Development of a geodatabase for the central-eastern Himalayas

Transcription

1 X Convegno Nazionale "GIT- Geosciences and Information Technologies Giugno 2015, San Leo (RN) Development of a geodatabase for the central-eastern Himalayas Pietro MOSCA 1, Chiara GROPPO 2,1 & Franco ROLFO 2,1 ( 1 )CNR-Istituto di Geoscienze e Georisorse, Torino ( 2 ) Dip. Scienze della Terra, Univ. Torino

2 Geologic mapping. modern geologic mapping cannot be only considered as simple digital/graphic representation of rock distributions, but it is an expression of several type of data collected, elaborated and interpreted at that time. So, description and storing of data play a fundamental and strategic role in geologic mapping standard models and standard vocabulary are then required (GeosciML )

3 CARG project, at a scale 1: Carta geologica del Piemonte, at a scale 1: geological mapping and related studies of central-eastern Himalayas

4 TORINO working group collected a large amount of data (quantitative) in the central-eastern Himalayas in the framework of different activities and projects. Field: structural to lithological data, rock samples, water samples Labs: thin sections, geochemical analyses geological maps (at different scales)..old ( 70s) and new data Working at a regional scale imposes a correct data management and storing of all these data data quality data traceability...and these are fundamental steps for correlation through the chain

5 Correlation of data

6 Working at a regional scale imposes a correct data management and storing of all these data data quality data traceability...and these are fundamental steps for correlation through the chain 1) Semantic harmonization 2)geometric/topologic harmonization Geodatabase Digital structure (.shp) DB with Descriptive standards Geological Knowledge transfer by using Description Standards: GeoSciML vocabulary

7 - From the GeologyCore application scheme included in European INSPIRE GE model Geologic Features The geometry of these features is described in the MappedFeature class referring to points, lines, and polygons (ArcGis) (Mosca et al., ROL 2015)

8 GeologicUnit_TypeValue Geological Knowledge transfer by using Description Standards The layout database categorizes the polygons on the basis of their attribution to (i) the main tectono-stratigraphic Unit (tectonostratigraphic unit_i, e.g., Greater Himalayan Sequence) and, (ii) the second-order tectono-stratigraphic unit (i.e. tectono-stratigraphic unit_ii, internal subdivisions of the main tectono-stratigraphic units; e.g., Lower Greater Himalayan Sequence) and reports (iii) the distinctive compositional properties of the rock body (lithologic unit; e.g. two micas +Grt+St+Ky micaschist and gneiss), and possibly (iv) its role as part of another rock body (Lithosome, Vein or dike lithosome, tectonic block, stratigraphic intercalation etc.; e.g. level of impure marbles in two Micas +Grt+St+Ky micaschist and gneiss).

9 GeologicUnit_TypeValue This layout reports also the corresponding nomenclature proposed in the literature and related sources

10 The geological structures include three feature classes: ShearDisplacementStructure (brittle to ductile faults), Fold, and Contact.

11 The Contact class is an extension to the core model and represents the geological contacts. Graphically it corresponds to the lines that involve each of the polygons of the mapped lithological units. Ex Igneous intrusive contact leucogranites gneiss

12 Method.. Observation method -outcrop observation measured/estimated value -indirect method -digital conversation from published source Ex foliation

13 Contact by indirect method Metamorphic facies contact (contact between rocks showing different metamorphic evolution/facies). Sometime, this is an Hidden discontinuity : not always corresponding to a structural discontinuity clearly evident on the field (i.e. single thrust or shear zones), but its occurrence is revealed by thermobarometric results

14 Rock Samples, water samples and their labs analyses Interdisciplinary Earth Data Alliance (IEDA) to support, sustain, and advance the geosciences by providing data services for observational solid earth data from the Ocean, Earth, and Polar Sciences. data to be discovered and reused by a diverse community now and in the future. IEDA is a partnership between EarthChem and the Marine Geoscience Data System. EarthChem its scope is the preservation, discovery, access and visualization of geochemical, geochronological, and petrological data. EarthChem includes the EarthChem 50 km Portal, NAVDAT, SedDB, PetDB and Geochron, Sesar projects and databases..old ( 70s) and new data

15 Rock Samples, water samples and their labs analyses 1 the Petrological Database PetDB is a global synthesis of chemical, isotopic, and mineralogical data for rocks, minerals, and melt inclusions. focuses on data for igneous and metamorphic rocks from the ocean floor, specifically mid-ocean ridge basalts and abyssal peridotites

16 2 Geochron is supporting data contributions for U-Pb, (U-Th)/He, and Ar-Ar geochronology and thermochronology

17 3 SESAR-System for Earth Sample Registration but samples should first be registered with International Geo Sample Numbers (IGSN), a 9-digit alphanumeric code. SESAR catalogs and preserves sample metadata profiles, and provides access to the sample catalog via the Global Sample Search. The IGSN should be used to identify the sample in the storage or archive. in the lab. in your data files. in publications Sample Hierarchy : parent-child relationships Sample s.s. (ex. Gneiss) Parent Children (sub-samples/children of a parent sample) (grains of zircons extracted from rocks for geochronological analysis,thin section.)

18 50 km Sample Related Sample Parent: no parent children: 09-05ts Sample 09-05ts Related Sample Parent: children: 09-05ch (an.chimiche)

19 Water samples Description, Geolocation, Collection, Projects, date of analyses Labs, analyst

20 classical papers (where geological maps, petrographic-chemical data are presented) are linked to an uniform /standard storage of data (..Geodatabase )

21 -Geologic map is expression of databases -Earth Science community needs standard models and vocabularies for the storage and exchange of geological data: this is the base for cooperation and projects development, and discovery of existing data (publications) -For samples: databases of EarthChem projects allow users to quickly and easily access comprehensive data sets over the web, and to extract subsets that include data from any number of publications based on queries customized to an investigator s interests. -in addition, this helps to preserve and valorize geologic data obtained/collected with time and economic efforts - but this is not yet seen as a necessity for most of the scientific community -..la nostra gelosia del dato..

22 grazie Langtang, aprile 2015