Environmental Engineering Reference
In-Depth Information
1
Large igneous provinces and explosive
basaltic volcanism
ingrid ukstins peate and linda t. elkins-tanton
1.1 Introduction
Large igneous provinces are recognized from the Precambrian at 3.79 Ga (Ernst,
2013), and extend through well-preserved examples from the Mesozoic and
Cenozoic (Ross
et al
.,
2005
; Bryan and Ferrari,
2013
, and references therein).
While originally inferred to consist of a layer-cake sequence of massive and
laterally continuous effusive basaltic lava
flows, detailed volcanostratigraphy
studies have generated a more nuanced view of province architecture, highlighting
that many provinces include a signi
cant component of clastic material derived
from volcanic and sedimentary formation mechanisms. Conversely, some of the
volumetrically largest basaltic volcaniclastic deposits appear to be associated with
large igneous provinces (Ross
et al
.,
2005
).
The importance of volcaniclastic deposits
-
and the implications for paleoenvir-
onmental reconstructions, eruption dynamics, and climate impact
-
is one of the key
concepts to emerge from scientific studies of large igneous provinces over the last 25
years. Ross
et al
.(
2005
) recognized, and highlighted, the near-ubiquitous occurrence
of ma
c volcaniclastic deposits as an integral component in large igneous provinces.
These deposits contain information
on primary fragmentation
mechanisms, eruptive processes, and depositional environments. Ma
-
some unique
-
c volcaniclas-
tic deposits provide a record of what we now recognize as complex temporal and
spatial volcanic heterogeneity in large igneous provinces, and allow us to reconstruct
their tectonic and physical evolution as an equally signi
cant and complementary
story to that of the geochemical evolution of magmatism. We provide a brief
overview of ma
c volcaniclastic deposits and formation mechanisms, and spotlight
recent work highlighting their utility for interpreting large-scale tectonic evolution
and climate impact issues related to large igneous province emplacement.
