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The Dzereg Basin is an actively evolving intracontinental basin in the Altai region of western Mongolia. The basin is sandwiched between two transpressional ranges, which occur at the termination zones of two regional-scale dextral strike-slip fault systems. The basin contains distinct Upper Mesozoic and Cenozoic stratigraphic sequences that are separated by an angular unconformity, which represents a regionally correlative peneplanation surface. Mesozoic strata are characterized by northwest and south±southeast-derived thick clast-supported conglomerates ( Jurassic) overlain by fine-grained lacustrine and alluvial deposits containing few fluvial channels (Cretaceous). Cenozoic deposits consist of dominantly alluvial fan and fluvial sediments shed from adjacent mountain ranges during the Oligocene±Holocene. The basin is still receiving sediment today, but is actively deforming and closing. Outwardly propagating thrust faults bound the ranges, whereas within the basin, active folding and thrusting occurs within two marginal deforming belts. Consequently, active fan deposition has shifted towards the basin centre with time, and previously deposited sediment has been uplifted, eroded and redeposited, leading to complex facies architecture. The geometry of folds and faults within the basin and the distribution of Mesozoic sediments suggest that the basin formed as a series of extensional half-grabens in the Jurassic±Cretaceous which have been transpressionally reactivated by normal fault inversion in the Tertiary. Other clastic basins in the region may therefore also be inherited Mesozoic depocentres. The Dzereg Basin is a world class laboratory for studying competing processes of uplift, deformation, erosion, sedimentation and depocentre migration in an actively forming intracontinental transpressional basin.

33 34 Latest Ordovician-earliest Silurian Tanezzuft Formation shales recovered from core material of 35 the shallow borehole JA-2 drilled in Jebel Asba at the eastern margin of the Kufra Basin, 36 southeastern Libya, yielded well-diversified palynomorph assemblages with transparent and 37 brownish to yellowish vesicles and organic matter (visual kerogen Type 1 and 2) from depth 38 interval 46.20 to 67.82 m. In addition, miospores including cryptospores, and Tasmanites sp. 39 ("Tasmanites with nodules"), scolecodonts, and a stratigraphically significant palaeo-marker, the 40 enigmatic, tubular organic structure Tortotubus protuberans, were also recorded frequently in 41 most samples. Kerogen colour based on miospores (TAI <3) and chitinozoan reflectance indicate 42 an immature facies for oil generation. The two uppermost samples (from 33.33 m and 46.20 m 43 depths) and the lowermost ones (from 67.92 to 73.21 m depth) contain rare palynomorphs and 44 other organic remains and have been partially affected by oxidation. 45 Furthermore, palynological and palynofacies analysis was carried out on cuttings from an 46 old well (UN-REMSA well), ca. 530 m towards the NNE from well JA-2. The composition of 47 the organic residue is similar in both wells. However, the UN-REMSA well yields fairly 48 numerous chitinozoans, scolecodonts and biofilms but lacks the "thread-like structures" and 49 "Tasmanites with nodules" observed in well JA-2. 50 All the investigated samples in well JA-2 are dominated by a single chitinozoan species, 51 Euconochitina moussegoudaensis Paris (in Le Hérissé et al., 2013). Based on correlation with 52 chitinozoan-bearing strata around the Ordovician−Silurian boundary, the analysed samples from 53 well JA-2 and from the UN-REMSA well are regarded as post-glacial, but still of either latest 54 Hirnantian age, or at least no younger than earliest Rhuddanian. A well-diversified acritarch, 55 3 miospore and cryptospore assemblage recorded in well JA-2 supports a marginal marine 56 (nearshore) depositional environment. This assemblage is no older than earliest Rhuddanian yet 57 the latest Hirnantian age of the assemblage cannot be completely ruled out as our current 58 knowledge on the post-glacial, latest Hirnantian acritarch and miospore assemblages is poorly 59 documented in North Africa. 60 61 63 Research highlights 64 ► We describe palynomorphs from subsurface shales of SE Libya. 65 ► The shales are of latest Hirnantian-earliest Rhuddanian age. 66 ► The shales are immature for oil generation. 67 ► Dominant chitinozoan species Euconochitina moussegoudaensis Paris. 68

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The Mongolian Altai is a Late Cenozoic intraplate strike-slip deformation belt which formed as a distant strain response to the Indo-Eurasian collision over 2000 km to the south. We report results from 5 weeks of detailed fieldwork carried out during summer 2000 in northwestern Mongolia investigating the crustal architecture of the Altai at latitude 48°N. The region can be divided into discrete Cenozoic structural domains each dominated by a major dextral strike-slip fault system or range-bounding thrust fault. Gentle bends along the major strike-slip faults are marked by transpressional uplifts including asymmetric thrust ridges, restraining bends, and triangular thrust-bounded massifs. These transpressional uplifts (Tsambagarav Massif, Altun Huhey Uul, Sair Uul, Hoh Serhiyn Nuruu, Omno Hayrhan Uula, Mengildyk Nuruu) comprise the highest mountains in the Mongolian Altai and are structural and metamorphic culminations exposing polydeformed greenschist-amphibolite grade basement recording at least two phases of Palaeozoic ductile deformation overprinted by Cenozoic brittle structures. Cenozoic thrust faults with the greatest amounts of displacement bound the W and SW sides of ranges throughout the region and consistently verge WSW. Each major range is essentially a NE-tilted block and this is reflected by asymmetric internal drainage patterns. Many faults are considered active because they deform surficial deposits, form prominent scarps, and define range fronts with low sinuosity where active alluvial fan deposition takes place. Reactivation of the prevailing NW-striking, NE-dipping Palaeozoic basement anisotropy is a regionally important control on the orientation and kinematics of Cenozoic faults. At first order, the Altai is spatially partitioned into a low-angle thrust belt that overthrusts the Junggar Basin on the Chinese side and a high-angle SW-vergent dextral transpressional belt on the Mongolian side. The mechanically rigid Hangay craton and Junggar basement block which bound the Altai on either side have played a major role in focusing Late Cenozoic deformation along their boundaries and within the Altai. The geometric relationship between rigid block boundaries, Palaeozoic basement structural anisotropy, and the dominantly NE SHmax (derived from India’s continued NE indentation) has dictated the kinematics of Late Cenozoic deformation in the Altai, Gobi Altai, and Sayan regions.