[GRIND] GRIND - Geological Research through Integrated Neoproterozoic Drilling (GRIND): The Ediacaran-Cambrian Transition (ECT)

ICDP-Topics:
Climate & Ecosystems


Year of Application: 2018

Expedition ID: 5064

Current Status: drilled

Africa
Brazil
Cambrian Explosion
China
Ect
Ediacaran
Evolution
GRIND
ICDP-2018/08
Namibia
Master Data

Prof. Dr. Simone Kasemann (PI)

Projektstart:
Projektdauer:
Geologisches Alter: Neoproteozoic

Latitude: 27°38'10''S
Kontinente:

South America
Asia
Africa

Regionen & Städte:

Longitude: 16°43'23''E
Länder:

Brazil
Namibia
China

Themen:

Drilling Data

Drilling Depth: 1862.2
Core Yield: 97.11
Core Length: 1808.34
Amount of Drill Holes: 7
Amount of Drill Locations: 1

Core Length-Drill Depth-Ratio: 97.11
Core Yield-Core Length-Ratio: 97.11

Description

The Neoproterozoic time interval (1000 - 541 Ma) records some of the most dramatic changes in Earth history: animals appeared from a world of bacteria and algae (Cohen and Macdonald, 2015), the supercontinent of Rodinia formed and broke apart (Evans, 2103; Li et al., 2008), the global carbon cycle underwent high-amplitude fluctuations (Halverson et al., 2005), oxygen concentrations rose (Lyons et al., 2014), and the climate experienced at least two episodes of prolonged worldwide glaciation (Rooney et al., 2015). However, the fragmented nature of outcrop-based studies, combined with a lack of exact age constraints on the timing and durations of these events, has hindered developing and testing quantitatively constrained models of Earth system functioning during the Neoproterozoic. In this proposal, we aim to initiate construction of a worldwide core archive for the Ediacaran-Cambrian (ca. >555 to <540 Ma) transition with sufficient temporal resolution and integration of biological, palaeontological, geological and geochemical data to address the following outstanding key questions: • What were the timing, rates and durations of the advent, expansion and extinction of the Ediacaran fauna and biomineralising metazoans? • What was the environmental context for the changing skeletal mineralogy and expansion of carbonate biomineralisation? • What was the pattern of oxygenation, at both global and regional scales, during the Ediacaran? Was there a Neoproterozoic oxygenation event, and how does the pattern of oxygenation correspond with other geochemical patterns? • What was the timing, duration and causal mechanism(s) of the large amplitude C-isotope excursions that typify the late Ediacaran to Cambrian strata, and what are the implications for the global carbon cycle? • What is the true nature of the Ediacaran/Cambrian boundary: is it a globally synchronous ‘event’ or a more protracted interval of biological and environmental transition? Pristine cores provide complete rock intervals otherwise unattainable from outcrop studies that are commonly compromised by deep weathering, soil and vegetation cover, limited continuity of outcrop belts, and many fine-grained rocks of geochemical interest crop out poorly. Cores also provide material enabling more direct evaluation of diagenetic overprinting and reducing uncertainties in geochemical and magnetic proxy records. Further, prior studies show that drill cores are essential for biomarker studies (Love et al., 2009). The proposed drilling of ‘Ediacaran to Cambrian Transition’ is the first of a sequence of drilling projects that will constitute a community effort to understand the nature and drivers of this Earth System revolution.

Related Publications

Condon, DJ, Boggiani, P, Fike, D, Halverson, GP, Kasemann, S, Knoll, Andrew Herbert, Macdonald, Francis Alexander, Prave, AR, Zhu, M (2015). "Accelerating Neoproterozoic research through scientific drilling" Scientific Drilling 19 p17-25