2023

Parth Shah gave an excellent talk on the results of his PhD thesis on PaleoPERCS (Paleo Early Career Seminar Series). Paeopercs is a virtual seminar series designed to showcase the research of Early Career Researchers in paleo- (ntology, ecology, ceanography, climate, etc.). This podium intends to serve as a venue to share research and strengthen our global community. The talk was greatly appreciated by the audience! Congrats Parth!

Follow this link for more information. 

A new paper just came out in Chemical Geology leaded by a previous postdoc! The study deals with description and interpretation of mass transport complexes in an Eocene marine record units in Israel with exceptional well-preserved sequences with high total organic content. We speculate that during the Eocene, allowing for only 0.1‰ of shelf carbon to be preserved through transport mechanisms would account for up to 13.7% of all organic carbon burial. As such, the potential to mobilize through this mechanism large quantities of organic carbon is significant. The mass transported features indicate detachment, movement and emplacement following initial sedimentation, in some cases more than once. Emplacement occurs into a chalk facies that can vary in appearance from darker (higher TOC) and lighter (lower TOC) lithofacies.nThis study demonstrates how transport mechanisms allow for the long-term burial of organic carbon in marine systems. When taking into consideration similar processes reported to occur in the world oceans today, it is clear that sediment transport and long-term burial of organic carbon is a fundamental part of the global carbon cycle. 

Follow this link for more information. 

Two students from our lab just graduated! Dr Aihemaiti Maitituerdi and Abdel-Aziz Yassine! Ahmad will continue in the lab working on a postdoc project while Abdel-Aziz got accepted as a PhD student in Bar-Ilan University in Israel. Congrats to both of you and all our best wishes for a great success in the new projects!

This month, several PetroLab members traveled to Rome for attending the INQUA meeting. Parth Shah gave a talk in the major room, which was full of attendees. Abdel-Aziz Yassine presented a poster on his MSc project. Nicolas Waldmann gave a talk on the Pliocene-Pleistocene transition in the Levant region based on lake records. In fact, Abdel-Aziz had the chance to give a short talk in front of all attendees as he received the excellence scholarship from INQUA who allowed him to carry out ostracod analyses in his record from Lake Hula. 

Congrats to all!

In this new paper leaded by Parth Shah, we investigate the response of lake ecosystem to climatic and environmental changes using a suite of paleo-proxies including ostracods, chironomids, and n-alkanes distribution from paleolake ‘Gayal el Bazal (Yemen). A previous study from this site has provided a continuous, and high-resolution dataset providing an understanding of precipitation during the last ca 1200 years, particularly during Medieval Climate Anomaly (MCA) and Little Ice Age (LIA). However, the response of the lake ecosystem to these changing hydro-climate conditions, including water-level, salinity, and productivity, remains unknown. The n-alkanes dataset shows that during pluvial interval such as the MCA, the lake experienced an increase in nutrient input resulting in enhanced aquatic productivity. Concurrently, ostracods assemblage displays an increased abundance of swimmer species suggesting an indirect response between ostracods and climate shifts. The chironomid community during the MCA interval is dominated by taxa belonging to the subfamilies of Chironomini, suggesting a warm, shallow, productive environment with macrophyte vegetation. The overall patterns in biological indicators reveal that their individual abundance and species/tribe distribution fluctuates in response to changes in the climate and hydrological conditions.

A new paper from one of our students was just published in Sedimentary Geology! The paper deals with geophysical interpretation of a 3D seismic block off-shore South Africa (Orange Basin) where stacked mass transported deposits and associated blocks were mapped. The interpreted blocks are preserved in three discrete fault-bounded morphological terrains within a Neogene mass-transport complex. These terrains vary in lengths from 2 km to 6 km; they have heights of 60 m to 150 m and are characterized by discrete and localized structural highs on the present-day seafloor. Block sizes vary across terrains suggesting differences in the block evolution process. Blocks near the ramp appear in seismic profiles comprising (a) Chaotic and transparent seismic reflections and (b) parallel to sub-parallel, continuous, low to moderate amplitude reflections. This variability in seismic facies of the blocks reflects the degree of their interaction and translation over a ramp at the basal shear zone of the mass transport complex, evidenced by the difference in the block features on the upslope portion of the ramp versus the downslope part. Notably, the deformation styles recorded in the blocks show the impact of the ramp during mass flow, which has broader implications for understanding the internal mechanisms of blocky mass transport complexes in many continental margins. Congrats Paschal!

A seminar was given on 26 April by Parth as part of the Monsoon Seminar Series (online). The talk included new data from Parth's PhD thesis and was entitled "Late Holocene monsoon dynamics in the Southern Arabian Desert and their linkage to regional and global climate drivers". Parth showed in the presentation results from his PhD research, which includes a multi-proxy analysis of cores obtained from two lakes in Yemen. The study demonstrated the impact of the Medieval Warm Period and Little Ice Age in the regional hydro-climate budget, which in turn influenced the local ecosystem. 
Click on this link for watching the full talk!

A seminar was given by Nicolas as part of the Monsoon Seminar Series (online) on evidence for northwards migrations of monsoon fronts in the Near East during the Pliocene.

In the presentation, we showed results from a recent study in which a multi-proxy approach is applied to both sediment cores and outcrop samples retrieved from three different lacustrine formations exposed in the Near East, which are chronologically constrained to the Pliocene and Early Pleistocene. The multi-proxy analyses indicate major fluctuations in the lakes hypsometry, transitions from anoxic to oxic conditions in the sediment-water interface, and major changes in the limnic states, indicating a response of the lake systems to changing conditions in the precipitation patterns through time. It appears that the different lakes responded to orbital-scale forcing, which may have played a key role in governing the dry-wet climate cycles in the Near East. Results from this study provide an important understanding of the hydrological conditions that may have dominated the region during a warmer climate phase, challenging previous estimations, while concurrently providing clues to the role of the climate system in greening the path of early hominin migrations out of Africa through the region. Click on the link for watching the full talk!