Introduction

Participants

 

R/V Pelagia Cruise GLOW
	Diary overview
Wednesday, 25 February
Halfway through the GLOW cruise on the R.V. Pelagia, an industrious and good natured spirit prevails on board. The work plan is extremely full with various aspects of research working in tandem. Plankton tows, seismics, box and piston coring are all underway in order to achieve the maximum scientific return for this venture. Unfortunately, sunbathing and pooltime have been dramatically reduced as the sun has all but disappeared and the rain has arrived in recent days. However, today we celebrate one of five birthdays on board the Pelagia, with cake and balloons becoming a regular feature. Irish coffee was a popular choice of tipple at lunch! Further successful plankton tows have yielded many exciting specimens of the as yet un sequenced planktonic foraminifer Hastigerinella digitata. Presently 51 specimens from approx. 14 species have been fixed for DNA analysis. The specimens much be extracted within two hours of the tow so the micropalaeontologists have worked extremely well under pressure. Between coring stations work has been underway to provide a detailed re-interpretation of Paleogene geological timeframes, the aim of which is a unified consistent framework. We resumed shooting the perimeter seismic lines and sailing towards the Tanzania - Mozambique border from the Davie Ridge, the coastline revealed itself in the dawn. This line that forms the westernmost boundary of the study area is especially important, forming the pivotal link between on- and offshore sites. We sailed close to the well at Mnazi Bay before completing a coast parallel transect. This cruise aims to build on previous extensive onshore work and extend the coastal knowledge to the offshore realm. Major regional faults and channels revealed themselves along the shelf as we could look to the coast and see their topographic expression in the hills around Mikindani and Pande, SE Tanzania. Key areas were located with the multibeam bathymetry and seismic lines where Paleogene sediments may outcrop. Age constraint on these areas is key for future research. Initial biostratigraphic work on the box and piston cores yield dates ranging from Recent to Mid-Miocene with possible reworkings. Thus, we have been able to estimate the ages of certain reflectors visible in the seismic sections and constrain the recent uplift of the Davie Ridge; an exciting and seismically active zone.   Completing the principal regional seismic lines has led to a working initial seismic stratigraphy. Links have been made with the nearest DSDP hole; Site 242 in the Mozambique Channel. Combined with the confirmed ages of outcropping reflectors from the coring, we are confident that the complete story of this area will reveal itself. Beautiful bathymetric images combined with initial subsurface dataare yielding excellent results. Uplift, rotation of microplates, the evolution of the East African Rift and submarine canyons are exciting topics of debate, and ones which will be discussed for quite some time. We anticipate savage and dynamic results in the coming days. The shipboard party