Identification

Title

Deep Mantle Recycling Revealed in Diamonds and their Mineral Inclusions (NERC Grant NE/J008583/1)

Abstract

Three Published Papers; Thomson et al CMP 2014 - Origin of Sub-Lithospheric diamonds from the Juina-5 Kimberlite (Brazil): constraints from Carbon Isotopes and Inclusion Compositions http://dx.doi.org/10.1007/s00410-014-1081-8. Thomson et al Nature 2016 - Slab melting as a barrier to deep carbon subduction http://dx.doi.org/10.1038/nature16174 Burnham et al 2015 - Stable Isotope evidence for Crustal Recycling as recorded by superdeep Diamonds http://dx.doi.org/10.1016/j.epsl.2015.10.023 NERC grant abstract: Natural diamonds are formed at high pressures and temperatures deep within the Earth's interior. When diamonds form, probably from carbonate-rich fluids and melts in the mantle, they sometimes encapsulate small pieces of the minerals that occur at great depth in the Earth. These are called mineral inclusions. The diamonds are then transported from Earth's deep mantle to the surface in uncommon magmas called kimberlites. Diamonds that contain these mineral inclusions are very rare, and offer a truly unique glimpse into what is an otherwise inaccessible portion of the Earth. Some very rare inclusions provide direct samples of lithologies present in the mantle transition zone (400 - 660 km) and the lower mantle (>660 km) - these are often called superdeep diamonds. The chemistry of the inclusions along with mineral phase relations yield important information about the kinds of lithologies they originated in, and constrain the conditions of diamond formation and the depth at which kimberlite magmas form. Thus, superdeep diamonds are very important for studying the types of materials that occur in the deep Earth, for elucidating deep mantle processes, and for understanding how carbon is cycled from the surface to the mantle and back to the surface again - the deep carbon cycle. For example, some diamonds contain materials that are very similar to those occurring near the earth's surface, such as minerals akin to oceanic crust or sediments, and these often have carbon isotopic compositions akin to organic carbon - although this is a controversial subject. From this, we can conclude that surface materials can be transported to great depth, helping to constrain models of mass transfer in Earth by mantle convection. Further, by dating when the diamonds formed, for example by dating of inclusions, we can effectively place time constraints in the geodynamic processes involved in diamond formation and uplift in the mantle. Inclusion-bearing diamonds suitable for study are very hard to come by. We are very fortunate to be in possession of several large suites (over 200 inclusion-bearing diamonds in all!) of diamonds from kimberlite pipes in the famous Juina region of Brazil, a region known for its superdeep diamonds. Our previous study on diamonds from the Juina region has yielded some fascinating results, and has led to a model of material recycling beneath Brazil that we have recently published in the journal Nature and in Contributions to Mineralogy and Petrology. We now wish to extend our investigations by studying new suites of diamonds from Juina to test our current model, and to make high-pressure temperature experiments that will allow us to determine at what depths the inclusions formed and equilibrated, and will provide information needed to constrain the rates at which diamonds were transported in the solid-state mantle, possibly in a mantle plume. Here, we propose a three-year project for a comprehensive mineralogical, geochemical, isotopic and experimental investigation of these unique diamonds and their mineral inclusions.

Resource type

nonGeographicDataset

Resource locator

http://dx.doi.org/10.1038/nature16174

function: download

http://dx.doi.org/10.1007/s00410-014-1081-8

function: download

http://dx.doi.org/10.1016/j.epsl.2015.10.023

function: download

Unique resource identifier

code

http://data.bgs.ac.uk/id/dataHolding/13607078

codeSpace

Dataset language

eng

Spatial reference system

code identifying the spatial reference system

Additional information source

Thomson et al CMP 2014 refers to NE/J500033/1 Thomson et al Nature 2016 refers to NE/J008583/1 and NE/J500033/1 Burnham et al 2015 refers to NE/J008583/1

Classification of spatial data and services

Topic category

geoscientificInformation

Keywords

Keyword set

keyword value

originating controlled vocabulary

title

GEMET - INSPIRE themes

reference date

date type

publication

effective date

2008-06-01

Keyword set

keyword value

Carbon cycle

Subduction

Geology

Geochemistry

Stable isotopes

Petrology

Diamonds

originating controlled vocabulary

title

BGS Thesaurus of Geosciences

reference date

date type

revision

effective date

2011

Keyword set

keyword value

NERC_DDC

Geographic location

West bounding longitude

East bounding longitude

North bounding latitude

South bounding latitude

Temporal reference

Temporal extent

Begin position

End position

2016-01

Dataset reference date

date type

publication

effective date

2016-01

Frequency of update

notApplicable

Quality and validity

Lineage

The publications may contain lineage information.

Conformity

Conformity report

specification

title

INSPIRE Implementing rules laying down technical arrangements for the interoperability and harmonisation of Geology

reference date

date type

publication

effective date

2011

degree

false

explanation

See the referenced specification

Conformity report

specification

title

Commission Regulation (EU) No 1089/2010 of 23 November 2010 implementing Directive 2007/2/EC of the European Parliament and of the Council as regards interoperability of spatial data sets and services

reference date

date type

publication

effective date

2010-12-08

degree

false

explanation

See http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2010:323:0011:0102:EN:PDF

Data format

name of format

version of format

Constraints related to access and use

Constraint set

Limitations on public access

Constraint set

Limitations on public access

The copyright of materials derived from the British Geological Survey's work is vested in the Natural Environment Research Council [NERC]. No part of this work may be reproduced or transmitted in any form or by any means, or stored in a retrieval system of any nature, without the prior permission of the copyright holder, via the BGS Intellectual Property Rights Manager. Use by customers of information provided by the BGS, is at the customer's own risk. In view of the disparate sources of information at BGS's disposal, including such material donated to BGS, that BGS accepts in good faith as being accurate, the Natural Environment Research Council (NERC) gives no warranty, expressed or implied, as to the quality or accuracy of the information supplied, or to the information's suitability for any use. NERC/BGS accepts no liability whatever in respect of loss, damage, injury or other occurence however caused.

Responsible organisations

Responsible party

contact position

School of Earth Sciences

organisation name

University of Bristol

full postal address

Wills Memorial Building, Queens Road, Clifton

Bristol

BS8 1RJ

email address

not available

responsible party role

pointOfContact

Metadata on metadata

Metadata point of contact

organisation name

British Geological Survey

full postal address

Environmental Science Centre,Keyworth

NOTTINGHAM

NG12 5GG

United Kingdom

telephone number

+44 115 936 3100

email address

enquiries@bgs.ac.uk

responsible party role

pointOfContact

Metadata date

2023-05-24

Metadata language

eng