺴﻴﺐ‬ ‫ﺗﻜﻮﻳﻦ‬ ‫ﺳﻤﺎآﺔ‬ 600 ‫م،‬ ‫ﺗﻜ‬ ‫اﻟﺬي‬ ‫و‬ ّ ‫ﻮ‬ ‫ﻓﻲ‬ ‫ن‬ ‫ﻋﻬﺪ‬ ‫اﻹ‬ ‫اﻷ‬ ‫ﻳﻮﺳﻴﻦ‬ ‫وﺳﻂ‬ ‫أ‬ ‫ﻓ‬ ‫ﺛﻨﺎء‬ ‫اﻟﺒﺤﺮ‬ ‫ﻃﻐﻴﺎن‬ ‫ﺘﺮة‬ ، ‫ﺣﻴﺚ‬ ‫ﻋﻠﻰ‬ ‫اﻟﺠﻴﺮﻳﺔ‬ ‫اﻟﺼﺨﺮﻳﺔ‬ ‫اﻟﺴﺤﻨﺎت‬ ‫هﺬﻩ‬ ‫ﺗﺮﺳﺒﺖ‬ ‫اﻹ‬ ‫و‬ ‫اﻟﺒﺎﻃﻨﺔ‬ ‫ﻟﻤﻨﻄﻘﺔ‬ ‫اﻟﺴﺎﺣﻠﻲ‬ ‫ﻣﺘﺪاد‬ ‫ﻣﺴﻘﻂ‬ ‫ﻣﺤﺎﻓﻈﺔ‬ . ‫ﺧﻤﺲ‬ ‫ﻣﻦ‬ ‫اﻟﺴﻴﺐ‬ ‫ﺗﻜﻮﻳﻦ‬ ‫ﻳﺘﺎﻟﻒ‬ ‫اﻟﻀﺤﻠﺔ‬ ‫اﻟﺒﺤﺮﻳﺔ‬ ‫اﻟﻤﻴﺎﻩ‬ ‫ﻓﻲ‬ ‫اﻟﻤﺘﺮﺳﺒﺔ‬ ‫اﻟﺠﻴﺮﻳﺔ‬ ‫ﻟﻠﺴﺤﻨﺎت‬ ‫ﺗﺮاآﻤﻴﺔ‬ ‫ﺑﻨﻴﺔ‬ ‫ﺗﻤﺜﻞ‬ ‫ﻣﺘﺮاﺻﺔ‬ ‫وﺣﺪات‬ ‫اﻟﻘﺎري‬ ‫اﻟﺠﺮف‬ ‫ﻣﻦ‬ . ‫هﺬﻩ‬ ‫ﺗﺘﻤﻴﺰ‬ ‫ﺑ‬ ‫اﻟﻄﺒﻘﺎت‬ ‫ﺈ‬ ‫ﺣﺘﻮاﺋﻬ‬ ‫ﺗﻤﺜﻞ‬ ‫ﺗﺮﺳﺒﺎت‬ ‫ﻋﻠﻰ‬ ‫ﺎ‬ ‫إ‬ ‫زدﻳﺎد‬ ً ‫ا‬ ‫ﻣﻄﺮد‬ َ ‫ا‬ ‫ﻋﻤﺮا‬ ‫اﻻﻗﻞ‬ ‫اﻟﻄﺒﻘﺎت‬ ‫ﻣﻊ‬ ‫اﻟﻤﻴﺎﻩ‬ ‫ﻋﻤﻖ‬ ‫ﻓﻲ‬ ، ‫ان‬ ‫ﺑﻤﻌﻨﻰ‬ ‫اﻟﻄﺒﻘﺎت‬ ‫اﻷ‬ ‫ﺗﻜﻮﻧﺖ‬ ‫ﻗﺪم‬ ً ‫ﺟﺪ‬ ‫ﺿﺤﻠﺔ‬ ‫ﻣﻴﺎﻩ‬ ‫ﻓﻲ‬ ‫اﻻﺣﺪث‬ ‫ﺑﻴﻨﻤﺎ‬ ‫ا‬ ‫ﻓ‬ ‫ﺗﺮﺳﺒﺖ‬ ‫ﻣﻴﺎﻩ‬ ‫ﻲ‬ ‫أ‬ ‫ﻋﻤﻖ‬ . ‫اﻻوﻟﻰ‬ ‫اﻟﻮﺣﺪة‬ ‫و‬ ‫اﻷ‬ ‫هﻲ‬ ‫و‬ ‫اﻟﻄﺒﻘﻲ‬ ‫اﻟﺘﻘﺎﻃﻊ‬ ‫ﻓﻴﻬﺎ‬ ‫ﻳﻜﺜﺮ‬ ‫ﺗﺮاآﻤﺎت‬ ‫ﺗﻤﺜﻞ‬ ‫ﻗﺪم‬ ‫ﺑﺎﻻﺣﺎﻓﻴﺮ‬ ‫ﻏﻨﻴﺔ‬ ‫ﺟﻴﺮﻳﺔ‬ ‫ﻃﺒﻘﺎت‬ ‫ﻣﻦ‬ ‫ﺗﺘﻜﻮن‬ ‫اﻟﻄﻴﻨﻲ‬ ‫اﻟﻨﺴﻴﺞ‬ ‫ﻗﻠﻴﻠﺔ‬ ‫و‬ ) packstones ( ‫ﺗﻤﺎﻣﺎ‬ ‫ﻣﻨﻌﺪم‬ ‫او‬ ) grainstones ( ‫ﻳﻮﺣﻲ‬ ‫ﻣﻤﺎ‬ ‫ﺑﻴﺌﺔ‬ ‫ﻓﻲ‬ ‫ﺗﻜﻮﻧﺖ‬ ‫اﻟﻮﺣﺪة‬ ‫هﺬﻩ‬ ‫ان‬ ‫واﻟﺠﺰر‬ ‫اﻟﻤﺪ‬ ‫ﺣﺮآﺎت‬ ‫ﺑﺴﺒﺐ‬ ‫ﻋﺎﻟﻴﺔ‬ ‫هﻴﺪروﻟﻴﻜﻴﺔ‬ ‫ﻃﺎﻗﺔ‬ ‫ذات‬ ‫ﺷﺎﻃﺌﻴﺔ‬ . ‫اﻟﺜﺎﻧﻴﺔ‬ ‫اﻟﻮﺣﺪة‬ ‫ﻣﻦ‬ ‫ﺗﺘﻜﻮن‬ ‫ﻋﻠﻰ‬ ‫ﺗﺤﺘﻮي‬ ‫و‬ ‫اﻟﻜﻠﺴﻴﺔ‬ ‫اﻟﻌﻘﺪ‬ ‫و‬ ‫اﻟﻜﺒﻴﺮة‬ ‫اﻟﻤﻨﺨﺮﺑﺎت‬ ‫ﻓﻴﻬﺎ‬ ‫ﺗﻜﺜﺮ‬ ‫ﻣﺘﻤﺎﻳﺰة‬ ‫ﻏﻴﺮ‬ ‫ﻃﺒﻘﺎت‬ ‫ﻋﻠﻰ‬ ‫داﻟﺔ‬ ‫ﻣﺘﻔﺎوﺗﺔ‬ ‫ﺑﺪرﺟﺎت‬ ‫اﻟﻄﻴﻨﻲ‬ ‫اﻟﻨﺴﻴﺞ‬ ‫ﺑﻴﺌﺔ‬ ‫ﻓﻲ‬ ‫ﺗﺮﺳﻴﺐ‬ ‫ﻣﺘﻮﺳﻄﺔ‬ ‫هﻴﺪروﻟﻴﻜﻴﺔ‬ ‫ﻃﺎﻗﺔ‬ ‫ذات‬ ‫اﻟﺨﻴﺮان‬ . ‫اﻟﺜﺎﻟﺜﺔ‬ ‫اﻟﻮﺣﺪة‬ ‫اﻟﻰ‬ ‫ﻣﺘﻮﺳﻄﺔ‬ ‫ﺳﻤﺎآﺔ‬ ‫ذات‬ ‫ﺟﻴﺮﻳﺔ‬ ‫ﻃﺒﻘﺎت‬ ‫ﻣﻦ‬ ‫ﺗﺘﻜﻮن‬ ‫اﻟﻄﻴﻨﻲ‬ ‫اﻟﻨﺴﻴﺞ‬ ‫ﻗﻠﻴﻠﺔ‬ ‫و‬ ‫ﺑﺎﻻﺣﺎﻓﻴﺮ‬ ‫ﻏﻨﻴﺔ‬ ‫هﻲ‬ ‫و‬ ‫آﺒﻴﺮة‬ ) packstones ( ‫ﺗﻤﺎﻣﺎ‬ ‫ﻣﻨﻌﺪم‬ ‫او‬ ) grainstones ( ‫اﻟﻮﺣﺪة‬ ‫ﺑﻬﺬﻩ‬ ‫ﺗﻮﺟﺪ‬ ‫و‬ ‫ﻋﺪ‬ ‫ﻣﻌﻴﻨﺔ‬ ‫ﻧﻄﺎﻗﺎت‬ ‫ﻓﻲ‬ ‫أﻓﻘﻴﺎ‬ ‫ﻣﺤﺼﻮرة‬ ‫اﻟﻜﻮﻧﺠﻠﻮﻣﺮات‬ ‫ﻣﻦ‬ ‫ﺳﺎت‬ . ‫و‬ ‫ﻳ‬ ‫و‬ ‫اﻟﻤﻘﻌﺮة‬ ‫اﻟﺮﺳﻮﺑﻴﺔ‬ ‫اﻟﺒﻨﻴﺎت‬ ‫و‬ ‫اﻟﻄﺒﻘﻲ‬ ‫اﻟﺘﻘﺎﻃﻊ‬ ‫ﻓﻴﻬﺎ‬ ‫ﻜﺜﺮ‬ ‫اﻟﻤﺤﺪﺑﺔ‬ ) hummocky and swaley cross-stratificiation ( ‫اﻟﻀﺤﻠﺔ‬ ‫اﻻﺟﺰاء‬ ‫ﻓﻲ‬ ‫ﺗﻜﻮﻧﺖ‬ ‫اﻧﻬﺎ‬ ‫ﻋﻠﻰ‬ ‫ﻗﺎﻃﻌﺔ‬ ‫دﻻﻟﺔ‬ ‫ﻳﺪل‬ ‫ﻣﻤﺎ‬ ‫ﻣﻦ‬ ‫اﻟﺠﺮف‬ ‫ﺗﻤﺘﺎز‬ ‫ﻓﺘﺮات‬ ‫ﺗﻌﺘﺮﻳﻪ‬ ‫آﺎﻧﺖ‬ ‫واﻟﺬي‬ ‫اﻟﻘﺎري‬ ‫اﻻﻋﺎﺻﻴﺮ‬ ‫ﺑﺸﺪة‬ . ‫أﻣﺎ‬ ‫اﻟﺮاﺑﻌﺔ‬ ‫اﻟﻮﺣﺪة‬ ‫ﺷﺒﻴ‬ ‫ﻓﻬﻲ‬ ‫ﻬ‬ ‫ﺣﻴﺚ‬ ‫ﻣﻦ‬ ‫اﻟﺜﺎﻧﻴﺔ‬ ‫ﺑﺎﻟﻮﺣﺪة‬ ‫ﺔ‬ ‫اﻟﻘﺎري‬ ‫اﻟﺠﺮف‬ ‫ﻣﻦ‬ ‫أﻋﻤﻖ‬ ‫ﻧﻄﺎق‬ ‫ﻓﻲ‬ ‫ﺗﺮﺳﺒﺖ‬ ‫اﻧﻬﺎ‬ ‫اﻻ‬ ‫اﻟﺴﺤﻨﺔ‬ . ‫اﺧﻴﺮا‬ ‫و‬ ‫اﻟﺨﺎﻣﺴﺔ‬ ‫اﻟﻮﺣﺪة‬ ‫ﻳﻐﻠﺐ‬ ‫ﺟﻴﺮﻳﺔ‬ ‫ﺳﺤﻨﺎت‬ ‫ﻋﻦ‬ ‫ﻋﺒﺎرة‬ ‫ﻓﻬﻲ‬ ‫اﻟﻄ‬ ‫اﻟﻨﺴﻴﺞ‬ ‫ﻋﻠﻴﻬﺎ‬ ‫ﻴ‬ ‫ﻨﻲ‬ ‫وﺑﻬﺎ‬ ‫ﻣﻦ‬ ‫ﻗﻠﻴﻠﺔ‬ ‫ﻧﺴﺒﺔ‬ ‫اﻟﻤﻨﺨﺮﺑﺎت‬ ‫اﻟﻜﻮرﺗﺰﻣﻤﺎ‬ ‫ﺣﺒﻴﺒﺎت‬ ‫ﻣﻦ‬ ‫آﻤﻴﺎت‬ ‫وﺟﻮد‬ ‫ﻣﻊ‬ ‫ﻣﺆﺷﺮ‬ ‫ﻳﻌﻄﻲ‬ ‫ا‬ ‫ﻋﻠﻰ‬ ‫زﻳﺎدة‬ ‫آﺒﻴﺮة‬ ‫اﻟﻘﺎري‬ ‫اﻟﺠﺮف‬ ‫ﻣﻴﺎﻩ‬ ‫ﻋﻤﻖ‬ ‫ﻓﻲ‬ . ‫إ‬ ‫اﻷ‬ ‫اﻟﻮﺣﺪات‬ ‫ﺗﺘﺎﺑﻊ‬ ‫ن‬ ‫اﻟﻤﺬآﻮرة‬ ‫ﺑﺎﻟﻄﺮﻳﻘﺔ‬ ‫اﻟﺬآﺮ‬ ‫ﻧﻔﺔ‬ ‫أ‬ ‫ﻳﺆآﺪ‬ ‫ﻋﻼﻩ‬ ‫أ‬ ‫ﻣﻦ‬ ‫ﺑﺪأ‬ ‫اﻟﺴﻴﺐ‬ ‫ﺗﻜﻮﻳﻦ‬ ‫ﺗﺮﺳﻴﺐ‬ ‫ن‬ ‫ﺿﺤﻠﺔ‬ ‫ﺷﺎﻃﺌﻴﺔ‬ ‫ﺑﻴﺌﺔ‬ ‫إ‬ ‫اﻟﺠﺮف‬ ‫ﻓﻲ‬ ‫ﻋﻤﻴﻘﺔ‬ ‫ﻣﻨﺎﻃﻖ‬ ‫ﻟﻰ‬ ‫اﻟﻘﺎري‬ ‫اﻟﺒﺤﺮ‬ ‫ﻃﻐﻴﺎن‬ ‫ﻓﺘﺮة‬ ‫ﻓﻲ‬ .

Dinosaur tracks are biogenic, sedimentary structures and not body fossils or biological objects in the common sense. They result from the complex interaction of the kinematics of the trackmaker, its foot anatomy, and the substrate properties, and from taphonomic processes acting prior to the incorporation of the tracks into the sedimentary record. The objective of this work is an interdisciplinary study of a large sample of dinosaur tracks and trackways linking sedimentology with vertebrate ichnology, palaeontology, and palaeoecology.

Excellent conditions are provided by the Late Jurassic (Kimmeridgian) Chevenez—Combe Ronde tracksite, which is one of several tracksites located on the future course of the Transjurane highway near Porrentruy (Canton Jura, NW Switzerland). Here, eight superimposed dinosaur track-bearing surfaces were systematically excavated level-by-level within a 0,65 m thick laminite interval, unearthing almost 1400 dinosaur tracks. The main track level, located at the base of the interval, is the most diverse ichnoassemblage composed of 14 trackways of tiny (Pes Length < 25 cm) and small (25 cm < PL < 50 cm) sauropods and 43 trackways of minute (PL < 10 cm), small (10 cm < PL < 20 cm), and medium-sized
(20 cm < PL < 30 cm) bipedal, tridactyl dinosaurs.

The main issues are: (1) identification of true tracks, undertracks, and overtracks, and their relationships with substrate properties, their link with the exposure index, and their utility in the reconstruction of the palaeoenvironment; (2) implications of the main track level ichnoassemblage for dinosaur behaviour, the terrestrial palaeoecosystem, and vertebrate ichnofacies; (3) relationships between variability in trackway patterns and configurations with locomotion speed, behaviour, and substrate properties as well as implications for locomotion capabilities; (4) Quantification and relevance of sauropod trackway gauge; and (5) interpretation of manus-dominated and pes-only sauropod trackways.

The approach is first actualistic by studying human footprints and processes acting during their formation and preservation on modern tidal-flats. In these highly structured environments, microbial mats are ubiquitous, strongly facies-specific, and occupy a key position during and after footprint formation. Undertracks readily form in biolaminated sediment, whilst underprints and deep tracks are common in unlaminated, water-saturated sediment. Most consolidated vertebrate tracks are affected by taphonomic processes, including renewed and/or repeated growth of microbial mats leading to the formation of modified true tracks, internal overtracks (track fills), and overtracks.

The sauropod tracks and the encasing laminite interval of the Combe Ronde site are then subject of detailed sedimentological and taphonomical analyses. This discloses the sediment properties at the time of track formation and reveals the processes modifying the tracks during subaerial exposure and integrating them into the sedimentary record. Track morphology, associated track features, and sedimentary features can be linked with the exposure index, identifying the palaeoenvironment as a supratidal flat not located in close proximity to a coastline. These flats were susceptible for track recording only during short periods after wetting due to a rainy period or due to occasional storms. Longer periods of subaerial exposure prior to burial are indicated by the presence of internal overtracks and/or overtracks, and rapid covering up is indicated by the lack of overtracks on top of tracks with large displacement rims. Cross-sections of sauropod tracks provide insight into the consolidation history of the substrate prior to track formation and into the walking dynamics of dinosaurs, confirming that sauropods put their hindfeet in a pronounced plantigrade way on the ground.

The level-by-level superimposition of the studied surfaces enables to identify true tracks, undertracks, and overtracks. The best-defined true tracks (anatomical morphotypes) of the main track level are then used for ichnotaxonomy and trackmaker identification, and the detailed analyses of trackway parameters, including trackway gauge, provide insight into the locomotion capabilities of dinosaurs.

The best-defined minute and small tridactyl tracks can be assigned to the ichnogenus Carmelopodus, extending it from the Middle Jurassic into the Late Jurassic. These tracks were likely left by a small theropod dinosaur similar in size to Compsognathus or Juravenator. The medium-sized tridactyl tracks of morphotype II exhibit some of the typical features of the ichnogenus Therangospodus (attributed to large and robust theropods) but also some of ornithopod ichnotaxa.

The sauropod trackways show a wide range of patterns and configurations but are all medium- to wide-gauge. Therefore, they are assigned tentatively to the ichnogenus Brontopodus attributed to derived “brachiosaurid” or “titanosaurid” dinosaurs. The variability of the trackways reflects the general locomotion capabilities of the trackmakers and is an expression of individual walking style and behaviour, which may be related to substrate properties. Trackway patterns (the degree of manus overprinting by the pes) and different trackway configurations including trackway gauge are not only related to locomotion speed, and they provide no evidence of a relationship with ontogeny.

The gauge of sauropod trackways can be quantified with the pes trackway ratio and the here defined [WAP/PL]-ratio (Width of the pes Angulation Pattern / Pes Length). Gauge is possibly related to the substrate and the behaviour of the trackmaker adapting to it, but this does not change the overall medium-gauge to wide-gauge appearance of the trackways. The manus-dominated and pes-only sauropod trackways of the Combe Ronde site are explained by trackmakers exerting more pressure on the manus than the pes, and by overprinting of the manus by the pes, respectively.

The alignment of trackways on the main track level shows no evidence of a nearby shoreline and of interactions between the different groups of dinosaurs. It indicates gregarious behaviour amongst tiny and small sauropods, and suggests that minute and small bipedal dinosaurs were frequent visitors on the supratidal flats.

The ichnoassemblage of the main track level is the first one found in the Jura Mountains displaying abundant minute and small tridactyl tracks. This is also typical for the other Ajoie ichnoassemblages, which further exhibit tracks of tiny to large (up to 1,1 m PL) sauropods, and tracks of medium-sized to large (up to 0,8 m PL) bipedal dinosaurs. Sauropod trackways include narrow-gauge and wide-gauge trackways indicating the presence of “basal” and derived sauropods. This suggests that dwarfed insular animals can be excluded as trackmakers of the tiny and small sauropod trackways of the Ajoie ichnoassemblages and the Combe Ronde tracksite and that the Jura carbonate platform was connected with the landmasses of the London-Brabant Massif and the Massif Central during periods of emersion. Dinosaurs used the Jura carbonate platform for the establishment of in situ, predominantly saurischian dinosaur populations, but also as a migration corridor between the massifs.

Because the Ajoie ichnoassemblages are dominated by small tridactyl tracks, they differ from other Jurassic tetrapod ichnofacies in carbonate settings, notably from the Brontopodus ichnofacies. In the case of those ichnoassemblages commonly attributed to the Brontopodus ichnofacies, the lack or rareness of small tridactyl tracks may indicate the absence of small trackmakers in those palaeoenvironments or unsuitable conditions for the formation and preservation of small tracks.

This study highlights the benefits of systematic and interdisciplinary analyses of dinosaur tracks, which disclose variations related to behaviour and to differences in substrate. This allows recognizing anatomical morphotypes and trackway configurations representative of typical trackmaker behaviour. The latter can then also be used in ichnotaxonomical classification. Similar approaches should be in the focus of future work and performed on the other tracksites and ichnoassemblages of the Ajoie. Together with the evidence from other tracksites of the Jura Mountains, this will contribute towards a better understanding of the terrestrial palaeoenvironments and palaeogeography, and of dinosaur palaeoecology and palaeobiogeography on the Jura carbonate platform.

The Pila Spi formation composed of seven lithotypes; carbonates (dolomite and dolomitic limestone), marl, shale/claystone, red argillaceous mudstone, sandstone, carbonate breccias and debris flow, which are arranged in repeated cycles of mixed siliciclastic-calciturbidites in a range of gravity-flow regime in the Koi Sanjaq area. Sedimentologic and facies evidences suggest developed marine environment for the Pila Spi Formation. Facies analysis and associated sedimentary structures including graded beddings decide turbidity and gravity flow regime origin of the rocks. Marine environment is supported by the identifying glauconite and fossils types, which is reported here for the first time rather than lagoon environment. The Pila Spi sequences are grouped into four facies associations confirming developed marine depositional systems, these are (from bottom to top) channeled-slumped fine and mega carbonate breccias, calciturbidites, faulted and slump carbonate mega-breccias, slump/slide carbonate mega-breccias facies associations respectively. Petrographic analysis of carbonate units of the Pila Spi rocks in Koi Sanjaq area indicated that they are composed of skeletal grains with subordinate non-skeletal grains of tuffaceous fragments, chert, chalcedony, volcanic ash, metamorphic and detrital iron oxides grains, with noticeable grains of glauconite. Varieties of marine fossils are identified includes planktonic bivalves and benthic forams of cool water, which support the deeper marine environment. Microfacies analysis reveals (15) types, these are; green algal boundstone, algal wackestone dolomudstone, algal dolostone/mudstone, framestone-mudstone, small benthic foraminiferal wackestone, algal packstone-mudstone, foraminiferal packstone-mudstone, algal dolostone, fossiliferous grainstone, foraminiferal packstone, stromatolite framestone, algal boundstone, calci-microbial grainstone-packstone, and large benthic Foraminiferal bioclasts floatstone. These microfacies types are grouped in four facies associations representing the depositional environments of the formation, these are; outer shelf, reef, forereef, reef, backreef.

Daerah penelitian terletak di daerah Desa Monggol, Kecamatan Saptosari,Kabupaten Gunungkidul, Daerah Istimewah Yogyakarta. Secara geografis Posisi dareah  penelitian  terletak  pada  110 32’15” – 110 32’21”  BT  dan  08 03’28” – 08 03’50” LS dengan luas daerah penelitian adalah sebesar 1km 2 (1km x 1km).

Geomorfologi  lokasi  penelitian  merupakan  kawasan  perbukitan  karst. Perbukitan karst ini tersebar luas, dicirikan oleh bukit – bukit kecil batugamping. Bukit – bukit batugamping tersebut umumnya berbentuk kerucut.
Stratigrafi Formasi Wonosari  yang  ada  pada  daerah  penelitian  satuan batugamping klastik. Batugamping  daerah  penelitian  tersusun  oleh  5  asosiasi fasies,  yaitu fasies  alga – foraminefera mudstone,  fasies  alga – foraminefera
wackestone, fasies alga – foraminifera packstone, fasies alga floatstone dan fasies batugamping kristalin.

Proses – proses  diagenesis  yang  terjadi  pada  daerah  penelitian  Formasi Wonosari yaitu micritisasi microbial, kompaksi, sementasi dan neomorfisme yang menandakan bahwa Formasi Wonosari pernah pada lingkungan diagenesis marine phreatic, burial, meteoric phreatic dan meteoric vadose.

Kata kunci : Formasi Wonosari, Fasies Batugamping, Diagenesis Batugamping

Dolomite is not a simple mineral; it can form as a primary precipitate, a diagenetic replacement, or as a hydrothermal/metamorphic phase, all that it requires is permeability, a mechanism that facilitates fluid flow, and a sufficient supply of magnesium. Dolomite can form in lakes, on or beneath the shallow seafloor, in zones of brine reflux, and in early to late burial settings. It may form from seawater, from continental waters, from the mixing of basinal brines, the mixing of hypersaline brine with seawater, or the mixing of seawater with meteoric water, or via the cooling of basinal brines. Bacterial metabolism may aid the process of precipitation in settings where sulfate-reducing species flourish and microbial action may control primary precipitation in some hypersaline anoxic lake settings.

Dolomite is a metastable mineral, early formed crystals can be replaced by later more stable phases with such replacements repeated a number of times during burial and metamorphism. Each new phase is formed by the partial or complete dissolution of an earlier dolomite. This continual re-equilibration during burial detracts from the ability of trace elements to indicate depositional conditions and resets the oxygen isotope signature of the dolomite at progressively higher temperatures.

Because subsurface dolomite evolves via dissolution and reprecipitation, a bed of dolomite can retain or create porosity and permeability to much greater burial depths and into higher temperature realms than a limestone counterpart. Dolomitization also creates new crystals, with new rhomb growth following the dissolution of less stable precursors. Repetition of this process, without complete pore cementation, can generate intercrystalline porosity a number of times in the rock's burial history. Intercrystalline porosity is a highly interconnected style of porosity that gives dolomite reservoirs their good fluid storage capacity and efficient drainage. The fact that many dolomite reservoirs formed via brine reflux means that they sit beneath an evaporite seal in both platform and basinwide evaporite settings. The same association of evaporites (sulfate source) and entrained hydrocarbons means that burial conditions are also suitable for thermochemical sulfate reduction and the precipitation of base metals. This tends to occur at higher temperatures (>60°C--80°C) and so the resulting dolomites tend to be ferroan and consist of saddle-shaped crystals.

Disusun oleh: MUHAMAD REYHAN AZIZ 230210140040 PROGRAM STUDI ILMU KELAUTAN FAKULTAS PERIKANAN DAN ILMU KELAUTAN UNIVERSITAS PADJADJARAN JATINANGOR 2016 KATA PENGANTAR Segala puji dan syukur kehadirat Allah SWT atas berkat rahmat dan karunia-Nya penyusun dapat menyelesaikan makalah mengenai "SEDIMENTOLOGI" dalam rangka menambah ilmu pengetahuan dan wawasan mengenai sedimen laut dan untuk memenuhi tugas mata kuliah "SEDIMENTOLOGI LAUT" di semester keempat ini dalam Program Studi Ilmu Kelautan Fakultas Perikanan dan Ilmu Kelautan Universitas Padjadjaran. Semoga makalah ini bermanfaat khususnya bagi pembaca dan umumnya bagi kita semua. Penyusun memohon maaf apabila masih banyak kekurangan dalam penyusunan makalah ini. Jatinangor, 15 Mei 2016 Penyusun

L’étude de deux coupes lithologiques à Djebel Aoud Sma (Monts des Ouled Ali, Bordure Sud du bassin du Bas Chélif) a permis d’étudier la série messinienne complète de ce secteur. Les diatomites du Djebel Aoud Sma ont été subdivisées lithologiquement en deux membres. Les résultats ichnologiques ont permis de les placer au sommet du premier membre diatomitique du bassin du Bas Chélif. Les calcaires sus-jacents ont été subdivisés également en unité pré-récifale et unité récifale. Ils ont été le siège d’apports détritiques périodiques, qui ont atteint leur maximum dans l’unité récifale. L’Halimeda-rich beds ; un faciès qui pourrait constituer un niveau index, connu dans toutes les plates-formes carbonatées messiniennes de la Méditerranée occidentale, a été mis en évidence aussi, où il a été découvert pour la première fois dans la plate-forme carbonatée de la bordure Sud du bassin du Bas Chélif (Tessala-Béni Chougrane). L’étude microfaciologique a permis d’interpréter le milieu de dépôt des deux unités carbonatées. L’unité pré-récifale correspond à une plate-forme carbonatée peu profonde, envasée et relativement calme, tandis que l’unité récifale s’est déposée dans un milieu peu profond également, relativement agité, présentant un talus (pente récifale). Aussi, les résultats de la géochimie ont permis d’étudier la composition en éléments majeurs de tous les faciès rencontrés dans les marnes grises, les diatomites et les calcaires. Les diatomites pures peuvent constituer un bon gisement à exploiter, et c’est ainsi pour les calcaires qui peuvent faire une bonne matière première pour la fabrication du ciment gris et blanc.

This paper describes the famous Cambrian section exposed at Beartooth Butte, Wyoming. The paper describes the depositional environments, explains the causes of grand cycles and their boundaries and possible causes for the Cambrian mass extinction or biomere boundaries.

The extended, well documented and richly illustrated monograph dedicated to LITHOSTRATRIGRAPHY OF SICILY, written by Luca Basilone from the University of Palermo, deserves a special presentation. It displays the results of over ten years of field work carried out under the expert and careful guidance of Raimondo Catalano and from related detailed sedimentologic, microcropaleontologic and microfacies analysis. The work is pertinent in particular to several geological sheets of the new geologic map at the scale 1:50 000 of the Italian CARG project, but it has a much broader context, that extends well beyond the sheets boundaries.

Post-collisional tectonic escape refers to the lateral escape or extrusion of fault-bounded geological blocks
as a result of collision or compression away from the collision zone and towards free edge of oceanic
margin. While the collision zone is represented by fold-thrust belts, the tectonic escape is accommodated
by large strike-slip faults and rifting and spreading of basement.
There are five significant collisional events fashioning the Cenozoic tectonics of Indonesia. The first was
collision of India to Eurasia started at 50 or 45 Ma (early-middle Eocene). The collision resulted in the
Himalayan Fold-Thrust Belt and was followed by the escape of the Sundaland southeastwards through
major strike-slip faults and the formation of sedimentary basins in the Sundaland as well as the opening
of marginal seas of the South China Sea and Andaman Sea. The faults occupied and reactivated
Mesozoic sutures within the Sundaland. The faults are Red River Fault-Sabah Shear, Tonle-Sap-Mekong
(Mae Ping) Fault, Three Pagoda Fault-Malay-Natuna-Lupar Line-Adang Fault, and the Sumatran Faults.
The second collision occurred at about 25 Ma (late Oligocene) when an oceanic island arcs constructed on
the southern margin of the Philippine Sea Plate collided with the northern margin of Australia Continent.
The collision resulted in fold-thrust belt of the Papua Central Ranges and was followed by tectonic
escapes of strike-slip faults and basin formation. The faults are Sorong-Yapen Fault, Waipoga Fault,
Gauttier Offset, and Apauwar-Nawa Fault. Opening of the North Irian Basin in northern Papua also
shows the post-collision tectonic escapes.
The third collision was the collision of the Bird’s Head microcontinent with Papua at 10 Ma (late
Miocene). The Lengguru Fold-Thrust Belt marks the collision zone. Strike-slip faults away from the
collision zone like the Tarera-Aiduna, Sorong, Waipoga, and Ransiki Faults may demonstrate the postcollision
tectonic escape. The Bintuni Basin located just to the west of the Lengguru Fold-Thrust Belt is a
foreland basin developing as a response to post-collision extensional structure.
The fourth collision occurred from 11 to 5 Ma (late Miocene to earliest Pliocene) when the Buton-Tukang
Besi and the Banggai-Sula microcontinents collided East Sulawesi ophiolite. The microcontinents were
detached from the Bird’s Head of Papua and escaped westwards by the Sorong Fault. The collision has
formed Batui Fold-Thrust Belt and was followed by post-collision tectonic escapes in forms of rotation
of arms of Sulawesi, formation of major strike-slip faults of Palu-Koro, Kolaka, Lawanopo, Hamilton,
Matano, and Balantak Faults, and the opening of the Gulf of Bone. More recent transtensional movement
is responsible for the opening of pull-apart basins of Poso, Matano and Towuti Lakes, as well as the Palu
Depression.
The last collision commenced at about 3 Ma (mid-Pliocene) when northern margin of Australia
Continent collided Banda Island Arc. The collision resulted in foreland fold-thrust belt from Timor,
Tanimbar to Seram. Lateral extension is observed to follow the arc-continent collision indicating a
tectonic escape. Major strike-slip faults were formed sub-paralleling the Timor Island and may relate to
the escape of the Sumba Island westwards. Extensional crustal collapse followed the arc-continent
collision and has resulted in the formation of the Weber Deep, Savu Basin, and opening of the Banda Sea. The cases in Indonesia show that tectonic escape is a widespread process and may have been very
important in the evolution of convergent region like Indonesia. The concept of tectonic escape can
contribute to the understanding of the process by which continents are assembled and slivered.

The Great Oxidation Event (GOE) is one of the most significant changes in seawater and atmospheric chemistry in Earth history. This rise in oxygen occurred between ca. 2.4 and 2.3 Ga and set the stage for oxidative chemical weathering, wholesale changes in ocean chemistry, and the evolution of multicelluar life. Most of what is known about this important event and the subsequent oxygenation history of the Precambrian Earth is based on either geochemistry or "data mining" published literature to understand the temporal abundance of bioelemental sediments. Bioelemental sediments include iron formation, chert, and phosphorite, which are precipitates of the nutrient elements Fe, Si, and P, respectively. Because biological processes leading to their accumulation often produce organic-rich sediment, black shale can also be included in the bioelemental spectrum. Thus, chemistry of bioelemental sediments potentially holds clues to the oxygenation of the Earth because they are not simply recorders of geologic processes, but intimately involved in Earth system evolution.

El origen y formación de las dolomitas ha sido un enigma por parte de la comunidad científica en las últimas décadas. En este trabajo de investigación, se llevó a cabo un estudio geoquímico de una secuencia litoestratigráfica de diversas facies de calizas macrofosilíferas y dolomitas, correspondientes al Miembro Punceres de la Formación El Cantil en La Cantera El Vivero, Sector Pertigalete, Edo. Anzoátegui - Venezuela, con el propósito de establecer su origen, las condiciones paleoambientales presentes durante la depositación y su evolución diagenética durante el tiempo geológico. Para cumplir con los objetivos planteados, se colectaron un total de once (11) muestras de roca; de modo que, diez (10) correspondían al Miembro Punceres (Fm. El Cantil), y una (1) al posible Miembro Caripe (Fm. Chimana). A cada muestra de roca se les realizó una previa descripción macroscópica, un análisis instrumental por Fluorescencia de Rayos-X (FRX) para determinar la concentración elemental de Al2O3, SiO2, K2O y V (ppm), y un posterior análisis químico por valoración complexométrica con EDTA (ácido etilendiamino-tetraacético) con el propósito de determinar la concentración elemental de MgO, CaO, MnO y Fe2O3. Por medio de la interpretación de los datos obtenidos a partir del levantamiento litoestratigráfico, se definieron tres (3) unidades informales, correspondientes al Miembro Punceres (Fm. El Cantil) (Unidad I y II) y al posible Miembro Caripe (Fm. Chimana) (Unidad III). Asimismo, se identificó la presencia de cuatro (4) facies de carbonatos dentro de las unidades informales I y II: 1) Mudstones diagenética o Cementstone; 2) Floatstone diagenética; 3) Rudstone diagenética; 4) Dolomicrosparstone; de las cuales, se estableció que el posible ambiente de depositación del Miembro Punceres se vincula a un evento de evolución progresiva de un complejo arrecifal rudístico, dentro de un margen de plataforma interna o semi-protegido por algún banco o montículo arrecifal, bajo condiciones ligeramente anóxicas, condicionado por eventos episódicos de transgresión y regresión marina; aunque también, se estableció la posible hipótesis de que algún evento tectónico posterior pudo haber afectado dicha secuencia carbonática, separando la misma en dos entes distintos (Unidad I y II). Por otra parte, en la Unidad III se identificó solo una facies de carbonato: 1) Mudstone pelágica; estableciendo un entorno de depositación más anóxico y de mayor profundidad en esta unidad, posiblemente, dentro del margen de plataforma externa. A través del análisis geoquímico se determinó que las dolomitas del Miembro Punceres, posiblemente, se originaron durante una diagénesis de soterramiento, a través de la filtración por reflujo de aguas de alta salinidad ricas en Mg y, quizás, por influencia de aguas de formación modificadas por la interacción agua-roca de origen sedimentario. Dichas dolomitas presentaron elevadas concentraciones de Fe2O3, MnO y V, a comparación de las calizas, indicando la evidencia de posibles fluidos dolomíticos enriquecidos en Fe2+, Mn2+ y VO2+, bajo condiciones ligeramente anóxicas; estableciendo niveles más anóxicos en los fluidos diagenéticos que originaron la capa de dolomita M2 - M3 (Unidad I), a comparación de la capa de dolomita M7 (Unidad II). Asimismo, en bases a las relaciones elementales MgO/CaO y MnO/CaO, se estableció una posible dolomitización más avanzada y más completa en la capa de dolomita M7. La baja concentración de K2O y CaO y el aumento de MgO, MnO y Fe2O3 en las capas de dolomitas, indica una posible sustitución iónica o reemplazo y recristalización durante el avance diagenético; sin embargo, las concentraciones de K2O en las capas de dolomitas M2 - M3 y M7 y la capa de caliza M1 (Unidad I) se vinculan con mayor criterio a un aumento en la salinidad en la plataforma carbonática; aunque también, se estableció que las elevadas concentraciones de K2O en las capas de calizas M4 a M11 (Unidad I, II y III) se debe, principalmente, a la presencia de minerales arcillosos, destacado por la contenido significativo de SiO2 y Al2O3 en las mismas.

In 2012 and 2013 extensive sedimentological field work was conducted to study the depositional setting, the regional geology and facies relationships, and measure sections of the Green River Formation in all the subbasins, in Wyoming, Colorado and Utah (USA). Several pervasive horizons of seismically induced deformation structures were identified mainly in profundal lacustrine sediments. Deformation is represented by brittle and plastic behaviour, as well as sediment injection and mass transport. The deformed layers are confined by undeformed beds which implies sporadic short-lived events that affected only near-surface sediments with susceptible rheological state at the time.
Based on: (1) the tectonic setting of the lacustrine basins; (2) the sedimentary environment and sedimentological characteristics of the successions in which the deformed layers occur; (3) their lateral extent and proximity to known active fault systems during the time of the deposition of host sediments; (4) their recurrence at different stratigraphic levels, intervals showing large-scale sedimentary deformation structures are interpreted as result of in-situ loss of shear strength, formed by increased pore pressure and vertical or horizontal stress induced by seismic activity

The Middle Jurassic–Lower Cretaceous strata of the NE Arabian Plate contain several prolifi c source rocks providing the charge to some of the largest worldclass petroleum systems. They are located within the Zagros Fold Belt and Mesopotamian Foreland Basins covering the northern, central and southeastern parts of Iraq, Kuwait and western and southwestern Iran, particularly the Lurestan and Khuzestan provinces. These source rocks include the Bajocian–
Bathonian Sargelu, the Callovian–Lower Kimmeridgian Naokelekan and the Upper Tithonian–Lower Berriasian Chia Gara formations of Iraq and their chronostratigraphic equivalents in Kuwait and Iran. They have charged the
main Cretaceous and Cenozoic (Tertiary) reservoirs throughout Iraq, Kuwait and Iran with more than 250 billion barrels of proven recoverable hydrocarbons.
These formations represent the transgressive system tracts of sequences deposited within deep basinal settings and anoxic environments. They are dominated by black shales and bituminous marly limestones, with high total organic carbon (TOC) contents (ranging from 1–18 wt%), and by marine Type
IIS kerogen. Their Rock-Eval S2 yields may reach up to 60 mg HC/g Rock,
particularly along the depocentre of the Mesopotamian Foreland Basin. The immature hydrogen index (HI) values might have been up to 700 mg HC/g TOC, whereas the present-day observed values vary depending on the location within the basin and the present-day maturity. The Source-Potential Index (SPI; i.e. mass of hydrocarbons in tons, which could be generated from an area of 1 sq m in case of 100% transformation ratio) averages around 2–3, but can even
reach up to 14–16 along the basins’ centres.
The Sargelu and the overlying Naokelekan-basinal Najmah formations (and their equivalents) could represent the best potential shale-gas/shale-oil plays in Iraq, Kuwait and Iran, due to their organic richness, favourable maturity and the presence of regional upper and lower seals. The estimated oil-in-place for the potential Sargelu shale-oil play in Iraq only is around 1,300–2,500 billion barrel oil-equivalent (BBOE) and in Kuwait is about 7–150 BBOE.

In Java, the Oligo-Miocene (Late Oligocene-Early Miocene) platform and reefal carbonates distribute widely. Some of these carbonates are the important producing reservoirs, such as Kujung in East Java and Middle Cibulakan/ Baturaja in West Java. The period is also noted for its volcanism known as the “Old
Andesite” which distribute along the southern part of Java Island. This contemporaneity is interesting to evaluate revealing the tectono-volcanic influences on the carbonate sedimentation.
In tectono-volcanic setting, two trends of the Oligo-Miocene carbonates can be recognized : (1) Northern Trend, including the Cepu-Surabaya-Madura, North Central Java, and Ciputat-Jatibarang areas consists of the carbonates of Kujung, Prupuh, Tuban, Poleng, Middle Cibulakan, and Baturaja and (2) Southern
Trend, including the Gunung Kidul-Banyumas-Jampang-Bayah-Sukabumi-Rajamandala areas. The Northern Trend has developed in the back-arc setting, 75-150 kms away from the Oligo-Miocene volcanic arc in southern Java. There is no volcanic material found within the carbonates of this trend. The
distal location from the volcanic arc is considered as the reason. The Southern Trend was within the intraarc setting. No reefal carbonates are found to develop contemporaneously with the volcanism in Gunung Kidul-Banyumas-Jampang areas. Significant reefs grew during the Oligo-Miocene in the ridges at the front of the Southern Mountains including Bayah-Sukabumi-Rajamandala areas. The volcanism in Bayah
area took place as earlier as Early Eocene and had diminished when Oligo-Miocene transgression resulted in reefal carbonates. In Sukabumi-Rajamandala areas, Rajamandala reefs developed prior to Jampang volcanism which took place in the Early Miocene. When this volcanism intensified, the Rajamandala reefs terminated to grow. The window of volcanic quiescence in Java from 18 – 12 Ma (Middle Miocene) which occurred contemporaneously with the maximum global sea transgression had resulted in significant reefal
carbonates development along the Southern Mountains of Java such as Wonosari/Punung in Gunung Kidul, Jonggrangan in Kulon Progo, Karangbolong/Kalipucang in Banyumas, and Bojonglopang in Jampang areas.
The study has provided the regional framework on the relationship among carbonate sedimentation and
tectonics and volcanism. What occurs in the Java Island on this relationship also occurs in other areas with active carbonate sedimentation and volcanism such as in Sumatra, South Sulawesi, and Philippine Arc.

ABSTRAK Batuan karbonat Formasi Parigi tersingkap baik di Komplek Kromong daerah Palimanan, Cirebon dimana studi fasies karbonat ini dilakukan. Berdasarkan karakter fisik dan biota yang dikandungnya, batuan karbonat Komplek Kromong dapat dikelompokkan menjadi 7 fasies, yakni : (1) fasies boundstone, (2) fasies rudstone, (3) fasies cross bedded grainstone, (4) fasies foraminiferal packstone, (5) fasies algal-foram packstone, (6) fasies floatstone, dan (7) fasies thin bedded wackestone-packstone. Fasies boundstone dapat dibagi menjadi 2 subfasies yaitu subfasies bafflestone dan subfasies framestone. Lingkungan pengendapan Formasi Parigi diperkirakan diendapkan pada lingkungan reef front, reef crest, back reef, lagoon-surge chanel dan tidal flat-tidal chanel. Hasil analisis fosil foraminifera besar menunjukkan umur Formasi Parigi adalah Miosen Awal. Berdasarkan pada pola lingkungan pengendapan Formasi Parigi diinterpretasikan terumbu bagian depan berada di sebelah timur laut, sedangkan terumbu bagian belakang di bagian baratdaya. ABSTRACT The carbonate of the Parigi Formation were exposed well in the Kromong Complex, Palimanan. Detailed study of carbonate facies rocks have been carried out in this area. Based on the physical character and content of biota, carbonate rocks of Kromong Complex can be grouped into 7 facies, i.e : (1) boundstone facies, (2) rudstone facies, (3) packstonegrainstone facies, (4) foraminiferal packstone facies, (5) algal -foram packstone facies, (6) floatstone facies, and (7) thin bedded wackestonepackstone facies. Boundstone facies can be devided into 2 subfacies, i.e Bafflestone Subfacies and Framestone Subfacies. The deposition of environment of Parigi formation are interpreted in the : reef front, reef crest, back reef, lagoon-surge channel and tidal flat-tidal channel. Results of foraminifera fossil analysis indicate that the Parigi Formation age is Early Miocene. Based of the pattern of the Parigi Formation deposition environment is interpreted the reef front part is in the northeast and back reef part is in the southwest.

Fasies adalah suatu tubuh batuan yang dicirikan oleh kombinasi ciri litologi, fisik dan biologi yang membedakannya dengan tubuh batuan yang berdekatan (Walker, 1992). Lokasi daerah penelitian secara administratif terletak di Kabupaten Badung, Provinsi Bali dan masuk kedalam peta geologi regional lembar Bali-Nusatenggara. Metode yang digunakan adalah pemetaan geologi dan measuring section. Kajian ini membahas tentang studi fasies pada karbonat Fomasi Selatan serta model lingkungan pengendapannya. Secara regional Formasi Selatan terdiri dari batugamping terumbu, napal setempat, batugamping terhablur ulang dan batugamping berfosil (Purbo-Hadiwijoyo, 1998). Pada lokasi pantai Dreamland dijumpai fasies bafflestone branching coral, rudstone, grainstone dan floatstone yang mengindikasikan fasies ini pada pertumbuhan fase stabilization-colonization, sedangkan dilokasi pantai Pandawa terdiri dari fasies bafflestone branching coral, rudstone dan floatstone yang merupakan pertumbuhan fase stabilizationcolonization. Daerah Ungasan mempunyai fasies bindstone coral reef (platy coral) dan framestone (head coral) yang merupakan pertumbuhan pada fase domination. Bedasarkan interpretasi fasies pada lokasi penelitian disimpulkan 3 lingkungan pengendapan : (1) Backreef-reef flat dengan ciri berlapis, dominasi matriks pasiran, floatstone, fosil pelecypoda, gastropoda dan terdapat branching coral secara setempat-setempat yang berselingan dengan rudstone (2) Reef crest -reef front dengan ciri didominasi oleh koloni coral berbentuk pipih (platy), branching coral secara setempat, fosil pelecypoda, berlapis, bioherm dan matriks berupa pasir kasar (3) Reef front -fore reef mempunyai ciri didominasi oleh branching coral berselingan dengan rudstone, beberapa fragmen pecahan branching coral, berlapis dengan dimensi lapisan yang cukup tebal.