A preliminary investigation of the lichen biota associated with recently deglaciated terrain in southeastern Alaska

Glaciers worldwide are currently retreating at unprecedented rates, revealing large tracts of newly exposed rock and till. We present the results of a preliminary, qualitative investigation of the lichen diversity of transient habitats near three glaciers in southeastern Alaska: Muir Glacier within Glacier Bay National Park, and Baird and Patterson Glaciers in the Tongass National Forest. This work is noteworthy as it (i) documents previously undescribed lichen species and communities within rapidly changing glacier habitats, (ii) illustrates the importance of cryptogams (lichens, bryophytes, algae, and cyanobacteria) in the primary colonization of recently deglaciated terrain, (iii) sets apart the lichen biota of recently deglaciated terrain in southeastern Alaska from that of other glacial regions worldwide (e.g., the European Alps, Svalbard, and southern South America) and even other parts of Alaska (e.g., Brooks Range), and (iv) emphasizes the importance of more lichen studies that focus on this rapidly changing habitat. The lichen biotas found at different successional stages near these glaciers are described and compared. The role of lichens and other cryptogams in post-glacial vegetation initiation, the threats to the lichen biota, and suggestions for the possible origins of the lichen propagules that colonize these newly exposed surfaces are also discussed.

Terrestrial photogrammetry: a method to gather data on fractures for DFN modelling from exposed rock surfaces

The stochastic generation of discrete fracture networks (DFN) is a method for modelling fracture patterns used to assess the in situ fragmentation in a volume of rock. The DFN modelling approach is based on the assumption that the natural fragmentation of rocks is a function of the length and connectivity of the fractures within the considered volume of rock. Thus, in order to generate a site-specific DFN, the primary geometric properties of the fracture surfaces within the rock volume (especially orientation, size and fracture intensity as well as the local spatial variability) must be defined as distribution functions (Elmo et al., 2014). The required base statistics are usually obtained from fracture analysis on boreholes, exposed rock surfaces or (to a limited extent) 3D seismics (e.g. Bisdom et al., 2014; Bemis et al., 2014). We adopted a terrestrial close-range photogrammetry approach to capture several outcrops and analyse fracture traces on the exposed rock surfaces, the chosen workflow is based around the use of free and open-source software. Images were acquired from several quarries in the Weschnitzpluton, a granodioritic to quartz monzodioritic pluton in the Bergstrasse Odenwald (e.g. Altherr et al., 1999) using a consumer-grade Nikon D5300 DSLR with fixed focal length instead of a drone or Lidar-system for legal reasons, partially tree-lined outcrops and cost efficiency. Since point clouds obtained from photogrammetry are inherently dimensionless, we used a spherical target with compass and bubble level for scale and proper spatial orientation (Froideval et al., 2019). The exact geolocation is not particularly important for the task, so the use of GPS, total station or georeferenced ground control points is not necessary. Dense point clouds were computed using the open source SfM photogrammetry suite Meshroom (AliceVision, 2021), which can be used for manual or semi-automatic detection of fracture surfaces and their orientation (Schnabel et al., 2007) and to generate orthorectified images of the rock surface to trace fracture lengths and nodes in a GIS (Nyberg et al., 2018). Our investigations proved terrestrial photogrammetry to be a valuable and easily accessible tool in the documentation of natural fracture patterns and a robust base for the generation of DFN networks.

Geology, Geochemistry and Petrographic Studies of Exposed Rock Units from Zhob and Qila Saifullah Districts of Balochistan

Present research exertion provides the information about the stratigraphy, geological structure, geochemistry and petrographic characteristics of the exposed sedimentary rock units and igneous intrusions around Zhob and Qila Saifullah districts of Balochistan. Sedimentary deposition in this area is attribute to both Pashin basin and Suleiman basin. The litho-stratigraphic sections of Suleiman basin are Spingwar formation and Loralai formation (Allozai Group) of Jurassic age and Goru formation, Parh limestone and Pab sandstone of Cretaceous age, whereas Pashin basin comprises of Nisai formation of Eocene age and Multana formation of 0ligocene - Miocene age. The structural features of the area are comprising of complex, doubly plunging, anticlines and synclines which have been truncated by reverse faults at different places.Geochemical analysis (X-Ray diffraction and X-Ray fluorescence) displays that Igneous Intrusions are comprising of Clay, Mica, Plagioclase and Spinal mineral with abundance of Al203 (11-14% wt.), Si02 (27-34 % wt.), Ca0 (6-17% wt.) and Fe203 (19-32% wt.), whereas sedimentary rocks are rich in Quartz, Calcite and Albite with abundance of Al203 (0-17% wt.), Si02 (1.35-78% wt.), Ca0 (0.92-55% wt.) and Fe203 (0.07-13% wt.). The petrographic studies of the carbonates indicate mudstone to wackstone, carbonate fabric with skeletal grains of Alveolina, Miliolids, Globotrancana, Algae, Stylolites and foraminifera, whereas the sandstone samples are rich in sub rounded to rounded quartz grain, feldspar and mica. Petrographic analysis of igneous intrusion shows muscovite, pyroxene needles, chlorite and opaque minerals. Economically the research area is appropriate for cement factory, glass industry and building stones.

A new Antipathozoanthus species (Cnidaria, Hexacorallia, Zoantharia) from the northwest Pacific Ocean

A new species of zoantharian within the genus Antipathozoanthus is described based on specimens collected from the coast of mainland Japan, northwest Pacific Ocean. Antipathozoanthus tubussp. nov. is characterized by its substrate (epibiotic on polychaete tube) and habitat (exposed rock). As well, the results of molecular phylogenetic analyses using concatenated multiple genetic markers also support the distinction between A. tubussp. nov. and its congenerics. Antipathozoanthus tubussp. nov. is the first species of Antipathozoanthus species reported to be epibiotic on polychaete tubes, and is the second species in the genus that is not associated with antipatharians.

BIOCOLONIZATION AND BIODETERIORATION OF MONUMENTS BY CYANOBACTERIA

Cyanobacteria are a morphologically diverse, remarkably adaptable and widely distributed group of photosynthetic prokaryotes, many of which colonize, grow and survive on/in water-limited and nutrient-poor lithic substrates, such as natural rocks/stones and walls of historic monuments and buildings as lithobionts or lithobiontic organisms. They are often the primary colonizers of lithic substrates. They possess protective mechanisms against various abiotic stresses, such as desiccation, high irradiance, high levels of UV-radiation and high temperature which are often encountered on exposed rock surfaces and external walls of lithic monuments and buildings. The biocolonization and growth of cyanobacteria as lithobionts are influenced by various propertiesof monuments, buildings or buildingstones as well as by environmental factors. As photoautotrophs and primary colonizers of lithic substrates, they facilitate and promote the growth and development of heterotrophic microbes, such as bacteria and fungi.The production of extracellular polymeric substances (EPS) leads to the formation of cyanobacteriadominated phototrophic biofilms or sub-aerial biofilms on exposed surfaces of monuments, buildings and rocks/stones. Globally, thebiocolonization, growth and activities of lithobiontic cyanobacteria and other organisms cause unpleasant discoloration, biodeterioration (bioweathering) of monuments and buildings of historical, cultural or religious importance, leading to the aesthetic damage, structural damage and economic loss.These constitute serious problems world-wide. The article provides an overview of the processes of biocolonization and biodeterioration of monuments by lithobiontic(rockinhabiting) cyanobacteria, and their survival as lithobionts.

Vascular plants on inselberg landscapes in Espírito Santo state: bases for the creation of a protected area in southeastern Brazil

Inselbergs are granitic or gneissic rocky outcrops prevalent in the landscape of southeastern Brazil. These ecosystems represent islands of isolated habitats that harbor a peculiar flora with high richness and endemism. The present study lists the species of vascular plants occurring in the Pedra da Andorinha Complex, located in the municipality of Jerônimo Monteiro/Cachoeiro de Itapemirim, southern Espírito Santo state, aiming to generate subsidies for the creation of a protected area. The survey was performed between July 2017 and October 2018, resulting in a record of 121 species, 96 genera, and 40 families. Bromeliaceae (17), Orchidaceae (12) and Fabaceae (10) were the richest families. The phytophysiognomy of exposed rock vegetation comprises a greater number of species (79 species) compared to the woody rupicolous communities (42). Eighteen of the collected species are threatened by extinction; a new species was discovered; and five were described based on materials previously collected in the studied location — Alcantarea patriae, Anthurium martinellii, Coleocephalocereus uebelmanniorum, Stigmatodon attenuatoides and Pitcairnia azouryi, the first four being endemic to the region. We also found Tabebuia reticulata, a rare species among Brazilian flora. Our results highlight the biological importance of the Pedra das Andorinhas Complex and reinforce the need to create a protected area to preserve biodiversity and the regional natural heritage.

Impact crater versus bioherm on the Nullarbor Plain, Australia

<p>The Nullarbor Plain is ~200,000 km<sup>2</sup> large planar karst surface in southern Australia, composed of middle Cenozoic shallow-water limestones of Eucla Group. The youngest formation, covering the top of the plain, is middle Miocene extremely fossiliferous sub-tropical Nullarbor Limestone. In the late Middle Miocene the area was uplifted and exposed to terrestrial denudation and erosion since. Although the plain is in general considered extremely flat, the present geomorphological features indicate a relatively complex geomorphology formed by a combination of tectonic deformation, fluvial and aeolian activity and karst denudation. Due to the absence of orogenesis and only minor influence of post-Miocene sediment deposition, the geomorphology of the Nullarbor preserved footprints of Earth processes through a long, middle Miocene-to-present, time span.</p><p>The presence of dry climate and consequent lack of vegetation also aided for numerous meteorite findings, but no visible impact deformations have been recorded. The latter, in combination with capability of the plain to inherit/imprint old geomorphological features, and accessibility of recently built 0.4 arc sec TanDEM-X-DEM by the German Aerospace Centre, motivated the search of a possible meteorite craters with spatial analysis of the plain. The analysis of DEM images revealed a single geomorphological feature with circular uplifted rim (diameter: 1200 m – 1300 m; height: 7 m in relation to outer elevation; width: 200 – 450 m), central uplift (diameter: 500 m; height: 10 m in relation to outer elevation), and a circular trough in between (2 – 3 m higher than outer elevation). Its morphology differs from other geomorphological features observable on the Nullarbor Plain, and represents a unique phenomenon, which cannot be explained as a part of tectonic, volcanic, fluvial, karst or aeolian processes.</p><p>This feature is therefore a candidate for a possible relict of a meteorite crater, which occurrence is supported by topographical characteristics including uniqueness of the shape compared to other features on the plain. On the other hand, geological characteristics of the exposed rock within the “crater” lack any of the general diagnostic evidence for impact events (e.g., shocked quartz, brecciation), but rather indicate presence of boundstones with frame-builders preserved in in-situ position and thus suggesting the preservation of a bioherm. The occurrences of bioherms, however, are seldom individual (unlike impact craters) and more likely occur in clusters. The question remaining for this conference discussion is whether dissolutional imprinting of an impact crater could denude any of the characteristic impact structures whilst preserving the shape, or are we looking at a single bioherm preserved as a primary marine depositional feature?</p><p>ACKNOWLEDGEMENT: We acknowledge the financial support of Slovenian Research Agency (P6-0101; I0-0031; N1-0162), the Australian Speleological Federation Karst Conservation Fund and TerraSAR-X / TanDEM-X (DEM_GEOL2288).</p>

Mineral chemistry and thermo-barometry of intrusives from northern side of Shahroud river around Zardkuh in Guilan province (northern Iran)

The study area is located in northern Iran and is part of the Alborz mountain range. The exposed rock units in the study area are mostly Eocene volcanic rocks with some Oligomiocene intrusive masses included and locally Paleocene, Jurassic, Permian and Carboniferous sedimentary outcrops. The intrusive rocks of the study area are mostly gabbro and olivine gabbro in terms of mineralogical composition, but intermediate types such as porphyry monzonite are also rarely seen. Based on the results of microprobe analysis, pyroxenes have augite and diopside compositions, orthopyroxenes are hypersthenes, biotites have magnesium biotite and phlogopite compositions, olivines have hyalosiderite compositions and amphiboles are pargasite and ferropargasite compositionally. The results of temperature and pressure evaluation indicate a temperature range of 650 to 1200 ° C and pressure range >2-5 KB. Based on the chemistry of clinopyroxene mineral of the mentioned intrusions, magma that made these intrusions is of the sub-alkaline type and is formed in a volcanic arc tectonic setting.