Furongian(upper Cambrian) Guole Konservat-Lagersttte from South China

The Guole biota contains common shelly fossils and some exceptionally well-preserved softbodied fossils. Stratigraphically, it is located in the mudstones and siltstones of the Sandu Formation near Guole Town, Jingxi County, Guangxi, South China. It is the first Furongian （late Cambrian） Burgess Shale-type biota found in the world, thereby filling the gap between middle Cambrian and Lower Ordovician Burgess Shale-type Lagerstaitten. Preliminary studies suggest that the Guole biota includes approximately seven metazoan groups as well as algae. These will provide important new evolutionary and ecological information.

Mesozoic Evaniidae (Insecta:Hymenoptera) in Spanish Amber:Reanalysis of the Phylogeny of the Evanioidea

One new genus and five new species of the family Evaniidae are described from the Early Cretaceous （Albian） Spanish amber of Pefiacerrada-I （Province of Burgos）, San Just and Arroyo de la Pascueta （both in the Province of Teruel）： Cretevania alonsoi sp. nov., C. montoyai sp. nov., C. alcalai sp. nov., C. rubusensis sp. nov., and lberoevania roblesi gen. and sp. nov. Taxonomic changes include Cretevania pristina （Zhang and Zhang, 2000） comb. nov., C. exquisita （Zhang, Rasnitsyn, Wang and Zhang, 2007） comb. nov., C. vesca （Zhang, Rasnltsyn, Wang and Zhang, 2007） comb. nov., and C. cyrtocerca （Deans, 2004） comb. nov., as a result of the reinterpretation of the genera Procretevania and Eovernevania. The new well preserved specimens of the genus Cretevania, together with the characters shown by the type specimens of the synonymized genera, give new information about their anatomical characters of taxonomical importance, and the genus Cretevania Rasnitsyn, 1975 is re-diagnosed. The holotypes of the Russian species in amber have been revised. A cladistic analysis of fossil and extant groups of the superfamily Evanioidea is included. Cretevania had a wide palaeogeographic distribution, with the highest diversity known from Spain. The 13 known Cretevania species show a high interspecific variation mainly in wing characteristics, and a wide range of body and wing size.

Ophiolite hosted chromitite formed by supra-subduction zone peridotite–plume interaction

Chromitite bodies hosted in peridotites typical of suboceanic mantle(s.l.ophiolitic)are found in the northern and central part of the Loma Caribe peridotite,in the Cordillera Central of the Dominican Republic.These chromitites are massive pods of small size(less than a few meters across)and veins that intrude both dunite and harzburgite.Compositionally,they are high-Cr chromitites[Cr#=Cr/(Cr+Al)atomic ratio=0.71-0.83]singularly enriched in TiO2(up to 1.25 wt.%),Fe2 O3(2.77-9.16 wt.%)as well as some trace elements(Ga,V,Co,Mn,and Zn)and PGE(up to 4548 ppb in whole-rock).This geochemical signature is unknown for chromitites hosted in oceanic upper mantle but akin to those chromites crystallized from mantle plume derived melts.Noteworthy,the melt estimated to be in equilibrium with such chromite from the Loma Caribe chromitites is similar to basalts derived from different source regions of a heterogeneous Caribbean mantle plume.This mantle plume is responsible for the formation of the Caribbean Large Igneous Province(CLIP).Dolerite dykes with back-arc basin basalt(BABB)and enriched mid-ocean ridge basalt(E-MORB)affinities commonly intrude the Loma Caribe peridotite,and are interpreted as evidence of the impact that the Caribbean plume had in the off-axis magmatism of the back-arc basin,developed after the Caribbean island-arc extension in the Late Cretaceous.We propose a model in which chromitites were formed in the shallow portion of the back-arc mantle as a result of the metasomatic reaction between the supra-subduction zone(SSZ)peridotites and upwelling plume-related melts.

Review of the El Soplao Amber Outcrop,Early Cretaceous of Cantabria,Spain

El Soplao outcrop, an Early Cretaceous amber deposit recently discovered in northern Spain （Cantabria）, has been shown to be the largest site of amber with arthropod inclusions that has been found in Spain so far. Relevant data provided herein for biogeochemistry of the amber, palynology, taphonomy and arthropod bioinclusions complement those previously published. This set of data suggests at least two botanical sources for the amber of El Soplao deposit. The first （type A amber） strongly supports a source related to Cheirolepidiaceae, and the second （type B amber） shows non-specific conifer biomarkers. Comparison of molecular composition of type A amber with Frenelopsis leaves （Cheirolepidiaceae） strongly suggests a biochemical affinity and a common botanical origin. A preliminary palynological study indicates a regional high taxonomical diversity, mainly of pteridophyte spores and gymnosperm pollen grains. According to the preliminary palynological data, the region was inhabited by conifer forests adapted to a dry season under a subtropical climate. The abundant charcoalified wood associated with the amber in the same beds is evidence of paleofires that most likely promoted both the resin production and an intensive erosion of the litter, and subsequent great accumulation of amber plus plant cuticles. In addition, for the first time in the fossil record, charcoalified plant fibers as bioinclnsions in amber are reported. Other relevant taphonomic data are the exceptional presence of serpulids and bryozoans on the surfaces of some amber pieces indicating both a long exposure on marine or brackish-water and a mixed assemblage of amber. Lastly, new findings of insect bioiuclusions, some of them uncommon in the fossil record or showing remarkable adaptations, are reported. In conclusion, a documented scenario for the origin of the El Soplao amber outcrop is provided.

Geotourism in the Salesopolis-Caraguatatuba Trail,Sao Paulo,Brazil:A Possibility to Utilize Geological Elements for Sustainable Development

The Salesópolis-Caraguatatuba trail lies slightly more than 130 km to ESE from the Sao Paulo city, and it is fully inserted within the Atlantic Forest. The region is particularly interesting because it brings together a complex lithological association and an exuberant topographical expression. A set of geological and geomorphological elements with high potentiality for the sustainable tourism development is documented in this paper. The geosites provide a wide variety of attraction, including valleys, streams, waterfalls and the unusual shapes of rocks. In each one of those outcrops, the visitors will have an exceptional opportunity for a better understanding about the processes that control the landscape evolution. In accordance with the new conception of geotourism, and taking as a basis the concepts of the geoscience for a rereading and interpretation of the several aspects of space and landscape, the sites catalogued should enable a new insight to increase environmental awareness of the local community, and, mainly, to encourage an innovative form of economic activity that has as a fundamental principle the nature preservation.

Evidence of Shock Metamorphism Effects in Allochthonous Breccia Deposits from the Colonia Crater,Sao Paulo,Brazil

The 3.6 km-diameter Colonia impact crater, centred at 2352'03"S and 4642'27"W,?lies 40 km to the south-west of the S?o Paulo city. The structure was formed on the crystalline basement rocks and displays a bowl-shaped with steeper slope near the top that decreases gently toward the centre of the crater. Over recent years were drilled two boreholes inside the crater, which reached a maximum depth of 142 m and 197 m. Geological profile suggests four different lithological associations: 1) unshocked crystalline basement rocks (197 - 140 m);2) fractured/brecciated basement rocks (140 - 110 m);3) polymictic allochthonous breccia deposits (110 - 40 m);and 4) post-impact deposits (40 - 0 m). Petrographic characterisation of the polymictic allochthonous breccia reveals a series of distinctive shock-metamorphic features, including, among others, planar deformation features in quartz, feldspar and mica, ballen silica, granular texture in zircon and melt-bearing impact rocks. The occurrence of melt particles and very high-pressure phase transformation in suevite breccia suggest a shock pressure regime higher than 60 GPa.

Characterization of Arroyo Verde Epithermal Deposit:Paragenesis,Mineral Geochemistry,Geochronology and Fluid Inclusions in Lower Chon Aike Volcanism,Argentina

Arroyo Verde epithermal deposit,in the North Patagonia region of Argentina,is located within the Lower Chon Aike volcanism and is developed between 192.6±2.5 Ma(mineralization host rock)and 189.5±2.6 Ma(overlying lava).Marifil volcanic complex is the host rock for these veins,veinlets and breccias.This particular small deposit has developed low to intermediate sulphidation characteristics,with gangue mineral textures associated with several ore minerals.Electron probe microanalysis determines electrum,silver minerals such as acanthite,and tetrahedrite,related Ag-Cu minerals like jalpaite,mckinstryite,stromeyerite,and base metals like chalcopyrite,sphalerite,galena and pyrite.Fluid inclusions in quartz of two out of five events indicate that these Low Jurassic veins were formed due to subtle boiling and dilution mechanisms and by low-salinity(3.4 wt.%to 6.7 wt.%NaCl Eq)magmatic-hydrothermal fluid at 225 to 310℃.The fluid inclusion measurements that indicate boiling(Event 3)were plotted,and based on this data,we interpret that the Arroyo Verde deposit has been eroded between 550 and 700 m.This particular character has not been previously recorded for other sectors of the eastern north Patagonian region.

Hyperpycnal littoral deltas:A case of study from the Lower Cretaceous Agrio Formation in the Neuquén Basin,Argentina

Recent advances in the understanding of deltaic deposits provide new tools for the study and analysis of deltaic deposits in shallow epicontinental seas.After the introduction of sequence stratigraphic concepts,meter-scale coarsening and thickening upward successions have been considered as“parasequences”originated by high-frequency sea-level changes.Nevertheless,recent studies enhanced the importance of wave-aided low-dense hyperpycnal flows in transporting fine-grained sediments in shallow shelfal areas.These poorly-known(and at the same time very common)types of delta,known as hyperpycnal littoral deltas(HLD),develop very low gradient progradational units,controlled by changes in the sediment supply instead of sea level changes.These small-scale progradational units are very common in shallow epicontinental seas like the Lower Cretaceous Agrio Formation in the Neuquén Basin.This study provides a first detailed analysis of hyperpycnal littoral deltas from the Agua de la Mula Member(upper Hauterivian-lower Barremian)of the Agrio Formation.This unit has been studied in three locations near Bajada del Agrio locality in the central part of the Neuquén Basin,Argentina.Six sandy facies,three heterolithic facies,three muddy facies and four calcareous facies were recognized.From facies analysis,three facies associations could be determined,corresponding to offshore/prodelta,distal ramp delta and proximal ramp delta.The three stratigraphic sections discussed in this study are internally composed of several small-scale sequences showing a coarsening and thickening upward pattern,transitionally going from muddy to sandy wave-dominated facies,and ending with calcareous bioclastics levels on top.These small-scale sequences are interpreted as delta front deposits of wave-influenced hyperpycnal littoral deltas,punctuated by calcareous intervals accumulated during periods of low sediment supply.It is interpreted that the development of hyperpycnal littoral deltas could have been facilitated by a decrease in sea water salinity related to an increasing runoff.