Modern Occurrences Research Articles

Archean tufted microbial mats and the Great Oxidation Event: new insights into an ancient problem

The macroscopic fossil record of the Archean consists solely of stromatolites and other microbialites, which seldom offer compelling clues to the identities of the organisms that formed them. Tufted microbial mats are an exception because their formation is known to require a suite of morphological and behavioural characteristics from which the behavioural and biological affinities of early microbialite-constructing microbes can be inferred. Here, the oldest yet reported convincing fossil tufted microbial mats are described and discussed in the context of other ancient and modern examples. Significantly, cyanobacteria dominate all known modern occurrences and may also have been the builders of ancient examples, the oldest of which predate by several hundred million years the earliest convincing cyanobacterial microfossils and most geochemical evidence for an oxygenated atmosphere.

Ivan the Terrible's Malady and Its Magical Cure

This paper discusses the testicular hydrocele which afflicted Tsar Ivan IV (Ivan the Terrible), Ivan’s alleged belief in witchcraft and employment of witches, the history of the Russian word kila, from its Greek origin to its employment as a Russian folk term for ‘a swelling, hernia’, and magic charms to cure it. From the evidence of two independent English manuscript dictionaries of Russian in the sixteenth and seventeenth centuries, the word kila in Old Russian texts of that period meant exclusively the swelling of the testicles caused by witchcraft. It is argued that Ivan would have known the word in that sense, believed that his condition was caused by witchcraft, and would have looked for a magical remedy. There are no recorded charms for this purpose dating from Ivan’s lifetime, but there are from the seventeenth century. In more modern occurrences of the word kila it seems mostly to have reverted to its previous non-specific sense of ‘swelling’ or ‘hernia’ – but Russian occult and medical websites show that the ‘hydrocele’ meaning survives as a folk term and that the sixteenth- and seventeenth-century association with witchcraft is also still well known.

A new asteroid (Echinodermata) faunule from the Early Cretaceous (Barremian) of Morocco

An asteroid (Echinodermata) faunule of four taxa representing three surviving families and a probable fourth is described from the Barremian (Early Cretaceous) of Morocco, northwest Africa. The four together suggest limited morphologic evolution since the Cretaceous but biogeographic and depth patterns have changed. Marocaster coronatus n. gen. n. sp. (Valvatida, Goniasteridae) combines apparent derived features of the dorsal disk and superomarginal shape with more stemward expressions of the abactinal ossicles. Betelgeusia orientalis n. sp. is a fourth Mesozoic occurrence of the Radiasteridae (Paxillosida), the new species similar to earlier occurrences from the Middle Jurassic of India, the Early Cretaceous of Texas, and the Late Cretaceous of Europe. Reported modern occurrences of the family are few, widely scattered, and limited to deeper water; the extinct species together testify to a once-broader familial distribution. Dipsacaster africanus n. sp., a member of the Astropectinidae (Paxillosida), is remarkably similar to extant congeners. Dipsacaster today is widely distributed in the Pacific Ocean but occurrences in the Atlantic are few. Because of preservation, a single small specimen of the Zoroasteridae? (Forcipulatida) cannot be identified with certainty. Extant zoroasterids are deep-water in distribution, although shallow-water Eocene representatives are known.

Significance of subtidal microbial deposits in Shark Bay, Australia

Microbial deposits at Shark Bay, Australia constitute one of the largest and most diverse modern occurrences around the world. The microbial carbonate system has developed in response to environmental change from near open marine into restricted embayment with hypersalinity and high evaporation. Bacterial sediments started depositing at about 2000 years BP, after the Holocene maximum flooding of sea level about 6800 years BP, due to increasing salinity as the sea level fell by about 2.5 m, within the Holocene highstand system tract. The extent and types of subtidal microbial substrate in this World Heritage area have not previously been fully systematically mapped and described. Here we document the importance of subtidal microbial deposits occupying as much as 10 times the occurrence area of the intertidal microbial mats and stromatolites and demonstrate that deeper structures have a cerebroid external morphology with a non laminated internal fabric. Subtidal structures contain consistently different internal fabrics with carbonate grains and fragments interbedded with aragonitic micrite arranged in millimetric laminae or sub-spherical patches, which display fabrics such as well laminated (Smooth), coarse laminated wavy (Colloform), sub-laminar to irregular with voids and biofragments of bivalves (Microbial Pavement), irregular clotted (Pustular) and non-laminated (Cerebroid), constituting carbonate sediment with stromatolitic facies (Smooth and Colloform), thrombolitic facies (Pustular) and cryptomicrobial non-laminated (Cerebroid and Microbial Pavement). Each microbial structure grows in specific settings according to water depth (MSL), with Cerebroid build-ups commonly occurring between − 1 and − 2.5 m and Microbial Pavement extending as deep as 6 m. Because of the late Holocene sea level fall microbial structures often record in their internal features a shallowing-up carbonate cycle. These newly documented extensive subtidal microbial structures, with distinctive morphologies and fabrics have importance as modern occurrences and provide potential analogues for understanding ancient microbial systems and environments.

Comment on “The ‘living-fossil’ community of the cyrtocrinid Cyathidium foresti and the deep-sea oyster Neopycnodonte zibrowii (Azores Archipelago)” by M. Wisshak, C. Neumann, J. Jakobsen and A. Freiwald [Palaeogeography, Palaeoclimatology, Palaeoecology 271 (2009) 77–83

Wisshak et al. (2009. The ‘living-fossil community’ of the cyrtocrinid Cyathidium foresti and the deep-sea oyster Neopycnodonte zibrowii (Azores Archipelago). Palaeogeography, Palaeoclimatology, Palaeoecology 271, 77–83) criticized the speculation by Donovan and Jakobsen that an association of Danian cyrtocrinids and barnacles may have occurred on a floating log. This association is unlikely to be allochthonous; no convenient hard substrate (= overhang) for attachment of these crinoids and barnacles was available close at hand; the holopodid migration into deeper water occurred at about this time, but a shallow water relic cannot be dismissed out of hand; and a strict Lyellian comparison with modern occurrences is not necessarily correct. We stand by our original speculation.

Lallemantia, an imported or introduced oil plant in Bronze Age northern Greece

This paper reports on seeds of Lallemantia (Lamiaceae) found at Bronze Age sites in northern Greece. At several of these sites, the seeds were found in significant concentrations in storage contexts, suggesting that they were deliberately stored for use by the inhabitants. Oil from the seeds of Lallemantia can be used for a variety of purposes, including food, lighting and medicine. This genus is not native to Greece, the nearest modern occurrences of Lallemantia species being in Anatolia from where they extend further east as far as Iran, or beyond. To date, it has not been found in Neolithic deposits in Greece, despite significant archaeobotanical research, especially in northern Greece. This suggests that it first appeared in Greece in the early Bronze Age, and indicates long distance contacts with communities to the east or north at this time. It is difficult to establish whether its continued use indicates that seeds of this genus were repeatedly brought into Greece throughout the Bronze Age or that the genus was introduced in the early Bronze Age and then locally cultivated. The presence of seeds, however, may suggest that Lallemantia was locally cultivated, as it would have been possible to import it in the form of oil. The appearance of a new import or introduction at this time adds to the evidence for external contact during the Bronze Age. Lallemantia may have been part of a group of oil producing taxa which became significant during the Bronze Age in northern Greece paralleling the increased importance of the olive in southern Greece.

Serpentine-nontronite-vermiculite mixed-layer clay from the Weches Formation, Claiborne Group, middle Eocene, northeast Texas

AbstractThe Weches Formation of the Claiborne Group (Eocene) in northeast Texas consists of clayey sandstones and mudrocks, both with variable proportions of dark green to brown clay peloids deposited in a marginal to open marine setting on the Gulf Coast margin. The composition of the dark green peloids, from two localities, has been investigated using X-ray diffraction, back-scattered electron microscopy with X-ray analysis, electron energy-loss spectroscopy (EELS), Mössbauer spectroscopy, chemical analysis and Fourier transform infrared spectroscopy. These peloids were previously described on the basis of their color as glauconite (Yancey and Davidoff, 1994); our results, however, show that the dark green indurated pellets are predominantly composed of mixed-layer clays with a high proportion of Fe-rich 7 Å serpentine layers coexisting with a mixed-layer phase containing glauconite, nontronite and vermiculite layers, in addition to discrete illite and kaolinte. Analyses by EELS of single particles with a chemical composition consistent with them being the Fe-rich clay indicate that the Fe is >95% ferric, while Mössbauer analyses of the bulk magnetically separated fraction for the same samples indicates a ferric iron content of ∼60–70%, despite the variable relative proportions of expandable and 7 Å layers. Taking into account that there is a significant amount of 2:1 layers containing ferric Fe, we interpret these data as indicating that the Fe in the 7 Å layers has a significant amount of Fe2+ even taking into account the high ferric Fe ratio from the EELS analysis when the coexisting 2:1 layers are considered. Thus, these 1:1 layers are closer to berthierine in composition than to odinite. The vermiculite layers in the Texas clay may indicate partial ‘verdinization’ of expandable 2:1 clay. A possible reaction is smectite → vermiculite → berthierine-like phase. We estimate a temperature of 20°C for the seawater in which the Texas clay formed, the lower end of the range for modern occurrences of odinite.

Genesis and geometry of the Meiklejohn Peak lime mud-mound, Bare Mountain Quadrangle, Nevada, USA: Ordovician limestone with submarine frost heave structures—a possible response to gas clathrate hydrate evolution

Abstract During the Early Middle Ordovician (Early Whiterockian) the Meiklejohn Peak lime mud-mound, a large whaleback or dolphin back dome, grew on a carbonate ramp tens to hundreds of kilometres offshore. This ramp extended from the northwest margin of Laurentia into the open waters of the ancestral Pacific Ocean to the north. The mound developed in an outer ramp environment, in relatively deep and cold water. A steep northern margin with a slope that exceeds 55° characterizes the mound. This margin is split by a 14-m long vertical fracture that separates a zone of slumped, drag-folded and brecciated rocks from the main mass of the mound. Failure along this fracture occurred subcutaneously, as highlighted by covering beds that are folded next to the mound. Brecciated blocks and clasts contain zebra and stromatactis structures indicating that these rocks and structures were lithified early in the history of the mound. The southern end of the mound is less steep and is characterized by large, echinodermal grainstone cross-beds. These deposits are part of a large, subaqueous dune that grew northwards and preceded the main development of the mound. Southward dipping and downlapping layers of mud-mound mudstone and wackestone overlie the dune. These muddy limestone layers are cut in several places by injection dykes and are pierced, near the contact with the underlying dune, by a 25-m long pipe filled with rotated nodular and brecciated mud-mound clasts. This long pipe extends to the edge of the mound and appears to have been a conduit where fluidized materials that came from the mound's interior were vented. The interior of the mound is typified by light grey limestone with zebra bands and stromatactis structures. Both structures represent former cavity systems that are filled with fibrous and bladed calcite and pelleted and laminated geopetal mudstone. Spar bands of zebra limestone often extend for several metres and appear to have been unsupported over these distances. Zebra banded rocks are also accompanied by snout and socket structures and, in some instances, are folded and sheared by curving kink bands. Zebra and stromatactis limestone structures found throughout the mud-mound resemble frost heave and cryoturbation structures identified in both Holocene and Pleistocene cryosols, and in laboratory experiments with advancing freezing fronts in clay-size sediment. Significantly, modern occurrences of methane clathrate hydrate (methane-charged ice) display parallel and digitate layering similar in depositional appearance to that of zebra and stromatactis limestone from Meiklejohn Peak. Early carbonate cements are also commonly associated with these modern clathrate hydrate deposits. Consequently, gas clathrate hydrates may have been the propping agent for zebra and stromatactis structures observed in the mud-mound. In this scenario, carbonate cements would have precipitated and stabilized these structures, both with the consolidation and dissociation of gas clathrate hydrates, and with the oxidation and reduction of associated gases. Stable δ 13 C and δ 18 O isotope ratios collected from mudstone and spar of zebra and stromatactis structures indicate that they were lithified in equilibrium with Ordovician seawater. The δ 13 C isotope ratios recorded at Meiklejohn Peak are similar to δ 13 C isotopic ratios obtained from ∑CO 2 evolving from modern seafloor. These isotopic ratios may indicate that frost heave structures in the Meiklejohn Peak mud-mound are the result of consolidation and dissociation of carbon dioxide clathrate hydrates. Even though the bulk of gas clathrate hydrates identified to date in modern ocean floors are composed of methane, carbon dioxide clathrate hydrates are known from the modern seafloor of the Okinawa Trough. They may also be common in areas of abundant carbonate sediment accumulation, as suggested by recent observations from the Great Australian Bight.

Molecular genetic evidence for the post‐Pleistocene divergence of populations of the arctic‐alpine ground beetle Amara alpina (Paykull) (Coleoptera: Carabidae)

Summary Aim This study examines the hypothesis that the biogeographic history of a species is reflected in the distribution of molecular genetic diversity and the phylogenies of extant populations. Location Populations of arctic‐alpine ground beetle Amara alpina were analysed from Beringia (Alaska and northernmost British Columbia), the Hudson Bay region, the northern Appalachian Mountains, and the central Rocky Mountains of North America. Methods Mitochondrial restriction site variation of specimens from twenty‐two populations were assayed by using radioactively labelled mtDNA to probe Southern membranes containing restriction enzyme digested total DNA. Restriction sites were mapped and genetic distances were calculated by pairwise comparison of presence and absence of restriction sites. Genetic distances were used in a molecular analysis of variance and to construct a minimal spanning tree. Parsimony methods were used to investigate the phylogenetic relationships between the haplotypes. These results were compared to an existing model for postglacial dispersal based on fossil and modern occurrences of arctic‐alpine beetles. Results Among the twenty‐two populations, fifteen haplotypes were detected. Genetic variation within each of the four regions corresponded to that expected from the palaeontologically based model. Beringian populations were the most genetically diverse. In contrast, no restriction site variation was observed in populations from the Hudson Bay region. Intermediate amounts of variation were observed in alpine populations of the Rocky and Appalachian Mountains. Maximum parsimony and cluster analysis provide evidence that at least two ancestral haplotypes existed in the Southern refugium from which the Rocky and the Appalachian Mountains populations were founded. Main conclusions The genetic results are generally consistent with the palaeontologically based model. The diversity of Beringian populations is consistent with this region having been continuously inhabited by Amara alpina throughout the Pleistocene. The Hudson Bay region was not deglaciated until about 6000 years, and its populations have no restriction site variation. The molecular genetic data support the interpretation that the Hudson Bay region was colonized from Beringia based on the occurrence of the same haplotype in both regions.

Ancient and modern occurrences of common fig (Ficus carica L.) in the British isles

Knowledge of the reproductive biology of the common fig ( Ficus carica) is essential for the interpretation of present and past occurrences of pips from archaeological layers as well as for understanding the status of trees, cultivated or wild. Only parthenocarpic varieties ripen figs in Britain and these cannot produce fertile pips. Common figs growing wild in Britain all come from pips from imported figs, often figs that had been eaten and the pips evacuated. There are many discoveries of pips from Roman and later urban and military sites in Britain. These pips too were derived from imported figs and not from locally cultivated trees. There is no proof that the Romans grew common fig in Britain and the earliest documentary evidence of cultivation is as late as the 15th century A.D.

Palaeoentomology of the Kap København Formation, a Plio-Pleistocene sequence in Peary Land, North Greenland

The Kap København Formation in eastern Peary Land, latitude 82°30', is dated to the Plio-Pleistocene transition period, c. 2 million years B.P. The shallow water marine sediments contain abundant remains of terrestrial and limnic insects, in particular beetles (Coleoptera). The insect fauna is diverse, comprising 155 named species, of which 140 are beetles. The Coleoptera are dominated by ground beetles (Carabidae), rove beetles (Staphylinidae) and weevils (Curculionidae). Apart from three unknown and possibly extinct species, including Diacheila matthewsi n. sp. described herein, all the insect taxa are extant. Most are extralimital forms of the recent circumpolar subarctic/boreal fauna. However, a high number of fossils represent taxa which are today either nearctic or palaearctic, in some cases with modern occurrences in northeastern Asia or western North America. Many species are hygrophilic (20 %), aquatic (16 %) or riparian (18 %), thereby showing the existence of a great variety of freshwater wetland biotopes. Another large group (14 %) are either dependent on trees for food or are obligate forest dwellers and therefore indicate forest environments. Still other species suggest arctic/alpine living conditions (14 %), and a few are indicative of steppe environments. The fossil insect fauna thus strongly supports and elaborates previous palaeo botanical results showing that Peary Land at the beginning of the Quaternary epoch was covered by a rich and varied vegetation, in the lowlands with trees and probably small forests. The palaeo climate was boreal and humid, with a July mean temperature of at least 8-11°C, but considerably warmer (13-19°C) in lowland areas or during certain time periods. There are indications of a shift in climate from subarctic to more southern boreal conditions during the deposition of the upper member (B) of the Kap København Formation.

Methane‐derived high‐Mg calcite submarine cement in Holocene nodules from the Fraser Delta, British Columbia, Canada

ABSTRACTCarbonate nodules and slabs in late Holocene shelly terrigenous deposits of the modern Fraser River delta (∼49°N) are formed close to the seafloor by precipitation from saline pore waters of mainly fibrous to bladed crystals of high‐Mg (∼ 10–20 mol% MgCO3) calcite cement as coalescing isopachous crusts on grains. Previous reports that the cement is low‐Mg calcite are not supported by this study. Highly negative δ13C values of − 7 to − 59‰ for the cements indicate that the bulk of their carbonate carbon was derived from the microbiological degradation of organic matter in the deltaic deposits during shallow burial. In particular, the production of biogenic methane (CH4) by anaerobic bacterial fermentation, its upward migration, chemical or biological oxidation to CO2 and neutralization in the near‐surface sediment, and diffusion to microenvironments relatively enriched in organic components, are a possible set of conditions influencing the process and sites of carbonate cementation. Methane‐derived Mg‐calcite appears also to be the major submarine cement in several other modern occurrences of lithified shallow‐water terrigenous sands and muds at non‐tropical latitudes.

Book reviews

Depositional and Diagenetic Spectra of Evaporites—a Core Workshop, ed. by C. C. Handford, R. G. Loucks and G. R. Davies.The Gironde Estuary, by J. M. Jouanneau and C. LatoucheSubaqueous Slope Failures—Experiments and Modern Occurrences, by H.‐U. SchwarzHydrocarbon Generation and Source Rock Evaluation (Origin of Petroleum III), compiled by Robert M. Cluff and Mary H. BarrowsThe Field Description of Sedimentary Rocks, by Maurice E. Tucker

Geochemical constraints on the evolution of the early continental crust

The most important process affecting both major and trace-element concentrations in the mantle and crust is melting producing silicate liquids which then migrate. Another process whose effects are becoming more apparent is the transport of elements by CO 2 - and H 2 O-rich fluids. Due to the relatively small amounts of fluids involved they have but little effect on the major-element abundances but may severely affect minor- and trace-element abundances in their source and the material through which they travel. The Archaean crust was a density filter which reduced the possibility of komatiite or high FeO melts with relative densities greater than about 3.0 from reaching the surface. Those melts retained in the lower crust or at the crust-mantle boundary would have enhanced the possibility of melting in the lower crust. The high FeO melts may have included the Archaean equivalents of alkali basalt whose derivatives may form an important component in the Archaean crust. The occurrence of ultramafic to basic to alkaline magmas in some Archaean greenstone belts is an assemblage most typical of modern ocean-island suites in continental environments. The rock types in the assemblage were modified by conditions of higher heat production during the Archaean and thus greater extents of melting and melting at greater depths. If modern ocean-island suites are associated with mantle plumes, which even now may be an important way to transport heat upward from the deeper mantle, it is suggested that during the Archaean mantle plumes were an important factor in the evolution of the continental crust. It appears that the Archaean continental crust was of comparable thickness to that of the present based on geobarometeric data. If the freeboard concept applied then, this would suggest that plate tectonics was also an active process during the Archaean. If so, it is probably no more realistic to assume that all Archaean greenstone belts had a similar tectonic setting than to assume that all modern occurrences of basic rocks have a common tectonic setting.

Stone rosettes as indicators of ancient shorelines: examples from the Precambrian Belcher Group, Northwest Territories

Flat-pebble conglomerates in the McLeary Formation of the Belcher Group display close packing of intraformational slabs in near-vertical arrays that appear distinctively polygonal in sections parallel to bedding. Such arrangements of flat pebbles, known by names such as stone rosettes and slone packings, are common on modem beaches, especially within the swash and backwash zone of shore platforms. Association of the McLeary stone rosettes with sedimentary features suggestive of shallow subtidal to supratidal origin (herringbone cross-bedding, reactivation surfaces, desiccation cracks, tepee structures, gypsum casts, oncolites, stromatolites, and probable beachrock) supports a hydrodynamic origin for these polygonal arrays of flat pebbles, an origin that has been demonstrated for modern occurrences. Where associated structures corroborate interpretation of a shallow-water origin, such stone rosettes provide evidence for ancient strandlines, and the designation "beach rosettes" is suggested as appropriate to distinguish them from stone rosettes formed by periglacial processes.

Palaeoecological interpretations of South Australian Precambrian stromatolites

Abstract Despite the palaeoecological emphasis of recent stromatolite research outside the USSR, controversy still exists regarding the environmental restriction of these organosedimentary structures and some analogies with modern occurrences have been maintained too rigidly. Palaeo‐environments should be determined where possible by a combination of all biological and sedimentological evidence. In South Australia, Precambrian carbonate rocks contain widespread stromatolites. The absence of independent biological environmental indicators necessitates a reliance on general stratigraphic and sedimentological data for the interpretation of regional palaeogeography and local environmental conditions. The Skillogalee Dolomite contains one predominant form of stromatolite almost throughout its extent, and it chiefly grew as biostromes in littoral and lagoonal settings on an extensive, level, carbonate‐depositing platform, probably of restricted access to the open sea. The interspace and associated sediments show evidence of varying energy conditions, degree of oxidation and possibly salinity, but the same stromatolite persists, although there is some modification of morphology in the higher energy environments. The Umbera‐tana Group has basinal shale and siltstone in its lower part, but during a subsequent widespread regression, the marginal parts of the basin were shallowed sufficiently to allow the growth of stromatolites, probably in water depths ranging from shallow subtidal to low supratidal. In addition, in the northern central part of the basin, offshore banks of shallow water limestone may have been related to areas of diapiric activity. The stromatolites of the Umberatana Group most often occur as bioherms of varying sizes intimately associated with ooid and intraclast grainstones, cross‐bedded sandy limestone, and, in marginal areas, penecontemporaneous dolomite. Different forms may occur in sequences of seemingly indistinguishable litho‐facies. These observations strengthen the view that stromatolite morphology is at least partly biologically controlled, the defined taxa being largely independent of the local environment.

Stratigraphic Distribution of Some Residual Organic Compounds in Upper Jurassic

Examination of some residual organic substances in Upper Jurassic rocks has shown several relationships between rock types and organic constituents. The organic carbon and nitrogen content as well as the residual amino acids and carbohydrates of these samples were discussed earlier (Palacas et al., 1960; Swain, 1961). The nearshore marine and non-marine Jurassic rocks have relatively more of the organic nitrogen represented by amino acids or amines, while the basinal and neritic samples have more of the organic nitrogen in the heterocyclic form or in humic complexes. Both the presumed saturated and aromatic hydrocarbon residues, extracted from littoral and neritic non-reservoir Jurassic rocks and separated chromatographically, are roughly equal in amount and are similar to modern occurrences. In basinal Jurassic rocks the aromatics tend to exceed the saturates, although exceptions occur. Several possible polycyclic aromatic hydrocarbons were detected in the basinal and some neritic, but less definitely in littoral samples. Residual asphaltenes in the Jurassic rocks are much less in amount than in Recent equivalents, probably because of post-depositional changes. Trace amounts of probably aromatic and heteroaromatic substances are widespread in the Jurassic samples studied. Among the substances possibly represented are: anthracene, naphthalene, pyridines, quinolinic acid, pyrazine, aniline, pyrimidine, purine, and several possible polycyclic aromatic hydrocarbons. Of these, anthracene and the pyridines occur most commonly, and also have been recognized in samples of other ages. The basinal marine Jurassic samples tend to have a predominance of one-ring residual aromatics, whereas the neritic and littoral samples seem to have relatively more two- and three-ring aromatics and porphyrins. No relation was found between the larger fossil remains and organic residues in the samples studied; the nannofossils may contribute to the organic residues but no quantitative relationship was found. Conclusions by others that air and surface water temperatures were higher in central North America during the Jurassic than at present are supported by the present study. Such contributing factors as organic productivity, preservation of organic residues, redox potentials, mineralogy, and color of sediments are discussed in relation to the residual organic matter.

The solar hypothesis of climatic changes

Research Article| January 01, 1914 The solar hypothesis of climatic changes ELLSWORTH HUNTINGTON ELLSWORTH HUNTINGTON 2With the cooperation of Charles. J. Kullmer and E. E. Free. Search for other works by this author on: GSW Google Scholar GSA Bulletin (1914) 25 (1): 477–590. https://doi.org/10.1130/GSAB-25-477 Article history received: 10 Jul 1914 first online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation ELLSWORTH HUNTINGTON; The solar hypothesis of climatic changes. GSA Bulletin 1914;; 25 (1): 477–590. doi: https://doi.org/10.1130/GSAB-25-477 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract IntroductionIn the study of glaciation and of other ancient climatic phenomena it has been tacitly assumed that changes of climate in the geological past have been due to causes which are not now in operation, or whose effects during the past few generations have been so small that they have escaped observation. This is a natural assumption. In the first place, the phenomena of the last Glacial period, which may serve as the standard example for all the main climatic changes, are so vastly greater than anything that we can now observe that the mind naturally supposes them to have been due to some cause of correspondingly grand proportions. In the second place, the phenomena of that period have appeared to be wholly different from anything now occurring. No one, for instance, has hitherto described any modern occurrences corresponding to the glacial accumulation of snow in Labrador and Scandinavia, . . . This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.