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The geology and stratigraphy of the lower Nanaimo group, Nanaimo, British Columbia
The western part of the Late Cretaceous Nanaimo Basin
is exposed on Vancouver Island at Nanaimo, British Columbia.
The five lowest members of the Nanaimo Group are present
and represent a complete sedimentary cycle. The two lowest
formations, the Comox and Haslam, represent the marine part
of the cycle. The Comox rests with angular unconformity on
the underlying Triassic Karmutsen volcanics, and is composed
of shallow marine deposits of sandstones, conglomerates
and limestones, one of the limestones being an algal
type not previously reported for the Nanaimo Basin. The
Haslam represents a quiet marine environment, possibly
lagoonal, which grades upward into a swampy environment
represented within the lower Extension Formation.
The Extension Formation represents the first of the
terrestrial part of the cycle. Above the Wellington Coal
Member, deposited in a swampy environment, lie channel
conglomerates and sandstones indicative of a braided stream
environment. The Newcastle Formation onlaps the Extension
Formation and is composed of sandstones, siltstones, conglomerates,
and the Newcastle and Douglas Coal Seams. The
environments of deposition of the Newcastle Formation are
postulated to be the upper floodplain of a short headed
stream. Paleocurrent data and composition of the rocks
indicate sources to the west.
The Protection Formation is the uppermost of the formations
in the area, and is composed of thick- and thin-bedded
sandstones. The sandstones indicate a barrier-beach
complex, probably deposited as the paleo-shoreline
migrated west during a transgression.
Subsequent faulting, and fluvial and glacial erosion
produced the present topography of the area
A quantitative comparison and analysis on the assessment indicators of greenhouse gases emission
The Diffusion of Humans and Cultures in the Course of the Spread of Farming
The most profound change in the relationship between humans and their
environment was the introduction of agriculture and pastoralism. [....] For an
understanding of the expansion process, it appears appropriate to apply a
diffusive model. Broadly, these numerical modeling approaches can be catego-
rized in correlative, continuous and discrete. Common to all approaches is the
comparison to collections of radiocarbon data that show the apparent wave of
advance of the transition to farming. However, these data sets differ in entry
density and data quality. Often they disregard local and regional specifics and
research gaps, or dating uncertainties. Thus, most of these data bases may only
be used on a very general, broad scale. One of the pitfalls of using
irregularly spaced or irregularly documented radiocarbon data becomes evident
from the map generated by Fort (this volume, Chapter 16): while the general
east-west and south-north trends become evident, some areas appear as having
undergone anomalously early transitions to farming. This may be due to faulty
entries into the data base or regional problems with radiocarbon dating, if not
unnoticed or undocumented laboratory mistakes.Comment: 20 pages, 5 figures, submitted to Diffusive Spreading in Nature,
Technology and Society, edited by Armin Bunde, J\"urgen Caro, J\"org
K\"arger, Gero Vogl, Chapter 1
Late Holocene climate: Natural or anthropogenic?
For more than a decade, scientists have argued about the warmth of the current interglaciation. Was the warmth of the preindustrial late Holocene natural in origin, the result of orbital changes that had not yet driven the system into a new glacial state? Or was it in considerable degree the result of humans intervening in the climate system through greenhouse gas emissions from early agriculture? Here we summarize new evidence that moves this debate forward by testing both hypotheses. By comparing late Holocene responses to those that occurred during previous interglaciations (in section 2), we assess whether the late Holocene responses look different (and thus anthropogenic) or similar (and thus natural). This comparison reveals anomalous (anthropogenic) signals. In section 3, we review paleoecological and archaeological syntheses that provide ground truth evidence on early anthropogenic releases of greenhouse gases. The available data document large early anthropogenic emissions consistent with the anthropogenic ice core anomalies, but more information is needed to constrain their size. A final section compares natural and anthropogenic interpretations of the δ13C trend in ice core CO2
Methodological approaches to determining the marine radiocarbon reservoir effect
The marine radiocarbon reservoir effect is an offset in 14C age between contemporaneous organisms from the terrestrial environment and organisms that derive their carbon from the marine environment. Quantification of this effect is of crucial importance for correct calibration of the <sup>14</sup>C ages of marine-influenced samples to the calendrical timescale. This is fundamental to the construction of archaeological and palaeoenvironmental chronologies when such samples are employed in <sup>14</sup>C analysis. Quantitative measurements of temporal variations in regional marine reservoir ages also have the potential to be used as a measure of process changes within Earth surface systems, due to their link with climatic and oceanic changes. The various approaches to quantification of the marine radiocarbon reservoir effect are assessed, focusing particularly on the North Atlantic Ocean. Currently, the global average marine reservoir age of surface waters, R(t), is c. 400 radiocarbon years; however, regional values deviate from this as a function of climate and oceanic circulation systems. These local deviations from R(t) are expressed as +R values. Hence, polar waters exhibit greater reservoir ages (δR = c. +400 to +800 <sup>14</sup>C y) than equatorial waters (δR = c. 0 <sup>14</sup>C y). Observed temporal variations in δR appear to reflect climatic and oceanographic changes. We assess three approaches to quantification of marine reservoir effects using known age samples (from museum collections), tephra isochrones (present onshore/offshore) and paired marine/terrestrial samples (from the same context in, for example, archaeological sites). The strengths and limitations of these approaches are evaluated using examples from the North Atlantic region. It is proposed that, with a suitable protocol, accelerator mass spectrometry (AMS) measurements on paired, short-lived, single entity marine and terrestrial samples from archaeological deposits is the most promising approach to constraining changes over at least the last 5 ky BP
Wolfgang Schott (1905–1989): the founder of quantitative paleoceanography
Wolfgang Schott is the pioneer in paleoceanography and has established this research field within marine geology. His papers from the first half of the twentieth century are all published in German; therefore, the most inspiring results are given here as original quotes in English, since they paved the ground for all scientific discussions on climate stratigraphy, past ocean currents, and glacial interglacial cycles
A simulation of the Neolithic transition in Western Eurasia
Farming and herding were introduced to Europe from the Near East and
Anatolia; there are, however, considerable arguments about the mechanisms of
this transition. Were it people who moved and outplaced the indigenous hunter-
gatherer groups or admixed with them? Or was it just material and information
that moved-the Neolithic Package-consisting of domesticated plants and animals
and the knowledge of its use? The latter process is commonly referred to as
cultural diffusion and the former as demic diffusion. Despite continuous and
partly combined efforts by archaeologists, anthropologists, linguists,
paleontologists and geneticists a final resolution of the debate has not yet
been reached. In the present contribution we interpret results from the Global
Land Use and technological Evolution Simulator (GLUES), a mathematical model
for regional sociocultural development embedded in the western Eurasian
geoenvironmental context during the Holocene. We demonstrate that the model is
able to realistically hindcast the expansion speed and the inhomogeneous
space-time evolution of the transition to agropastoralism in Europe. GLUES, in
contrast to models that do not resolve endogenous sociocultural dynamics, also
describes and explains how and why the Neolithic advanced in stages. In the
model analysis, we uncouple the mechanisms of migration and information
exchange. We find that (1) an indigenous form of agropastoralism could well
have arisen in certain Mediterranean landscapes, but not in Northern and
Central Europe, where it depended on imported technology and material, (2) both
demic diffusion by migration or cultural diffusion by trade may explain the
western European transition equally well, (3) [...]Comment: Accepted Author Manuscript version accepted for publication in
Journal of Archaeological Science. A definitive version will be subsequently
published in the Journal of Archaological Scienc
The Atlantic Ocean at the last glacial maximum: 1. Objective mapping of the GLAMAP sea-surface conditions
Recent efforts of the German paleoceanographic community have resulted in a unique data set of reconstructed sea-surface temperature for the Atlantic Ocean during the Last Glacial Maximum, plus estimates for the extents of glacial sea ice. Unlike prior attempts, the contributing research groups based their data on a common definition of the Last Glacial Maximum chronozone and used the same modern reference data for calibrating the different transfer techniques. Furthermore, the number of processed sediment cores was vastly increased. Thus the new data is a significant advance not only with respect to quality, but also to quantity. We integrate these new data and provide monthly data sets of global sea-surface temperature and ice cover, objectively interpolated onto a regular 1°x1° grid, suitable for forcing or validating numerical ocean and atmosphere models. This set is compared to an existing subjective interpolation of the same base data, in part by employing an ocean circulation model. For the latter purpose, we reconstruct sea surface salinity from the new temperature data and the available oxygen isotope measurements
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