Darwin Glass: Tasmania’s Cosmic Gem
816,000 years ago, a bolide slammed into western Tasmania. The intense heat fused the local bedrock into a unique impact glass. Today, these green shards hold microscopic secrets: bubbles of ancient atmosphere and trapped organic biomarkers that challenge our understanding of life’s resilience in cosmic events.
Age
~816 kYA
Pleistocene Epoch
Location
Mt. Darwin
Western Tasmania, South of Queenstown
Type
Impactite
Fused sedimentary rock (sandstone/shale)
The Formation Event
Darwin glass is not volcanic. It was born in milliseconds under extreme pressure and temperature. Understanding the chaos of its creation helps explain why materials are trapped inside.
The Impact
A meteorite strikes a swampy, peat-rich basin in Tasmania. The kinetic energy is instantly converted to heat.
Melting & Ejection
Target rock and organic swamp matter melts instantly. Molten blobs are ejected into the atmosphere.
Quenching
The molten ejecta cools rapidly in flight, solidifying into glass before hitting the ground, trapping gases.
Discovery
Over 800,000 years, the crater fills with sediment (now indistinct), but the glass shards remain scattered.
🔬 Lab 1: Gas Bubble Analysis
Tiny bubbles (vesicles) within the glass act as “flight recorders.” By analyzing the gas trapped inside, we can determine the composition of the impact site. Move your cursor over the glass sample below to analyze specific bubbles.
Virtual Microscope View (100x)
Representation of a polished Darwin Glass section.
Spectrometry Results
Scientific Context
Normal atmosphere is ~78% N₂, 21% O₂. Darwin glass bubbles often show elevated CO₂ and varying Argon levels, suggesting the impact vaporized organic-rich swamps (peat) rather than just bare rock.
🌱 Lab 2: Organic Biomarkers
Can life survive a meteor impact? Surprisingly, yes. Researchers have found spherical organic inclusions in Darwin Glass. These are likely bits of ancient Tasmanian peat swamp that were “shock-fused” and trapped before they could burn away. This has huge implications for finding life on Mars—impact glass could be the perfect preservation vessel.
Spectral Analysis Control
Compare the chemical signature (Raman Spectra) of the inclusions found in Darwin Glass against known biological references.
Key Finding
The spectral peaks of the glass inclusions match Peat/Lignin, not just charcoal. This means the material was sealed instantly, preserving complex bio-molecules inside the glass prison.
Raman Shift (cm⁻¹)
Simulated Raman Shift data based on Howard et al. (2018) & generic lignin spectra.