Evans blue removal from wastewater by rarasaponin–bentonite

The feasibility of natural bentonite and rarasaponin–bentonite for Evans blue removal from aqueous solution was studied. Rarasaponin is a natural surfactant obtained from Sapindus rarak DC was used as modifying agent for natural bentonite modification. Adsorption experiments were conducted in a batch system at various temperatures. Several temperature-dependent isotherm models (Langmuir, Freundlich, Sips and Toth) were used to represent equilibrium data. It was found that Toth model represents the adsorption equilibrium data better than other models. Kinetic data were best represented by the pseudo-first order model. The controlling mechanism of the adsorption of Evans blue onto natural bentonite and rarasaponin–bentonite was physical adsorption.     

Effects of continuous chlorination on spat of the American oyster (Crassostrea virginica)

Newly settled spat of the American oyster (Crassostrea virginica) exhibited reduced survival and growth when exposed to chronic chlorination (as Na-OCl). Spat exposed to nominal concentrations of 0.250 and 0.500 mg per 1 chlorine-produced oxidant (CPO) had only 20% survival after 12 weeks, compared to 64% survival in controls. Spat growth was retarded by nominal concentrations as low as 0.125 mg per I CPO. Shell height of control oysters increased 103% after 12 weeks, while spat exposed to 0.125 mg per I CPO grew 39% and spat exposed to 0.250 mg per I CPO had no net growth. Surviving spat exposed to 0.500 mg per I CPO showed an apparent growth increase of 160%, due mainly to heavy mortality among smaller-sized spat. The numbers of spat (whether surviving or not) that showed any growth over the 12-week exposure period decreased with increasing chlorine concentration. Larger spat were found to be more resistant than smaller spat to increased chlorination. The mechanism of growth inhibition in spat (mantle retraction and cessation of feeding) appeared to be similar to that found in adult oysters exposed to chlorine.     

Evidence of high sea level during isotope stage 5c in Queensland,Australia

Thirty-nine species of scleractinian corals have been recovered from under a high dune on the western (mainland) side of North Stradbroke Island, eastern Australia. The corals are associated with thin intertidal sediments and their good condition implies burial in situ and preservation in a saturated zone. Most likely this occurred as the coast prograded and a large dune advanced into the littoral zone, burying intertidal sediments and coral. The species assemblage indicates a sheltered environment but one open to the ocean without wide fluctuations in salinity. Three species yielded a mean ${}^{230}\text{Th}{}^{234}\text{U}$ age of 105,000 yr B.P. which is significantly younger than the nearest Pleistocene corals at Evans Head, New South Wales. The corals provide evidence of a sea stand near present sea level during isotope Stage 5c, which is considerably higher than previously suggested for this period. Their good condition implies that the overlying parabolic dune is of comparable age and formed during that high stand of sea level. Also, the isotope age provides a maximum period for the development of giant podzols in the podzol chronosequences on coastal dunes in southern Queensland.     

Subduction related antigorite CPO patterns from forearc mantle in the Sanbagawa belt,southwest Japan

Antigorite (Atg) is stable throughout large parts of the wedge mantle of most subduction zones. Atg shows strong acoustic anisotropy and crystallographic preferred orientation (CPO) patterns of this mineral may contribute significantly to seismic anisotropy in convergent margins. Atg CPO patterns from the Higashi-Akaishi (HA) forearc mantle body of southwest Japan adds to the data set suggesting the most common Atg CPO pattern has a c-axis perpendicular to the foliation and a b-axis parallel to the stretching lineation. Statistical analysis using the eigenvector method of Atg CPO from two mutually perpendicular directions in the same sample (YZ-section and XZ-section) shows no significant differences implying sample preparation has no significant affect on the resulting Atg CPO. Reuss (uniform stress) averages of anisotropy for the Higashi-Akaishi samples are approximately treble the values for Voigt (uniform strain) averages. When comparing calculated anisotropy of hydrated mantle peridotite samples—such as the Higashi-Akaishi unit—with observed S-wave delay times in convergent margins, the appropriate averaging method needs to be considered.     

Toxicological and physiological responses of the fish,Leiostomus xanthurus,exposed to chlorine produced oxidants

The sublethal and lethal effects of chlorine produced oxidants (CPO) on juveniles of the estuarine teleost,Leiostomus xanthurus, were investigated in flowing water tests conducted at 30 ±1°C and 26 to 31‰ salinity. Short-term LT50 tests were conducted at two nominal concentrations of NaOCl, 1.0 and 1.4 mg/l (respective measured CPO concentrations 0.09 and 0.12 mg/l) which were sublethal in 2,880 minute exposures; and three nominal concentrations, 1.6, 1.8 and 3.2 mg/l NaOCl (respective measured CPO concentrations 0.13, 0.20 and 0.37 mg/l) which were acutely toxic. Opercular ventilation rates in exposed spot were much higher than in control fish, but returned to rates only slightly above those of controls during the latter portion of the 2,880 minute exposure to the two sublethal CPO concentrations. Opercular rates at the three acutely toxic CPO concentrations remained much higher than control rates until the exposed fish died. Blood pH after 2,880 minutes of exposure to the sublethal concentrations of CPO; or at the respective estimated LT50 for lethal concentrations, showed significant decreases ( \(\bar X\) as low as 6.84) compared to controls \((\bar X 7.35)\) . No significant changes in the % methemoglobin were observed. Oxygen uptake by spot was depressed at all of the measured concentrations of CPO tested. Histopathological examination showed that gill respiratory epithelial tissues sloughed away from the underlying pillar cells. Complete denudation of circulatory tissues and hemangiectic secondary lamellae were observed in gill tissues from fish exposed to the highest CPO concentration of 0.37 mg/l.     

Characterization of bioflocculants produced by bacteria isolated from crude petroleum oil

The aim of this study was to look for high efficient bioflocculant-producing microorganisms. Among 36 bacterial colonies isolated from a crude petroleum oil sample, three of them as Bacillus subtilis and Pseudomonas spp. exhibited flocculation activity exceeding 90 % after 3 days of cultivation. They were identified by 16 S rDNA sequence analysis as Bacillus subtilis and Pseudomonas sp. Spectroscopic analysis of the polymers by nuclear magnetic resonance and fourier-transform infrared revealed that the polymers were glycoproteins. These polymers were soluble in water and insoluble in any organic solvents tested. The effects of bioflocculant dosage, temperature and pH on the flocculation activity were evaluated. The maximum bioflocculation activities were observed at an optimum bioflocculant dosage of 3.5 mg/L (strains Bacillus subtilis and Pseudomonas) and 5.0 mg/L (strain CPO14), respectively. In addition, these biopolymers were able to flocculate kaolin suspension (5 g/L) over a wide range of pH (pH 3–9) and temperature (5–50 °C) tested in the presence of CaCl₂. The highest flocculation activities of strains CPO8, CPO13 and CPO14 were 96.03 %, 92.17 % and 97.59 %, respectively in the early stationary phase (at 24 h), while the cell production reached its maximum in the stationary phase (at 72 h). Their efficient flocculation capabilities suggest potential applications in industries.     

Feeding habits of red drum (Sciaenops ocellatus) in Galveston Bay, Texas: Seasonal diet variation and predator-prey size relationships

Feeding habits, seasonal diet variation, and predator size-prey size relationships of red drum (Sciaenops ocellatus) were investigated in Galveston Bay, Texas through stomach contents analysis. A total of 598 red drum ranging from 291–763 mm total length were collected and their stomach contents analyzed during fall 1997 and spring 1998. The diet of red drum showed significant seasonal patterns, and was dominated by white shrimp (Penaeus setiferus) during fall and gulf menhaden (Brevoortia patronus) during spring. Blue crab (Callinectes sapidus) was an important component of red drum diets during both seasons. Significant differences existed between prey types consumed during fall and spring as red drum diet reflected seasonal variation in prey availability. Predictive regression equations were generated to estimate original carapace width of blue crabs from several measurements taken from carapace fragments recovered in red drum stomachs. Regressions were highly significant (r²>0.97) and increased the number of blue crabs with size information nearly three fold. Predator size-prey size relationships were determined for red drum feeding on white shrimp, gulf menhaden, and blue crab. Although regression slopes were statistically significant, prey sizes increased only slightly with increasing red drum size. Comparisons of prey sizes consumed by red drum with sizes occurring in the field indicate that red drum feed in nearshore shallow water habitats, which serve as nursery areas for many juvenile fishes and crustaceans. Our findings demonstrate that red drum feed on several prey species of commercial and recreational value and may have important effects on estuarine community structure.     

Geochemistry, petrofabrics and seismic properties of eclogites from the Chinese Continental Scientific Drilling boreholes in the Sulu UHP terrane, eastern China

We present an integrated study of geochemistry, petrofabrics and seismic properties of strongly sheared eclogites from the Chinese Continental Scientific Drilling (CCSD) project in the Sulu ultrahigh-pressure (UHP) metamorphic terrane, eastern China. First, geochemical data characterize diverse protoliths of the studied eclogites. The positive Eu- and Sr-anomalies, negative Nb anomaly and flat portion of heavy rare earth elements in coarse-grained rutile eclogites (samples B270 and B295) suggest a cumulate origin in the continental crust, whereas the negative Nb anomaly and enrichment of light rare earth elements in retrograde eclogites (samples B504, B15 and B19) imply an origin of continental basalts or island arc basalts. Second, P-wave velocities (V_p) of three typical eclogite samples were measured under confining pressures up to 500 MPa and temperatures to 700 °C. At 500 MPa and room temperature, the mean V_p reaches 8.50-8.53 km/s in samples B270 and B295 but drops to 7.86 km/s in sample B504, and the P-wave anisotropy changes from 1.7-2.7% to 5.5%, respectively. The pressure and temperature derivatives of V_p are larger in the retrograde eclogite than in fresh ones. Third, the electron backscatter diffraction (EBSD) measurements of the eclogites reveal random crystal preferred orientation (CPO) of garnet and pronounced CPO of omphacite, which is characterized by a strong concentration of [001]-axes sub-parallel to the lineation and of (010)-poles perpendicular to the foliation. The asymmetric CPO of omphacite in sample B270 recorded a top-to-the-south shear event during subduction of the Yangtze plate. The calculated fastest V_p is generally sub-parallel to the lineation, but a different deformation environment during exhumation could form second-order variations in omphacite CPO and affect the V_p distribution in eclogites (e.g., the fastest V_p is at ~ 35° from the foliation in sample B295). Comparison between measured and calculated seismic properties indicates that the CPO of omphacite controls the seismic anisotropy of eclogites at high pressure, and compositional layering and retrograde minerals will increase the anisotropy. Calculated P-wave velocities agree well with velocities measured at 500 MPa and room temperature for fresh eclogites, but much higher than those of retrograde eclogite. As a case study, the laboratory-derived V_p-P and V_p-T relationships were used to estimate P-wave velocities of eclogites and peridotites beneath the Western Superior Province, Canada. The results indicate that besides the fabric-induced anisotropy, the direction dependence of pressure and temperature derivatives of V_p can significantly increase seismic anisotropy of eclogites with depth, which results in eclogites being an important candidate for the seismic anisotropy in the upper mantle. Due to their very high density and velocity, garnet-rich eclogites within peridotite could be detected in seismic reflections in subduction zones.     

Trends in Abundance of Coastal Birds and Human Activity on a Texas Barrier Island Over Three Decades

Trends in abundance of the 28 most common species of coastal birds on Mustang Island, Texas, were assessed for a 29-year period (1979–2007) during which the study area experienced a substantial increase in human activity. Ten of the 28 species examined declined significantly (P < 0.05) over the study period. Six of these were larids (herring gull, Forster’s tern, royal tern, gull-billed tern, Caspian tern, black skimmer), which exhibited declines in mean abundance of 53% to 88%. Other significant species declines were the great blue heron (39% decline) and the shorebirds Wilson’s plover (63%), red knot (54%), and black-bellied plover (34%). Four species showed significant increases in local abundance. Mean number of people on the beach increased fivefold during the study period. This unique dataset allows for an extremely rare assessment of bird populations in direct relation to human disturbance and may have implications for managing coastal birds worldwide.     

Microfacies and environmental study of the lower cretaceous yamama formation in Ratawi field

The Yamama Formation is the main Lower Cretaceous (late Berriasian–Valangenian) carbonate reservoir in southern Iraq. Petrographic study from thin-section examination shows that the skeletal grains included calcareous algae from both red and green algae. Red algae is concentrated in the upper part of the Formation, and the most important of this algae species is Permocalculus ssp. Green algae is less common, and its concentration is in the middle part of the Formation. The most species found in the Yamama Formation is dasycladeans, and both small and large species of benthonic foraminifera such as Nautiloculina, Textularia, Trocholina, Pseudocyclammina, and Everticyclammina are also present. The non-skeleton grains included oolites, pellets, and micrite. Six cyclic type microfacies have been recognized for Yamama Formation in Ratawi-3 (Rt-3) and Ratawi-4 (Rt-4) Wells, namely peloidal packstone–grainstone, algal wackestone–packstone, oolitic–peloidal grainstone, bioclastic wackestone–packstone, foraminiferal wackestone, and mudstone microfacies. The latter has been divided into two submicrofacies: argillaceous lime mudstone and fossiliferous lime mudstone. The lateral extension of these microfacies has been identified by integrating the thin-section data and well logs’ character variations with similar characteristic for microfacies. The Yamama Formation was affected by five diagenetic processes, which are micritization, cementation, recrystallization, silicification, and stylolites. The Yamama Formation was deposited during a regressive period within the outer ramp, shoal, and inner ramp setting.     

Reproductive success of wading birds using<Emphasis Type="Italic">Phragmites</Emphasis> marsh and upland nesting habitats

Colonial nesting of long-legged wading birds (Ciconiiformes) in the coastal northeastern U.S. is limited primarily to islands, which provide isolated habitats that are relatively free of ground predators. Estuarine wetlands in this heavily developed region, including foraging wetlands and fringe marshes surrounding nesting islands, are often dominated byPhragmites australis. On Pea Patch Island in Delaware Bay, site of one of the largest and most enduring mixed-species heron colonies on the East Coast, wading birds nest inPhragmites marsh habitat as well as in adjacent upland shrubs and trees. BecausePhragmites is aggressively managed in Delaware Bay, we investigated the relative habitat value of marsh and upland nesting sites for the purpose of developing recommendations for marsh and wildlife management. Utilization of marsh habitat by nesting birds ranged from 27–82% during 1993–1998. Two species (great blue heronArdea herodias and great egretA. alba) never nested inPhragmites, four species (little blue heronEgretta caerulea, snowy egretE. thula, cattle egretBubulcus ibis, and black-crowned night-heronNycticorax nycticorax) nested in approximately equal proportions in both habitats, and one species (glossy ibisPlegadis falcinellus) was largely confined to marsh nesting. Productivity (egg and nestling production) varied between habitats for some species. Cattle egrets produced larger clutches and had higher hatching rates inPhragmites compared to upland habitat. Little blue herons were more successful in the uplands. Managers should retainPhragmites marsh at colony sites, such as Pea Patch Island, where it provides critical habitat for nesting wading birds both as substrate for nesting and buffer habitat to control human disturbance.     

Food habits of red drum and spotted seatrout in a restored mangrove impoundment

Benthic resource utilization by, red drum (Sciaenops ocellatus) and spotted seatrout (Cynoscion nebulosus) was studied in a restored, mangrove-rimmed impoundment (Cabbagehead Bayou) of Upper Tampa Bay, Florida, and in a nearby, natural site of unaltered tidal regime (Double Branch Bay). Diets of fish captured from August 1990 to May 1992 were determined from stomach content analysis. Simultaneously, food availability was evaluated by sampling benthic macroinvertebrates, mobile decapods, and small fish. Red drum and spotted seatrout utilized the restored habitat 1 yr after it was opened to tidal influence. Both species also were collected in the natural mangrove. Although there were noted differences in benthic assemblages between the two sites, red drum and spotted seatrout exhibited flexibility in diet, feeding on abundant and accessible prey. The high abundance of microcrustacea, such as amphipods, on detritus accumulated in the restored habitat constituted a main food resource for both fish species. Major food items in the diet of small (<200 mm) red drum were amphipods, mysids, and nereid and arenicolid polychaetes. Large (200–590 mm) red drum fed on polychaetes, xanthid crabs, palaemonid shrimp, and small fishes. Spotted seatrout preyed primarily upon mysids, shrimp, and small fishes, and to a lesser extent, upon a nereid polychaete. Our findings on fish feeding in a restored mangrove impoundment indicated that the detrital-associated benthic community is utilized by reinvading fish within a short time period, suggesting that not only habitat but food resources were augmented by the reopening of this wetland.     

Predation on estuarine infauna: Response patterns of component species

The effect of predation by blue crabs and fishes on all species of infaunal macrobenthos of a subtidal sandy bottom in the York River, Virginia, was investigated by manipulative field experiments. Wire mesh cages were used both to exclude all large predators from and to confine different predators to small areas of the natural bottom. After 2 months, many species showed significant differences between the various treatments. There were similar patterns of species responses in three separate years. Species tended to fit one of two categories. Those species which had tough tubes, which lived deep in the sediment, or which could quickly retract deep into the sediment were shown experimentally not to change much in abundance regardless of whether predators were excluded or included. These species were generally the numerical dominants in the natural community—e.g.Peloscolex gabriellae, Heteromastus filiformis, Spiochaetopterus oculatus, andPhoronis psammophila. Other species which lived near the surface or exposed on the surface responded to experimentally altered predation intensity with large changes in density. These species were either uncommon or only sporadically abundant in the natural community—e.g.Polydora ligni, Streblospio benedicti, Mulinia lateralis, andLyonsia hyalina. This evidence indicates that the abundant species in the natural community are abundant because they avoid predators.     

An investigation of cathodoluminescence in albite from the A-type Georgeville granite,Nova Scotia

Cathodoluminescence (CL) reveals red and blue colors within single, non-turbid albite (Ab_98–99) grains from the Georgeville granite, Nova Scotia. A 720 nm X-ray excited optical luminescence (XEOL) peak characterizes red CL regions, while a 280 nm XEOL feature dominates blue CL regions. Synchrotron X-ray fluorescence results indicate that red CL and the 720 nm XEOL peak intensities relate to total Fe concentrations. The relationship between red CL and Fe content is confirmed by electron microprobe (EMPA) and laser ablation-inductively coupled mass spectrometry (LA-ICP-MS). The XEOL technique is used to exclude the Fe K-edge as the cause of red CL. X-ray absorption spectroscopy results indicate that Fe in both the red and blue CL regions is Fe³⁺, and that red CL activation may relate to the Si–Al order of the feldspar and to the distribution of Fe on tetrahedral sites. The CL textures, combined with EMPA and LA-ICPMS analyses, indicate that blue CL albite (Ab₉₈) regions contain higher concentrations of Ca, Ti, Pb and rare earth elements, and were replaced, in part, by a more Fe-rich, trace element depleted albite (Ab₉₉) which displays red CL. Complex diffraction contrasts and amorphous deposits identified in transmission electron microscope images suggest that aqueous fluids have reacted with both red and blue CL regions. Fluid inclusion homogenization temperatures of up to 430 °C provide a lower estimate of the fluid temperature.     

Variability of the HeI line profiles in the spectrum of the hot O9.5V star HD 93521

CCD spectra acquired with the PFES echelle spectrograph on the 6 m telescope of the Special Astrophysical Observatory (Russian Academy of Sciences) were used to study short-term variations in the HeI-line profiles in the spectrum of HD 93521. For all the lines, the variability pattern relative to the mean profile is the same, and can be described as a sinusoidal wave passing through the profiles, from the blue to the red wings. The variability amplitudes and time scales are different for different HeI lines. We studied variations of the radial velocities at the level of 0.5 R ₀ of the line residual intensity, for the absorption bisector and the blue and red halves of the absorption profile. The variation time scales and amplitudes for the line halves differ from one HeI line to another, and show good correlations with the line central depths. Going from the weak to the strong lines, the time scale of the radial-velocity variations measured for both halves of the absorption profile increases, and the amplitude decreases. The time scale of the radial-velocity variations for weak lines is, on average, twice the time scale for strong HeI lines. A variable absorption feature was detected in the profiles of strong HeI lines, which moves across the profile synchronously with the star’s axial rotation. Generally, the observed line variations are probably due to nonradial photospheric pulsations, together with the influence of the stellar wind on the profiles of the strong lines.     

Fabric analysis of quartzites with negative magnetic susceptibility – Does AMS provide information of SPO or CPO of quartz?

We ask the question whether petrofabric data from anisotropy of magnetic susceptibility (AMS) analysis of deformed quartzites gives information about shape preferred orientation (SPO) or crystallographic preferred orientation (CPO) of quartz. Since quartz is diamagnetic and has a negative magnetic susceptibility, 11 samples of nearly pure quartzites with a negative magnetic susceptibility were chosen for this study. After performing AMS analysis, electron backscatter diffraction (EBSD) analysis was done in thin sections prepared parallel to the K₁K₃ plane of the AMS ellipsoid. Results show that in all the samples quartz SPO is sub-parallel to the orientation of the magnetic foliation. However, in most samples no clear correspondance is observed between quartz CPO and K₁ (magnetic lineation) direction. This is contrary to the parallelism observed between K₁ direction and orientation of quartz c-axis in the case of undeformed single quartz crystal. Pole figures of quartz indicate that quartz c-axis tends to be parallel to K₁ direction only in the case where intracrystalline deformation of quartz is accommodated by prism <c> slip. It is therefore established that AMS investigation of quartz from deformed rocks gives information of SPO. Thus, it is concluded that petrofabric information of quartzite obtained from AMS is a manifestation of its shape anisotropy and not crystallographic preferred orientation.     

The microbial community in the layered sediments at Laguna Figueroa,Baja California,Mexico: Does it have Precambrian analogues?

In the hypersaline lagoon at Laguna Figueroa vertically stratified diverse communities of microorganisms thrive. The modern sediments of Baja California at Laguna Figueroa contain cyanobacterial communities and sedimentary structures produced by these blue greens that have already been studied by Horodyski and his colleagues. This paper provides an introduction to the complex microbial communities, primarily those that underlie the laminated Microcoleus mats. They are composed of anaerobic photosynthetic and heterotrophic bacteria.The following genera of cyanobacteria at least are components of these mat communities: Lyngbya, Microcoleus, Entophysalis, Phormidium, Pseudoanabaena, Anabaena and Schizothrix. Among the photosynthetic bacteria several species of Thiocapsa-like microbes formed major surface components of certain mats and scums; rhodospirilli, rhodopseudomonads, chromatis and others were seen.The following nonphotosynthetic bacteria were identified: Nocardia sp., three types of spirilli, two types of Spirochaeta sp., two types of Desulfovibria sp., a new strain of red Beneckea and four distinctive unidentified coccoid and filamentous bacteria. Reasons are given for believing several of the species are new to science and that the microbial diversity is far greater than the approximately twenty species reported here. Eukaryotes are extremely rare. Only one species of animal, a herpachtechoid copepod, was ever seen in the 8-km long microbial communities of the hypersaline basin. Dunaliella salina, a chlorophyte and Aspergillus sydowi, an ascomycetous fungus were the only eukaryotes that were observed to be regular components of mat communities. Ciliates, amoebae (including a chrysarchnion-like microbe) and diatom tests, mostly empty, were the only other eukaryotes observed. Attempts to enrich for eukaryotic microorganisms were not successful whereas attempts to enrich for bacteria, especially anaerobes led to such a profusion of forms that to continue detailed study of them was beyond our means. Unidentified small rods and cocci constituted the largest fraction of individuals in the subsurface community. The microbes isolated from mats are adapted for alternating dry and wet conditions as well as high concentrations of salt and low concentrations of oxygen.     

IR photometry of the symbiotic star BF Cyg: Detection of the red giant’s ellipsoidal brightness variability

We present the results of our IR photometric observations of the classical symbiotic star BF Cyg acquired in 1978–2003. The variability range in the J and K bands was ～0.2^m. A periodic component in the cool star’s brightness variations is clearly visible, its period being half the orbital one and its J amplitude being ～0.15^m. This component is associated with the ellipsoidal shape of the red giant, which model calculations show fills its Roche lobe. This is required in order to reproduce ellipsoidal brightness variability with such a large amplitude: the calculated amplitude for a red giant filling 90% of its Roche lobe is half the observed value. At the same time, it was not possible to confidently chose the optimum component-mass ratio, q = M _giant /M_hot, and orbital inclination, i, from possible values in the ranges q = 2–4, i = 70°–90°. Including the contribution from the hot radiation sources (the hot component and ionized envelope), which vary with a period equal to the orbital period, has a considerable influence on the estimated parameters associated with the red giant’s ellipsoidal brightness variations, and this contribution cannot be neglected. The deviations of the observed from the calculated light curve are irregular, with the rms deviation being σ(O-C) ≈ 0.04^m.     

Post-deformational annealing of calcite rocks

The evolution of microstructure and crystallographic preferred orientation (CPO) during post-deformational annealing was studied on three calcite rock types differing in purity and grain size: Carrara marble (98% calcite, mean grain size of 115 μm), Solnhofen limestone (96%, 5 μm) and synthetic calcite aggregates (99%, 7 μm). Samples were first deformed in torsion at 727 °C at a shear strain rate of 3 × 10^{− 4} s^{− 1} to a shear strain of 5 and subsequently heat-treated at 727 °C for various durations between 0 and 24 h. Microstructures and CPOs were analysed by optical microscopy, image analysis and electron backscatter diffraction (EBSD).All rock types deformed in the dislocation creep field at the same applied conditions, but their microstructures and CPOs after deformation and after annealing differed depending on starting grain size and material composition. In Carrara marble and in the synthetic calcite aggregate, a strong CPO developed during deformation accompanied by dynamic recrystallisation with significant changes in grain size. During annealing, widespread grain growth and subtle changes of CPO occurred, and equilibrated foam microstructures were approached after long annealing times. The CPO is the only feature in annealed samples indicating an earlier deformation phase, although it is not always identical to the CPO formed during deformation. In the more impure Solnhofen limestone, secondary phases on grain boundaries suppressed grain boundary mobility and prevented both the formation of a recrystallisation CPO during deformation and grain size modification during deformation and annealing.