H2020Индивидуална стипендия2016–2018

AAT-NAA · Advancing Apatite Thermochronology: Novel analytical approaches for high eU apatites.

„Хоризонт 2020“ — Действия „Мария Склодовска-Кюри“

Период: 2016-09-01 → 2018-10-01
Финансиране от ЕС: 173 076 €
Участници: 1
Схема: MSCA-IF-EF-ST

Линиите свързват координатора с партньорите.

Накратко на български

Термохронологията на минерала апатит проследява как скалите са се охлаждали или загрявали при движението им към повърхността или в дълбините на земната кора. Това помага за разбирането на еволюцията на релефа и развитието на седиментни басейни с въглеводороди.

Този кратък обзор е генериран от изкуствен интелект

Кратко обяснение, генерирано от езиков модел по текста на CORDIS. Оригиналът е по-долу.

Резултати накратко

Advancing Apatite Thermochronology: Novel analytical approaches for high eU apatites.

Rocks in the Earth’s crust are cooled as they are exhumed to the surface and heated as they are buried beneath overlying rock. Using low temperature thermochronometry (LTT) dating on accessory minerals, we can constrain rock thermal histories and resolve the timing and rate of rock exhumation or burial. This information is important for understanding the evolution of topography and the development of potential hydrocarbon rich sedimentary basins. Knowledge of the properties that govern the temperature sensitivity of different LTTs is crucial to their successful application. The rate of fission track thermal annealing over c. 120–60°C defines the sensitivity of the apatite fission-track (AFT) thermochronometer. The rate of He diffusion from apatite over 90–30°C defines the sensitivity of the apatite (U-Th)/He (AHe) thermochronometer. The temperature sensitivity of both systems is also influenced by mineral composition and radiation damage accumulation and annealing (RDAA); however, our understanding of these additional influences remains incomplete. This lack of understanding has resulted in AFT and AHe data that are over-dispersed and challenging to explain using existing models, particularly from rocks that have spent long periods (10s-100s of Myrs) at temperatures of c. 120–30°C. The objectives of this project were to advance AFT and AHe methodology, establish analytical capabilities at the Université de Rennes 1 (UR1) and provide new insights into the thermal history of the crust at geological settings presumed to be stable.

Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз

Цел на проекта

Low temperature thermochronometry (LTT) dating is a powerful tool in geoscience, used worldwide, to provide unique information on the thermal history of rocks. Using these insights geologists can achieve a better understanding of geological processes that have occurred over million year timescales even in settings where erosion has removed much of the geological record. Despite the success of these techniques in tackling geological problems, there still exists a major gap in our knowledge over the fundamental principles that underlie these dating systems. Much of this uncertainty stems from an incomplete understanding of inter and intra-crystal compositional variation and the influence this has on the kinetics of the dating system. Reaching a complete understanding of crustal thermal histories also remains a major challenge as the lowest temperature thermochronometers, apatite fission track (AFT) and apatite (U-Th)/He (AHe), are only sensitive over a temperature range of c. 120 – 40°C. The lower temperature limit of this range is also dependant on apatites having low degrees of radiation damage that can enhance retention of He within apatite. This project will advance AFT and AHe methodology by focusing on apatites enriched in U and Th from geological settings considered stable. The first goal is to obtain detailed REE compositional analysis using LA-ICP-MS to refine fission track annealing models and obtain high precision measurements of parent elements to improve AFT age data. The second goal is to ensure that the maximum amount of thermal history information is extract from the 4He concentration profile in the apatite crystal. This will be achieved by a combination of 4He/3He analysis and multi-single-grain AHe analysis of broken apatite crystals. By achieving these two goals the project will advance methodology, establish analytical capabilities at the host organisation and provide new insights into the thermal history of the crust at stable geological settings.

Оригинален текст от CORDIS (на английски).

Участници

UNIVERSITE DE RENNES I · RENNES CEDEXКоординаторФранция