MagIC

WELCOME to the Mag.I.C project!

MagIC – Petrology and Geochemistry of Igneous Rocks from Macao: Implications for the Crustal Evolution of Southern China / 澳门火成岩之岩石学与地球化学—对华南地壳演化的影响)

This project aimed to develop a detailed digital cartographic map of the igneous rocks of Macao, useful for professionals from different areas and to understand the geological history of the territory. The main results included: (1) absolute age determination from Macau magmatic events; (2) based on mineralogical and geochemical studies we have constrained the magma evolution and; (3) we contributed to a deeper understanding of the South China tectono-magmatic evolution.

Project reference: FDCT 043/2014/A1 (2014-2018)

updated on August, 2019

TEAM

Ph.D. Principal Investigator (PI) from ISE, USJ, Macau

Ph.D. Team member from FCUL/IDL, Portugal

XinYu Gao

Ph.D Team member from GIG, CAS – 中国科学院广州地球化学研究所 , China

Luisa Duarte

Ph.D. Consultant from LNEG

Varon Lou

M.Sc. Research Assistant from ISE, USJ, Macau

Ph.D. Student from ISE, USJ, Macau

Ricardo Borges

Research Assistant (GIS) from ISE, USJ, Macau

ABSTRACT

Igneous rocks, in particular granitic ones, are of utmost importance to assess the tectonothermal evolution of continents and to decipher their geodynamic setting. During Mesozoic ages, the Southeastern China region (Cathasya block), where Macao is localized, was affected by granitic plutonism generated during the Indosinian (Triassic) and Yanshanian orogenies (Jurasic-Cretaceous), overprinting all previous events in the South China Fold Belt (SCFB). In Macao, the most complete document reporting the geology of the territory was published, in 1992, under Luísa Ribeiro coordination, the consultant of this project. It consists of the Macao Geological Map 1:5000 scale, and its memoir, where the main geological units and structures of Macao were presented. Until the beginning of this project proposal, there was a significant gap in the knowledge of the geology and geodynamic evolution of Macao compared with surrounding areas. The geology of Hong Kong and Guangdong (also included in the Cathaysia block) has been the subject of numerous SCI publications. In contrast, there were no SCI publications on the geology of Macao. To fill this gap, this project focused in obtaining new scientific knowledge about the origin and evolution of the territory of Macao, and also to spread and publish this new knowledge within the local and international scientific community. In his project, we developed a new trilingual digital geological map of Macao and, among several new scientific discoveries accomplished along the execution of the work, we emphasize the determination of the age of Macao magmatic rocks as well as of its geodynamic evolution. Briefly, Macao granites were emplaced in two main periods ranging from 164.5 ± 0.6 Ma to 162.9 ± 0.7 Ma and 156.6 ± 0.2 Ma to 155.5 ± 0.8 Ma, separated by ca. 6 Ma. Inherited zircons point to the existence of a basement with ages up to Paleo-Proterozoic and late Archean in the region. In addition, younger dacitic rocks were dated at 150.6 ± 0.6 Ma and <120 Ma. Macao granitic suite was incrementally assembled during a period of ca. 9 Ma and the transition from granitic magmatism (Middle to Upper Jurassic) to the younger dacite dykes (Upper Jurassic to Lower Cretaceous) most likely correspond to a change in the regional tectonic setting. Isotope and geochemical compositions together with model ages and mixing modelling strongly suggest that Macao granitic magmas were generated by partial melting of infracrustal medium-to-high K basaltic Paleo-Proterozoic to Mesoproterozoic protoliths heated by, and mixed to some degrees with, the contemporaneous underplating and/or intrusion of hot, mantle-derived magmas. The Jurassic Macao granites are interpreted as being produced in an intraplate extensional setting related to the foundering of a previously flat-slab (Paleo-Pacific plate) beneath SE China continent.

More info here: http://ise.usj.edu.mo/research/projects/geology-of-macau/

摘要

火成岩,尤其是花岗岩,对于揭开大陆的构造演化和动力学背景之谜至关重要。中生代时期,澳门所处的华东南板块(华夏古陆)受印支期(三叠纪)和燕山构造期所产生的花岗质岩浆影响,叠印了华南褶皱带以往所有的活动。澳门在地质和地理上归属于华夏陆块,从而为理解华南的地壳演化过程提供制约。1992年,在本项目顾问路易莎·里贝罗(Luísa Ribeiro)的协调下,澳门境内最完整的官方地质报告文件出版。在该研究报告中,介绍了澳门主要的地质单元和结构,其中还包含了比例为1:5000的澳门地质图。
在本项目开始前,澳门的地质与地球动力学研究和认识与周围地区相比还存在很大差距。香港和广东的地质(也包括在华夏地块中)一直是许多SCI出版物的研究对象。但相比之下,直到现在都还没有关于澳门地质的SCI出版物发表过。为了填补这一研究空白,本项目的重点是研究澳门地体的起源和地质演化,从而获得新的科学认识,并将研究成果和认识在本地和国际学界中传播和发表。在这个项目中,我们还编制了一张新的澳门三语数字地质图
在这个项目所取得的一系列新科学发现中,我们会重点强调澳门岩浆岩年龄的厘定及其地球动力学的演化过程。总的来说,澳门的花岗岩侵入活动主要分为两期,164.5 ± 0.6 Ma(百万年)到 162.9 ± 0.7 Ma为第一期, 156.6 ± 0.2 Ma 到155.5 ± 0.8 Ma为第二期,中间相隔约6Ma。花岗岩中的继承锆石指示该地区存在着一个古元古代至晚太古代的古老基底。此外,也发现更年轻的英安质岩石的年龄为150.6 ± 0.6 Ma和<120 Ma。澳门的花岗岩套是在一个约9Ma的时期内逐步侵位形成的,从中晚侏罗纪的花岗质岩浆活动向晚侏罗-早白垩的英安质岩墙的转变很可能对应于区域构造环境的变化。
澳门花岗岩的同位素和地球化学成分,模式年龄和岩浆混合模拟表明澳门花岗质岩浆是由古元古代至中元古代的下地壳中~高钾质的玄武质原岩经中生代底侵或侵入的高温地幔岩浆加热从而部分熔融产生的,在这过程中,同时伴随着一定程度的岩浆混合作用。澳门侏罗纪花岗岩可以解释为是在板内伸展的环境中产生的,这个伸展环境与古太平洋板块由平板俯冲向板块拆沉的构造转变有关。

OBJECTIVES OF THE PROJECT
Task 1. – Digital Cartography
To refine the knowledge on the main lithologies areal distribution in order to develop a detailed digital map of the igneous rocks from Macao.
 
Task 2. – Petrography
To obtain a detailed characterization of the mineralogy and petrography of igneous rocks from Macao and compare these results with data from correspondent geological areas from the Cathaysian block.
 
Task 3. Geochronology
The main goal of this task was to precisely date the magmatic events preserved in the geological region where Macao is included. 
 
Task 4 – Geochemistry
The main goal of this task was the construction of a petrogenetic model for each of the igneous lithotypes from the geological region where Macao is included by a detailed characterization of their geochemical properties (whole-rock major and trace elements, rare earth elements, and isotopic signatures).
 
For results and outputs see the geology of Macau webpage and publications
Collaboration with other institutions

IDL – Instituto Don Luiz

LNEG – Laboratório Nacional de Energia e Geologia (Laboratório de Geologia e Minas), Portugal

JSGL – Jack Satterly Geochronology Laboratory, Canada

GIGCAS –  Guangzhou Institute of Geochemistry of the Chinese Academy of Sciences, China

GeoFCUL – Departamento de Geologia da Faculdade de Ciências da Universidade de Lisboa

HKU – University of Hong Kong

 

Companies and public institutions that
have been contribution to the project

With field visits and samples:
MPS – Macau Professional Services, Limited, Macau
LECM – Macau Laboratory of Civil Engineering / 澳門土木工程實驗室, Macau
LNEG – Laboratório Nacional de Energia e Geologia (Laboratório de Geologia e Minas), Portugal
CGGC – China Gezhouba Group Corporation, Macau
中德工程有限公司, Macau
南光石油化工有限公司, Macau
Macau Golf and Country Club / 澳門高爾夫球鄉村俱樂部, Macau

Other contributions:
SMG – Macao Meteorological and Geophysical Bureau / 地球物理暨氣象局, Macau

Mag.I.C. Publications and Communications

–  Quelhas, P., Dias, Á A., Mata, J., Don, D., Ribeiro, L. (2019) High-precision geochronology of Mesozoic magmatism in Macao, Southeast China: evidence for multistage granite emplacement. Geoscience Frontiers. https://doi.org/10.1016/j.gsf.2019.04.011

– Quelhas P, Dias Á A, Mata J & Wayne Davis D (2019) Goldschmidt Abstracts, 258. 21st August. Barcelona. https://goldschmidt.info/2019/abstracts/abstractView?id=2019004459

– Quelhas, P., Mata, J., Lou, U. T., Ribeiro, M. L., Borges, R., Dias, Á A (2018). A origem e evolução dos magmas graníticos de Macao à luz de dados de geoquímica elementar e isotópica / Source and evolution of Macao granitic magmas: insights from wholerock geochemistry and isotopic signatures.. XIV Congresso de Geoquímica dos Países de Língua Portuguesa e XIX Semana de Geoquímica (XIV CGPLP/XIX SG, international conference. 25-29 March 2018, Trás-os-Montes e Alto Douro, Portugal.

– Dias, Á A (2017) Opening talk about the geology of MacaoISE, Macao. Meeting on Mesozoic magmatism of Macao and Hong Kong in the context of SE China geodynamics / 澳門與香港的中生代岩漿作用 (oral communication) 22-27 April 2017, ISE, Macau

– Quelhas, P. (2017) Mesozoic magmatism in Macao: What is known so far and future developments. Mesozoic magmatism of Macao and Hong Kong in the context of SE China geodynamics / 澳門與香港的中生代岩漿作用 (oral communication)22-27 April 2017, ISE, Macau

– Quelhas, P., Mata, J., Lou, U. T., Ribeiro, M. L., Borges, R., Dias Á A. (2017) New Geochemical Constraints on I-Type Granites of Macao: Petrogenesis and Geodynamic Implications. 27th Goldschmidt Conference. 2126, 06d 13-18, August 2017. Paris, France

– Quelhas P M, Mata J, Lou U T, Ribeiro M R and Dias Á A (2016) Mesozoic Granitic Magmatism in Macao, Southeast China. AGU Fall meeting 12-16 December 2016, San Francisco, USA

– Dias Á A, Quelhas P, Lou U, Mata J & Ribeiro M L (2016) Petrology and Geochemistry of Granitic Rocks from Macao. 26th Goldschmidt Conference, Yokohama, Japan. 61, 05c. POSTER

– Dias, Á A (2015) Presentation of the Magic Project. First Meeting on the Geology of Macao, Macao

– Quelhas, P (2016) Preliminary data from Macau petrology: Summary of the field work and first petrographic analysis. First Meeting on the Geology of Macao, Macao

– Lou, V (2015) Plutonic Rocks from SE China focused in Macau (what is mentioned in the Chinese references). First Meeting on the Geology of Macao, Macao

– Gao X-Y (2015) Presentation of GIG-CAS (The Guangzhou Institute of Geochemistry of the Chinese Academy of Sciences) and its facilities. First Meeting on the Geology of Macao, Macao

For more information visit: 

Other references
  • Ribeiro, M.L. (2010) Macau, evolução do conhecimento geológico, Ciências Geológicas – Ensino, Investigação e sua História, Volume VII – Geologia das Ex-Colónias da Ásia e Oceania: Lisbon, Sociedade Geológica de Portugal, p. 259 – 266. http://repositorio.lneg.pt/bitstream/10400.9/1301/1/34425.pdf
  • So, CL & Ribeiro, ML (1997) Portugal Macao Geology. Encyclopedia of World Regional Geology. pp. 620 – 621 E.M. Moores & R. W. Fairbridge, (eds). Encyclopedia of Earth Sc. Series. Chapman & Hall, London.
  • Ribeiro, M. L., Macedo, C. A. R., Ramos, J. M. F., and Dias, R. P. (2000) K – Ar ages for the Macao granites (SE China) and the magmatic migration at the Yenshianian times, in Proceedings Congresso Internacional de Geologia, Rio de Janeiro, Brasil. p. G1804006.
  • Ribeiro, M. L., Ramos, J. M. F., Pereira, E., and Dias, R. P. (1992) Carta Geológica de Macau na escala 1:5000 (inclui Notícia Explicativa): Serviços Geológicos de Portugal.
  • Marques, F. M. S. F. (1988) Contribuição para o conhecimento geológico e geotécnico do Território de Macau. Master thesis: FCUL, 184 p.
  • Carrington da Costa, J., and Lemos, M. S. (1964) Fisiografia e Geologia da Província de Macau: Centro de Informação e Turismo.
  • Lemos, M. S. (1963) Esboço Geológico da Província Ultramarina de Macau, Escala 1/25 000: Centro de Informação e Turismo.
  • Carrington da Costa, J. (1944) Geologia da Província de Macau, Bol. Soc. Geol. de Portugal, Volume III: Porto, Imprensa Moderna, Ltd., p. 47.